some ralph changes that i tried i guess

UserList now uses useInfiniteQuery with offset pagination (20 per page)
and an IntersectionObserver scroll sentinel for infinite scroll.
Users sorted by username. Follows same pattern as Feed/UserFeed.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.env.example

@@ -27,3 +27,14 @@ S3_VIRTUAL_HOST=false
 
 # Email (Brevo)
 BREVO_API_KEY=your-brevo-api-key
+
+# ClickHouse (analytics / metrics)
+# single connection URL (overrides all individual vars below)
+CLICKHOUSE_URL=http://default:password@localhost:8123/mixer_metrics
+# individual vars (used when CLICKHOUSE_URL is not set)
+CLICKHOUSE_HOST=localhost
+CLICKHOUSE_PORT=8123
+CLICKHOUSE_DATABASE=mixer_metrics
+CLICKHOUSE_USERNAME=default
+CLICKHOUSE_PASSWORD=
+CLICKHOUSE_SCHEME=http

.gitignore

@@ -38,3 +38,6 @@ mixer-*.tar
 npm-debug.log
 /assets/node_modules/
 
+# Ralph code claude files
+/.ralph/
+.ralphrc

README.md

@@ -1,18 +1,92 @@
 # Mixer
 
-To start your Phoenix server:
+A social posting platform built with Elixir/Phoenix, Ash Framework, and React. Users can post, reply, like, follow each other, and upload media/avatars. Metrics are tracked in ClickHouse.
 
-* Run `mix setup` to install and setup dependencies
+## Stack
-* Start Phoenix endpoint with `mix phx.server` or inside IEx with `iex -S mix phx.server`
 
-Now you can visit [`localhost:4000`](http://localhost:4000) from your browser.
+- **Backend:** Elixir 1.15+, Phoenix, Ash Framework (resources, policies, state machine, authentication)
+- **Frontend:** React + TypeScript, bundled via esbuild, styled with Tailwind CSS + DaisyUI
+- **Databases:** PostgreSQL (primary data), ClickHouse (metrics/analytics)
+- **Storage:** S3-compatible object storage (MinIO locally, any S3-compatible service in prod)
+- **Email:** Swoosh (local mailbox in dev, Brevo in prod)
+- **API layer:** AshTypescript RPC (type-safe TS client auto-generated from Ash resources)
 
-Ready to run in production? Please [check our deployment guides](https://hexdocs.pm/phoenix/deployment.html).
+## Dev environment setup
 
-## Learn more
+### Prerequisites
 
-* Official website: https://www.phoenixframework.org/
+- Elixir 1.15+ and Erlang/OTP (via [asdf](https://asdf-vm.com) or system package manager)
-* Guides: https://hexdocs.pm/phoenix/overview.html
+- PostgreSQL running locally (default: `postgres`/`postgres` on `localhost:5432`)
-* Docs: https://hexdocs.pm/phoenix
+- ClickHouse running locally (default: `default`/no password on `localhost:8123`, database `mixer_metrics`)
-* Forum: https://elixirforum.com/c/phoenix-forum
+- MinIO running locally on `localhost:9000` with credentials `minioadmin`/`minioadmin`
-* Source: https://github.com/phoenixframework/phoenix
+
+### MinIO setup
+
+Start MinIO and create the bucket before running the app:
+
+```bash
+# Start MinIO (adjust data dir as needed)
+minio server /data --console-address ":9001"
+
+# Create the bucket (using the MinIO CLI or the web console at http://localhost:9001)
+mc alias set local http://localhost:9000 minioadmin minioadmin
+mc mb local/mixer-bucket
+mc anonymous set public local/mixer-bucket
+```
+
+### First-time setup
+
+```bash
+# Install Elixir dependencies and set up both databases
+mix setup
+```
+
+`mix setup` runs `mix deps.get`, creates and migrates both the PostgreSQL and ClickHouse databases, and seeds initial data.
+
+### Running the server
+
+```bash
+mix phx.server
+```
+
+Visit [http://localhost:4000](http://localhost:4000). The frontend assets (esbuild + Tailwind) are compiled and watched automatically.
+
+### Email in development
+
+Magic-link sign-in emails are delivered to the local Swoosh mailbox. View them at [http://localhost:4000/dev/mailbox](http://localhost:4000/dev/mailbox).
+
+### Regenerating the TypeScript RPC client
+
+After changing Ash resource actions or attributes, regenerate the typed TS client:
+
+```bash
+mix ash_typescript.generate
+```
+
+The output goes to `assets/js/ash_rpc.ts`.
+
+## Production environment variables
+
+| Variable | Description |
+|---|---|
+| `DATABASE_URL` | PostgreSQL connection URL (`ecto://user:pass@host/db`) |
+| `SECRET_KEY_BASE` | Phoenix secret key (generate with `mix phx.gen.secret`) |
+| `TOKEN_SIGNING_SECRET` | Ash authentication token signing secret |
+| `CLICKHOUSE_URL` | ClickHouse connection URL (or use individual vars below) |
+| `CLICKHOUSE_HOST` | ClickHouse host |
+| `CLICKHOUSE_PORT` | ClickHouse port (default `8123`) |
+| `CLICKHOUSE_DATABASE` | ClickHouse database name (default `mixer_metrics`) |
+| `CLICKHOUSE_USERNAME` | ClickHouse username (default `default`) |
+| `CLICKHOUSE_PASSWORD` | ClickHouse password |
+| `S3_ACCESS_KEY_ID` | S3 access key |
+| `S3_SECRET_ACCESS_KEY` | S3 secret key |
+| `S3_HOST` | S3 host (e.g. `s3.amazonaws.com`) |
+| `S3_BUCKET` | S3 bucket name |
+| `S3_ASSET_HOST` | Public base URL for serving assets (e.g. `https://cdn.example.com`) |
+| `S3_SCHEME` | S3 scheme (default `https://`) |
+| `S3_PORT` | S3 port (default `80`) |
+| `S3_VIRTUAL_HOST` | Use virtual-hosted S3 URLs (default `false`) |
+| `BREVO_API_KEY` | Brevo (Sendinblue) API key for transactional email |
+| `PHX_HOST` | Public hostname (default `mixer.jimweaver.com`) |
+| `PORT` | HTTP port (default `4000`) |
+| `PHX_SERVER` | Set to `true` to start the HTTP server in a release |

assets/css/app.css

@@ -152,15 +152,6 @@ html, body {
   margin: 0 auto;
 }
 
-@media (max-width: 960px) {
-  .mx-root { grid-template-columns: 64px 1fr; }
-  .mx-rightbar { display: none; }
-}
-@media (max-width: 640px) {
-  .mx-root { grid-template-columns: 1fr; }
-  .mx-sidebar { display: none; }
-}
-
 /* ── Sidebar ── */
 .mx-sidebar {
   position: sticky;
@@ -312,6 +303,12 @@ html, body {
   user-select: none;
 }
 
+.mx-tweet-avatar--lg {
+  width: 56px;
+  height: 56px;
+  font-size: 1.25rem;
+}
+
 .mx-compose-body { flex: 1; }
 
 .mx-compose-textarea, .mx-edit-textarea {
@@ -699,6 +696,104 @@ html, body {
   margin-bottom: 1rem;
 }
 
+/* ── Comment button on tweet cards ── */
+.mx-comment-btn {
+  text-decoration: none;
+  margin-left: 0.5rem;
+  color: var(--mx-fg2);
+  transition: color 0.15s, border-color 0.15s, background 0.15s, transform 0.15s;
+}
+.mx-comment-btn:hover {
+  color: var(--mx-accent);
+  border-color: color-mix(in oklch, var(--mx-accent) 35%, transparent);
+  background: color-mix(in oklch, var(--mx-accent) 10%, transparent);
+  transform: translateY(-1px);
+}
+
+/* Non-interactive reply count badge in detail view */
+.mx-comment-count-badge {
+  margin-left: 0.5rem;
+  cursor: default;
+  pointer-events: none;
+  color: var(--mx-fg2);
+}
+
+/* ── Comments section (below tweet detail) ── */
+.mx-comments-section {
+  border-top: 1px solid var(--mx-border);
+  margin-top: 0.5rem;
+  padding: 0 1.5rem 1.5rem;
+}
+
+.mx-comments-divider {
+  display: flex;
+  align-items: center;
+  gap: 0.75rem;
+  padding: 1rem 0 0.75rem;
+  font-size: 0.8125rem;
+  font-weight: 600;
+  color: var(--mx-fg2);
+  text-transform: uppercase;
+  letter-spacing: 0.06em;
+}
+.mx-comments-divider::after {
+  content: "";
+  flex: 1;
+  height: 1px;
+  background: var(--mx-border);
+}
+
+.mx-comments-list {
+  display: flex;
+  flex-direction: column;
+  gap: 0.5rem;
+  margin-top: 0.75rem;
+}
+
+/* Comment card — slightly indented, more compact */
+.mx-comment {
+  padding: 0.75rem 1rem;
+  border-radius: var(--mx-radius-sm);
+}
+
+/* Small avatar variant for comments and compose-comment */
+.mx-tweet-avatar--sm {
+  width: 28px;
+  height: 28px;
+  min-width: 28px;
+  font-size: 0.75rem;
+}
+
+/* Compact compose box for replies */
+.mx-compose--comment {
+  padding: 0.75rem 0;
+  border-bottom: 1px solid var(--mx-border);
+  margin-bottom: 0.25rem;
+}
+.mx-compose--comment .mx-compose-avatar--sm { align-self: flex-start; }
+.mx-compose-textarea--sm {
+  min-height: 2.5rem;
+  padding: 0.4rem 0.6rem;
+  font-size: 0.9375rem;
+}
+
+.mx-btn-post--sm {
+  padding: 0.35rem 0.875rem;
+  font-size: 0.8125rem;
+}
+
+/* Small empty state */
+.mx-empty--sm {
+  padding: 1.5rem 0.5rem;
+}
+
+/* Small sign-in CTA */
+.mx-signin-cta--sm {
+  padding: 0.75rem 0;
+  font-size: 0.875rem;
+  color: var(--mx-muted);
+}
+
 /* ── Clickable media thumb (used in detail view) ── */
 .mx-media-thumb {
   background: none;
@@ -802,3 +897,330 @@ html, body {
   background: var(--mx-border);
   margin: 4px 0;
 }
+
+/* ─────────────────────────────────────────────────────────────────────────────
+   Mobile bottom navigation bar
+   Only shown at ≤640 px (sidebar is hidden at that breakpoint).
+───────────────────────────────────────────────────────────────────────────── */
+.mx-mobile-nav {
+  display: none;
+  position: fixed;
+  bottom: 0;
+  left: 0;
+  right: 0;
+  z-index: 50;
+  height: 60px;
+  align-items: center;
+  justify-content: space-around;
+  background: color-mix(in oklch, var(--mx-bg) 92%, transparent);
+  backdrop-filter: blur(16px);
+  -webkit-backdrop-filter: blur(16px);
+  border-top: 1px solid var(--mx-border);
+  /* respect iPhone home indicator */
+  padding-bottom: env(safe-area-inset-bottom, 0px);
+}
+
+@media (max-width: 960px) {
+  .mx-mobile-nav { display: flex; }
+}
+
+.mx-mobile-nav-item {
+  display: flex;
+  flex: 1;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  gap: 3px;
+  color: var(--mx-muted);
+  text-decoration: none;
+  font-size: 0.65rem;
+  font-weight: 500;
+  padding: 0.25rem 0;
+  transition: color 0.15s;
+  -webkit-tap-highlight-color: transparent;
+}
+
+.mx-mobile-nav-item--active { color: var(--mx-accent); }
+
+.mx-mobile-nav-item svg {
+  flex-shrink: 0;
+}
+
+/* Centred compose button — raised pill */
+.mx-mobile-nav-compose {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  flex-shrink: 0;
+  width: 48px;
+  height: 48px;
+  border-radius: 50%;
+  background: var(--mx-accent);
+  color: #fff;
+  border: none;
+  cursor: pointer;
+  box-shadow: 0 4px 16px color-mix(in oklch, var(--mx-accent) 55%, transparent);
+  transition: background 0.15s, transform 0.12s, box-shadow 0.15s;
+  -webkit-tap-highlight-color: transparent;
+}
+
+.mx-mobile-nav-compose:hover {
+  background: var(--mx-accent2);
+  box-shadow: 0 6px 20px color-mix(in oklch, var(--mx-accent) 65%, transparent);
+  transform: scale(1.06);
+}
+
+.mx-mobile-nav-compose:active { transform: scale(0.94); }
+
+/* ─────────────────────────────────────────────────────────────────────────────
+   Mobile compose overlay (full-screen drafting page)
+   Hidden on desktop — only the mobile nav can trigger it.
+───────────────────────────────────────────────────────────────────────────── */
+@keyframes mx-overlay-in {
+  from { opacity: 0; transform: translateY(28px); }
+  to   { opacity: 1; transform: translateY(0); }
+}
+
+.mx-compose-overlay {
+  display: none;
+}
+
+@media (max-width: 960px) {
+  .mx-compose-overlay {
+    display: flex;
+    flex-direction: column;
+    position: fixed;
+    inset: 0;
+    z-index: 100;
+    background: var(--mx-bg);
+    animation: mx-overlay-in 0.22s cubic-bezier(0.34, 1.1, 0.64, 1);
+  }
+}
+
+.mx-compose-overlay-header {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  padding: 1rem 1.25rem;
+  border-bottom: 1px solid var(--mx-border);
+  background: color-mix(in oklch, var(--mx-bg) 85%, transparent);
+  backdrop-filter: blur(12px);
+  -webkit-backdrop-filter: blur(12px);
+  position: sticky;
+  top: 0;
+  z-index: 1;
+}
+
+.mx-compose-overlay-title {
+  font-family: 'Instrument Serif', Georgia, serif;
+  font-size: 1.125rem;
+  font-style: italic;
+  letter-spacing: -0.01em;
+  color: var(--mx-fg);
+}
+
+.mx-compose-overlay-cancel {
+  background: none;
+  border: none;
+  color: var(--mx-fg2);
+  font-size: 0.9rem;
+  font-family: inherit;
+  cursor: pointer;
+  padding: 0.25rem 0;
+  min-width: 60px;
+  transition: color 0.15s;
+}
+
+.mx-compose-overlay-cancel:hover { color: var(--mx-fg); }
+
+.mx-compose-overlay-body {
+  flex: 1;
+  overflow-y: auto;
+  padding: 1.25rem;
+}
+
+/* ───────────────────────────────────────────────────────────────────────────────
+   Responsive layout overrides
+   IMPORTANT: these rules must live AFTER all component base rules so that
+   the cascade works correctly (later rule of equal specificity wins).
+─────────────────────────────────────────────────────────────────────────────── */
+
+/* Tablet + mobile (≤ 960 px): single column, no side panels, bottom nav */
+@media (max-width: 960px) {
+  .mx-root         { grid-template-columns: 1fr; }
+  .mx-sidebar      { display: none; }
+  .mx-rightbar     { display: none; }
+  /* room for fixed bottom nav */
+  .mx-main         { padding-bottom: 72px; }
+  /* hide inline compose — the overlay FAB handles it */
+  .mx-compose-wrapper { display: none; }
+}
+
+/* ── Avatar image ── */
+.mx-avatar-img {
+  width: 100%;
+  height: 100%;
+  object-fit: cover;
+  border-radius: inherit;
+  display: block;
+}
+
+/* ── Tweet sub-handle (@username) ── */
+.mx-tweet-subhandle {
+  font-size: 0.78rem;
+  color: var(--mx-muted);
+  font-weight: 400;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+  max-width: 120px;
+}
+
+/* ── Profile editor ── */
+.mx-profile-editor {
+  padding: 1.5rem 1.25rem;
+  display: flex;
+  flex-direction: column;
+  gap: 1.25rem;
+  max-width: 480px;
+}
+
+.mx-profile-avatar-section {
+  display: flex;
+  flex-direction: column;
+  align-items: flex-start;
+  gap: 0.5rem;
+}
+
+.mx-profile-avatar-wrap {
+  position: relative;
+  width: 80px;
+  height: 80px;
+}
+
+.mx-profile-avatar-img {
+  width: 80px;
+  height: 80px;
+  border-radius: 50%;
+  object-fit: cover;
+  display: block;
+  border: 2px solid var(--mx-border2);
+}
+
+.mx-profile-avatar-placeholder {
+  width: 80px;
+  height: 80px;
+  border-radius: 50%;
+  background: linear-gradient(135deg, var(--mx-accent) 0%, var(--mx-accent2) 100%);
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  font-size: 2rem;
+  font-weight: 700;
+  color: white;
+  user-select: none;
+}
+
+.mx-profile-avatar-edit-btn {
+  position: absolute;
+  bottom: 0;
+  right: 0;
+  width: 26px;
+  height: 26px;
+  border-radius: 50%;
+  background: var(--mx-accent);
+  border: 2px solid var(--mx-bg);
+  color: white;
+  cursor: pointer;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  transition: background 0.15s;
+}
+.mx-profile-avatar-edit-btn:hover { background: var(--mx-accent2); }
+.mx-profile-avatar-edit-btn:disabled { opacity: 0.6; cursor: not-allowed; }
+
+.mx-profile-stats {
+  display: flex;
+  gap: 1.25rem;
+  font-size: 0.875rem;
+  color: var(--mx-muted);
+}
+.mx-profile-stats strong { color: var(--mx-fg); }
+
+.mx-profile-field {
+  display: flex;
+  flex-direction: column;
+  gap: 0.375rem;
+}
+
+.mx-profile-label {
+  font-size: 0.75rem;
+  font-weight: 600;
+  color: var(--mx-fg2);
+  letter-spacing: 0.04em;
+  text-transform: uppercase;
+}
+
+.mx-profile-input {
+  background: var(--mx-surface);
+  border: 1px solid var(--mx-border2);
+  border-radius: var(--mx-radius-sm);
+  padding: 0.5rem 0.75rem;
+  color: var(--mx-fg);
+  font-family: inherit;
+  font-size: 0.9375rem;
+  width: 100%;
+  transition: border-color 0.15s;
+  outline: none;
+}
+.mx-profile-input:focus { border-color: var(--mx-accent); }
+.mx-profile-input--readonly { color: var(--mx-muted); cursor: not-allowed; }
+
+.mx-profile-input-wrap {
+  display: flex;
+  align-items: center;
+  background: var(--mx-surface);
+  border: 1px solid var(--mx-border2);
+  border-radius: var(--mx-radius-sm);
+  padding: 0 0.75rem;
+  transition: border-color 0.15s;
+}
+.mx-profile-input-wrap:focus-within { border-color: var(--mx-accent); }
+
+.mx-profile-at {
+  color: var(--mx-muted);
+  font-size: 0.9375rem;
+  pointer-events: none;
+  user-select: none;
+}
+
+.mx-profile-input--handle {
+  border: none;
+  border-radius: 0;
+  padding-left: 0.25rem;
+  background: transparent;
+}
+.mx-profile-input--handle:focus { border-color: transparent; }
+
+.mx-profile-hint {
+  font-size: 0.72rem;
+  color: var(--mx-muted);
+  margin-top: 0.125rem;
+}
+
+/* Narrow phones (≤ 640 px): tighten spacing */
+@media (max-width: 640px) {
+  .mx-feed  { padding: 0.625rem; gap: 0.5rem; }
+  .mx-tweet { padding: 0.875rem; }
+  .mx-tweet-handle {
+    overflow: hidden;
+    text-overflow: ellipsis;
+    white-space: nowrap;
+    max-width: 180px;
+  }
+  .mx-header { padding: 0.75rem 1rem; }
+  .mx-detail { padding: 0.875rem 1rem; }
+  /* 5-item nav: slightly smaller labels so nothing wraps */
+  .mx-mobile-nav-item { font-size: 0.6rem; }
+}

assets/js/App.tsx

@@ -0,0 +1,200 @@
+import React, { useState } from "react";
+import { QueryClientProvider, QueryClient } from "@tanstack/react-query";
+import { AuthCtx } from "./context";
+import { useIsDesktop } from "./hooks";
+import { ComposeTweet } from "./components/compose";
+import { Feed, FollowingFeed, RefreshButton } from "./components/feed";
+import { TweetDetail } from "./components/tweet-detail";
+import { UserList, UserDetail } from "./components/users";
+import { MyProfile } from "./components/profile";
+import { MobileNav, MobileComposePage } from "./components/nav";
+
+const queryClient = new QueryClient({
+  defaultOptions: { queries: { staleTime: 10_000 } },
+});
+
+export function App() {
+  const appEl = document.getElementById("app")!;
+  const email = appEl.dataset.currentUserEmail ?? "";
+  const userId = appEl.dataset.currentUserId ?? "";
+  const username = appEl.dataset.currentUserUsername ?? "";
+  const displayName = appEl.dataset.currentUserDisplayName ?? "";
+  const avatarUrl = appEl.dataset.currentUserAvatarUrl ?? "";
+  const tweetId = appEl.dataset.tweetId || null;
+  const page = appEl.dataset.page ?? "feed";
+  const profileUserId = appEl.dataset.userId || null;
+
+  const [mobileCompose, setMobileCompose] = useState(false);
+  const isDesktop = useIsDesktop();
+
+  const onFeedPage = page === "feed" || page === "tweet";
+  const onFollowingPage = page === "following";
+  const onUsersPage = page === "users" || page === "user-detail";
+  const onProfilePage = page === "profile";
+
+  function renderMain() {
+    switch (page) {
+      case "tweet":
+        return (
+          <>
+            <header className="mx-header">
+              <h1 className="mx-header-title">Tweet</h1>
+            </header>
+            <TweetDetail tweetId={tweetId!} />
+          </>
+        );
+      case "following":
+        return (
+          <>
+            <header className="mx-header">
+              <h1 className="mx-header-title">Following</h1>
+              <RefreshButton queryKey={["following_tweets"]} />
+            </header>
+            <FollowingFeed />
+          </>
+        );
+      case "users":
+        return (
+          <>
+            <header className="mx-header">
+              <h1 className="mx-header-title">Users</h1>
+            </header>
+            <UserList />
+          </>
+        );
+      case "user-detail":
+        return (
+          <>
+            <header className="mx-header">
+              <h1 className="mx-header-title">Profile</h1>
+            </header>
+            <UserDetail userId={profileUserId!} />
+          </>
+        );
+      case "profile":
+        return (
+          <>
+            <header className="mx-header">
+              <h1 className="mx-header-title">My Profile</h1>
+            </header>
+            <MyProfile />
+          </>
+        );
+      default:
+        return (
+          <>
+            <header className="mx-header">
+              <h1 className="mx-header-title">Feed</h1>
+              <RefreshButton />
+            </header>
+
+            <div className="mx-compose-wrapper">
+              {email ? (
+                <ComposeTweet />
+              ) : (
+                <div className="mx-signin-cta">
+                  <p>Sign in to start mixing.</p>
+                  <a className="mx-btn-post" href="/register">Sign in</a>
+                </div>
+              )}
+            </div>
+
+            <div className="mx-divider" />
+
+            <Feed />
+          </>
+        );
+    }
+  }
+
+  return (
+    <AuthCtx.Provider value={{ email, userId, username, displayName, avatarUrl }}>
+      <QueryClientProvider client={queryClient}>
+        <div className="mx-root">
+          {isDesktop && (
+            <aside className="mx-sidebar">
+              <div className="mx-logo">
+                <span className="mx-logo-icon">⬡</span>
+                <span className="mx-logo-text">Mixer</span>
+              </div>
+              <nav className="mx-nav">
+                <a className={`mx-nav-item${onFeedPage ? " mx-nav-active" : ""}`} href="/feed">
+                  <svg width="18" height="18" viewBox="0 0 24 24" fill="currentColor">
+                    <path d="M10 20v-6h4v6h5v-8h3L12 3 2 12h3v8z" />
+                  </svg>
+                  Feed
+                </a>
+                <a className={`mx-nav-item${onFollowingPage ? " mx-nav-active" : ""}`} href="/following">
+                  <svg width="18" height="18" viewBox="0 0 24 24" fill="currentColor">
+                    <path d="M12 17.27L18.18 21l-1.64-7.03L22 9.24l-7.19-.61L12 2 9.19 8.63 2 9.24l5.46 4.73L5.82 21z" />
+                  </svg>
+                  Following
+                </a>
+                <a className={`mx-nav-item${onUsersPage ? " mx-nav-active" : ""}`} href="/users">
+                  <svg width="18" height="18" viewBox="0 0 24 24" fill="currentColor">
+                    <path d="M16 11c1.66 0 2.99-1.34 2.99-3S17.66 5 16 5c-1.66 0-3 1.34-3 3s1.34 3 3 3zm-8 0c1.66 0 2.99-1.34 2.99-3S9.66 5 8 5C6.34 5 5 6.34 5 8s1.34 3 3 3zm0 2c-2.33 0-7 1.17-7 3.5V19h14v-2.5c0-2.33-4.67-3.5-7-3.5zm8 0c-.29 0-.62.02-.97.05 1.16.84 1.97 1.97 1.97 3.45V19h6v-2.5c0-2.33-4.67-3.5-7-3.5z" />
+                  </svg>
+                  Users
+                </a>
+                <a className={`mx-nav-item${onProfilePage ? " mx-nav-active" : ""}`} href="/profile">
+                  <svg width="18" height="18" viewBox="0 0 24 24" fill="currentColor">
+                    <path d="M12 12c2.21 0 4-1.79 4-4s-1.79-4-4-4-4 1.79-4 4 1.79 4 4 4zm0 2c-2.67 0-8 1.34-8 4v2h16v-2c0-2.66-5.33-4-8-4z" />
+                  </svg>
+                  Profile
+                </a>
+              </nav>
+              <div className="mx-sidebar-footer">
+                {email ? (
+                  <>
+                    <span className="mx-version" style={{ color: "var(--mx-fg2)" }}>
+                      {displayName || username || email}
+                    </span>
+                    {username && (
+                      <span className="mx-version">@{username}</span>
+                    )}
+                    <a className="mx-auth-link" href="/sign-out">Sign out</a>
+                  </>
+                ) : (
+                  <>
+                    <a className="mx-auth-link" href="/register">Create account</a>
+                    <a className="mx-auth-link" href="/sign-in">Sign in</a>
+                  </>
+                )}
+                <span className="mx-version">v0.1.0</span>
+              </div>
+            </aside>
+          )}
+
+          <main className="mx-main">
+            {renderMain()}
+          </main>
+
+          {isDesktop && (
+            <div className="mx-rightbar">
+              <div className="mx-info-card">
+                <h3 className="mx-info-title">About Mixer</h3>
+                <p className="mx-info-body">
+                  A minimal social feed built with Ash Framework, Phoenix, and React.
+                </p>
+                <div className="mx-stack">
+                  {["Ash 3", "Phoenix 1.8", "AshTypescript", "React 19"].map((s) => (
+                    <span key={s} className="mx-tag">{s}</span>
+                  ))}
+                </div>
+              </div>
+            </div>
+          )}
+        </div>
+
+        <MobileNav page={page} onCompose={() => setMobileCompose(true)} />
+
+        {mobileCompose && (
+          <MobileComposePage
+            email={email}
+            onClose={() => setMobileCompose(false)}
+          />
+        )}
+      </QueryClientProvider>
+    </AuthCtx.Provider>
+  );
+}

assets/js/ash_rpc.ts

@@ -541,6 +541,83 @@ export async function validateReadUser(
 }
 
 
+export type UpdateProfileInput = {
+  username?: string | null;
+  displayName?: string | null;
+};
+
+export type UpdateProfileFields = UnifiedFieldSelection<usersResourceSchema>[];
+
+export type InferUpdateProfileResult<
+  Fields extends UpdateProfileFields | undefined,
+> = InferResult<usersResourceSchema, Fields>;
+
+export type UpdateProfileResult<Fields extends UpdateProfileFields | undefined = undefined> = | { success: true; data: InferUpdateProfileResult<Fields>; }
+| { success: false; errors: AshRpcError[]; }
+
+;
+
+/**
+ * Update an existing User
+ *
+ * @ashActionType :update
+ */
+export async function updateProfile<Fields extends UpdateProfileFields | undefined = undefined>(
+  config: {
+  tenant?: string;
+  identity: UUID;
+  input?: UpdateProfileInput;
+  fields?: Fields;
+  headers?: Record<string, string>;
+  fetchOptions?: RequestInit;
+  customFetch?: (input: RequestInfo | URL, init?: RequestInit) => Promise<Response>;
+}
+): Promise<UpdateProfileResult<Fields extends undefined ? [] : Fields>> {
+  const payload = {
+    action: "update_profile",
+    ...(config.tenant !== undefined && { tenant: config.tenant }),
+    identity: config.identity,
+    input: config.input,
+    ...(config.fields !== undefined && { fields: config.fields })
+  };
+
+  return executeActionRpcRequest<UpdateProfileResult<Fields extends undefined ? [] : Fields>>(
+    payload,
+    config
+  );
+}
+
+
+/**
+ * Validate: Update an existing User
+ *
+ * @ashActionType :update
+ * @validation true
+ */
+export async function validateUpdateProfile(
+  config: {
+  tenant?: string;
+  identity: UUID | string;
+  input?: UpdateProfileInput;
+  headers?: Record<string, string>;
+  fetchOptions?: RequestInit;
+  customFetch?: (input: RequestInfo | URL, init?: RequestInit) => Promise<Response>;
+}
+): Promise<ValidationResult> {
+  const payload = {
+    action: "update_profile",
+    ...(config.tenant !== undefined && { tenant: config.tenant }),
+    identity: config.identity,
+    input: config.input
+  };
+
+  return executeValidationRpcRequest<ValidationResult>(
+    payload,
+    config
+  );
+}
+
+
 export type ReadMediaFields = UnifiedFieldSelection<mediaResourceSchema>[];
 
 
@@ -644,6 +721,7 @@ export async function validateReadMedia(
 
 export type CreateTweetInput = {
   content: string;
+  parentTweetId?: UUID | null;
   mediaId?: UUID;
 };
 
@@ -843,6 +921,73 @@ export async function validateLikeTweet(
 }
 
 
+export type ReadFollowingFeedFields = UnifiedFieldSelection<tweetsResourceSchema>[];
+export type InferReadFollowingFeedResult<
+  Fields extends ReadFollowingFeedFields,
+> = Array<InferResult<tweetsResourceSchema, Fields>>;
+
+export type ReadFollowingFeedResult<Fields extends ReadFollowingFeedFields> = | { success: true; data: InferReadFollowingFeedResult<Fields>; }
+| { success: false; errors: AshRpcError[]; }
+
+;
+
+/**
+ * Read Tweet records
+ *
+ * @ashActionType :read
+ */
+export async function readFollowingFeed<Fields extends ReadFollowingFeedFields>(
+  config: {
+  tenant?: string;
+  fields: Fields;
+  filter?: tweetsFilterInput;
+  sort?: SortString<tweetsSortField> | SortString<tweetsSortField>[];
+  headers?: Record<string, string>;
+  fetchOptions?: RequestInit;
+  customFetch?: (input: RequestInfo | URL, init?: RequestInit) => Promise<Response>;
+}
+): Promise<ReadFollowingFeedResult<Fields>> {
+  const payload = {
+    action: "read_following_feed",
+    ...(config.tenant !== undefined && { tenant: config.tenant }),
+    ...(config.fields !== undefined && { fields: config.fields }),
+    ...(config.filter && { filter: config.filter }),
+    ...(config.sort && { sort: Array.isArray(config.sort) ? config.sort.join(",") : config.sort })
+  };
+
+  return executeActionRpcRequest<ReadFollowingFeedResult<Fields>>(
+    payload,
+    config
+  );
+}
+
+
+/**
+ * Validate: Read Tweet records
+ *
+ * @ashActionType :read
+ * @validation true
+ */
+export async function validateReadFollowingFeed(
+  config: {
+  tenant?: string;
+  headers?: Record<string, string>;
+  fetchOptions?: RequestInit;
+  customFetch?: (input: RequestInfo | URL, init?: RequestInit) => Promise<Response>;
+}
+): Promise<ValidationResult> {
+  const payload = {
+    action: "read_following_feed",
+    ...(config.tenant !== undefined && { tenant: config.tenant })
+  };
+
+  return executeValidationRpcRequest<ValidationResult>(
+    payload,
+    config
+  );
+}
+
+
 export type ReadTweetFields = UnifiedFieldSelection<tweetsResourceSchema>[];
 
 

assets/js/ash_types.ts

@@ -25,9 +25,12 @@ export type followsAttributesOnlySchema = {
 // users Schema
 export type usersResourceSchema = {
   __type: "Resource";
-  __primitiveFields: "id" | "email" | "followerCount" | "followingCount" | "amIFollowing" | "myFollowId";
+  __primitiveFields: "id" | "email" | "username" | "displayName" | "avatarUrl" | "followerCount" | "followingCount" | "amIFollowing" | "myFollowId";
   id: UUID;
   email: string;
+  username: string | null;
+  displayName: string | null;
+  avatarUrl: string | null;
   followerCount: number;
   followingCount: number;
   amIFollowing: boolean;
@@ -38,9 +41,12 @@ export type usersResourceSchema = {
 
 export type usersAttributesOnlySchema = {
   __type: "Resource";
-  __primitiveFields: "id" | "email";
+  __primitiveFields: "id" | "email" | "username" | "displayName" | "avatarUrl";
   id: UUID;
   email: string;
+  username: string | null;
+  displayName: string | null;
+  avatarUrl: string | null;
 };
 
 
@@ -71,16 +77,23 @@ export type mediaAttributesOnlySchema = {
 // tweets Schema
 export type tweetsResourceSchema = {
   __type: "Resource";
-  __primitiveFields: "id" | "content" | "likes" | "userId" | "insertedAt" | "state" | "likedByMe" | "userEmail";
+  __primitiveFields: "id" | "content" | "likes" | "userId" | "insertedAt" | "state" | "parentTweetId" | "commentCount" | "likedByMe" | "userEmail" | "userUsername" | "userDisplayName" | "userAvatarUrl";
   id: UUID;
   content: string;
   likes: number;
   userId: UUID;
   insertedAt: UtcDateTimeUsec;
   state: "posted" | "drafted";
+  parentTweetId: UUID | null;
+  commentCount: number;
   likedByMe: boolean;
   userEmail: string | null;
+  userUsername: string | null;
+  userDisplayName: string | null;
+  userAvatarUrl: string | null;
   user: { __type: "Relationship"; __resource: usersResourceSchema; };
+  parentTweet: { __type: "Relationship"; __resource: tweetsResourceSchema | null; };
+  comments: { __type: "Relationship"; __array: true; __resource: tweetsResourceSchema; };
   media: { __type: "Relationship"; __array: true; __resource: mediaResourceSchema; };
 };
 
@@ -88,13 +101,14 @@ export type tweetsResourceSchema = {
 
 export type tweetsAttributesOnlySchema = {
   __type: "Resource";
-  __primitiveFields: "id" | "content" | "likes" | "userId" | "insertedAt" | "state";
+  __primitiveFields: "id" | "content" | "likes" | "userId" | "insertedAt" | "state" | "parentTweetId";
   id: UUID;
   content: string;
   likes: number;
   userId: UUID;
   insertedAt: UtcDateTimeUsec;
   state: "posted" | "drafted";
+  parentTweetId: UUID | null;
 };
 
 
@@ -129,6 +143,27 @@ export type usersFilterInput = {
     in?: Array<string>;
   };
 
+  username?: {
+    eq?: string;
+    notEq?: string;
+    in?: Array<string>;
+    isNil?: boolean;
+  };
+
+  displayName?: {
+    eq?: string;
+    notEq?: string;
+    in?: Array<string>;
+    isNil?: boolean;
+  };
+
+  avatarUrl?: {
+    eq?: string;
+    notEq?: string;
+    in?: Array<string>;
+    isNil?: boolean;
+  };
+
   followerCount?: {
     eq?: number;
     notEq?: number;
@@ -251,6 +286,13 @@ export type tweetsFilterInput = {
     in?: Array<"posted" | "drafted">;
   };
 
+  parentTweetId?: {
+    eq?: UUID;
+    notEq?: UUID;
+    in?: Array<UUID>;
+    isNil?: boolean;
+  };
+
   userEmail?: {
     eq?: string;
     notEq?: string;
@@ -258,6 +300,38 @@ export type tweetsFilterInput = {
     isNil?: boolean;
   };
 
+  userUsername?: {
+    eq?: string;
+    notEq?: string;
+    in?: Array<string>;
+    isNil?: boolean;
+  };
+
+  userDisplayName?: {
+    eq?: string;
+    notEq?: string;
+    in?: Array<string>;
+    isNil?: boolean;
+  };
+
+  userAvatarUrl?: {
+    eq?: string;
+    notEq?: string;
+    in?: Array<string>;
+    isNil?: boolean;
+  };
+
+  commentCount?: {
+    eq?: number;
+    notEq?: number;
+    greaterThan?: number;
+    greaterThanOrEqual?: number;
+    lessThan?: number;
+    lessThanOrEqual?: number;
+    in?: Array<number>;
+    isNil?: boolean;
+  };
+
   likedByMe?: {
     eq?: boolean;
     notEq?: boolean;
@@ -266,6 +340,10 @@ export type tweetsFilterInput = {
 
   user?: usersFilterInput;
 
+  parentTweet?: tweetsFilterInput;
+
+  comments?: tweetsFilterInput;
+
   media?: mediaFilterInput;
 
 };
@@ -274,26 +352,26 @@ export type tweetsFilterInput = {
 export const followsFilterFields = ["id"] as const;
 export type followsFilterField = (typeof followsFilterFields)[number];
 
-export const usersFilterFields = ["id", "email", "followerCount", "followingCount", "amIFollowing", "myFollowId"] as const;
+export const usersFilterFields = ["id", "email", "username", "displayName", "avatarUrl", "followerCount", "followingCount", "amIFollowing", "myFollowId"] as const;
 export type usersFilterField = (typeof usersFilterFields)[number];
 
 export const mediaFilterFields = ["id", "s3Key", "userId", "tweetId", "user", "tweet"] as const;
 export type mediaFilterField = (typeof mediaFilterFields)[number];
 
-export const tweetsFilterFields = ["id", "content", "likes", "userId", "insertedAt", "state", "userEmail", "likedByMe", "user", "media"] as const;
+export const tweetsFilterFields = ["id", "content", "likes", "userId", "insertedAt", "state", "parentTweetId", "userEmail", "userUsername", "userDisplayName", "userAvatarUrl", "commentCount", "likedByMe", "user", "parentTweet", "comments", "media"] as const;
 export type tweetsFilterField = (typeof tweetsFilterFields)[number];
 
 
 export const followsSortFields = ["id"] as const;
 export type followsSortField = (typeof followsSortFields)[number];
 
-export const usersSortFields = ["id", "email", "followerCount", "followingCount", "amIFollowing", "myFollowId"] as const;
+export const usersSortFields = ["id", "email", "username", "displayName", "avatarUrl", "followerCount", "followingCount", "amIFollowing", "myFollowId"] as const;
 export type usersSortField = (typeof usersSortFields)[number];
 
 export const mediaSortFields = ["id", "s3Key", "userId", "tweetId"] as const;
 export type mediaSortField = (typeof mediaSortFields)[number];
 
-export const tweetsSortFields = ["id", "content", "likes", "userId", "insertedAt", "state", "userEmail", "likedByMe"] as const;
+export const tweetsSortFields = ["id", "content", "likes", "userId", "insertedAt", "state", "parentTweetId", "userEmail", "userUsername", "userDisplayName", "userAvatarUrl", "commentCount", "likedByMe"] as const;
 export type tweetsSortField = (typeof tweetsSortFields)[number];
 
 

assets/js/components/compose.tsx

@@ -0,0 +1,294 @@
+import React, { useState, useRef, useEffect, useContext } from "react";
+import { useMutation, useQueryClient } from "@tanstack/react-query";
+import { createTweet, buildCSRFHeaders } from "../ash_rpc";
+import { uploadFile } from "../upload";
+import { AuthCtx } from "../context";
+import { Avatar, CharCount } from "./ui";
+
+const MAX = 280;
+
+export function ComposeTweet({ onSuccess }: { onSuccess?: () => void }) {
+  const { username, displayName, email, avatarUrl } = useContext(AuthCtx);
+  const [text, setText] = useState("");
+  const [error, setError] = useState<string | null>(null);
+  const [pendingFile, setPendingFile] = useState<File | null>(null);
+  const [previewUrl, setPreviewUrl] = useState<string | null>(null);
+  const [mediaId, setMediaId] = useState<string | null>(null);
+  const [uploading, setUploading] = useState(false);
+  const [uploadError, setUploadError] = useState<string | null>(null);
+  const textareaRef = useRef<HTMLTextAreaElement>(null);
+  const fileInputRef = useRef<HTMLInputElement>(null);
+  const qc = useQueryClient();
+
+  const mutation = useMutation({
+    mutationFn: async (content: string) => {
+      const res = await createTweet({
+        input: { content, mediaId: mediaId ?? undefined },
+        fields: ["id", "content", "userId", "state"],
+        headers: buildCSRFHeaders(),
+      });
+      if (!res.success) throw new Error(res.errors?.[0]?.message ?? "Failed");
+      return res.data;
+    },
+    onSuccess: () => {
+      qc.invalidateQueries({ queryKey: ["tweets"] });
+      qc.invalidateQueries({ queryKey: ["following_tweets"] });
+      setText("");
+      setError(null);
+      setMediaId(null);
+      setPendingFile(null);
+      setUploadError(null);
+      if (previewUrl) {
+        URL.revokeObjectURL(previewUrl);
+        setPreviewUrl(null);
+      }
+      onSuccess?.();
+    },
+    onError: (e: Error) => setError(e.message),
+  });
+
+  async function handleFileChange(e: React.ChangeEvent<HTMLInputElement>) {
+    const file = e.target.files?.[0];
+    if (!file) return;
+    e.target.value = "";
+    if (previewUrl) URL.revokeObjectURL(previewUrl);
+    const localUrl = URL.createObjectURL(file);
+    setPendingFile(file);
+    setPreviewUrl(localUrl);
+    setMediaId(null);
+    setUploadError(null);
+    setUploading(true);
+    const csrfToken = buildCSRFHeaders()["X-CSRF-Token"] as string;
+    const result = await uploadFile(file, csrfToken);
+    setUploading(false);
+    if ("error" in result) {
+      setUploadError(result.error);
+      setPendingFile(null);
+      URL.revokeObjectURL(localUrl);
+      setPreviewUrl(null);
+    } else {
+      setMediaId(result.mediaId);
+    }
+  }
+
+  function removeAttachment() {
+    if (previewUrl) URL.revokeObjectURL(previewUrl);
+    setPendingFile(null);
+    setPreviewUrl(null);
+    setMediaId(null);
+    setUploadError(null);
+  }
+
+  function handleKeyDown(e: React.KeyboardEvent<HTMLTextAreaElement>) {
+    if ((e.metaKey || e.ctrlKey) && e.key === "Enter") {
+      e.preventDefault();
+      submit();
+    }
+  }
+
+  function submit() {
+    const trimmed = text.trim();
+    if (!trimmed) return;
+    if (trimmed.length > MAX) {
+      setError(`Max ${MAX} characters`);
+      return;
+    }
+    setError(null);
+    mutation.mutate(trimmed);
+  }
+
+  useEffect(() => {
+    const el = textareaRef.current;
+    if (!el) return;
+    el.style.height = "auto";
+    el.style.height = `${el.scrollHeight}px`;
+  }, [text]);
+
+  return (
+    <div className="mx-compose">
+      <Avatar avatarUrl={avatarUrl} name={displayName || username || email} />
+      <div className="mx-compose-body">
+        <textarea
+          ref={textareaRef}
+          className="mx-compose-textarea"
+          placeholder="What's mixing?"
+          value={text}
+          onChange={(e) => setText(e.target.value)}
+          onKeyDown={handleKeyDown}
+          rows={2}
+          maxLength={MAX + 1}
+        />
+        {previewUrl && pendingFile && (
+          <div style={{ position: "relative", marginTop: "0.5rem", display: "inline-block" }}>
+            {/\.(mp4|mov)$/i.test(pendingFile.name) ? (
+              <video
+                src={previewUrl}
+                controls
+                style={{ maxWidth: "100%", maxHeight: "200px", borderRadius: "0.5rem", display: "block" }}
+              />
+            ) : (
+              <img
+                src={previewUrl}
+                alt="attachment preview"
+                style={{ maxWidth: "100%", maxHeight: "200px", borderRadius: "0.5rem", display: "block" }}
+              />
+            )}
+            {uploading && (
+              <div style={{
+                position: "absolute", inset: 0, background: "rgba(0,0,0,0.4)",
+                borderRadius: "0.5rem", display: "flex", alignItems: "center", justifyContent: "center",
+                color: "#fff", fontSize: "0.75rem"
+              }}>
+                Uploading…
+              </div>
+            )}
+            <button
+              type="button"
+              onClick={removeAttachment}
+              style={{
+                position: "absolute", top: "4px", right: "4px",
+                background: "rgba(0,0,0,0.6)", border: "none", borderRadius: "50%",
+                width: "20px", height: "20px", cursor: "pointer",
+                color: "#fff", fontSize: "12px", lineHeight: 1,
+                display: "flex", alignItems: "center", justifyContent: "center"
+              }}
+              title="Remove attachment"
+            >
+              ×
+            </button>
+          </div>
+        )}
+        {uploadError && <p className="mx-compose-error">{uploadError}</p>}
+        {error && <p className="mx-compose-error">{error}</p>}
+        <div className="mx-compose-footer">
+          <div style={{ display: "flex", alignItems: "center", gap: "0.5rem" }}>
+            <button
+              type="button"
+              className="mx-action-btn"
+              title="Attach image or video"
+              onClick={() => fileInputRef.current?.click()}
+              disabled={uploading || mutation.isPending}
+            >
+              <svg width="16" height="16" viewBox="0 0 24 24" fill="currentColor">
+                <path d="M21 19V5c0-1.1-.9-2-2-2H5c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h14c1.1 0 2-.9 2-2zM8.5 13.5l2.5 3.01L14.5 12l4.5 6H5l3.5-4.5z" />
+              </svg>
+            </button>
+            <input
+              ref={fileInputRef}
+              type="file"
+              accept="image/*,video/mp4,video/quicktime"
+              style={{ display: "none" }}
+              onChange={handleFileChange}
+            />
+            {uploading && (
+              <span style={{ fontSize: "0.75rem", color: "var(--mx-muted)" }}>
+                {pendingFile?.name}
+              </span>
+            )}
+          </div>
+          <div className="mx-compose-actions">
+            <CharCount current={text.length} max={MAX} />
+            <button
+              className="mx-btn-post"
+              onClick={submit}
+              disabled={!text.trim() || mutation.isPending || uploading}
+            >
+              {mutation.isPending ? "Posting…" : "Post"}
+            </button>
+          </div>
+        </div>
+      </div>
+    </div>
+  );
+}
+
+export function ComposeComment({
+  parentTweetId,
+  onSuccess,
+}: {
+  parentTweetId: string;
+  onSuccess?: () => void;
+}) {
+  const [text, setText] = useState("");
+  const [error, setError] = useState<string | null>(null);
+  const textareaRef = useRef<HTMLTextAreaElement>(null);
+  const qc = useQueryClient();
+
+  const { username, displayName, email, avatarUrl } = useContext(AuthCtx);
+
+  const mutation = useMutation({
+    mutationFn: async (content: string) => {
+      const res = await createTweet({
+        input: { content, parentTweetId },
+        fields: ["id", "content", "userId", "state"],
+        headers: buildCSRFHeaders(),
+      });
+      if (!res.success) throw new Error(res.errors?.[0]?.message ?? "Failed");
+      return res.data;
+    },
+    onSuccess: () => {
+      qc.invalidateQueries({ queryKey: ["comments", parentTweetId] });
+      qc.invalidateQueries({ queryKey: ["tweet", parentTweetId] });
+      qc.invalidateQueries({ queryKey: ["tweets"] });
+      qc.invalidateQueries({ queryKey: ["following_tweets"] });
+      setText("");
+      setError(null);
+      onSuccess?.();
+    },
+    onError: (e: Error) => setError(e.message),
+  });
+
+  function handleKeyDown(e: React.KeyboardEvent<HTMLTextAreaElement>) {
+    if ((e.metaKey || e.ctrlKey) && e.key === "Enter") {
+      e.preventDefault();
+      submit();
+    }
+  }
+
+  function submit() {
+    const trimmed = text.trim();
+    if (!trimmed) return;
+    if (trimmed.length > MAX) { setError(`Max ${MAX} characters`); return; }
+    setError(null);
+    mutation.mutate(trimmed);
+  }
+
+  useEffect(() => {
+    const el = textareaRef.current;
+    if (!el) return;
+    el.style.height = "auto";
+    el.style.height = `${el.scrollHeight}px`;
+  }, [text]);
+
+  return (
+    <div className="mx-compose mx-compose--comment">
+      <Avatar avatarUrl={avatarUrl} name={displayName || username || email} size="sm" />
+      <div className="mx-compose-body">
+        <textarea
+          ref={textareaRef}
+          className="mx-compose-textarea mx-compose-textarea--sm"
+          placeholder="Post your reply…"
+          value={text}
+          onChange={(e) => setText(e.target.value)}
+          onKeyDown={handleKeyDown}
+          rows={1}
+          maxLength={MAX + 1}
+        />
+        {error && <p className="mx-compose-error">{error}</p>}
+        <div className="mx-compose-footer">
+          <div />
+          <div className="mx-compose-actions">
+            <CharCount current={text.length} max={MAX} />
+            <button
+              className="mx-btn-post mx-btn-post--sm"
+              onClick={submit}
+              disabled={!text.trim() || mutation.isPending}
+            >
+              {mutation.isPending ? "Replying…" : "Reply"}
+            </button>
+          </div>
+        </div>
+      </div>
+    </div>
+  );
+}

assets/js/components/feed.tsx

@@ -0,0 +1,199 @@
+import React, { useRef, useEffect, useContext, useState } from "react";
+import { useInfiniteQuery, useQueryClient } from "@tanstack/react-query";
+import { readTweet, readFollowingFeed, buildCSRFHeaders } from "../ash_rpc";
+import { AuthCtx } from "../context";
+import { FEED_PAGE_SIZE } from "../constants";
+import { Spinner, ErrorBanner } from "./ui";
+import { TweetCard } from "./tweet-card";
+import type { Tweet } from "../types";
+
+export function Feed() {
+  const sentinelRef = useRef<HTMLDivElement>(null);
+
+  const {
+    data,
+    isLoading,
+    isError,
+    error,
+    fetchNextPage,
+    hasNextPage,
+    isFetchingNextPage,
+  } = useInfiniteQuery({
+    queryKey: ["tweets"],
+    queryFn: async ({ pageParam }: { pageParam: number }) => {
+      const res = await readTweet({
+        fields: ["id", "content", "likes", "likedByMe", "commentCount", "userId", "state", "userEmail", "userUsername", "userDisplayName", "userAvatarUrl", "insertedAt", { media: ["id", "s3Key"] }],
+        sort: "-insertedAt",
+        page: { limit: FEED_PAGE_SIZE, offset: pageParam },
+        filter: { parentTweetId: { isNil: true } },
+        headers: buildCSRFHeaders(),
+      });
+      if (!res.success) throw new Error("Failed to load tweets");
+      const pageData = res.data as any;
+      const tweets: Tweet[] = Array.isArray(pageData) ? pageData : (pageData?.results ?? []);
+      const hasMore: boolean = Array.isArray(pageData) ? false : (pageData?.hasMore ?? false);
+      return { tweets, hasMore, nextOffset: pageParam + FEED_PAGE_SIZE };
+    },
+    initialPageParam: 0,
+    getNextPageParam: (lastPage) => lastPage.hasMore ? lastPage.nextOffset : undefined,
+  });
+
+  useEffect(() => {
+    const el = sentinelRef.current;
+    if (!el) return;
+    const observer = new IntersectionObserver(
+      (entries) => {
+        if (entries[0].isIntersecting && hasNextPage && !isFetchingNextPage) {
+          fetchNextPage();
+        }
+      },
+      { threshold: 0.1 },
+    );
+    observer.observe(el);
+    return () => observer.disconnect();
+  }, [hasNextPage, isFetchingNextPage, fetchNextPage]);
+
+  if (isLoading) return <Spinner />;
+  if (isError) return <ErrorBanner message={(error as Error)?.message ?? "Could not load tweets"} />;
+
+  const tweets = data?.pages.flatMap((p) => p.tweets) ?? [];
+
+  if (tweets.length === 0) {
+    return (
+      <div className="mx-empty">
+        <div className="mx-empty-icon">◎</div>
+        <p className="mx-empty-title">Nothing posted yet</p>
+        <p className="mx-empty-sub">Be the first to mix something in.</p>
+      </div>
+    );
+  }
+
+  return (
+    <div className="mx-feed">
+      {tweets.map((t) => (
+        <TweetCard key={t.id} tweet={t} />
+      ))}
+      <div ref={sentinelRef} style={{ height: "1px" }} />
+      {isFetchingNextPage && <Spinner />}
+    </div>
+  );
+}
+
+export function FollowingFeed() {
+  const { userId } = useContext(AuthCtx);
+  const sentinelRef = useRef<HTMLDivElement>(null);
+
+  const {
+    data,
+    isLoading,
+    isError,
+    error,
+    fetchNextPage,
+    hasNextPage,
+    isFetchingNextPage,
+  } = useInfiniteQuery({
+    queryKey: ["following_tweets"],
+    queryFn: async ({ pageParam }: { pageParam: number }) => {
+      const res = await readFollowingFeed({
+        fields: ["id", "content", "likes", "likedByMe", "commentCount", "userId", "state", "userEmail", "userUsername", "userDisplayName", "userAvatarUrl", "insertedAt", { media: ["id", "s3Key"] }],
+        sort: "-insertedAt",
+        page: { limit: FEED_PAGE_SIZE, offset: pageParam },
+        filter: { parentTweetId: { isNil: true } },
+        headers: buildCSRFHeaders(),
+      });
+      if (!res.success) throw new Error("Failed to load following feed");
+      const pageData = res.data as any;
+      const tweets: Tweet[] = Array.isArray(pageData) ? pageData : (pageData?.results ?? []);
+      const hasMore: boolean = Array.isArray(pageData) ? false : (pageData?.hasMore ?? false);
+      return { tweets, hasMore, nextOffset: pageParam + FEED_PAGE_SIZE };
+    },
+    initialPageParam: 0,
+    getNextPageParam: (lastPage) => lastPage.hasMore ? lastPage.nextOffset : undefined,
+    enabled: !!userId,
+  });
+
+  useEffect(() => {
+    const el = sentinelRef.current;
+    if (!el) return;
+    const observer = new IntersectionObserver(
+      (entries) => {
+        if (entries[0].isIntersecting && hasNextPage && !isFetchingNextPage) {
+          fetchNextPage();
+        }
+      },
+      { threshold: 0.1 },
+    );
+    observer.observe(el);
+    return () => observer.disconnect();
+  }, [hasNextPage, isFetchingNextPage, fetchNextPage]);
+
+  if (!userId) {
+    return (
+      <div className="mx-empty">
+        <div className="mx-empty-icon">★</div>
+        <p className="mx-empty-title">Your personalised feed</p>
+        <p className="mx-empty-sub">
+          <a href="/sign-in" style={{ color: "var(--mx-accent)", textDecoration: "none" }}>Sign in</a>
+          {" "}to see posts from people you follow.
+        </p>
+      </div>
+    );
+  }
+
+  if (isLoading) return <Spinner />;
+  if (isError) return <ErrorBanner message={(error as Error)?.message ?? "Could not load following feed"} />;
+
+  const tweets = data?.pages.flatMap((p) => p.tweets) ?? [];
+
+  if (tweets.length === 0) {
+    return (
+      <div className="mx-empty">
+        <div className="mx-empty-icon">★</div>
+        <p className="mx-empty-title">Nothing here yet</p>
+        <p className="mx-empty-sub">
+          Follow some people from the{" "}
+          <a href="/users" style={{ color: "var(--mx-accent)", textDecoration: "none" }}>Users</a>
+          {" "}page to fill this feed.
+        </p>
+      </div>
+    );
+  }
+
+  return (
+    <div className="mx-feed">
+      {tweets.map((t) => (
+        <TweetCard key={t.id} tweet={t} />
+      ))}
+      <div ref={sentinelRef} style={{ height: "1px" }} />
+      {isFetchingNextPage && <Spinner />}
+    </div>
+  );
+}
+
+export function RefreshButton({ queryKey = ["tweets"] }: { queryKey?: string[] }) {
+  const qc = useQueryClient();
+  const [spinning, setSpinning] = useState(false);
+
+  async function refresh() {
+    setSpinning(true);
+    await qc.invalidateQueries({ queryKey });
+    setTimeout(() => setSpinning(false), 600);
+  }
+
+  return (
+    <button className="mx-refresh-btn" onClick={refresh} title="Refresh feed">
+      <svg
+        width="15"
+        height="15"
+        viewBox="0 0 24 24"
+        fill="currentColor"
+        style={{
+          transition: "transform 0.6s ease",
+          transform: spinning ? "rotate(360deg)" : "rotate(0deg)",
+        }}
+      >
+        <path d="M17.65 6.35A7.958 7.958 0 0 0 12 4c-4.42 0-7.99 3.58-7.99 8s3.57 8 7.99 8c3.73 0 6.84-2.55 7.73-6h-2.08A5.99 5.99 0 0 1 12 18c-3.31 0-6-2.69-6-6s2.69-6 6-6c1.66 0 3.14.69 4.22 1.78L13 11h7V4l-2.35 2.35z" />
+      </svg>
+    </button>
+  );
+}

assets/js/components/media.tsx

@@ -0,0 +1,55 @@
+import React, { useEffect } from "react";
+import { createPortal } from "react-dom";
+import { getAssetHost } from "../utils";
+import type { MediaItem } from "../types";
+
+export function TweetMedia({ media }: { media: MediaItem[] }) {
+  const assetHost = getAssetHost();
+  return (
+    <div style={{ marginTop: "0.5rem", display: "flex", flexDirection: "column", gap: "0.5rem" }}>
+      {media.map((m) =>
+        /\.(mp4|mov)$/i.test(m.s3Key) ? (
+          <video
+            key={m.id}
+            src={`${assetHost}/${m.s3Key}`}
+            controls
+            style={{ maxWidth: "100%", borderRadius: "0.5rem" }}
+          />
+        ) : (
+          <img
+            key={m.id}
+            src={`${assetHost}/${m.s3Key}`}
+            alt=""
+            style={{ maxWidth: "100%", borderRadius: "0.5rem", display: "block" }}
+          />
+        )
+      )}
+    </div>
+  );
+}
+
+export function MediaLightbox({ item, onClose }: { item: MediaItem; onClose: () => void }) {
+  const assetHost = getAssetHost();
+
+  useEffect(() => {
+    const handler = (e: KeyboardEvent) => {
+      if (e.key === "Escape") onClose();
+    };
+    document.addEventListener("keydown", handler);
+    return () => document.removeEventListener("keydown", handler);
+  }, [onClose]);
+
+  return createPortal(
+    <div className="mx-lightbox" onClick={onClose}>
+      <button className="mx-lightbox-close" onClick={onClose}>✕</button>
+      <div className="mx-lightbox-content" onClick={(e) => e.stopPropagation()}>
+        {/\.(mp4|mov)$/i.test(item.s3Key) ? (
+          <video src={`${assetHost}/${item.s3Key}`} controls autoPlay className="mx-lightbox-media" />
+        ) : (
+          <img src={`${assetHost}/${item.s3Key}`} alt="" className="mx-lightbox-media" />
+        )}
+      </div>
+    </div>,
+    document.body
+  );
+}

assets/js/components/nav.tsx

@@ -0,0 +1,109 @@
+import React from "react";
+import { ComposeTweet } from "./compose";
+
+export function MobileNav({
+  page,
+  onCompose,
+}: {
+  page: string;
+  onCompose: () => void;
+}) {
+  const onFeedPage = page === "feed" || page === "tweet";
+  const onFollowingPage = page === "following";
+  const onUsersPage = page === "users" || page === "user-detail";
+  const onProfilePage = page === "profile";
+
+  return (
+    <nav className="mx-mobile-nav">
+      <a
+        href="/feed"
+        className={`mx-mobile-nav-item${onFeedPage ? " mx-mobile-nav-item--active" : ""}`}
+      >
+        <svg width="22" height="22" viewBox="0 0 24 24" fill="currentColor">
+          <path d="M10 20v-6h4v6h5v-8h3L12 3 2 12h3v8z" />
+        </svg>
+        <span>Feed</span>
+      </a>
+
+      <a
+        href="/following"
+        className={`mx-mobile-nav-item${onFollowingPage ? " mx-mobile-nav-item--active" : ""}`}
+      >
+        <svg width="22" height="22" viewBox="0 0 24 24" fill="currentColor">
+          <path d="M12 17.27L18.18 21l-1.64-7.03L22 9.24l-7.19-.61L12 2 9.19 8.63 2 9.24l5.46 4.73L5.82 21z" />
+        </svg>
+        <span>Following</span>
+      </a>
+
+      <button
+        className="mx-mobile-nav-compose"
+        onClick={onCompose}
+        aria-label="New post"
+      >
+        <svg
+          width="20"
+          height="20"
+          viewBox="0 0 24 24"
+          fill="none"
+          stroke="currentColor"
+          strokeWidth="2.5"
+          strokeLinecap="round"
+          strokeLinejoin="round"
+        >
+          <line x1="12" y1="5" x2="12" y2="19" />
+          <line x1="5" y1="12" x2="19" y2="12" />
+        </svg>
+      </button>
+
+      <a
+        href="/users"
+        className={`mx-mobile-nav-item${onUsersPage ? " mx-mobile-nav-item--active" : ""}`}
+      >
+        <svg width="22" height="22" viewBox="0 0 24 24" fill="currentColor">
+          <path d="M16 11c1.66 0 2.99-1.34 2.99-3S17.66 5 16 5c-1.66 0-3 1.34-3 3s1.34 3 3 3zm-8 0c1.66 0 2.99-1.34 2.99-3S9.66 5 8 5C6.34 5 5 6.34 5 8s1.34 3 3 3zm0 2c-2.33 0-7 1.17-7 3.5V19h14v-2.5c0-2.33-4.67-3.5-7-3.5zm8 0c-.29 0-.62.02-.97.05 1.16.84 1.97 1.97 1.97 3.45V19h6v-2.5c0-2.33-4.67-3.5-7-3.5z" />
+        </svg>
+        <span>Users</span>
+      </a>
+
+      <a
+        href="/profile"
+        className={`mx-mobile-nav-item${onProfilePage ? " mx-mobile-nav-item--active" : ""}`}
+      >
+        <svg width="22" height="22" viewBox="0 0 24 24" fill="currentColor">
+          <path d="M12 12c2.21 0 4-1.79 4-4s-1.79-4-4-4-4 1.79-4 4 1.79 4 4 4zm0 2c-2.67 0-8 1.34-8 4v2h16v-2c0-2.66-5.33-4-8-4z" />
+        </svg>
+        <span>Profile</span>
+      </a>
+    </nav>
+  );
+}
+
+export function MobileComposePage({
+  email,
+  onClose,
+}: {
+  email: string;
+  onClose: () => void;
+}) {
+  return (
+    <div className="mx-compose-overlay">
+      <div className="mx-compose-overlay-header">
+        <button className="mx-compose-overlay-cancel" onClick={onClose}>
+          Cancel
+        </button>
+        <span className="mx-compose-overlay-title">New Post</span>
+        <div style={{ minWidth: "60px" }} />
+      </div>
+      <div className="mx-compose-overlay-body">
+        {email ? (
+          <ComposeTweet onSuccess={onClose} />
+        ) : (
+          <div className="mx-signin-cta">
+            <p>Sign in to start mixing.</p>
+            <a className="mx-btn-post" href="/register">Sign in</a>
+          </div>
+        )}
+      </div>
+    </div>
+  );
+}

assets/js/components/profile.tsx

@@ -0,0 +1,208 @@
+import React, { useState, useRef, useEffect, useContext } from "react";
+import { useQuery, useMutation, useQueryClient } from "@tanstack/react-query";
+import { readUser, updateProfile, buildCSRFHeaders } from "../ash_rpc";
+import { uploadAvatar } from "../upload";
+import { AuthCtx } from "../context";
+import { getAssetHost } from "../utils";
+import { Spinner } from "./ui";
+import type { User } from "../types";
+
+export function ProfileEditor({ userId }: { userId: string }) {
+  const assetHost = getAssetHost();
+  const qc = useQueryClient();
+
+  const { data: user, isLoading } = useQuery({
+    queryKey: ["user", userId],
+    queryFn: async () => {
+      const res = await readUser({
+        fields: ["id", "email", "username", "displayName", "avatarUrl", "followerCount", "followingCount", "amIFollowing"],
+        filter: { id: { eq: userId } },
+        headers: buildCSRFHeaders(),
+      });
+      if (!res.success) throw new Error("Failed to load user");
+      const results = Array.isArray(res.data) ? res.data : (res.data as any)?.results ?? [];
+      return (results[0] as User) ?? null;
+    },
+  });
+
+  const [username, setUsername] = useState("");
+  const [displayName, setDisplayName] = useState("");
+  const [saveError, setSaveError] = useState<string | null>(null);
+  const [saveSuccess, setSaveSuccess] = useState(false);
+  const [avatarUploading, setAvatarUploading] = useState(false);
+  const [avatarError, setAvatarError] = useState<string | null>(null);
+  const [previewAvatarUrl, setPreviewAvatarUrl] = useState<string | null>(null);
+  const avatarInputRef = useRef<HTMLInputElement>(null);
+
+  useEffect(() => {
+    if (user) {
+      setUsername(user.username ?? "");
+      setDisplayName(user.displayName ?? "");
+    }
+  }, [user?.id]);
+
+  const saveMutation = useMutation({
+    mutationFn: async () => {
+      const res = await updateProfile({
+        identity: userId,
+        input: {
+          username: username.trim() || null,
+          displayName: displayName.trim() || null,
+        },
+        fields: ["id", "username", "displayName", "avatarUrl"],
+        headers: buildCSRFHeaders(),
+      });
+      if (!res.success) throw new Error((res.errors?.[0] as any)?.message ?? "Save failed");
+      return res.data;
+    },
+    onSuccess: () => {
+      qc.invalidateQueries({ queryKey: ["user", userId] });
+      setSaveSuccess(true);
+      setSaveError(null);
+      setTimeout(() => setSaveSuccess(false), 3000);
+    },
+    onError: (e: Error) => setSaveError(e.message),
+  });
+
+  async function handleAvatarChange(e: React.ChangeEvent<HTMLInputElement>) {
+    const file = e.target.files?.[0];
+    if (!file) return;
+    e.target.value = "";
+    if (previewAvatarUrl) URL.revokeObjectURL(previewAvatarUrl);
+    setPreviewAvatarUrl(URL.createObjectURL(file));
+    setAvatarError(null);
+    setAvatarUploading(true);
+    const csrfToken = buildCSRFHeaders()["X-CSRF-Token"] as string;
+    const result = await uploadAvatar(file, csrfToken);
+    setAvatarUploading(false);
+    if ("error" in result) {
+      setAvatarError(result.error);
+      if (previewAvatarUrl) URL.revokeObjectURL(previewAvatarUrl);
+      setPreviewAvatarUrl(null);
+    } else {
+      qc.invalidateQueries({ queryKey: ["user", userId] });
+    }
+  }
+
+  if (isLoading || !user) return <Spinner />;
+
+  const currentAvatarUrl = previewAvatarUrl
+    ? previewAvatarUrl
+    : user.avatarUrl
+    ? `${assetHost}/${user.avatarUrl}`
+    : null;
+
+  return (
+    <div className="mx-profile-editor">
+      <div className="mx-profile-avatar-section">
+        <div className="mx-profile-avatar-wrap">
+          {currentAvatarUrl ? (
+            <img src={currentAvatarUrl} alt="Your avatar" className="mx-profile-avatar-img" />
+          ) : (
+            <div className="mx-profile-avatar-placeholder">
+              <span>{(user.displayName || user.username || user.email || "M")[0].toUpperCase()}</span>
+            </div>
+          )}
+          <button
+            className="mx-profile-avatar-edit-btn"
+            onClick={() => avatarInputRef.current?.click()}
+            disabled={avatarUploading}
+            title="Change avatar"
+          >
+            {avatarUploading ? (
+              <div className="mx-spinner" style={{ width: "14px", height: "14px", borderWidth: "2px" }} />
+            ) : (
+              <svg width="14" height="14" viewBox="0 0 24 24" fill="currentColor">
+                <path d="M3 17.25V21h3.75L17.81 9.94l-3.75-3.75L3 17.25zm17.71-10.04a1 1 0 0 0 0-1.41l-2.31-2.31a1 1 0 0 0-1.41 0l-1.79 1.79 3.75 3.75 1.76-1.82z" />
+              </svg>
+            )}
+          </button>
+          <input
+            ref={avatarInputRef}
+            type="file"
+            accept="image/*"
+            style={{ display: "none" }}
+            onChange={handleAvatarChange}
+          />
+        </div>
+        {avatarError && <p className="mx-compose-error" style={{ marginTop: "0.5rem" }}>{avatarError}</p>}
+      </div>
+
+      <div className="mx-profile-stats">
+        <span><strong>{user.followerCount ?? 0}</strong> followers</span>
+        <span><strong>{user.followingCount ?? 0}</strong> following</span>
+      </div>
+
+      <div className="mx-profile-field">
+        <label className="mx-profile-label">Email</label>
+        <input
+          type="text"
+          className="mx-profile-input mx-profile-input--readonly"
+          value={String(user.email)}
+          readOnly
+        />
+      </div>
+
+      <div className="mx-profile-field">
+        <label className="mx-profile-label">Display name</label>
+        <input
+          type="text"
+          className="mx-profile-input"
+          placeholder="Your display name"
+          value={displayName}
+          onChange={(e) => setDisplayName(e.target.value)}
+          maxLength={50}
+        />
+      </div>
+
+      <div className="mx-profile-field">
+        <label className="mx-profile-label">Username</label>
+        <div className="mx-profile-input-wrap">
+          <span className="mx-profile-at">@</span>
+          <input
+            type="text"
+            className="mx-profile-input mx-profile-input--handle"
+            placeholder="your_handle"
+            value={username}
+            onChange={(e) => setUsername(e.target.value.replace(/[^a-zA-Z0-9_]/g, ""))}
+            maxLength={30}
+          />
+        </div>
+        <p className="mx-profile-hint">3–30 characters. Letters, numbers, underscores only.</p>
+      </div>
+
+      {saveError && <p className="mx-compose-error">{saveError}</p>}
+      {saveSuccess && <p style={{ fontSize: "0.8rem", color: "var(--mx-green)", marginBottom: "0.5rem" }}>✓ Saved!</p>}
+
+      <div style={{ display: "flex", gap: "0.75rem", alignItems: "center" }}>
+        <button
+          className="mx-btn-post"
+          onClick={() => saveMutation.mutate()}
+          disabled={saveMutation.isPending}
+        >
+          {saveMutation.isPending ? "Saving…" : "Save changes"}
+        </button>
+        <a href="/sign-out" className="mx-btn-cancel" style={{ textDecoration: "none" }}>Sign out</a>
+      </div>
+    </div>
+  );
+}
+
+export function MyProfile() {
+  const { userId } = useContext(AuthCtx);
+
+  if (!userId) {
+    return (
+      <div className="mx-empty">
+        <div className="mx-empty-icon">◎</div>
+        <p className="mx-empty-title">Your profile</p>
+        <p className="mx-empty-sub">
+          <a href="/sign-in" style={{ color: "var(--mx-accent)", textDecoration: "none" }}>Sign in</a>
+          {" "}to view your profile.
+        </p>
+      </div>
+    );
+  }
+
+  return <ProfileEditor userId={userId} />;
+}

assets/js/components/tweet-card.tsx

@@ -0,0 +1,365 @@
+import React, { useState, useContext } from "react";
+import { useMutation, useQueryClient } from "@tanstack/react-query";
+import { destroyTweet, updateTweet, likeTweet, unlikeTweet, buildCSRFHeaders } from "../ash_rpc";
+import { AuthCtx } from "../context";
+import { timeAgo, userDisplayLabel } from "../utils";
+import { Avatar, ContextMenu } from "./ui";
+import { TweetMedia } from "./media";
+import type { Tweet, ContextMenuItem } from "../types";
+
+export function CommentIcon() {
+  return (
+    <svg width="16" height="16" viewBox="0 0 24 24" fill="currentColor">
+      <path d="M20 2H4c-1.1 0-2 .9-2 2v18l4-4h14c1.1 0 2-.9 2-2V4c0-1.1-.9-2-2-2zm0 14H5.17L4 17.17V4h16v12z" />
+    </svg>
+  );
+}
+
+export function TweetCard({ tweet }: { tweet: Tweet }) {
+  const { userId: currentUserId } = useContext(AuthCtx);
+  const canModify = !!currentUserId && tweet.userId === currentUserId;
+  const canLike = !!currentUserId;
+
+  const [editing, setEditing] = useState(false);
+  const [editText, setEditText] = useState(tweet.content);
+  const [error, setError] = useState<string | null>(null);
+  const [confirmDelete, setConfirmDelete] = useState(false);
+  const [ctxMenu, setCtxMenu] = useState<{ x: number; y: number } | null>(null);
+  const qc = useQueryClient();
+
+  const tweetUrl = `${window.location.origin}/feed/${tweet.id}`;
+
+  const ctxItems: ContextMenuItem[] = canModify
+    ? [
+        {
+          type: "item",
+          label: "Edit",
+          onClick: () => {
+            setEditText(tweet.content);
+            setEditing(true);
+            setConfirmDelete(false);
+          },
+        },
+        { type: "separator" },
+        {
+          type: "item",
+          label: "Share",
+          onClick: () => navigator.clipboard.writeText(tweetUrl),
+        },
+      ]
+    : [
+        {
+          type: "item",
+          label: "View",
+          onClick: () => { window.location.href = tweetUrl; },
+        },
+        { type: "separator" },
+        {
+          type: "item",
+          label: "Share",
+          onClick: () => navigator.clipboard.writeText(tweetUrl),
+        },
+      ];
+
+  const deleteMutation = useMutation({
+    mutationFn: async () => {
+      const res = await destroyTweet({ identity: tweet.id, headers: buildCSRFHeaders() });
+      if (!res.success) throw new Error(res.errors?.[0]?.message ?? "Failed to delete");
+    },
+    onSuccess: () => {
+      qc.invalidateQueries({ queryKey: ["tweets"] });
+      qc.invalidateQueries({ queryKey: ["following_tweets"] });
+    },
+    onError: (e: Error) => setError(e.message),
+  });
+
+  const updateMutation = useMutation({
+    mutationFn: async (content: string) => {
+      const res = await updateTweet({
+        identity: tweet.id,
+        input: { content },
+        fields: ["id", "content", "userId", "state"],
+        headers: buildCSRFHeaders(),
+      });
+      if (!res.success) throw new Error(res.errors?.[0]?.message ?? "Failed to update");
+    },
+    onSuccess: () => {
+      qc.invalidateQueries({ queryKey: ["tweets"] });
+      qc.invalidateQueries({ queryKey: ["following_tweets"] });
+      setEditing(false);
+      setError(null);
+    },
+    onError: (e: Error) => setError(e.message),
+  });
+
+  const likeMutation = useMutation({
+    mutationFn: async () => {
+      const action = tweet.likedByMe ? unlikeTweet : likeTweet;
+      const res = await action({
+        identity: tweet.id,
+        fields: ["id", "likes", "likedByMe"],
+        headers: buildCSRFHeaders(),
+      });
+      if (!res.success) throw new Error(res.errors?.[0]?.message ?? "Failed to update like");
+    },
+    onSuccess: () => {
+      qc.invalidateQueries({ queryKey: ["tweets"] });
+      qc.invalidateQueries({ queryKey: ["following_tweets"] });
+      setError(null);
+    },
+    onError: (e: Error) => setError(e.message),
+  });
+
+  function saveEdit() {
+    const trimmed = editText.trim();
+    if (!trimmed) return;
+    updateMutation.mutate(trimmed);
+  }
+
+  return (
+    <article
+      className="mx-tweet"
+      style={{ cursor: "pointer" }}
+      onClick={() => { window.location.href = `/feed/${tweet.id}`; }}
+      onContextMenu={(e) => { e.preventDefault(); setCtxMenu({ x: e.clientX, y: e.clientY }); }}
+    >
+      <Avatar avatarUrl={tweet.userAvatarUrl} name={tweet.userDisplayName || tweet.userUsername || tweet.userEmail} />
+      <div className="mx-tweet-body">
+        <div className="mx-tweet-header">
+          <span className="mx-tweet-handle">{userDisplayLabel({ displayName: tweet.userDisplayName, username: tweet.userUsername, email: tweet.userEmail })}</span>
+          {tweet.userUsername && (
+            <span className="mx-tweet-subhandle">@{tweet.userUsername}</span>
+          )}
+          <span className="mx-tweet-dot">·</span>
+          <span className="mx-tweet-time" title={tweet.insertedAt ? new Date(tweet.insertedAt).toLocaleString() : undefined}>{timeAgo(tweet.insertedAt)}</span>
+          {canModify && (
+            <div className="mx-tweet-actions">
+              <button
+                className="mx-action-btn"
+                title="Edit"
+                onClick={(e) => {
+                  e.stopPropagation();
+                  setEditText(tweet.content);
+                  setEditing(true);
+                  setConfirmDelete(false);
+                }}
+              >
+                <svg width="14" height="14" viewBox="0 0 24 24" fill="currentColor">
+                  <path d="M3 17.25V21h3.75L17.81 9.94l-3.75-3.75L3 17.25zm17.71-10.04a1 1 0 0 0 0-1.41l-2.31-2.31a1 1 0 0 0-1.41 0l-1.79 1.79 3.75 3.75 1.76-1.82z" />
+                </svg>
+              </button>
+              <button
+                className={`mx-action-btn mx-action-delete${confirmDelete ? " mx-action-confirm" : ""}`}
+                title={confirmDelete ? "Confirm delete" : "Delete"}
+                onClick={(e) => {
+                  e.stopPropagation();
+                  if (!confirmDelete) {
+                    setConfirmDelete(true);
+                    setTimeout(() => setConfirmDelete(false), 3000);
+                  } else {
+                    deleteMutation.mutate();
+                  }
+                }}
+              >
+                {deleteMutation.isPending ? (
+                  <span style={{ fontSize: "0.65rem" }}>…</span>
+                ) : confirmDelete ? (
+                  <svg width="14" height="14" viewBox="0 0 24 24" fill="currentColor">
+                    <path d="M9 16.17L4.83 12l-1.42 1.41L9 19 21 7l-1.41-1.41L9 16.17z" />
+                  </svg>
+                ) : (
+                  <svg width="14" height="14" viewBox="0 0 24 24" fill="currentColor">
+                    <path d="M6 19c0 1.1.9 2 2 2h8c1.1 0 2-.9 2-2V7H6v12zM19 4h-3.5l-1-1h-5l-1 1H5v2h14V4z" />
+                  </svg>
+                )}
+              </button>
+            </div>
+          )}
+        </div>
+
+        {editing ? (
+          <div className="mx-edit-area">
+            <textarea
+              className="mx-edit-textarea"
+              value={editText}
+              onChange={(e) => setEditText(e.target.value)}
+              autoFocus
+              rows={3}
+            />
+            {error && <p className="mx-compose-error">{error}</p>}
+            <div className="mx-edit-footer">
+              <button
+                className="mx-btn-cancel"
+                onClick={() => { setEditing(false); setError(null); }}
+              >
+                Cancel
+              </button>
+              <button
+                className="mx-btn-save"
+                onClick={saveEdit}
+                disabled={!editText.trim() || updateMutation.isPending}
+              >
+                {updateMutation.isPending ? "Saving…" : "Save"}
+              </button>
+            </div>
+          </div>
+        ) : (
+          <p className="mx-tweet-text">{tweet.content}</p>
+        )}
+
+        {tweet.media && tweet.media.length > 0 && (
+          <TweetMedia media={tweet.media} />
+        )}
+
+        <div className="mx-tweet-footer">
+          <button
+            className={`mx-like-btn${tweet.likedByMe ? " mx-like-btn-active" : ""}`}
+            onClick={(e) => { e.stopPropagation(); likeMutation.mutate(); }}
+            disabled={!canLike || likeMutation.isPending}
+            title={
+              canLike
+                ? tweet.likedByMe
+                  ? "Remove like"
+                  : "Like post"
+                : "Sign in to like posts"
+            }
+          >
+            <svg width="16" height="16" viewBox="0 0 24 24" fill="currentColor">
+              <path d="M12.1 21.35 10.55 19.93C5.4 15.27 2 12.19 2 8.5 2 5.42 4.42 3 7.5 3c1.74 0 3.41.81 4.5 2.09C13.09 3.81 14.76 3 16.5 3 19.58 3 22 5.42 22 8.5c0 3.69-3.4 6.77-8.55 11.44z" />
+            </svg>
+            <span>{tweet.likes}</span>
+          </button>
+          <a
+            href={`/feed/${tweet.id}`}
+            className="mx-like-btn mx-comment-btn"
+            onClick={(e) => e.stopPropagation()}
+            title="View comments"
+          >
+            <CommentIcon />
+            <span>{tweet.commentCount ?? 0}</span>
+          </a>
+        </div>
+
+        {error && !editing && <p className="mx-compose-error">{error}</p>}
+      </div>
+      {ctxMenu && (
+        <ContextMenu
+          x={ctxMenu.x}
+          y={ctxMenu.y}
+          items={ctxItems}
+          onClose={() => setCtxMenu(null)}
+        />
+      )}
+    </article>
+  );
+}
+
+export function CommentCard({
+  comment,
+  parentTweetOwnerId,
+}: {
+  comment: Tweet;
+  parentTweetOwnerId?: string;
+}) {
+  const { userId: currentUserId } = useContext(AuthCtx);
+  const canLike = !!currentUserId;
+  const canModify =
+    !!currentUserId &&
+    (comment.userId === currentUserId || parentTweetOwnerId === currentUserId);
+  const [confirmDelete, setConfirmDelete] = useState(false);
+  const [error, setError] = useState<string | null>(null);
+  const qc = useQueryClient();
+
+  const deleteMutation = useMutation({
+    mutationFn: async () => {
+      const res = await destroyTweet({ identity: comment.id, headers: buildCSRFHeaders() });
+      if (!res.success) throw new Error(res.errors?.[0]?.message ?? "Failed to delete");
+    },
+    onSuccess: () => {
+      qc.invalidateQueries({ queryKey: ["comments", comment.parentTweetId] });
+      qc.invalidateQueries({ queryKey: ["tweet", comment.parentTweetId] });
+      qc.invalidateQueries({ queryKey: ["tweets"] });
+      qc.invalidateQueries({ queryKey: ["following_tweets"] });
+    },
+    onError: (e: Error) => setError(e.message),
+  });
+
+  const likeMutation = useMutation({
+    mutationFn: async () => {
+      const action = comment.likedByMe ? unlikeTweet : likeTweet;
+      const res = await action({
+        identity: comment.id,
+        fields: ["id", "likes", "likedByMe"],
+        headers: buildCSRFHeaders(),
+      });
+      if (!res.success) throw new Error(res.errors?.[0]?.message ?? "Failed");
+    },
+    onSuccess: () => qc.invalidateQueries({ queryKey: ["comments", comment.parentTweetId] }),
+    onError: (e: Error) => setError(e.message),
+  });
+
+  return (
+    <article className="mx-tweet mx-comment">
+      <Avatar
+        avatarUrl={comment.userAvatarUrl}
+        name={comment.userDisplayName || comment.userUsername || comment.userEmail}
+        size="sm"
+      />
+      <div className="mx-tweet-body">
+        <div className="mx-tweet-header">
+          <span className="mx-tweet-handle">{userDisplayLabel({ displayName: comment.userDisplayName, username: comment.userUsername, email: comment.userEmail })}</span>
+          {comment.userUsername && (
+            <span className="mx-tweet-subhandle">@{comment.userUsername}</span>
+          )}
+          <span className="mx-tweet-dot">·</span>
+          <span className="mx-tweet-time" title={comment.insertedAt ? new Date(comment.insertedAt).toLocaleString() : undefined}>{timeAgo(comment.insertedAt)}</span>
+          {canModify && (
+            <div className="mx-tweet-actions">
+              <button
+                className={`mx-action-btn mx-action-delete${confirmDelete ? " mx-action-confirm" : ""}`}
+                title={confirmDelete ? "Confirm delete" : "Delete"}
+                onClick={(e) => {
+                  e.stopPropagation();
+                  if (!confirmDelete) {
+                    setConfirmDelete(true);
+                    setTimeout(() => setConfirmDelete(false), 3000);
+                  } else {
+                    deleteMutation.mutate();
+                  }
+                }}
+              >
+                {deleteMutation.isPending ? (
+                  <span style={{ fontSize: "0.65rem" }}>…</span>
+                ) : confirmDelete ? (
+                  <svg width="14" height="14" viewBox="0 0 24 24" fill="currentColor">
+                    <path d="M9 16.17L4.83 12l-1.42 1.41L9 19 21 7l-1.41-1.41L9 16.17z" />
+                  </svg>
+                ) : (
+                  <svg width="14" height="14" viewBox="0 0 24 24" fill="currentColor">
+                    <path d="M6 19c0 1.1.9 2 2 2h8c1.1 0 2-.9 2-2V7H6v12zM19 4h-3.5l-1-1h-5l-1 1H5v2h14V4z" />
+                  </svg>
+                )}
+              </button>
+            </div>
+          )}
+        </div>
+        <p className="mx-tweet-text">{comment.content}</p>
+        {comment.media && comment.media.length > 0 && <TweetMedia media={comment.media} />}
+        <div className="mx-tweet-footer">
+          <button
+            className={`mx-like-btn${comment.likedByMe ? " mx-like-btn-active" : ""}`}
+            onClick={() => likeMutation.mutate()}
+            disabled={!canLike || likeMutation.isPending}
+            title={canLike ? (comment.likedByMe ? "Remove like" : "Like reply") : "Sign in to like replies"}
+          >
+            <svg width="16" height="16" viewBox="0 0 24 24" fill="currentColor">
+              <path d="M12.1 21.35 10.55 19.93C5.4 15.27 2 12.19 2 8.5 2 5.42 4.42 3 7.5 3c1.74 0 3.41.81 4.5 2.09C13.09 3.81 14.76 3 16.5 3 19.58 3 22 5.42 22 8.5c0 3.69-3.4 6.77-8.55 11.44z" />
+            </svg>
+            <span>{comment.likes}</span>
+          </button>
+        </div>
+        {error && <p className="mx-compose-error">{error}</p>}
+      </div>
+    </article>
+  );
+}

assets/js/components/tweet-detail.tsx

@@ -0,0 +1,279 @@
+import React, { useState, useRef, useEffect, useContext } from "react";
+import { useQuery, useInfiniteQuery, useMutation, useQueryClient } from "@tanstack/react-query";
+import { readTweet, destroyTweet, updateTweet, likeTweet, unlikeTweet, buildCSRFHeaders } from "../ash_rpc";
+import { AuthCtx } from "../context";
+import { getAssetHost, userDisplayLabel } from "../utils";
+import { COMMENTS_PAGE_SIZE } from "../constants";
+import { Spinner, ErrorBanner, Avatar } from "./ui";
+import { MediaLightbox } from "./media";
+import { CommentIcon, CommentCard } from "./tweet-card";
+import { ComposeComment } from "./compose";
+import type { Tweet, MediaItem } from "../types";
+
+export function TweetDetail({ tweetId }: { tweetId: string }) {
+  const { userId: currentUserId, email } = useContext(AuthCtx);
+  const [lightboxItem, setLightboxItem] = useState<MediaItem | null>(null);
+  const [confirmDelete, setConfirmDelete] = useState(false);
+  const [editing, setEditing] = useState(false);
+  const [editText, setEditText] = useState("");
+  const [error, setError] = useState<string | null>(null);
+  const qc = useQueryClient();
+  const assetHost = getAssetHost();
+
+  const { data: tweet, isLoading, isError } = useQuery({
+    queryKey: ["tweet", tweetId],
+    queryFn: async () => {
+      const res = await readTweet({
+        fields: ["id", "content", "likes", "likedByMe", "commentCount", "userId", "state", "userEmail", "userUsername", "userDisplayName", "userAvatarUrl", "insertedAt", { media: ["id", "s3Key"] }],
+        filter: { id: { eq: tweetId } },
+        headers: buildCSRFHeaders(),
+      });
+      if (!res.success) throw new Error("Failed to load tweet");
+      const results = Array.isArray(res.data) ? res.data : (res.data as any)?.results ?? [];
+      return (results[0] as Tweet) ?? null;
+    },
+  });
+
+  const commentsSentinelRef = useRef<HTMLDivElement>(null);
+
+  const {
+    data: commentsData,
+    isLoading: commentsLoading,
+    fetchNextPage: fetchNextComments,
+    hasNextPage: hasMoreComments,
+    isFetchingNextPage: isFetchingMoreComments,
+  } = useInfiniteQuery({
+    queryKey: ["comments", tweetId],
+    queryFn: async ({ pageParam }: { pageParam: number }) => {
+      const res = await readTweet({
+        fields: ["id", "content", "likes", "likedByMe", "parentTweetId", "userId", "state", "userEmail", "userUsername", "userDisplayName", "userAvatarUrl", "insertedAt", { media: ["id", "s3Key"] }],
+        filter: { parentTweetId: { eq: tweetId } },
+        sort: "insertedAt",
+        page: { limit: COMMENTS_PAGE_SIZE, offset: pageParam },
+        headers: buildCSRFHeaders(),
+      });
+      if (!res.success) throw new Error("Failed to load comments");
+      const pageData = res.data as any;
+      const comments: Tweet[] = Array.isArray(pageData) ? pageData : (pageData?.results ?? []);
+      const hasMore: boolean = Array.isArray(pageData) ? false : (pageData?.hasMore ?? false);
+      return { comments, hasMore, nextOffset: pageParam + COMMENTS_PAGE_SIZE };
+    },
+    initialPageParam: 0,
+    getNextPageParam: (lastPage) => lastPage.hasMore ? lastPage.nextOffset : undefined,
+  });
+
+  useEffect(() => {
+    const el = commentsSentinelRef.current;
+    if (!el) return;
+    const observer = new IntersectionObserver(
+      (entries) => {
+        if (entries[0].isIntersecting && hasMoreComments && !isFetchingMoreComments) {
+          fetchNextComments();
+        }
+      },
+      { threshold: 0.1 },
+    );
+    observer.observe(el);
+    return () => observer.disconnect();
+  }, [hasMoreComments, isFetchingMoreComments, fetchNextComments]);
+
+  const deleteMutation = useMutation({
+    mutationFn: async () => {
+      const res = await destroyTweet({ identity: tweetId, headers: buildCSRFHeaders() });
+      if (!res.success) throw new Error(res.errors?.[0]?.message ?? "Failed to delete");
+    },
+    onSuccess: () => { window.location.href = "/feed"; },
+    onError: (e: Error) => setError(e.message),
+  });
+
+  const updateMutation = useMutation({
+    mutationFn: async (content: string) => {
+      const res = await updateTweet({
+        identity: tweetId,
+        input: { content },
+        fields: ["id", "content", "userId", "state"],
+        headers: buildCSRFHeaders(),
+      });
+      if (!res.success) throw new Error(res.errors?.[0]?.message ?? "Failed to update");
+    },
+    onSuccess: () => {
+      qc.invalidateQueries({ queryKey: ["tweet", tweetId] });
+      setEditing(false);
+      setError(null);
+    },
+    onError: (e: Error) => setError(e.message),
+  });
+
+  const likeMutation = useMutation({
+    mutationFn: async () => {
+      if (!tweet) return;
+      const action = tweet.likedByMe ? unlikeTweet : likeTweet;
+      const res = await action({ identity: tweetId, fields: ["id", "likes", "likedByMe"], headers: buildCSRFHeaders() });
+      if (!res.success) throw new Error(res.errors?.[0]?.message ?? "Failed to update like");
+    },
+    onSuccess: () => qc.invalidateQueries({ queryKey: ["tweet", tweetId] }),
+    onError: (e: Error) => setError(e.message),
+  });
+
+  if (isLoading) return <Spinner />;
+  if (isError || !tweet) return <ErrorBanner message="Could not load tweet" />;
+
+  const canModify = !!currentUserId && tweet.userId === currentUserId;
+  const canLike = !!currentUserId;
+
+  return (
+    <div className="mx-detail">
+      <div className="mx-detail-header">
+        <a href="/feed" className="mx-back-btn">
+          <svg width="16" height="16" viewBox="0 0 24 24" fill="currentColor">
+            <path d="M20 11H7.83l5.59-5.59L12 4l-8 8 8 8 1.41-1.41L7.83 13H20v-2z" />
+          </svg>
+          Back
+        </a>
+        {canModify && (
+          <div style={{ display: "flex", gap: "0.5rem" }}>
+            <button
+              className="mx-action-btn"
+              title="Edit"
+              onClick={() => { setEditText(tweet.content); setEditing(true); }}
+            >
+              <svg width="14" height="14" viewBox="0 0 24 24" fill="currentColor">
+                <path d="M3 17.25V21h3.75L17.81 9.94l-3.75-3.75L3 17.25zm17.71-10.04a1 1 0 0 0 0-1.41l-2.31-2.31a1 1 0 0 0-1.41 0l-1.79 1.79 3.75 3.75 1.76-1.82z" />
+              </svg>
+            </button>
+            <button
+              className={`mx-action-btn mx-action-delete${confirmDelete ? " mx-action-confirm" : ""}`}
+              title={confirmDelete ? "Confirm delete" : "Delete"}
+              onClick={() => {
+                if (!confirmDelete) {
+                  setConfirmDelete(true);
+                  setTimeout(() => setConfirmDelete(false), 3000);
+                } else {
+                  deleteMutation.mutate();
+                }
+              }}
+            >
+              {deleteMutation.isPending ? (
+                <span style={{ fontSize: "0.65rem" }}>…</span>
+              ) : confirmDelete ? (
+                <svg width="14" height="14" viewBox="0 0 24 24" fill="currentColor">
+                  <path d="M9 16.17L4.83 12l-1.42 1.41L9 19 21 7l-1.41-1.41L9 16.17z" />
+                </svg>
+              ) : (
+                <svg width="14" height="14" viewBox="0 0 24 24" fill="currentColor">
+                  <path d="M6 19c0 1.1.9 2 2 2h8c1.1 0 2-.9 2-2V7H6v12zM19 4h-3.5l-1-1h-5l-1 1H5v2h14V4z" />
+                </svg>
+              )}
+            </button>
+          </div>
+        )}
+      </div>
+
+      <div className="mx-detail-body">
+        <div className="mx-detail-author">
+          <Avatar avatarUrl={tweet.userAvatarUrl} name={tweet.userDisplayName || tweet.userUsername || tweet.userEmail} />
+          <div>
+            <span className="mx-tweet-handle">{userDisplayLabel({ displayName: tweet.userDisplayName, username: tweet.userUsername, email: tweet.userEmail })}</span>
+            {tweet.userUsername && (
+              <div style={{ fontSize: "0.8rem", color: "var(--mx-muted)" }}>@{tweet.userUsername}</div>
+            )}
+          </div>
+        </div>
+
+        {editing ? (
+          <div className="mx-edit-area">
+            <textarea
+              className="mx-edit-textarea"
+              value={editText}
+              onChange={(e) => setEditText(e.target.value)}
+              autoFocus
+              rows={4}
+            />
+            {error && <p className="mx-compose-error">{error}</p>}
+            <div className="mx-edit-footer">
+              <button className="mx-btn-cancel" onClick={() => { setEditing(false); setError(null); }}>Cancel</button>
+              <button
+                className="mx-btn-save"
+                onClick={() => { const t = editText.trim(); if (t) updateMutation.mutate(t); }}
+                disabled={!editText.trim() || updateMutation.isPending}
+              >
+                {updateMutation.isPending ? "Saving…" : "Save"}
+              </button>
+            </div>
+          </div>
+        ) : (
+          <p className="mx-detail-content">{tweet.content}</p>
+        )}
+
+        {tweet.media && tweet.media.length > 0 && (
+          <div className="mx-detail-media">
+            {tweet.media.map((m) => (
+              <button key={m.id} className="mx-media-thumb" onClick={() => setLightboxItem(m)}>
+                {/\.(mp4|mov)$/i.test(m.s3Key) ? (
+                  <video src={`${assetHost}/${m.s3Key}`} />
+                ) : (
+                  <img src={`${assetHost}/${m.s3Key}`} alt="" />
+                )}
+              </button>
+            ))}
+          </div>
+        )}
+
+        <div className="mx-tweet-footer" style={{ marginTop: "1rem" }}>
+          <button
+            className={`mx-like-btn${tweet.likedByMe ? " mx-like-btn-active" : ""}`}
+            onClick={() => likeMutation.mutate()}
+            disabled={!canLike || likeMutation.isPending}
+            title={canLike ? (tweet.likedByMe ? "Remove like" : "Like post") : "Sign in to like posts"}
+          >
+            <svg width="16" height="16" viewBox="0 0 24 24" fill="currentColor">
+              <path d="M12.1 21.35 10.55 19.93C5.4 15.27 2 12.19 2 8.5 2 5.42 4.42 3 7.5 3c1.74 0 3.41.81 4.5 2.09C13.09 3.81 14.76 3 16.5 3 19.58 3 22 5.42 22 8.5c0 3.69-3.4 6.77-8.55 11.44z" />
+            </svg>
+            <span>{tweet.likes}</span>
+          </button>
+          <span className="mx-like-btn mx-comment-count-badge" style={{ cursor: "default" }}>
+            <CommentIcon />
+            <span>{tweet.commentCount ?? 0} {(tweet.commentCount ?? 0) === 1 ? "reply" : "replies"}</span>
+          </span>
+        </div>
+
+        {error && !editing && <p className="mx-compose-error">{error}</p>}
+      </div>
+
+      {lightboxItem && <MediaLightbox item={lightboxItem} onClose={() => setLightboxItem(null)} />}
+
+      <div className="mx-comments-section">
+        <div className="mx-comments-divider">
+          <span>Replies</span>
+        </div>
+
+        {email ? (
+          <ComposeComment parentTweetId={tweetId} />
+        ) : (
+          <div className="mx-signin-cta mx-signin-cta--sm">
+            <p><a href="/sign-in" style={{ color: "var(--mx-accent)", textDecoration: "none" }}>Sign in</a> to reply.</p>
+          </div>
+        )}
+
+        {commentsLoading ? (
+          <Spinner />
+        ) : (() => {
+          const comments = commentsData?.pages.flatMap((p) => p.comments) ?? [];
+          return comments.length > 0 ? (
+            <div className="mx-comments-list">
+              {comments.map((c) => (
+                <CommentCard key={c.id} comment={c} parentTweetOwnerId={tweet?.userId} />
+              ))}
+              <div ref={commentsSentinelRef} style={{ height: "1px" }} />
+              {isFetchingMoreComments && <Spinner />}
+            </div>
+          ) : (
+            <div className="mx-empty mx-empty--sm">
+              <p className="mx-empty-sub">No replies yet. Be the first!</p>
+            </div>
+          );
+        })()}
+      </div>
+    </div>
+  );
+}

assets/js/components/ui.tsx

@@ -0,0 +1,129 @@
+import React, { useRef, useEffect } from "react";
+import { createPortal } from "react-dom";
+import { getAssetHost } from "../utils";
+import type { ContextMenuItem } from "../types";
+
+export function Spinner() {
+  return (
+    <div style={{ display: "flex", justifyContent: "center", padding: "2rem" }}>
+      <div className="mx-spinner" />
+    </div>
+  );
+}
+
+export function ErrorBanner({ message }: { message: string }) {
+  return (
+    <div className="mx-error-banner">
+      <span className="mx-error-icon">⚠</span>
+      {message}
+    </div>
+  );
+}
+
+export function CharCount({ current, max }: { current: number; max: number }) {
+  const remaining = max - current;
+  const pct = current / max;
+  const color =
+    pct > 0.9 ? "#ef4444" : pct > 0.75 ? "#f59e0b" : "var(--mx-muted)";
+  return (
+    <span style={{ color, fontSize: "0.75rem", fontVariantNumeric: "tabular-nums" }}>
+      {remaining}
+    </span>
+  );
+}
+
+export function Avatar({
+  avatarUrl,
+  name,
+  size = "md",
+}: {
+  avatarUrl?: string | null;
+  name?: string | null;
+  size?: "sm" | "md" | "lg";
+}) {
+  const assetHost = getAssetHost();
+  const initial = ((name ?? "")[0] || "M").toUpperCase();
+  const cls =
+    size === "sm"
+      ? "mx-tweet-avatar mx-tweet-avatar--sm"
+      : size === "lg"
+      ? "mx-tweet-avatar mx-tweet-avatar--lg"
+      : "mx-tweet-avatar";
+
+  return (
+    <div className={cls}>
+      {avatarUrl ? (
+        <img
+          src={`${assetHost}/${avatarUrl}`}
+          alt={name ?? "avatar"}
+          className="mx-avatar-img"
+        />
+      ) : (
+        <span>{initial}</span>
+      )}
+    </div>
+  );
+}
+
+export function ContextMenu({
+  x,
+  y,
+  items,
+  onClose,
+}: {
+  x: number;
+  y: number;
+  items: ContextMenuItem[];
+  onClose: () => void;
+}) {
+  const ref = useRef<HTMLDivElement>(null);
+
+  useEffect(() => {
+    function handleMouseDown(e: MouseEvent) {
+      if (ref.current && !ref.current.contains(e.target as Node)) onClose();
+    }
+    function handleKeyDown(e: KeyboardEvent) {
+      if (e.key === "Escape") onClose();
+    }
+    document.addEventListener("mousedown", handleMouseDown);
+    document.addEventListener("keydown", handleKeyDown);
+    return () => {
+      document.removeEventListener("mousedown", handleMouseDown);
+      document.removeEventListener("keydown", handleKeyDown);
+    };
+  }, [onClose]);
+
+  const itemCount = items.filter((i) => i.type === "item").length;
+  const sepCount = items.filter((i) => i.type === "separator").length;
+  const menuH = itemCount * 34 + sepCount * 9 + 8;
+  const menuW = 180;
+  const left = Math.min(x, window.innerWidth - menuW - 8);
+  const top = Math.min(y, window.innerHeight - menuH - 8);
+
+  return createPortal(
+    <div
+      ref={ref}
+      className="mx-context-menu"
+      style={{ left, top }}
+      onContextMenu={(e) => e.preventDefault()}
+    >
+      {items.map((item, i) =>
+        item.type === "separator" ? (
+          <div key={i} className="mx-context-menu-separator" />
+        ) : (
+          <button
+            key={i}
+            className="mx-context-menu-item"
+            onClick={() => {
+              item.onClick();
+              onClose();
+            }}
+          >
+            {item.label}
+          </button>
+        )
+      )}
+    </div>,
+    document.body
+  );
+}

assets/js/components/users.tsx

@@ -0,0 +1,288 @@
+import React, { useState, useRef, useEffect, useContext } from "react";
+import { useQuery, useInfiniteQuery } from "@tanstack/react-query";
+import { readUser, readTweet, buildCSRFHeaders } from "../ash_rpc";
+import { AuthCtx } from "../context";
+import { FEED_PAGE_SIZE, USERS_PAGE_SIZE } from "../constants";
+import { userDisplayLabel } from "../utils";
+import { useFollowUser } from "../hooks";
+import { Spinner, ErrorBanner, Avatar, ContextMenu } from "./ui";
+import { TweetCard } from "./tweet-card";
+import type { User, Tweet, ContextMenuItem } from "../types";
+
+export function FollowButton({
+  amIFollowing,
+  isPending,
+  onToggle,
+}: {
+  amIFollowing: boolean;
+  isPending: boolean;
+  onToggle: () => void;
+}) {
+  return (
+    <button
+      className={`mx-follow-btn${amIFollowing ? " mx-follow-btn--following" : ""}`}
+      disabled={isPending}
+      onClick={(e) => { e.stopPropagation(); onToggle(); }}
+    >
+      {isPending ? "…" : amIFollowing ? "Unfollow" : "Follow"}
+    </button>
+  );
+}
+
+export function UserCard({ user }: { user: User }) {
+  const { userId: currentUserId } = useContext(AuthCtx);
+  const [ctxMenu, setCtxMenu] = useState<{ x: number; y: number } | null>(null);
+  const { follow, unfollow, isPending } = useFollowUser(user.id);
+
+  const userUrl = `${window.location.origin}/users/${user.id}`;
+  const canFollow = !!currentUserId && currentUserId !== user.id;
+  const amIFollowing = user.amIFollowing ?? false;
+
+  const ctxItems: ContextMenuItem[] = [
+    { type: "item", label: "Share", onClick: () => navigator.clipboard.writeText(userUrl) },
+    ...(canFollow ? [
+      { type: "separator" as const },
+      amIFollowing
+        ? { type: "item" as const, label: "Unfollow", onClick: unfollow }
+        : { type: "item" as const, label: "Follow", onClick: follow },
+    ] : []),
+  ];
+
+  return (
+    <article
+      className="mx-tweet"
+      style={{ cursor: "pointer" }}
+      onClick={() => { window.location.href = `/users/${user.id}`; }}
+      onContextMenu={(e) => { e.preventDefault(); setCtxMenu({ x: e.clientX, y: e.clientY }); }}
+    >
+      <Avatar avatarUrl={user.avatarUrl} name={user.displayName || user.username || user.email} />
+      <div className="mx-tweet-body">
+        <div className="mx-tweet-header">
+          <span className="mx-tweet-handle">{userDisplayLabel(user)}</span>
+          {user.username && (
+            <span className="mx-tweet-subhandle">@{user.username}</span>
+          )}
+        </div>
+        {(user.followerCount !== undefined || user.followingCount !== undefined) && (
+          <div className="mx-tweet-meta" style={{ fontSize: "0.8rem", color: "var(--mx-muted)", marginTop: "4px" }}>
+            <span>{user.followerCount ?? 0} followers</span>
+            <span style={{ marginLeft: "12px" }}>{user.followingCount ?? 0} following</span>
+          </div>
+        )}
+      </div>
+      {canFollow && (
+        <div style={{ display: "flex", alignItems: "center", flexShrink: 0 }}>
+          <FollowButton amIFollowing={amIFollowing} isPending={isPending} onToggle={amIFollowing ? unfollow : follow} />
+        </div>
+      )}
+      {ctxMenu && (
+        <ContextMenu x={ctxMenu.x} y={ctxMenu.y} items={ctxItems} onClose={() => setCtxMenu(null)} />
+      )}
+    </article>
+  );
+}
+
+export function UserList() {
+  const sentinelRef = useRef<HTMLDivElement>(null);
+
+  const {
+    data,
+    isLoading,
+    isError,
+    error,
+    fetchNextPage,
+    hasNextPage,
+    isFetchingNextPage,
+  } = useInfiniteQuery({
+    queryKey: ["users"],
+    queryFn: async ({ pageParam }: { pageParam: number }) => {
+      const res = await readUser({
+        fields: ["id", "email", "username", "displayName", "avatarUrl", "followerCount", "followingCount", "amIFollowing"],
+        sort: "username",
+        page: { limit: USERS_PAGE_SIZE, offset: pageParam },
+        headers: buildCSRFHeaders(),
+      });
+      if (!res.success) throw new Error("Failed to load users");
+      const pageData = res.data as any;
+      const users: User[] = Array.isArray(pageData) ? pageData : (pageData?.results ?? []);
+      const hasMore: boolean = Array.isArray(pageData) ? false : (pageData?.hasMore ?? false);
+      return { users, hasMore, nextOffset: pageParam + USERS_PAGE_SIZE };
+    },
+    initialPageParam: 0,
+    getNextPageParam: (lastPage) => lastPage.hasMore ? lastPage.nextOffset : undefined,
+  });
+
+  useEffect(() => {
+    const el = sentinelRef.current;
+    if (!el) return;
+    const observer = new IntersectionObserver(
+      (entries) => {
+        if (entries[0].isIntersecting && hasNextPage && !isFetchingNextPage) {
+          fetchNextPage();
+        }
+      },
+      { threshold: 0.1 },
+    );
+    observer.observe(el);
+    return () => observer.disconnect();
+  }, [hasNextPage, isFetchingNextPage, fetchNextPage]);
+
+  if (isLoading) return <Spinner />;
+  if (isError) return <ErrorBanner message={(error as Error)?.message ?? "Could not load users"} />;
+
+  const users = data?.pages.flatMap((p) => p.users) ?? [];
+
+  if (users.length === 0) {
+    return (
+      <div className="mx-empty">
+        <div className="mx-empty-icon">◎</div>
+        <p className="mx-empty-title">No users yet</p>
+        <p className="mx-empty-sub">Be the first to sign up.</p>
+      </div>
+    );
+  }
+
+  return (
+    <div className="mx-feed">
+      {users.map((u) => (
+        <UserCard key={u.id} user={u} />
+      ))}
+      <div ref={sentinelRef} style={{ height: "1px" }} />
+      {isFetchingNextPage && <Spinner />}
+    </div>
+  );
+}
+
+export function UserFeed({ userId }: { userId: string }) {
+  const sentinelRef = useRef<HTMLDivElement>(null);
+
+  const {
+    data,
+    isLoading,
+    isError,
+    error,
+    fetchNextPage,
+    hasNextPage,
+    isFetchingNextPage,
+  } = useInfiniteQuery({
+    queryKey: ["user-tweets", userId],
+    queryFn: async ({ pageParam }: { pageParam: number }) => {
+      const res = await readTweet({
+        fields: ["id", "content", "likes", "likedByMe", "commentCount", "userId", "state", "userEmail", "userUsername", "userDisplayName", "userAvatarUrl", "insertedAt", { media: ["id", "s3Key"] }],
+        sort: "-insertedAt",
+        page: { limit: FEED_PAGE_SIZE, offset: pageParam },
+        filter: { userId: { eq: userId }, parentTweetId: { isNil: true } },
+        headers: buildCSRFHeaders(),
+      });
+      if (!res.success) throw new Error("Failed to load tweets");
+      const pageData = res.data as any;
+      const tweets: Tweet[] = Array.isArray(pageData) ? pageData : (pageData?.results ?? []);
+      const hasMore: boolean = Array.isArray(pageData) ? false : (pageData?.hasMore ?? false);
+      return { tweets, hasMore, nextOffset: pageParam + FEED_PAGE_SIZE };
+    },
+    initialPageParam: 0,
+    getNextPageParam: (lastPage) => lastPage.hasMore ? lastPage.nextOffset : undefined,
+  });
+
+  useEffect(() => {
+    const el = sentinelRef.current;
+    if (!el) return;
+    const observer = new IntersectionObserver(
+      (entries) => {
+        if (entries[0].isIntersecting && hasNextPage && !isFetchingNextPage) {
+          fetchNextPage();
+        }
+      },
+      { threshold: 0.1 },
+    );
+    observer.observe(el);
+    return () => observer.disconnect();
+  }, [hasNextPage, isFetchingNextPage, fetchNextPage]);
+
+  if (isLoading) return <Spinner />;
+  if (isError) return <ErrorBanner message={(error as Error)?.message ?? "Could not load posts"} />;
+
+  const tweets = data?.pages.flatMap((p) => p.tweets) ?? [];
+
+  if (tweets.length === 0) {
+    return (
+      <div className="mx-empty">
+        <div className="mx-empty-icon">◎</div>
+        <p className="mx-empty-title">No posts yet</p>
+      </div>
+    );
+  }
+
+  return (
+    <div className="mx-feed">
+      {tweets.map((t) => (
+        <TweetCard key={t.id} tweet={t} />
+      ))}
+      <div ref={sentinelRef} style={{ height: "1px" }} />
+      {isFetchingNextPage && <Spinner />}
+    </div>
+  );
+}
+
+export function UserDetail({ userId, isStandalone = false }: { userId: string; isStandalone?: boolean }) {
+  const { userId: currentUserId } = useContext(AuthCtx);
+  const { follow, unfollow, isPending } = useFollowUser(userId);
+  const { data: user, isLoading, isError } = useQuery({
+    queryKey: ["user", userId],
+    queryFn: async () => {
+      const res = await readUser({
+        fields: ["id", "email", "username", "displayName", "avatarUrl", "followerCount", "followingCount", "amIFollowing"],
+        filter: { id: { eq: userId } },
+        headers: buildCSRFHeaders(),
+      });
+      if (!res.success) throw new Error("Failed to load user");
+      const results = Array.isArray(res.data) ? res.data : (res.data as any)?.results ?? [];
+      return (results[0] as User) ?? null;
+    },
+  });
+
+  if (isLoading) return <Spinner />;
+  if (isError || !user) return <ErrorBanner message="Could not load user" />;
+
+  const isOwnProfile = currentUserId === userId;
+  const canFollow = !!currentUserId && !isOwnProfile;
+  const amIFollowing = user.amIFollowing ?? false;
+
+  return (
+    <div className="mx-detail">
+      {!isStandalone && (
+        <div className="mx-detail-header">
+          <a href="/users" className="mx-back-btn">
+            <svg width="16" height="16" viewBox="0 0 24 24" fill="currentColor">
+              <path d="M20 11H7.83l5.59-5.59L12 4l-8 8 8 8 1.41-1.41L7.83 13H20v-2z" />
+            </svg>
+            Back
+          </a>
+        </div>
+      )}
+      <div className="mx-detail-body">
+        <div className="mx-detail-author">
+          <Avatar avatarUrl={user.avatarUrl} name={user.displayName || user.username || user.email} size="lg" />
+          <div style={{ flex: 1 }}>
+            <div style={{ display: "flex", alignItems: "center", gap: "12px", flexWrap: "wrap" }}>
+              <div>
+                <div className="mx-tweet-handle" style={{ fontSize: "1.1rem" }}>{userDisplayLabel(user)}</div>
+                {user.username && (
+                  <div style={{ fontSize: "0.85rem", color: "var(--mx-muted)" }}>@{user.username}</div>
+                )}
+              </div>
+              {canFollow && (
+                <FollowButton amIFollowing={amIFollowing} isPending={isPending} onToggle={amIFollowing ? unfollow : follow} />
+              )}
+            </div>
+            <div style={{ fontSize: "0.85rem", color: "var(--mx-muted)", marginTop: "8px", display: "flex", gap: "16px" }}>
+              <span><strong style={{ color: "var(--mx-fg)" }}>{user.followerCount ?? 0}</strong> followers</span>
+              <span><strong style={{ color: "var(--mx-fg)" }}>{user.followingCount ?? 0}</strong> following</span>
+            </div>
+          </div>
+        </div>
+      </div>
+      <UserFeed userId={userId} />
+    </div>
+  );
+}

assets/js/constants.ts

@@ -0,0 +1,3 @@
+export const FEED_PAGE_SIZE = 10;
+export const COMMENTS_PAGE_SIZE = 10;
+export const USERS_PAGE_SIZE = 20;

assets/js/context.ts

@@ -0,0 +1,9 @@
+import { createContext } from "react";
+
+export const AuthCtx = createContext({
+  email: "",
+  userId: "",
+  username: "",
+  displayName: "",
+  avatarUrl: "",
+});

assets/js/hooks.ts

@@ -0,0 +1,79 @@
+import { useSyncExternalStore } from "react";
+import { useMutation, useQueryClient } from "@tanstack/react-query";
+import { followUser, unfollowUser, buildCSRFHeaders } from "./ash_rpc";
+
+// ── useIsDesktop ──────────────────────────────────────────────────────────────
+// Returns true when viewport is wider than 960px. Reacts to resize.
+
+const DESKTOP_MQ =
+  typeof window !== "undefined"
+    ? window.matchMedia("(min-width: 961px)")
+    : null;
+
+function subscribe(cb: () => void) {
+  DESKTOP_MQ?.addEventListener("change", cb);
+  return () => DESKTOP_MQ?.removeEventListener("change", cb);
+}
+
+export function useIsDesktop(): boolean {
+  return useSyncExternalStore(
+    subscribe,
+    () => DESKTOP_MQ?.matches ?? true,
+    () => true,
+  );
+}
+
+// ── useFollowUser ─────────────────────────────────────────────────────────────
+
+export function useFollowUser(targetUserId: string) {
+  const qc = useQueryClient();
+
+  const followMutation = useMutation({
+    mutationFn: async () => {
+      const res = await followUser({
+        input: { followingId: targetUserId },
+        headers: buildCSRFHeaders(),
+      });
+      if (!res.success) {
+        const message =
+          "errors" in res && Array.isArray(res.errors)
+            ? (res.errors[0] as any)?.message
+            : "Follow failed";
+        throw new Error(message);
+      }
+      return res;
+    },
+    onSuccess: () => {
+      qc.invalidateQueries({ queryKey: ["users"] });
+      qc.invalidateQueries({ queryKey: ["user", targetUserId] });
+    },
+  });
+
+  const unfollowMutation = useMutation({
+    mutationFn: async () => {
+      const res = await unfollowUser({
+        input: { followingId: targetUserId },
+        headers: buildCSRFHeaders(),
+      });
+      if (!res.success) {
+        const message =
+          "errors" in res && Array.isArray(res.errors)
+            ? (res.errors[0] as any)?.message
+            : "Unfollow failed";
+        throw new Error(message);
+      }
+      return res;
+    },
+    onSuccess: () => {
+      qc.invalidateQueries({ queryKey: ["users"] });
+      qc.invalidateQueries({ queryKey: ["user", targetUserId] });
+    },
+  });
+
+  return {
+    follow: () => followMutation.mutate(),
+    unfollow: () => unfollowMutation.mutate(),
+    isPending: followMutation.isPending || unfollowMutation.isPending,
+    error: followMutation.error || unfollowMutation.error,
+  };
+}

assets/js/types.ts

@@ -0,0 +1,34 @@
+export type User = {
+  id: string;
+  email: string;
+  username?: string | null;
+  displayName?: string | null;
+  avatarUrl?: string | null;
+  followerCount?: number;
+  followingCount?: number;
+  amIFollowing?: boolean;
+  myFollowId?: string | null;
+};
+
+export type MediaItem = { id: string; s3Key: string };
+
+export type Tweet = {
+  id: string;
+  content: string;
+  likes: number;
+  likedByMe?: boolean;
+  commentCount?: number;
+  parentTweetId?: string | null;
+  userId: string;
+  state: string;
+  media?: MediaItem[];
+  userEmail?: string | null;
+  userUsername?: string | null;
+  userDisplayName?: string | null;
+  userAvatarUrl?: string | null;
+  insertedAt?: string | null;
+};
+
+export type ContextMenuItem =
+  | { type: "item"; label: string; onClick: () => void }
+  | { type: "separator" };

assets/js/upload.ts

@@ -9,6 +9,29 @@ export interface UploadError {
   error: string;
 }
 
+export interface AvatarUploadResult {
+  success: true;
+  avatarUrl: string;
+}
+
+export async function uploadAvatar(
+  file: File,
+  csrfToken: string
+): Promise<AvatarUploadResult | UploadError> {
+  const formData = new FormData();
+  formData.append("file", file);
+  const res = await fetch("/upload/avatar", {
+    method: "POST",
+    headers: { "X-CSRF-Token": csrfToken },
+    body: formData,
+  });
+  const json = await res.json();
+  if (!res.ok || !json.success) {
+    return { error: json.error ?? "Upload failed" };
+  }
+  return json as AvatarUploadResult;
+}
+
 export async function uploadFile(
   file: File,
   csrfToken: string

assets/js/utils.ts

@@ -0,0 +1,32 @@
+export function timeAgo(insertedAt?: string | null): string {
+  if (!insertedAt) return "just now";
+  const now = Date.now();
+  const then = new Date(insertedAt).getTime();
+  const diffSec = Math.floor((now - then) / 1000);
+  if (diffSec < 5) return "just now";
+  if (diffSec < 60) return `${diffSec}s`;
+  const diffMin = Math.floor(diffSec / 60);
+  if (diffMin < 60) return `${diffMin}m`;
+  const diffHr = Math.floor(diffMin / 60);
+  if (diffHr < 24) return `${diffHr}h`;
+  const diffDay = Math.floor(diffHr / 24);
+  if (diffDay < 7) return `${diffDay}d`;
+  return new Date(insertedAt).toLocaleDateString(undefined, { month: "short", day: "numeric" });
+}
+
+export function getAssetHost(): string {
+  const appEl = document.getElementById("app");
+  return appEl?.dataset.assetHost ?? "http://localhost:9000";
+}
+
+export function userDisplayLabel(u: {
+  displayName?: string | null;
+  username?: string | null;
+  email?: string | null;
+}): string {
+  return u.displayName || u.username || u.email || "@mixer";
+}
+
+export function userHandle(u: { username?: string | null; email?: string | null }): string {
+  return u.username ? `@${u.username}` : u.email ?? "@mixer";
+}

assets/tsconfig.json

@@ -28,7 +28,9 @@
       "*": ["../deps/*"]
     },
     "allowJs": true,
-    "noEmit": true
+    "noEmit": true,
+    "target": "es5",
+    "lib": ["ES2015", "DOM"]
   },
   "include": ["js/**/*"]
 }

config/config.exs

@@ -94,7 +94,7 @@ config :spark,
   ]
 
 config :mixer,
-  ecto_repos: [Mixer.Repo],
+  ecto_repos: [Mixer.Repo, Mixer.ClickhouseRepo],
   generators: [timestamp_type: :utc_datetime],
   ash_domains: [Mixer.Accounts, Mixer.Posts],
   ash_authentication: [return_error_on_invalid_magic_link_token?: true]
@@ -126,7 +126,17 @@ config :esbuild,
     args:
       ~w(js/index.tsx js/app.js --bundle --target=es2022 --outdir=../priv/static/assets --external:/fonts/* --external:/images/* --alias:@=. --splitting --format=esm),
     cd: Path.expand("../assets", __DIR__),
-    env: %{"NODE_PATH" => Enum.join([Path.expand("../deps", __DIR__), Path.expand(Mix.Project.build_path()), Path.expand("../_build/dev", __DIR__)], ":")}
+    env: %{
+      "NODE_PATH" =>
+        Enum.join(
+          [
+            Path.expand("../deps", __DIR__),
+            Path.expand(Mix.Project.build_path()),
+            Path.expand("../_build/dev", __DIR__)
+          ],
+          ":"
+        )
+    }
   ]
 
 # Configure tailwind (the version is required)
@@ -148,6 +158,11 @@ config :logger, :default_formatter,
 # Use Jason for JSON parsing in Phoenix
 config :phoenix, :json_library, Jason
 
+# ClickHouse repo — migrations live in priv/clickhouse/migrations
+config :mixer, Mixer.ClickhouseRepo,
+  priv: "priv/clickhouse",
+  migration_source: "ch_schema_migrations"
+
 # Import environment specific config. This must remain at the bottom
 # of this file so it overrides the configuration defined above.
 import_config "#{config_env()}.exs"

config/dev.exs

@@ -106,3 +106,12 @@ config :ex_aws, :s3,
 config :waffle,
   bucket: "mixer-bucket",
   asset_host: "http://localhost:9000"
+
+# ClickHouse (default local install)
+config :mixer, Mixer.ClickhouseRepo,
+  scheme: "http",
+  hostname: "localhost",
+  port: 8123,
+  database: "mixer_metrics",
+  username: "default",
+  password: ""

config/runtime.exs

@@ -22,6 +22,11 @@ end
 
 config :mixer, MixerWeb.Endpoint, http: [port: String.to_integer(System.get_env("PORT", "4000"))]
 
+# ClickHouse is available in all environments via env vars when set
+if clickhouse_url = System.get_env("CLICKHOUSE_URL") do
+  config :mixer, Mixer.ClickhouseRepo, url: clickhouse_url
+end
+
 if config_env() == :prod do
   database_url =
     System.get_env("DATABASE_URL") ||
@@ -40,6 +45,19 @@ if config_env() == :prod do
     # pool_count: 4,
     socket_options: maybe_ipv6
 
+  # ClickHouse — configure via CLICKHOUSE_URL or individual vars
+  unless System.get_env("CLICKHOUSE_URL") do
+    config :mixer, Mixer.ClickhouseRepo,
+      scheme: System.get_env("CLICKHOUSE_SCHEME", "http"),
+      hostname:
+        System.get_env("CLICKHOUSE_HOST") ||
+          raise("Missing environment variable `CLICKHOUSE_HOST`!"),
+      port: String.to_integer(System.get_env("CLICKHOUSE_PORT", "8123")),
+      database: System.get_env("CLICKHOUSE_DATABASE", "mixer_metrics"),
+      username: System.get_env("CLICKHOUSE_USERNAME", "default"),
+      password: System.get_env("CLICKHOUSE_PASSWORD", "")
+  end
+
   # The secret key base is used to sign/encrypt cookies and other secrets.
   # A default value is used in config/dev.exs and config/test.exs but you
   # want to use a different value for prod and you most likely don't want

config/test.exs

@@ -42,3 +42,12 @@ config :phoenix_live_view,
 # Sort query params output of verified routes for robust url comparisons
 config :phoenix,
   sort_verified_routes_query_params: true
+
+# ClickHouse — point at a dedicated test database
+config :mixer, Mixer.ClickhouseRepo,
+  scheme: "http",
+  hostname: "localhost",
+  port: 8123,
+  database: "mixer_metrics_test",
+  username: "default",
+  password: ""

fix_plan.md

@@ -0,0 +1,28 @@
+# Fix Plan
+
+## Completed
+
+- [x] `tweet_like` tests: `user_fixture` missing `authorize?: false`, `Ash.Query.filter` needed `require Ash.Query`, `Ash.ForbiddenField.forbidden?/1` doesn't exist (use `match?`), `like` noop returned stale tweet struct → fixed all
+
+## In Progress / Next
+
+- [x] `unlike` noop returns stale tweet struct — same issue as `like` noop; reload from DB
+- [x] `decrement_likes` can go below 0 — use `GREATEST(likes - 1, 0)` via SQL fragment
+
+## Backlog
+
+- [x] Self-follow validation used `get_attribute(:follower_id)` which is nil at validation time (relate_actor runs after) — fixed to use `context.actor.id`
+- [x] Follow/unfollow test coverage (9 tests)
+- [x] User list pagination — useInfiniteQuery + scroll sentinel, USERS_PAGE_SIZE=20, sorted by username
+- [ ] No CHECK constraint on `likes >= 0` at DB level (low priority, app logic prevents it)
+- [ ] `read :following_feed` — nil actor returns empty list (not a bug)
+- [ ] No search for users or tweets
+- [x] Tweet creation, update, delete, comment tests (13 tests)
+- [ ] Missing test coverage: auth flows
+
+## Notes
+
+- Stack: Elixir/Phoenix + Ash Framework + React/TypeScript
+- Tests: `mix test` — 10 tests, all should pass
+- Build: `mix precommit` alias runs compile + test + format checks
+- No ClickHouse in test env (expected, non-fatal errors in test output)

lib/mixer/accounts.ex

@@ -1,6 +1,19 @@
 defmodule Mixer.Accounts do
   use Ash.Domain, otp_app: :mixer, extensions: [AshTypescript.Rpc, AshAdmin.Domain]
 
+  typescript_rpc do
+    resource Mixer.Accounts.User do
+      rpc_action :read_user, :read
+      rpc_action :update_profile, :update_profile
+    end
+
+    resource Mixer.Accounts.Follow do
+      rpc_action :read_follow, :read
+      rpc_action :follow_user, :follow
+      rpc_action :unfollow_user, :unfollow
+    end
+  end
+
   admin do
     show? true
   end
@@ -12,15 +25,4 @@ defmodule Mixer.Accounts do
 
     resource Mixer.Accounts.Follow
   end
-
-  typescript_rpc do
-    resource Mixer.Accounts.User do
-      rpc_action :read_user, :read
-    end
-    resource Mixer.Accounts.Follow do
-      rpc_action :read_follow, :read
-      rpc_action :follow_user, :follow
-      rpc_action :unfollow_user, :unfollow
-    end
-  end
 end

lib/mixer/accounts/avatar_uploader.ex

@@ -0,0 +1,33 @@
+defmodule Mixer.Accounts.AvatarUploader do
+  use Waffle.Definition
+
+  @versions [:original, :thumb]
+  @extensions ~w(.jpg .jpeg .png .gif .webp)
+
+  def validate({file, _scope}) do
+    ext = file.file_name |> Path.extname() |> String.downcase()
+    if ext in @extensions, do: :ok, else: {:error, "unsupported file type #{ext}"}
+  end
+
+  # Resize to a 256×256 square (centre-crop) and convert to WebP for efficiency
+  def transform(:thumb, _) do
+    {:convert, "-strip -thumbnail 256x256^ -gravity center -extent 256x256 -format webp", :webp}
+  end
+
+  # Store both versions under avatars/:user_id/
+  def storage_dir(_version, {_file, scope}), do: "avatars/#{scope.user_id}"
+
+  def filename(:original, {file, _scope}) do
+    Path.basename(file.file_name, Path.extname(file.file_name))
+  end
+
+  def filename(:thumb, _), do: "thumb"
+
+  def s3_object_headers(:thumb, _), do: [content_type: "image/webp"]
+
+  def s3_object_headers(_version, {file, _scope}) do
+    [content_type: MIME.from_path(file.file_name)]
+  end
+
+  def acl(_version, _), do: :public_read
+end

lib/mixer/accounts/follow.ex

@@ -1,5 +1,6 @@
 defmodule Mixer.Accounts.Follow do
   require Ash.Query
+
   use Ash.Resource,
     domain: Mixer.Accounts,
     data_layer: AshPostgres.DataLayer,
@@ -20,25 +21,6 @@ defmodule Mixer.Accounts.Follow do
     type_name "follows"
   end
 
-  attributes do
-    uuid_primary_key :id
-    create_timestamp :created_at
-  end
-
-  relationships do
-    belongs_to :follower, Mixer.Accounts.User do
-      primary_key? true
-      allow_nil? false
-      attribute_writable? true
-    end
-
-    belongs_to :following, Mixer.Accounts.User do
-      primary_key? true
-      allow_nil? false
-      attribute_writable? true
-    end
-  end
-
   actions do
     defaults [:read, :destroy]
 
@@ -48,11 +30,12 @@ defmodule Mixer.Accounts.Follow do
       upsert_identity :unique_follow
       accept [:following_id]
       change relate_actor(:follower)
-      validate fn changeset, _context ->
+
-        follower_id = Ash.Changeset.get_attribute(changeset, :follower_id)
+      validate fn changeset, context ->
+        actor_id = context.actor && context.actor.id
         following_id = Ash.Changeset.get_attribute(changeset, :following_id)
 
-        if follower_id == following_id do
+        if actor_id && actor_id == following_id do
           {:error, field: :following_id, message: "You cannot follow yourself"}
         else
           :ok
@@ -82,10 +65,6 @@ defmodule Mixer.Accounts.Follow do
     end
   end
 
-  identities do
-    identity :unique_follow, [:follower_id, :following_id]
-  end
-
   policies do
     policy action_type(:read) do
       authorize_if always()
@@ -99,4 +78,27 @@ defmodule Mixer.Accounts.Follow do
       authorize_if actor_present()
     end
   end
+
+  attributes do
+    uuid_primary_key :id
+    create_timestamp :created_at
+  end
+
+  relationships do
+    belongs_to :follower, Mixer.Accounts.User do
+      primary_key? true
+      allow_nil? false
+      attribute_writable? true
+    end
+
+    belongs_to :following, Mixer.Accounts.User do
+      primary_key? true
+      allow_nil? false
+      attribute_writable? true
+    end
+  end
+
+  identities do
+    identity :unique_follow, [:follower_id, :following_id]
+  end
 end

lib/mixer/accounts/user.ex

@@ -37,6 +37,7 @@ defmodule Mixer.Accounts.User do
       password :password do
         identity_field :email
         hash_provider AshAuthentication.BcryptProvider
+        require_confirmed_with :confirmed_at
 
         resettable do
           sender Mixer.Accounts.User.Senders.SendPasswordResetEmail
@@ -176,9 +177,21 @@ defmodule Mixer.Accounts.User do
         sensitive? true
       end
 
+      argument :username, :string do
+        description "The desired username for the user (letters, numbers, underscores)."
+        allow_nil? false
+
+        constraints match: ~r/^[a-zA-Z0-9_]+$/,
+                    min_length: 3,
+                    max_length: 30
+      end
+
       # Sets the email from the argument
       change set_attribute(:email, arg(:email))
 
+      # Sets the username from the argument
+      change set_attribute(:username, arg(:username))
+
       # Hashes the provided password
       change AshAuthentication.Strategy.Password.HashPasswordChange
 
@@ -210,6 +223,18 @@ defmodule Mixer.Accounts.User do
       get_by :email
     end
 
+    update :update_profile do
+      description "Update the user's public profile (username, display name)."
+      accept [:username, :display_name]
+      require_atomic? false
+    end
+
+    update :update_avatar do
+      description "Store the S3 key of the user's processed avatar thumbnail."
+      accept [:avatar_url]
+      require_atomic? false
+    end
+
     update :reset_password_with_token do
       argument :reset_token, :string do
         allow_nil? false
@@ -255,6 +280,15 @@ defmodule Mixer.Accounts.User do
         allow_nil? true
       end
 
+      argument :username, :string do
+        description "Username chosen during first-time magic link registration."
+        allow_nil? true
+
+        constraints match: ~r/^[a-zA-Z0-9_]+$/,
+                    min_length: 3,
+                    max_length: 30
+      end
+
       upsert? true
       upsert_identity :unique_email
       upsert_fields [:email]
@@ -265,6 +299,37 @@ defmodule Mixer.Accounts.User do
       change {AshAuthentication.Strategy.RememberMe.MaybeGenerateTokenChange,
               strategy_name: :remember_me}
 
+      # Set username on new users (or existing users who haven't set one yet)
+      change fn changeset, _ctx ->
+        case Ash.Changeset.get_argument(changeset, :username) do
+          nil ->
+            changeset
+
+          username ->
+            # Set the attribute directly so the unique_username identity's
+            # eager_check_with fires during Form.validate, surfacing "already
+            # taken" errors in the UI before the action is submitted.
+            changeset = Ash.Changeset.change_attribute(changeset, :username, username)
+
+            # Also update via after_action to handle existing users who have no
+            # username yet: for upserts, only upsert_fields are applied to the
+            # conflicting row, so change_attribute above won't touch them.
+            Ash.Changeset.after_action(changeset, fn _cs, user ->
+              if is_nil(user.username) do
+                user
+                |> Ash.Changeset.for_update(:update_profile, %{username: username},authorize?: false)
+                |> Ash.update()
+                |> case do
+                  {:ok, updated} -> {:ok, updated}
+                  {:error, error} -> {:error, error}
+                end
+              else
+                {:ok, user}
+              end
+            end)
+        end
+      end
+
       metadata :token, :string do
         allow_nil? false
       end
@@ -292,6 +357,14 @@ defmodule Mixer.Accounts.User do
     policy action_type(:read) do
       authorize_if always()
     end
+
+    policy action(:update_profile) do
+      authorize_if expr(id == ^actor(:id))
+    end
+
+    policy action(:update_avatar) do
+      authorize_if expr(id == ^actor(:id))
+    end
   end
 
   attributes do
@@ -307,6 +380,23 @@ defmodule Mixer.Accounts.User do
     end
 
     attribute :confirmed_at, :utc_datetime_usec
+
+    attribute :username, :string do
+      public? true
+
+      constraints match: ~r/^[a-zA-Z0-9_]+$/,
+                  min_length: 3,
+                  max_length: 30
+    end
+
+    attribute :display_name, :string do
+      public? true
+      constraints max_length: 50
+    end
+
+    attribute :avatar_url, :string do
+      public? true
+    end
   end
 
   relationships do
@@ -349,5 +439,10 @@ defmodule Mixer.Accounts.User do
 
   identities do
     identity :unique_email, [:email]
+    identity :unique_username, [:username] do
+      eager_check_with Mixer.Accounts
+      message "is already taken"
+      nils_distinct? true
+    end
   end
 end

lib/mixer/accounts/user/senders/send_magic_link_email.ex

@@ -31,14 +31,21 @@ defmodule Mixer.Accounts.User.Senders.SendMagicLinkEmail do
   defp body(params) do
     # NOTE: You may have to change this to match your magic link acceptance URL.
     link = url(~p"/magic_link/#{params[:token]}")
-    email_template("Your magic link", "Hello, #{params[:email]}!", """
+
-      <p style="margin:0 0 20px 0;color:#4B5563;font-size:16px;line-height:1.6;">
+    email_template(
-        Use the button below to sign in to Mixer. This link is valid for a short time and can only be used once.
+      "Your magic link",
-      </p>
+      "Hello, #{params[:email]}!",
-      <p style="margin:0 0 32px 0;color:#4B5563;font-size:16px;line-height:1.6;">
+      """
-        If you didn't request this, you can safely ignore this email.
+        <p style="margin:0 0 20px 0;color:#4B5563;font-size:16px;line-height:1.6;">
-      </p>
+          Use the button below to sign in to Mixer. This link is valid for a short time and can only be used once.
-    """, link, "Sign In to Mixer")
+        </p>
+        <p style="margin:0 0 32px 0;color:#4B5563;font-size:16px;line-height:1.6;">
+          If you didn't request this, you can safely ignore this email.
+        </p>
+      """,
+      link,
+      "Sign In to Mixer"
+    )
   end
 
   defp email_template(title, greeting, content, button_url, button_label) do

lib/mixer/accounts/user/senders/send_new_user_confirmation_email.ex

@@ -22,14 +22,21 @@ defmodule Mixer.Accounts.User.Senders.SendNewUserConfirmationEmail do
 
   defp body(params) do
     link = url(~p"/confirm_new_user/#{params[:token]}")
-    email_template("Confirm your email", "Welcome to Mixer!", """
+
-      <p style="margin:0 0 20px 0;color:#4B5563;font-size:16px;line-height:1.6;">
+    email_template(
-        Thanks for signing up. Just one more step — confirm your email address to activate your account.
+      "Confirm your email",
-      </p>
+      "Welcome to Mixer!",
-      <p style="margin:0 0 32px 0;color:#4B5563;font-size:16px;line-height:1.6;">
+      """
-        If you didn't create an account on Mixer, you can safely ignore this email.
+        <p style="margin:0 0 20px 0;color:#4B5563;font-size:16px;line-height:1.6;">
-      </p>
+          Thanks for signing up. Just one more step — confirm your email address to activate your account.
-    """, link, "Confirm Email Address")
+        </p>
+        <p style="margin:0 0 32px 0;color:#4B5563;font-size:16px;line-height:1.6;">
+          If you didn't create an account on Mixer, you can safely ignore this email.
+        </p>
+      """,
+      link,
+      "Confirm Email Address"
+    )
   end
 
   defp email_template(title, greeting, content, button_url, button_label) do

lib/mixer/accounts/user/senders/send_password_reset_email.ex

@@ -22,14 +22,21 @@ defmodule Mixer.Accounts.User.Senders.SendPasswordResetEmail do
 
   defp body(params) do
     link = url(~p"/password-reset/#{params[:token]}")
-    email_template("Reset your password", "Password reset request", """
+
-      <p style="margin:0 0 20px 0;color:#4B5563;font-size:16px;line-height:1.6;">
+    email_template(
-        We received a request to reset the password for your Mixer account. Click the button below to choose a new one.
+      "Reset your password",
-      </p>
+      "Password reset request",
-      <p style="margin:0 0 32px 0;color:#4B5563;font-size:16px;line-height:1.6;">
+      """
-        If you didn't request a password reset, you can safely ignore this email — your password will not change.
+        <p style="margin:0 0 20px 0;color:#4B5563;font-size:16px;line-height:1.6;">
-      </p>
+          We received a request to reset the password for your Mixer account. Click the button below to choose a new one.
-    """, link, "Reset My Password")
+        </p>
+        <p style="margin:0 0 32px 0;color:#4B5563;font-size:16px;line-height:1.6;">
+          If you didn't request a password reset, you can safely ignore this email — your password will not change.
+        </p>
+      """,
+      link,
+      "Reset My Password"
+    )
   end
 
   defp email_template(title, greeting, content, button_url, button_label) do

lib/mixer/application.ex

@@ -10,6 +10,10 @@ defmodule Mixer.Application do
     children = [
       MixerWeb.Telemetry,
       Mixer.Repo,
+      # ClickHouse repo for analytics — started before the metrics buffer
+      Mixer.ClickhouseRepo,
+      # In-memory event buffer that batches writes to ClickHouse
+      Mixer.Metrics.Buffer,
       {DNSCluster, query: Application.get_env(:mixer, :dns_cluster_query) || :ignore},
       {Phoenix.PubSub, name: Mixer.PubSub},
       # Start a worker by calling: Mixer.Worker.start_link(arg)

lib/mixer/clickhouse_repo.ex

@@ -0,0 +1,13 @@
+defmodule Mixer.ClickhouseRepo do
+  @moduledoc """
+  Ecto repository for ClickHouse, backed by the `ecto_ch` / `Ch` adapter.
+
+  Used exclusively for analytics writes (via `Mixer.Metrics.Buffer`) and
+  read queries (via `Mixer.Metrics`). It is **not** an Ash repo and must
+  never be used for transactional application data.
+  """
+
+  use Ecto.Repo,
+    otp_app: :mixer,
+    adapter: Ecto.Adapters.ClickHouse
+end

lib/mixer/metrics.ex

@@ -0,0 +1,291 @@
+defmodule Mixer.Metrics do
+  @moduledoc """
+  Public API for tracking and querying post (tweet) metrics via ClickHouse.
+
+  ## Tracking events
+
+  Tracking calls are non-blocking — events are handed off to the in-memory
+  `Mixer.Metrics.Buffer` GenServer and written to ClickHouse in batches.
+
+      # Record a tweet view (anonymous)
+      Mixer.Metrics.track_view(tweet_id)
+
+      # Record a view with a logged-in user and their IP
+      Mixer.Metrics.track_view(tweet_id, user_id: user.id, ip_address: conn.remote_ip)
+
+  ## Querying metrics
+
+  Query functions execute synchronous ClickHouse SQL and return plain maps.
+
+      {:ok, summary} = Mixer.Metrics.get_summary(tweet_id)
+      # => %{views: 42, likes: 7, unlikes: 1, comments: 3, shares: 0}
+
+      {:ok, rows} = Mixer.Metrics.get_top_posts(10)
+      # => [%{tweet_id: "...", views: 99}, ...]
+  """
+
+  require Logger
+
+  alias Mixer.ClickhouseRepo
+  alias Mixer.Metrics.Buffer
+
+  # ---------------------------------------------------------------------------
+  # Event types
+  # ---------------------------------------------------------------------------
+
+  @type event_type ::
+          :view | :post | :comment | :like | :unlike | :share | :delete_post | :delete_comment
+
+  @type track_opt ::
+          {:user_id, binary() | nil}
+          | {:ip_address, binary() | :inet.ip_address() | nil}
+
+  # ---------------------------------------------------------------------------
+  # Tracking helpers
+  # ---------------------------------------------------------------------------
+
+  @doc """
+  Track a tweet view event.
+
+  ## Options
+
+    * `:user_id` — UUID of the viewing user (nil for anonymous)
+    * `:ip_address` — originating IP; accepts a string or an `:inet` tuple
+  """
+  @spec track_view(binary(), [track_opt()]) :: :ok
+  def track_view(tweet_id, opts \\ []), do: enqueue("view", tweet_id, opts)
+
+  @doc "Track a tweet like event."
+  @spec track_like(binary(), [track_opt()]) :: :ok
+  def track_like(tweet_id, opts \\ []), do: enqueue("like", tweet_id, opts)
+
+  @doc "Track a tweet unlike event."
+  @spec track_unlike(binary(), [track_opt()]) :: :ok
+  def track_unlike(tweet_id, opts \\ []), do: enqueue("unlike", tweet_id, opts)
+
+  @doc "Track a comment (reply) event on a tweet."
+  @spec track_comment(binary(), [track_opt()]) :: :ok
+  def track_comment(tweet_id, opts \\ []), do: enqueue("comment", tweet_id, opts)
+
+  @doc "Track a tweet share / repost event."
+  @spec track_share(binary(), [track_opt()]) :: :ok
+  def track_share(tweet_id, opts \\ []), do: enqueue("share", tweet_id, opts)
+
+  @doc """
+  Track a new top-level tweet being published.
+
+  The event is recorded against the new tweet's own ID.
+  """
+  @spec track_post(binary(), [track_opt()]) :: :ok
+  def track_post(tweet_id, opts \\ []), do: enqueue("post", tweet_id, opts)
+
+  @doc """
+  Track a top-level tweet being deleted.
+
+  The event is recorded against the deleted tweet's ID.
+  Note: cascade-deleted comments are not individually tracked — only the
+  explicit user-initiated destroy action emits this event.
+  """
+  @spec track_delete_post(binary(), [track_opt()]) :: :ok
+  def track_delete_post(tweet_id, opts \\ []), do: enqueue("delete_post", tweet_id, opts)
+
+  @doc """
+  Track a comment (reply) being deleted.
+
+  The event is recorded against the *parent* tweet's ID so that
+  `get_summary/1` can reflect net comment activity on a tweet.
+  """
+  @spec track_delete_comment(binary(), [track_opt()]) :: :ok
+  def track_delete_comment(tweet_id, opts \\ []), do: enqueue("delete_comment", tweet_id, opts)
+
+  # ---------------------------------------------------------------------------
+  # Query helpers
+  # ---------------------------------------------------------------------------
+
+  @doc """
+  Return a summary of all event counts for a single tweet.
+
+  Returns `{:ok, map}` on success or `{:error, reason}` on failure.
+
+  ## Example
+
+      {:ok, %{views: 12, likes: 3, unlikes: 0, comments: 5, shares: 1}} =
+        Mixer.Metrics.get_summary(tweet_id)
+  """
+  @spec get_summary(binary()) :: {:ok, map()} | {:error, term()}
+  def get_summary(tweet_id) do
+    sql = """
+    SELECT
+      countIf(event_type = 'view')    AS views,
+      countIf(event_type = 'like')    AS likes,
+      countIf(event_type = 'unlike')  AS unlikes,
+      countIf(event_type = 'comment') AS comments,
+      countIf(event_type = 'share')   AS shares
+    FROM post_events
+    WHERE tweet_id = {tweet_id:String}
+    """
+
+    case ClickhouseRepo.query(sql, %{"tweet_id" => tweet_id}) do
+      {:ok, result} ->
+        {:ok, row_to_summary(result)}
+
+      {:error, reason} ->
+        Logger.error("[Mixer.Metrics] get_summary failed for #{tweet_id}: #{inspect(reason)}")
+        {:error, reason}
+    end
+  end
+
+  @doc """
+  Return view counts bucketed by UTC hour for the past `hours` hours.
+
+  Useful for rendering a sparkline on a tweet detail page.
+
+  ## Example
+
+      {:ok, rows} = Mixer.Metrics.get_hourly_views(tweet_id, 24)
+      # => [%{hour: ~N[2026-04-07 00:00:00], views: 5}, ...]
+  """
+  @spec get_hourly_views(binary(), pos_integer()) :: {:ok, [map()]} | {:error, term()}
+  def get_hourly_views(tweet_id, hours \\ 24) when is_integer(hours) and hours > 0 do
+    sql = """
+    SELECT
+      toStartOfHour(occurred_at) AS hour,
+      count()                    AS views
+    FROM post_events
+    WHERE
+      tweet_id   = {tweet_id:String}
+      AND event_type = 'view'
+      AND occurred_at >= now() - toIntervalHour({hours:UInt32})
+    GROUP BY hour
+    ORDER BY hour ASC
+    """
+
+    case ClickhouseRepo.query(sql, %{"tweet_id" => tweet_id, "hours" => hours}) do
+      {:ok, %{rows: rows}} ->
+        {:ok, Enum.map(rows, fn [hour, views] -> %{hour: hour, views: views} end)}
+
+      {:error, reason} ->
+        Logger.error("[Mixer.Metrics] get_hourly_views failed: #{inspect(reason)}")
+        {:error, reason}
+    end
+  end
+
+  @doc """
+  Return the top `limit` tweets ordered by total view count across all time.
+
+  ## Example
+
+      {:ok, rows} = Mixer.Metrics.get_top_posts(10)
+      # => [%{tweet_id: "...", views: 99}, %{tweet_id: "...", views: 72}, ...]
+  """
+  @spec get_top_posts(pos_integer()) :: {:ok, [map()]} | {:error, term()}
+  def get_top_posts(limit \\ 10) when is_integer(limit) and limit > 0 do
+    sql = """
+    SELECT
+      tweet_id,
+      countIf(event_type = 'view') AS views
+    FROM post_events
+    GROUP BY tweet_id
+    ORDER BY views DESC
+    LIMIT {limit:UInt32}
+    """
+
+    case ClickhouseRepo.query(sql, %{"limit" => limit}) do
+      {:ok, %{rows: rows}} ->
+        {:ok, Enum.map(rows, fn [tweet_id, views] -> %{tweet_id: tweet_id, views: views} end)}
+
+      {:error, reason} ->
+        Logger.error("[Mixer.Metrics] get_top_posts failed: #{inspect(reason)}")
+        {:error, reason}
+    end
+  end
+
+  @doc """
+  Return per-event-type counts for a list of tweet IDs in a single query.
+
+  Handy for batch-enriching a feed with metrics without N+1 queries.
+
+  ## Example
+
+      {:ok, map} = Mixer.Metrics.get_bulk_summaries(tweet_ids)
+      # => %{"<uuid>" => %{views: 5, likes: 2, ...}, ...}
+  """
+  @spec get_bulk_summaries([binary()]) :: {:ok, %{binary() => map()}} | {:error, term()}
+  def get_bulk_summaries([]), do: {:ok, %{}}
+
+  def get_bulk_summaries(tweet_ids) when is_list(tweet_ids) do
+    # ecto_ch supports passing arrays as query parameters
+    sql = """
+    SELECT
+      tweet_id,
+      countIf(event_type = 'view')    AS views,
+      countIf(event_type = 'like')    AS likes,
+      countIf(event_type = 'unlike')  AS unlikes,
+      countIf(event_type = 'comment') AS comments,
+      countIf(event_type = 'share')   AS shares
+    FROM post_events
+    WHERE tweet_id IN {tweet_ids:Array(String)}
+    GROUP BY tweet_id
+    """
+
+    case ClickhouseRepo.query(sql, %{"tweet_ids" => tweet_ids}) do
+      {:ok, %{rows: rows}} ->
+        summaries =
+          Map.new(rows, fn [tweet_id, views, likes, unlikes, comments, shares] ->
+            {tweet_id,
+             %{
+               views: views,
+               likes: likes,
+               unlikes: unlikes,
+               comments: comments,
+               shares: shares
+             }}
+          end)
+
+        {:ok, summaries}
+
+      {:error, reason} ->
+        Logger.error("[Mixer.Metrics] get_bulk_summaries failed: #{inspect(reason)}")
+        {:error, reason}
+    end
+  end
+
+  # ---------------------------------------------------------------------------
+  # Private helpers
+  # ---------------------------------------------------------------------------
+
+  defp enqueue(event_type, tweet_id, opts) do
+    event = %{
+      event_type: event_type,
+      tweet_id: tweet_id,
+      user_id: Keyword.get(opts, :user_id),
+      occurred_at: DateTime.utc_now() |> DateTime.truncate(:second),
+      ip_address: opts |> Keyword.get(:ip_address) |> format_ip()
+    }
+
+    Buffer.track(event)
+  end
+
+  defp format_ip(nil), do: nil
+  defp format_ip(ip) when is_binary(ip), do: ip
+
+  defp format_ip({a, b, c, d}), do: "#{a}.#{b}.#{c}.#{d}"
+
+  defp format_ip({a, b, c, d, e, f, g, h}) do
+    [a, b, c, d, e, f, g, h]
+    |> Enum.map_join(":", &Integer.to_string(&1, 16))
+  end
+
+  defp row_to_summary(%{rows: [[views, likes, unlikes, comments, shares] | _]}) do
+    %{
+      views: views,
+      likes: likes,
+      unlikes: unlikes,
+      comments: comments,
+      shares: shares
+    }
+  end
+
+  # ClickHouse returns no rows when the tweet has zero events — default to 0
+  defp row_to_summary(_), do: %{views: 0, likes: 0, unlikes: 0, comments: 0, shares: 0}
+end

lib/mixer/metrics/buffer.ex

@@ -0,0 +1,151 @@
+defmodule Mixer.Metrics.Buffer do
+  @moduledoc """
+  GenServer that accumulates post metric events in memory and flushes them
+  to ClickHouse in batches.
+
+  Two conditions trigger a flush:
+
+  1. **Timer** — every `@flush_interval` milliseconds (default 10 s).
+  2. **Threshold** — whenever the in-memory buffer reaches `@max_buffer_size`
+     rows (default 500).
+
+  If ClickHouse is unavailable the error is logged and the buffered events
+  are discarded rather than retried indefinitely, preventing unbounded memory
+  growth. For production deployments that require durability, consider adding
+  a persistent queue in front of this buffer.
+  """
+
+  use GenServer
+
+  require Logger
+
+  alias Mixer.Metrics.PostEvent
+
+  @flush_interval :timer.seconds(10)
+  @max_buffer_size 500
+
+  # ---------------------------------------------------------------------------
+  # Public API
+  # ---------------------------------------------------------------------------
+
+  @doc """
+  Start the buffer process and link it to the calling process.
+
+  Accepts an optional keyword list of overrides:
+
+    * `:flush_interval` — milliseconds between scheduled flushes
+    * `:max_buffer_size` — row count that triggers an immediate flush
+  """
+  @spec start_link(keyword()) :: GenServer.on_start()
+  def start_link(opts \\ []) do
+    GenServer.start_link(__MODULE__, opts, name: __MODULE__)
+  end
+
+  @doc """
+  Enqueue a single analytics event map for buffered insertion into ClickHouse.
+
+  The map must contain at minimum the fields required by `Mixer.Metrics.PostEvent`:
+  `:event_type`, `:tweet_id`, `:occurred_at`. Other fields are optional.
+
+  This call is asynchronous (cast) and returns `:ok` immediately.
+  """
+  @spec track(map()) :: :ok
+  def track(event) when is_map(event) do
+    GenServer.cast(__MODULE__, {:track, event})
+  end
+
+  @doc """
+  Force an immediate flush of all buffered events to ClickHouse, regardless
+  of the timer or threshold. Returns `:ok` after the flush completes.
+
+  Primarily useful in tests.
+  """
+  @spec flush() :: :ok
+  def flush do
+    GenServer.call(__MODULE__, :flush)
+  end
+
+  # ---------------------------------------------------------------------------
+  # GenServer callbacks
+  # ---------------------------------------------------------------------------
+
+  @impl GenServer
+  def init(opts) do
+    flush_interval = Keyword.get(opts, :flush_interval, @flush_interval)
+    max_buffer_size = Keyword.get(opts, :max_buffer_size, @max_buffer_size)
+
+    schedule_flush(flush_interval)
+
+    state = %{
+      events: [],
+      count: 0,
+      flush_interval: flush_interval,
+      max_buffer_size: max_buffer_size
+    }
+
+    {:ok, state}
+  end
+
+  @impl GenServer
+  def handle_cast({:track, event}, state) do
+    new_count = state.count + 1
+    new_events = [event | state.events]
+
+    if new_count >= state.max_buffer_size do
+      do_flush(new_events)
+      {:noreply, %{state | events: [], count: 0}}
+    else
+      {:noreply, %{state | events: new_events, count: new_count}}
+    end
+  end
+
+  @impl GenServer
+  def handle_call(:flush, _from, state) do
+    do_flush(state.events)
+    {:reply, :ok, %{state | events: [], count: 0}}
+  end
+
+  @impl GenServer
+  def handle_info(:flush, state) do
+    do_flush(state.events)
+    schedule_flush(state.flush_interval)
+    {:noreply, %{state | events: [], count: 0}}
+  end
+
+  @impl GenServer
+  def terminate(_reason, state) do
+    # Best-effort flush on shutdown so we don't lose buffered events during
+    # graceful stops (e.g., deploys).
+    do_flush(state.events)
+    :ok
+  end
+
+  # ---------------------------------------------------------------------------
+  # Private helpers
+  # ---------------------------------------------------------------------------
+
+  defp do_flush([]), do: :ok
+
+  defp do_flush(events) do
+    rows = Enum.reverse(events)
+    count = length(rows)
+
+    try do
+      # ClickHouse async inserts acknowledge writes immediately and always
+      # return num_rows: 0 — the data is queued for background commitment.
+      # We use our own row count for the log so it is always accurate.
+      Mixer.ClickhouseRepo.insert_all(PostEvent, rows)
+      Logger.debug("[Mixer.Metrics.Buffer] Flushed #{count} event(s) to ClickHouse")
+    rescue
+      error ->
+        Logger.error(
+          "[Mixer.Metrics.Buffer] Failed to flush #{count} event(s) to ClickHouse: " <>
+            Exception.message(error)
+        )
+    end
+  end
+
+  defp schedule_flush(interval) do
+    Process.send_after(self(), :flush, interval)
+  end
+end

lib/mixer/metrics/post_event.ex

@@ -0,0 +1,47 @@
+defmodule Mixer.Metrics.PostEvent do
+  @moduledoc """
+  Ecto schema that maps to the `post_events` table in ClickHouse.
+
+  Each row represents a single analytics event tied to a tweet (post).
+  The table uses a MergeTree engine ordered by `(occurred_at, event_type,
+  tweet_id)` for efficient time-range scans and per-tweet aggregations.
+
+  ## Event types
+
+  | event_type         | `tweet_id` refers to  | Description                                     |
+  |--------------------|-----------------------|-------------------------------------------------|
+  | `"view"`           | the viewed tweet      | Tweet detail page was loaded                    |
+  | `"post"`           | the new tweet         | A new top-level tweet was published             |
+  | `"comment"`        | the parent tweet      | A reply was posted; count against the parent    |
+  | `"like"`           | the liked tweet       | A user liked a tweet                            |
+  | `"unlike"`         | the unliked tweet     | A user removed their like                       |
+  | `"share"`          | the shared tweet      | A user shared / reposted a tweet                |
+  | `"delete_post"`    | the deleted tweet     | A top-level tweet was deleted by its author     |
+  | `"delete_comment"` | the parent tweet      | A reply was deleted; count against the parent   |
+  """
+
+  use Ecto.Schema
+
+  @primary_key false
+
+  schema "post_events" do
+    # Must be Ch-typed so ecto_ch emits LowCardinality(String) in the RowBinary
+    # header, matching the ClickHouse table DDL exactly.
+    field :event_type, Ch, type: "LowCardinality(String)"
+
+    # The tweet that the event relates to
+    field :tweet_id, Ecto.UUID
+
+    # The acting user; may be nil for anonymous views.
+    # Must be Ch-typed so ecto_ch emits Nullable(UUID) in the RowBinary header,
+    # matching the ClickHouse table DDL exactly.
+    field :user_id, Ch, type: "Nullable(UUID)"
+
+    # Wall-clock time of the event (UTC, second precision)
+    field :occurred_at, :utc_datetime
+
+    # Optional originating IP, useful for deduplicating anonymous views.
+    # Nullable(String) for the same reason as user_id above.
+    field :ip_address, Ch, type: "Nullable(String)"
+  end
+end

lib/mixer/posts.ex

@@ -3,6 +3,22 @@ defmodule Mixer.Posts do
     otp_app: :mixer,
     extensions: [AshTypescript.Rpc, AshAdmin.Domain]
 
+  typescript_rpc do
+    resource Mixer.Posts.Tweet do
+      rpc_action :create_tweet, :create
+      rpc_action :like_tweet, :like
+      rpc_action :read_tweet, :read
+      rpc_action :read_following_feed, :following_feed
+      rpc_action :unlike_tweet, :unlike
+      rpc_action :update_tweet, :update
+      rpc_action :destroy_tweet, :destroy
+    end
+
+    resource Mixer.Posts.Media do
+      rpc_action :read_media, :read
+    end
+  end
+
   admin do
     show? true
   end
@@ -12,19 +28,4 @@ defmodule Mixer.Posts do
     resource Mixer.Posts.TweetLike
     resource Mixer.Posts.Media
   end
-
-  typescript_rpc do
-    resource Mixer.Posts.Tweet do
-      rpc_action :create_tweet, :create
-      rpc_action :like_tweet, :like
-      rpc_action :read_tweet, :read
-      rpc_action :unlike_tweet, :unlike
-      rpc_action :update_tweet, :update
-      rpc_action :destroy_tweet, :destroy
-    end
-
-    resource Mixer.Posts.Media do
-      rpc_action :read_media, :read
-    end
-  end
 end

lib/mixer/posts/media.ex

@@ -38,6 +38,24 @@ defmodule Mixer.Posts.Media do
     end
   end
 
+  policies do
+    policy action_type(:read) do
+      authorize_if always()
+    end
+
+    policy action(:upload) do
+      authorize_if actor_present()
+    end
+
+    policy action(:link_to_tweet) do
+      authorize_if relates_to_actor_via(:user)
+    end
+
+    policy action_type(:destroy) do
+      authorize_if relates_to_actor_via(:user)
+    end
+  end
+
   attributes do
     uuid_primary_key :id
 
@@ -64,22 +82,4 @@ defmodule Mixer.Posts.Media do
       public? true
     end
   end
-
-  policies do
-    policy action_type(:read) do
-      authorize_if always()
-    end
-
-    policy action(:upload) do
-      authorize_if actor_present()
-    end
-
-    policy action(:link_to_tweet) do
-      authorize_if relates_to_actor_via(:user)
-    end
-
-    policy action_type(:destroy) do
-      authorize_if relates_to_actor_via(:user)
-    end
-  end
 end

lib/mixer/posts/media_uploader.ex

@@ -10,7 +10,8 @@ defmodule Mixer.Posts.MediaUploader do
     if ext in @extensions, do: :ok, else: {:error, "unsupported file type #{ext}"}
   end
 
-  def storage_dir(_version, {_file, scope}), do: "uploads/media/#{scope.user_id}/#{scope.media_id}"
+  def storage_dir(_version, {_file, scope}),
+    do: "uploads/media/#{scope.user_id}/#{scope.media_id}"
 
   def filename(_version, {file, _scope}) do
     Path.basename(file.file_name, Path.extname(file.file_name))

lib/mixer/posts/tweet.ex

@@ -12,10 +12,10 @@ defmodule Mixer.Posts.Tweet do
   postgres do
     table "tweets"
     repo Mixer.Repo
-  end
 
-  typescript do
+    references do
-    type_name "tweets"
+      reference :parent_tweet, on_delete: :delete
+    end
   end
 
   state_machine do
@@ -27,15 +27,27 @@ defmodule Mixer.Posts.Tweet do
     end
   end
 
+  typescript do
+    type_name "tweets"
+  end
+
   actions do
-    defaults [:read, :destroy]
+    defaults [:read]
+
+    read :following_feed do
+      filter expr(
+               user_id == ^actor(:id) or
+                 exists(user.followers, follower_id == ^actor(:id))
+             )
+    end
 
     create :create do
       upsert? true
-      accept [:content]
+      accept [:content, :parent_tweet_id]
       argument :media_id, :uuid, allow_nil?: true
       change relate_actor(:user)
       change transition_state(:posted)
+
       change fn changeset, context ->
         case Ash.Changeset.get_argument(changeset, :media_id) do
           nil ->
@@ -45,13 +57,58 @@ defmodule Mixer.Posts.Tweet do
             Ash.Changeset.after_action(changeset, fn _changeset, tweet ->
               Mixer.Posts.Media
               |> Ash.get!(media_id, authorize?: false)
-              |> Ash.Changeset.for_update(:link_to_tweet, %{tweet_id: tweet.id}, actor: context.actor)
+              |> Ash.Changeset.for_update(:link_to_tweet, %{tweet_id: tweet.id},
+                actor: context.actor
+              )
               |> Ash.update!()
 
               {:ok, tweet}
             end)
         end
       end
+
+      # Track post / comment creation metrics.
+      # Root tweets emit a "post" event recorded against their own ID.
+      # Replies emit a "comment" event recorded against the parent tweet ID so
+      # that `get_summary/1` can count how many replies a tweet has received.
+      change fn changeset, context ->
+        parent_tweet_id = Ash.Changeset.get_attribute(changeset, :parent_tweet_id)
+        user_id = context.actor && context.actor.id
+
+        Ash.Changeset.after_action(changeset, fn _changeset, tweet ->
+          if parent_tweet_id do
+            Mixer.Metrics.track_comment(parent_tweet_id, user_id: user_id)
+          else
+            Mixer.Metrics.track_post(tweet.id, user_id: user_id)
+          end
+
+          {:ok, tweet}
+        end)
+      end
+    end
+
+    # Explicit destroy so we can attach a metrics hook. The policy and cascade
+    # behaviour are identical to the previous default :destroy action.
+    destroy :destroy do
+      require_atomic? false
+
+      change fn changeset, context ->
+        # Capture the record's identity *before* deletion — after the action
+        # completes the row no longer exists.
+        tweet_id = changeset.data.id
+        parent_tweet_id = changeset.data.parent_tweet_id
+        user_id = context.actor && context.actor.id
+
+        Ash.Changeset.after_action(changeset, fn _changeset, result ->
+          if parent_tweet_id do
+            Mixer.Metrics.track_delete_comment(parent_tweet_id, user_id: user_id)
+          else
+            Mixer.Metrics.track_delete_post(tweet_id, user_id: user_id)
+          end
+
+          {:ok, result}
+        end)
+      end
     end
 
     update :update do
@@ -66,10 +123,11 @@ defmodule Mixer.Posts.Tweet do
         Ash.Changeset.after_action(changeset, fn _changeset, tweet ->
           case ensure_like(tweet, context.actor) do
             {:created, _like} ->
+              Mixer.Metrics.track_like(tweet.id, user_id: context.actor && context.actor.id)
               increment_likes(tweet, context.actor)
 
             {:noop, _like} ->
-              {:ok, tweet}
+              Ash.get(__MODULE__, tweet.id, authorize?: false)
 
             {:error, error} ->
               {:error, error}
@@ -86,10 +144,11 @@ defmodule Mixer.Posts.Tweet do
         Ash.Changeset.after_action(changeset, fn _changeset, tweet ->
           case remove_like(tweet, context.actor) do
             {:deleted, _like} ->
+              Mixer.Metrics.track_unlike(tweet.id, user_id: context.actor && context.actor.id)
               decrement_likes(tweet, context.actor)
 
             {:noop, _like} ->
-              {:ok, tweet}
+              Ash.get(__MODULE__, tweet.id, authorize?: false)
 
             {:error, error} ->
               {:error, error}
@@ -107,7 +166,34 @@ defmodule Mixer.Posts.Tweet do
     update :decrement_likes do
       accept []
       require_atomic? false
-      change atomic_update(:likes, expr(likes - 1))
+      change atomic_update(:likes, expr(fragment("GREATEST(? - 1, 0)", likes)))
+    end
+  end
+
+  policies do
+    policy action_type(:read) do
+      authorize_if always()
+    end
+
+    policy action_type(:create) do
+      authorize_if actor_present()
+    end
+
+    policy action(:update) do
+      authorize_if relates_to_actor_via(:user)
+    end
+
+    policy action(:destroy) do
+      authorize_if relates_to_actor_via(:user)
+      authorize_if relates_to_actor_via([:parent_tweet, :user])
+    end
+
+    policy action(:like) do
+      authorize_if actor_present()
+    end
+
+    policy action(:unlike) do
+      authorize_if actor_present()
     end
   end
 
@@ -145,6 +231,18 @@ defmodule Mixer.Posts.Tweet do
       public? true
     end
 
+    belongs_to :parent_tweet, Mixer.Posts.Tweet do
+      attribute_type :uuid
+      attribute_writable? true
+      allow_nil? true
+      public? true
+    end
+
+    has_many :comments, Mixer.Posts.Tweet do
+      destination_attribute :parent_tweet_id
+      public? true
+    end
+
     has_many :media, Mixer.Posts.Media do
       public? true
     end
@@ -156,41 +254,31 @@ defmodule Mixer.Posts.Tweet do
     calculate :user_email, :string, expr(user.email) do
       public? true
     end
+
+    calculate :user_username, :string, expr(user.username) do
+      public? true
+    end
+
+    calculate :user_display_name, :string, expr(user.display_name) do
+      public? true
+    end
+
+    calculate :user_avatar_url, :string, expr(user.avatar_url) do
+      public? true
+    end
   end
 
   aggregates do
+    count :comment_count, :comments do
+      public? true
+    end
+
     exists :liked_by_me, :tweet_likes do
       public? true
       filter expr(user_id == ^actor(:id))
     end
   end
 
-  policies do
-    policy action_type(:read) do
-      authorize_if always()
-    end
-
-    policy action_type(:create) do
-      authorize_if actor_present()
-    end
-
-    policy action(:update) do
-      authorize_if relates_to_actor_via(:user)
-    end
-
-    policy action(:destroy) do
-      authorize_if relates_to_actor_via(:user)
-    end
-
-    policy action(:like) do
-      authorize_if actor_present()
-    end
-
-    policy action(:unlike) do
-      authorize_if actor_present()
-    end
-  end
-
   defp ensure_like(_tweet, nil), do: {:error, Ash.Error.Forbidden.exception([])}
 
   defp ensure_like(tweet, actor) do

lib/mixer/posts/tweet_like.ex

@@ -23,6 +23,20 @@ defmodule Mixer.Posts.TweetLike do
     end
   end
 
+  policies do
+    policy action_type(:read) do
+      authorize_if always()
+    end
+
+    policy action(:create) do
+      authorize_if actor_present()
+    end
+
+    policy action_type(:destroy) do
+      authorize_if relates_to_actor_via(:user)
+    end
+  end
+
   attributes do
     uuid_primary_key :id
 
@@ -52,18 +66,4 @@ defmodule Mixer.Posts.TweetLike do
   identities do
     identity :unique_user_tweet, [:tweet_id, :user_id]
   end
-
-  policies do
-    policy action_type(:read) do
-      authorize_if always()
-    end
-
-    policy action(:create) do
-      authorize_if actor_present()
-    end
-
-    policy action_type(:destroy) do
-      authorize_if relates_to_actor_via(:user)
-    end
-  end
 end

lib/mixer_web/auth_overrides.ex

@@ -9,12 +9,15 @@ defmodule MixerWeb.AuthOverrides do
 
   # For a complete reference, see https://hexdocs.pm/ash_authentication_phoenix/ui-overrides.html
 
-  # override AshAuthentication.Phoenix.Components.Banner do
+  override AshAuthentication.Phoenix.Components.Banner do
-  #   set :image_url, "https://media.giphy.com/media/g7GKcSzwQfugw/giphy.gif"
+    set :image_url, nil
-  #   set :text_class, "bg-red-500"
+    set :dark_image_url, nil
-  # end
+    set :text, "⬡ Mixer"
+    set :text_class, "text-3xl font-bold tracking-tight"
+  end
 
-  # override AshAuthentication.Phoenix.Components.SignIn do
+  # Inject the username field into the password registration form
-  #  set :show_banner, false
+  override AshAuthentication.Phoenix.Components.Password do
-  # end
+    set :register_extra_component, &MixerWeb.AuthComponents.username_field/1
+  end
 end

lib/mixer_web/components/auth_components.ex

@@ -0,0 +1,55 @@
+defmodule MixerWeb.AuthComponents do
+  @moduledoc """
+  Extra components injected into AshAuthentication.Phoenix forms.
+  """
+
+  use Phoenix.Component
+
+  @doc """
+  Renders a username input field inside the password registration form.
+
+  Receives `form` (an `AshPhoenix.Form`) as an assign via the
+  `register_extra_component` override.
+  """
+  def username_field(assigns) do
+    field = assigns.form[:username]
+
+    assigns =
+      assigns
+      |> assign(:field_id, field.id)
+      |> assign(:field_name, field.name)
+      |> assign(:field_value, field.value || "")
+      |> assign(:field_errors, field.errors)
+
+    ~H"""
+    <div class="mt-2 mb-2">
+      <label for={@field_id} class="block text-sm font-medium text-base-content mb-1">
+        Username
+      </label>
+      <div class="flex">
+        <span class="flex items-center justify-center px-4 bg-base-200 border border-base-300 border-r-0 rounded-l-lg text-base-content/50 select-none">@</span>
+        <input
+          type="text"
+          id={@field_id}
+          name={@field_name}
+          value={@field_value}
+          class={"input w-full rounded-l-none #{if @field_errors != [], do: "input-error", else: ""}"}
+          placeholder="your_handle"
+          required
+        />
+      </div>
+      <p :for={error <- @field_errors} class="mt-1 text-xs text-error">
+        {translate_error(error)}
+      </p>
+    </div>
+    """
+  end
+
+  def translate_error({msg, opts}) do
+    if count = opts[:count] do
+      Gettext.dngettext(MixerWeb.Gettext, "errors", msg, msg, count, opts)
+    else
+      Gettext.dgettext(MixerWeb.Gettext, "errors", msg, opts)
+    end
+  end
+end

lib/mixer_web/components/layouts/root.html.heex

@@ -4,8 +4,23 @@
     <meta charset="utf-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1" />
     <meta name="csrf-token" content={get_csrf_token()} />
-    <.live_title default="Mixer" suffix=" · Phoenix Framework">
+    <link rel="icon" href={~p"/favicon.ico"} sizes="any" />
-      {assigns[:page_title]}
+    <% meta_title = assigns[:page_title] || "Mixer"
+
+    meta_description =
+      assigns[:page_description] ||
+        "Mixer is a social feed for all. Come join the conversation — built with Elixir." %>
+    <meta name="description" content={meta_description} />
+    <meta name="robots" content={assigns[:robots] || "index, follow"} />
+    <meta property="og:site_name" content="Mixer" />
+    <meta property="og:title" content={meta_title} />
+    <meta property="og:description" content={meta_description} />
+    <meta property="og:type" content="website" />
+    <meta name="twitter:card" content="summary" />
+    <meta name="twitter:title" content={meta_title} />
+    <meta name="twitter:description" content={meta_description} />
+    <.live_title suffix=" · Mixer">
+      {assigns[:page_title] || "Mixer"}
     </.live_title>
     <link phx-track-static rel="stylesheet" href={~p"/assets/css/app.css"} />
     <script defer phx-track-static type="module" src={~p"/assets/app.js"}>

lib/mixer_web/components/layouts/spa_root.html.heex

@@ -8,7 +8,37 @@ SPDX-License-Identifier: MIT
     <meta charset="utf-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1" />
     <meta name="csrf-token" content={get_csrf_token()} />
-    <.live_title default="AshTypescript">Page</.live_title>
+    <link rel="icon" href={~p"/favicon.ico"} sizes="any" />
+    <% {spa_title, spa_description} =
+      case @page do
+        "feed" -> {"Mixer · Feed", "See the latest posts from everyone on Mixer."}
+        "tweet" -> {"Mixer · Post", "Read this post and join the conversation on Mixer."}
+        "following" -> {"Mixer · Following", "Posts from the people you follow on Mixer."}
+        "profile" -> {"Mixer · My Profile", "View and manage your Mixer profile."}
+        "users" -> {"Mixer · People", "Discover and follow people on Mixer."}
+        "user-detail" -> {"Mixer · Profile", "View this user's profile and posts on Mixer."}
+        _ -> {"Mixer", "A social feed built in Elixir."}
+      end %>
+    <meta name="description" content={spa_description} />
+    <meta name="robots" content="index, follow" />
+    <meta property="og:site_name" content="Mixer" />
+    <meta property="og:title" content={spa_title} />
+    <meta property="og:description" content={spa_description} />
+    <meta property="og:type" content="website" />
+    <meta name="twitter:card" content="summary" />
+    <meta name="twitter:title" content={spa_title} />
+    <meta name="twitter:description" content={spa_description} />
+    <.live_title default="Mixer">
+      {case @page do
+        "feed" -> "Mixer · Feed"
+        "tweet" -> "Mixer · Post"
+        "following" -> "Mixer · Following"
+        "profile" -> "Mixer · My Profile"
+        "users" -> "Mixer · People"
+        "user-detail" -> "Mixer · Profile"
+        _ -> "Mixer"
+      end}
+    </.live_title>
     <link phx-track-static rel="stylesheet" href={~p"/assets/css/app.css"} />
   </head>
   <body>

lib/mixer_web/controllers/auth_controller.ex

@@ -35,8 +35,11 @@ defmodule MixerWeb.AuthController do
           You can confirm your account using the link we sent to you, or by resetting your password.
           """
 
+        {_, %AshAuthentication.Errors.UnconfirmedUser{}} ->
+          "You must confirm your email address before signing in. Please check your inbox for a confirmation email."
+
         _ ->
-          "Incorrect email or password"
+          "Incorrect email or password or unconfirmed email"
       end
 
     conn

lib/mixer_web/controllers/page_controller.ex

@@ -2,7 +2,13 @@ defmodule MixerWeb.PageController do
   use MixerWeb, :controller
 
   def home(conn, _params) do
-    render(conn, :home)
+    if conn.assigns[:current_user] do
+      redirect(conn, to: ~p"/feed")
+    else
+      conn
+      |> assign(:page_title, "Mixer")
+      |> render(:home)
+    end
   end
 
   def index(conn, _params) do
@@ -10,9 +16,19 @@ defmodule MixerWeb.PageController do
   end
 
   def show(conn, %{"tweet_id" => tweet_id}) do
+    user_id = conn.assigns[:current_user] && conn.assigns[:current_user].id
+    Mixer.Metrics.track_view(tweet_id, user_id: user_id, ip_address: conn.remote_ip)
     render_spa(conn, %{page: "tweet", tweet_id: tweet_id, user_id: nil})
   end
 
+  def following(conn, _params) do
+    render_spa(conn, %{page: "following", tweet_id: nil, user_id: nil})
+  end
+
+  def profile(conn, _params) do
+    render_spa(conn, %{page: "profile", tweet_id: nil, user_id: nil})
+  end
+
   def users_index(conn, _params) do
     render_spa(conn, %{page: "users", tweet_id: nil, user_id: nil})
   end
@@ -28,11 +44,11 @@ defmodule MixerWeb.PageController do
     conn
     |> put_root_layout(html: {MixerWeb.Layouts, :spa_root})
     |> render(:index,
-        current_user: conn.assigns[:current_user],
+      current_user: conn.assigns[:current_user],
-        media_host: "#{asset_host}/#{bucket}",
+      media_host: "#{asset_host}/#{bucket}",
-        page: page,
+      page: page,
-        tweet_id: tweet_id,
+      tweet_id: tweet_id,
-        user_id: user_id
+      user_id: user_id
-      )
+    )
   end
 end

lib/mixer_web/controllers/page_html/home.html.heex

@@ -5,7 +5,7 @@
     <p class="text-base-content/60 text-lg mb-10">A social feed built with Ash &amp; Phoenix.</p>
     <div class="flex flex-col sm:flex-row gap-3 justify-center">
       <a href="/register" class="btn btn-primary btn-lg rounded-full px-8">Create account</a>
-      <a href="/auth/sign-in" class="btn btn-ghost btn-lg rounded-full px-8">Sign in</a>
+      <a href="/sign-in" class="btn btn-ghost btn-lg rounded-full px-8">Sign in</a>
     </div>
     <p class="mt-8 text-sm text-base-content/40">
       Already have an account?

lib/mixer_web/controllers/page_html/index.html.heex

@@ -1,8 +1,15 @@
-<div id="app"
+<div
-    data-current-user-id={if @current_user, do: @current_user.id, else: ""}
+  id="app"
-    data-current-user-email={if @current_user, do: @current_user.email, else: ""}
+  data-current-user-id={if @current_user, do: @current_user.id, else: ""}
-    data-asset-host={@media_host}
+  data-current-user-email={if @current_user, do: @current_user.email, else: ""}
-    data-page={@page}
+  data-current-user-username={if @current_user, do: @current_user.username || "", else: ""}
-    data-tweet-id={@tweet_id || ""}
+  data-current-user-display-name={
-    data-user-id={@user_id || ""}>
+    if @current_user, do: @current_user.display_name || "", else: ""
+  }
+  data-current-user-avatar-url={if @current_user, do: @current_user.avatar_url || "", else: ""}
+  data-asset-host={@media_host}
+  data-page={@page}
+  data-tweet-id={@tweet_id || ""}
+  data-user-id={@user_id || ""}
+>
 </div>

lib/mixer_web/controllers/upload_controller.ex

@@ -2,6 +2,7 @@ defmodule MixerWeb.UploadController do
   use MixerWeb, :controller
 
   alias Mixer.Posts.MediaUploader
+  alias Mixer.Accounts.AvatarUploader
 
   def create(conn, %{"file" => %Plug.Upload{} = upload}) do
     actor = conn.assigns[:current_user]
@@ -46,4 +47,50 @@ defmodule MixerWeb.UploadController do
     |> put_status(:bad_request)
     |> json(%{error: "no file provided"})
   end
+
+  # ── Avatar upload ──────────────────────────────────────────────────────────
+
+  def upload_avatar(conn, %{"file" => %Plug.Upload{} = upload}) do
+    actor = conn.assigns[:current_user]
+
+    unless actor do
+      conn
+      |> put_status(:unauthorized)
+      |> json(%{error: "authentication required"})
+    else
+      scope = %{user_id: actor.id}
+
+      case AvatarUploader.store({upload, scope}) do
+        {:ok, _file_name} ->
+          # The thumb is always stored as avatars/:user_id/thumb.webp.
+          # Append a timestamp so the browser doesn't serve a stale cached image
+          # when the user updates their avatar (the URL changes, S3 ignores the param).
+          thumb_key = "avatars/#{actor.id}/thumb.webp?v=#{System.system_time(:millisecond)}"
+
+          actor
+          |> Ash.Changeset.for_update(:update_avatar, %{avatar_url: thumb_key}, actor: actor)
+          |> Ash.update()
+          |> case do
+            {:ok, _user} ->
+              json(conn, %{success: true, avatarUrl: thumb_key})
+
+            {:error, error} ->
+              conn
+              |> put_status(:unprocessable_entity)
+              |> json(%{success: false, error: inspect(error)})
+          end
+
+        {:error, reason} ->
+          conn
+          |> put_status(:unprocessable_entity)
+          |> json(%{success: false, error: reason})
+      end
+    end
+  end
+
+  def upload_avatar(conn, _params) do
+    conn
+    |> put_status(:bad_request)
+    |> json(%{error: "no file provided"})
+  end
 end

lib/mixer_web/live/magic_sign_in_live.ex

@@ -0,0 +1,188 @@
+defmodule MixerWeb.MagicSignInLive do
+  @moduledoc """
+  Custom magic-link sign-in LiveView that collects a username for new users.
+
+  When a user clicks their magic link, this page is shown instead of the
+  default auto-submit. If the user is brand new (no account) or has no
+  username set yet, we ask them to choose one before completing sign-in.
+  """
+
+  use AshAuthentication.Phoenix.Overrides.Overridable,
+    root_class: "CSS class for the root `div` element.",
+    magic_sign_in_id: "Element ID for the `MagicSignIn` LiveComponent."
+
+  use AshAuthentication.Phoenix.Web, :live_view
+
+  alias AshAuthentication.Info
+  alias AshPhoenix.Form
+  alias Phoenix.LiveView.{Rendered, Socket}
+
+  import AshAuthentication.Phoenix.Components.Helpers, only: [auth_path: 5]
+  import PhoenixHTMLHelpers.Form, only: [hidden_input: 3, submit: 2]
+  import Slug
+
+  @doc false
+  @impl true
+  def mount(params, session, socket) do
+    overrides =
+      session
+      |> Map.get("overrides", [AshAuthentication.Phoenix.Overrides.Default])
+
+    resource = session["resource"]
+    strategy_name = session["strategy"]
+    token = params["token"] || params["magic_link"]
+
+    strategy = Info.strategy!(resource, strategy_name)
+    subject_name = Info.authentication_subject_name!(resource)
+    domain = Info.authentication_domain!(resource)
+
+    # Determine whether this user needs to pick a username
+    needs_username? = needs_username?(token, resource, domain)
+
+    form =
+      resource
+      |> Form.for_action(strategy.sign_in_action_name,
+        params: %{"token" => token},
+        domain: domain,
+        as: subject_name |> to_string(),
+        id: "#{subject_name}-#{strategy_name}-sign-in-form" |> slugify(),
+        context: %{strategy: strategy, private: %{ash_authentication?: true}}
+      )
+
+    socket =
+      socket
+      |> assign(overrides: overrides)
+      |> assign(:token, token)
+      |> assign(:strategy, strategy)
+      |> assign(:subject_name, subject_name)
+      |> assign(:resource, resource)
+      |> assign(:needs_username?, needs_username?)
+      |> assign(:form, form)
+      |> assign(:trigger_action, false)
+      |> assign(:current_tenant, session["tenant"])
+      |> assign(:auth_routes_prefix, session["auth_routes_prefix"])
+
+    {:ok, socket}
+  end
+
+  @doc false
+  @impl true
+  @spec handle_params(map, String.t(), Socket.t()) :: {:noreply, Socket.t()}
+  def handle_params(_params, _uri, socket), do: {:noreply, socket}
+
+  @doc false
+  @impl true
+  @spec render(Socket.assigns()) :: Rendered.t()
+  def render(assigns) do
+    ~H"""
+    <div class="min-h-screen flex flex-col items-center justify-center bg-base-100 p-4">
+      <div class="w-full max-w-sm mb-8 text-center">
+        <.live_component
+          module={AshAuthentication.Phoenix.Components.Banner}
+          id="magic-sign-in-banner"
+          overrides={@overrides}
+        />
+      </div>
+
+      <div class="w-full max-w-sm p-6 bg-base-100 border border-base-200 rounded-xl shadow-sm">
+        <.form :let={form} for={@form} phx-change="validate" phx-submit="submit" phx-trigger-action={@trigger_action}
+          action={auth_path(@socket, @subject_name, @auth_routes_prefix, @strategy, :sign_in)}
+          method="POST">
+
+          {hidden_input(form, :token, [])}
+
+          <%!-- Using the unified component --%>
+          <MixerWeb.AuthComponents.username_field :if={@needs_username?} form={form} />
+
+          {submit("Sign in", class: "btn btn-primary w-full", phx_disable_with: "Signing in...")}
+        </.form>
+      </div>
+    </div>
+    """
+  end
+
+  @doc false
+  @impl true
+  @spec handle_event(String.t(), map(), Socket.t()) :: {:noreply, Socket.t()}
+  def handle_event("submit", params, socket) do
+    subject_name =
+      socket.assigns.subject_name
+      |> to_string()
+      |> slugify()
+
+    form_params = Map.get(params, subject_name, %{})
+
+    # Use Form.validate with :all_errors to surface uniqueness constraints
+    form =
+      socket.assigns.form
+      |> Form.validate(form_params, errors: true)
+
+    if form.valid? do
+      # Only trigger the POST redirect if the data is truly valid
+      {:noreply, assign(socket, form: form, trigger_action: true)}
+    else
+      socket =
+        socket
+        |> assign(form: form, trigger_action: false)
+      {:noreply, socket}
+    end
+  end
+
+  @impl true
+  def handle_event("validate", params, socket) do
+    subject_name = socket.assigns.subject_name |> to_string() |> slugify()
+    form_params = Map.get(params, subject_name, %{})
+
+    form = Form.validate(socket.assigns.form, form_params, errors: true)
+    {:noreply, assign(socket, form: form)}
+  end
+
+  # ── Helpers ──────────────────────────────────────────────────────────────────
+
+  # Returns true if the user is new or has no username set yet.
+  defp needs_username?(nil, _resource, _domain), do: true
+
+  defp needs_username?(token, resource, domain) do
+    with {:ok, claims} <- AshAuthentication.Jwt.peek(token),
+         # 1. Try to find an existing user from the claims
+         user <- find_user(claims, resource, domain),
+         # 2. If a user exists, check if they already have a username
+         false <- is_nil(user) do
+      is_nil(user.username) or user.username == ""
+    else
+      _ ->
+        # Unknown / new user — ask for username to be safe
+        true
+    end
+  end
+
+  defp find_user(claims, resource, domain) do
+    # Try 'sub' first if it looks like a user subject (e.g. "User:123")
+    sub = Map.get(claims, "sub")
+
+    user =
+      if is_binary(sub) and String.contains?(sub, ":") do
+        case AshAuthentication.subject_to_user(sub, resource) do
+          {:ok, user} -> user
+          _ -> nil
+        end
+      end
+
+    # If not found via subject, try 'identity' (common in magic link tokens)
+    user ||
+      case Map.get(claims, "identity") || Map.get(claims, "email") do
+        email when is_binary(email) ->
+          # Use for_read with the explicit action and arguments
+          resource
+          |> Ash.Query.for_read(:get_by_email, %{email: email})
+          |> Ash.read_one(domain: domain, authorize?: false)
+          |> case do
+            {:ok, user} -> user
+            _ -> nil
+          end
+
+        _ ->
+          nil
+      end
+  end
+end

lib/mixer_web/router.ex

@@ -40,11 +40,14 @@ defmodule MixerWeb.Router do
     get "/", PageController, :home
     get "/feed", PageController, :index
     get "/feed/:tweet_id", PageController, :show
+    get "/following", PageController, :following
+    get "/profile", PageController, :profile
     get "/users", PageController, :users_index
     get "/users/:user_id", PageController, :user_show
     post "/rpc/run", AshTypescriptRpcController, :run
     post "/rpc/validate", AshTypescriptRpcController, :validate
     post "/upload", UploadController, :create
+    post "/upload/avatar", UploadController, :upload_avatar
     auth_routes AuthController, Mixer.Accounts.User, path: "/auth"
     sign_out_route AuthController
 
@@ -72,6 +75,7 @@ defmodule MixerWeb.Router do
 
     # Remove this if you do not use the magic link strategy.
     magic_sign_in_route(Mixer.Accounts.User, :magic_link,
+      live_view: MixerWeb.MagicSignInLive,
       auth_routes_prefix: "/auth",
       overrides: [MixerWeb.AuthOverrides, Elixir.AshAuthentication.Phoenix.Overrides.DaisyUI]
     )

mix.exs

@@ -91,7 +91,8 @@ defmodule Mixer.MixProject do
       {:ex_aws, "~> 2.1.2"},
       {:ex_aws_s3, "~> 2.0"},
       {:hackney, "~> 1.9"},
-      {:sweet_xml, "~> 0.6"}
+      {:sweet_xml, "~> 0.6"},
+      {:ecto_ch, "~> 0.3"}
     ]
   end
 
@@ -133,18 +134,21 @@ defmodule Mixer.MixProject do
         build: [
           "ash-framework": [
             # The description tells people how to use this skill.
-            description: "Use this skill working with Ash Framework or any of its extensions. Always consult this when making any domain changes, features or fixes.",
+            description:
+              "Use this skill working with Ash Framework or any of its extensions. Always consult this when making any domain changes, features or fixes.",
             # Include all Ash dependencies
             usage_rules: [:ash, ~r/^ash_/]
           ],
           "phoenix-framework": [
-            description: "Use this skill working with Phoenix Framework. Consult this when working with the web layer, controllers, views, liveviews etc.",
+            description:
+              "Use this skill working with Phoenix Framework. Consult this when working with the web layer, controllers, views, liveviews etc.",
             # Include all Phoenix dependencies
             usage_rules: [:phoenix, ~r/^phoenix_/]
           ]
         ]
       ]
     ]
+
     [
       file: "AGENTS.md",
       usage_rules: ["usage_rules:all"],
@@ -152,11 +156,13 @@ defmodule Mixer.MixProject do
         location: ".agents/skills",
         build: [
           "ash-framework": [
-            description: "Use this skill working with Ash Framework or any of its extensions. Always consult this when making any domain changes, features or fixes.",
+            description:
+              "Use this skill working with Ash Framework or any of its extensions. Always consult this when making any domain changes, features or fixes.",
             usage_rules: [:ash, ~r/^ash_/]
           ],
           "phoenix-framework": [
-            description: "Use this skill working with Phoenix Framework. Consult this when working with the web layer, controllers, views, liveviews etc.",
+            description:
+              "Use this skill working with Phoenix Framework. Consult this when working with the web layer, controllers, views, liveviews etc.",
             usage_rules: [:phoenix, ~r/^phoenix_/]
           ]
         ]

mix.lock

@@ -20,6 +20,7 @@
   "castore": {:hex, :castore, "1.0.18", "5e43ef0ec7d31195dfa5a65a86e6131db999d074179d2ba5a8de11fe14570f55", [:mix], [], "hexpm", "f393e4fe6317829b158fb74d86eb681f737d2fe326aa61ccf6293c4104957e34"},
   "cc_precompiler": {:hex, :cc_precompiler, "0.1.11", "8c844d0b9fb98a3edea067f94f616b3f6b29b959b6b3bf25fee94ffe34364768", [:mix], [{:elixir_make, "~> 0.7", [hex: :elixir_make, repo: "hexpm", optional: false]}], "hexpm", "3427232caf0835f94680e5bcf082408a70b48ad68a5f5c0b02a3bea9f3a075b9"},
   "certifi": {:hex, :certifi, "2.15.0", "0e6e882fcdaaa0a5a9f2b3db55b1394dba07e8d6d9bcad08318fb604c6839712", [:rebar3], [], "hexpm", "b147ed22ce71d72eafdad94f055165c1c182f61a2ff49df28bcc71d1d5b94a60"},
+  "ch": {:hex, :ch, "0.7.1", "116c08094b30d095c3bd6a8fe4ebe19fdaaf3dce84e2413cfdd6af157baf6303", [:mix], [{:db_connection, "~> 2.9.0", [hex: :db_connection, repo: "hexpm", optional: false]}, {:decimal, "~> 2.0", [hex: :decimal, repo: "hexpm", optional: false]}, {:ecto, "~> 3.13.0", [hex: :ecto, repo: "hexpm", optional: true]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}, {:mint, "~> 1.0", [hex: :mint, repo: "hexpm", optional: false]}], "hexpm", "3c1c900291ff9c4c077cd1dc0c265051a3f1d26320d58b37ed9e91b33d41a868"},
   "cinder": {:hex, :cinder, "0.12.1", "02ae4988e025fb32c37e4e7f2e491586b952918c0dd99d856da13271cd680e16", [:mix], [{:ash, "~> 3.0", [hex: :ash, repo: "hexpm", optional: false]}, {:ash_phoenix, "~> 2.3", [hex: :ash_phoenix, repo: "hexpm", optional: false]}, {:gettext, "~> 1.0.0", [hex: :gettext, repo: "hexpm", optional: false]}, {:phoenix_live_view, "~> 1.0", [hex: :phoenix_live_view, repo: "hexpm", optional: false]}, {:spark, "~> 2.0", [hex: :spark, repo: "hexpm", optional: false]}], "hexpm", "a48b5677c1f57619d9d7564fb2bd7928f93750a2e8c0b1b145852a30ecf2aa20"},
   "comeonin": {:hex, :comeonin, "5.5.1", "5113e5f3800799787de08a6e0db307133850e635d34e9fab23c70b6501669510", [:mix], [], "hexpm", "65aac8f19938145377cee73973f192c5645873dcf550a8a6b18187d17c13ccdb"},
   "conv_case": {:hex, :conv_case, "0.2.3", "c1455c27d3c1ffcdd5f17f1e91f40b8a0bc0a337805a6e8302f441af17118ed8", [:mix], [], "hexpm", "88f29a3d97d1742f9865f7e394ed3da011abb7c5e8cc104e676fdef6270d4b4a"},
@@ -29,6 +30,7 @@
   "dns_cluster": {:hex, :dns_cluster, "0.2.0", "aa8eb46e3bd0326bd67b84790c561733b25c5ba2fe3c7e36f28e88f384ebcb33", [:mix], [], "hexpm", "ba6f1893411c69c01b9e8e8f772062535a4cf70f3f35bcc964a324078d8c8240"},
   "dotenvy": {:hex, :dotenvy, "1.1.1", "00e318f3c51de9fafc4b48598447e386f19204dc18ca69886905bb8f8b08b667", [:mix], [], "hexpm", "c8269471b5701e9e56dc86509c1199ded2b33dce088c3471afcfef7839766d8e"},
   "ecto": {:hex, :ecto, "3.13.5", "9d4a69700183f33bf97208294768e561f5c7f1ecf417e0fa1006e4a91713a834", [:mix], [{:decimal, "~> 2.0", [hex: :decimal, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}, {:telemetry, "~> 0.4 or ~> 1.0", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "df9efebf70cf94142739ba357499661ef5dbb559ef902b68ea1f3c1fabce36de"},
+  "ecto_ch": {:hex, :ecto_ch, "0.8.6", "f31b507e86690c003f46e75d6e742e6b5d8ce34b6b10a86604b1c3aa785e0b56", [:mix], [{:ch, "~> 0.5.0 or ~> 0.6.0 or ~> 0.7.0", [hex: :ch, repo: "hexpm", optional: false]}, {:ecto_sql, "~> 3.13.0", [hex: :ecto_sql, repo: "hexpm", optional: false]}], "hexpm", "6ca9f1cf9680452b1925c6a3a7b5e3d8b12e38ee134b03c6a45a8b26434fad97"},
   "ecto_sql": {:hex, :ecto_sql, "3.13.5", "2f8282b2ad97bf0f0d3217ea0a6fff320ead9e2f8770f810141189d182dc304e", [:mix], [{:db_connection, "~> 2.4.1 or ~> 2.5", [hex: :db_connection, repo: "hexpm", optional: false]}, {:ecto, "~> 3.13.0", [hex: :ecto, repo: "hexpm", optional: false]}, {:myxql, "~> 0.7", [hex: :myxql, repo: "hexpm", optional: true]}, {:postgrex, "~> 0.19 or ~> 1.0", [hex: :postgrex, repo: "hexpm", optional: true]}, {:tds, "~> 2.1.1 or ~> 2.2", [hex: :tds, repo: "hexpm", optional: true]}, {:telemetry, "~> 0.4.0 or ~> 1.0", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "aa36751f4e6a2b56ae79efb0e088042e010ff4935fc8684e74c23b1f49e25fdc"},
   "elixir_make": {:hex, :elixir_make, "0.9.0", "6484b3cd8c0cee58f09f05ecaf1a140a8c97670671a6a0e7ab4dc326c3109726", [:mix], [], "hexpm", "db23d4fd8b757462ad02f8aa73431a426fe6671c80b200d9710caf3d1dd0ffdb"},
   "esbuild": {:hex, :esbuild, "0.10.0", "b0aa3388a1c23e727c5a3e7427c932d89ee791746b0081bbe56103e9ef3d291f", [:mix], [{:jason, "~> 1.4", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "468489cda427b974a7cc9f03ace55368a83e1a7be12fba7e30969af78e5f8c70"},

priv/clickhouse/migrations/.formatter.exs

@@ -0,0 +1,4 @@
+[
+  import_deps: [:ecto_ch],
+  inputs: ["*.exs"]
+]

priv/clickhouse/migrations/20260407000001_create_post_events.exs

@@ -0,0 +1,49 @@
+defmodule Mixer.ClickhouseRepo.Migrations.CreatePostEvents do
+  use Ecto.Migration
+
+  @doc """
+  Creates the `post_events` table using a MergeTree engine.
+
+  Key design decisions:
+
+  * `LowCardinality(String)` for `event_type` — the cardinality is tiny
+    (5–10 values), so ClickHouse can store it as a dictionary, giving both
+    compression and faster filtering.
+
+  * `Nullable(UUID)` / `Nullable(String)` for optional columns — ClickHouse
+    handles NULLs differently from PostgreSQL; we make the nullable fields
+    explicit so the schema is unambiguous.
+
+  * `ORDER BY (occurred_at, event_type, tweet_id)` — optimises the two most
+    common query patterns:
+      1. Time-range scans (`WHERE occurred_at >= now() - interval 24 HOUR`)
+      2. Per-tweet aggregations (`WHERE tweet_id = ?`)
+
+  * `PARTITION BY toYYYYMM(occurred_at)` — monthly partitions make it cheap
+    to drop old data with `ALTER TABLE … DROP PARTITION`.
+
+  * `TTL occurred_at + INTERVAL 1 YEAR DELETE` — automatically reclaim disk
+    space after two years. Adjust as required.
+  """
+  def up do
+    execute("""
+    CREATE TABLE IF NOT EXISTS post_events
+    (
+        event_type  LowCardinality(String),
+        tweet_id    UUID,
+        user_id     Nullable(UUID),
+        occurred_at DateTime,
+        ip_address  Nullable(String)
+    )
+    ENGINE = MergeTree()
+    PARTITION BY toYYYYMM(occurred_at)
+    ORDER BY (occurred_at, event_type, tweet_id)
+    TTL occurred_at + INTERVAL 1 YEAR DELETE
+    SETTINGS index_granularity = 8192
+    """)
+  end
+
+  def down do
+    execute("DROP TABLE IF EXISTS post_events")
+  end
+end

priv/clickhouse/seeds.exs

@@ -0,0 +1,11 @@
+# Script for populating the database. You can run it as:
+#
+#     mix run priv/clickhouse/seeds.exs
+#
+# Inside the script, you can read and write to any of your
+# repositories directly:
+#
+#     Mixer.ClickhouseRepo.insert!(%Mixer.SomeSchema{})
+#
+# We recommend using the bang functions (`insert!`, `update!`
+# and so on) as they will fail if something goes wrong.

priv/repo/migrations/20260330053523_setup_posts_and_tweets.exs

@@ -18,7 +18,8 @@ defmodule Mixer.Repo.Migrations.SetupPostsAndTweets do
             name: "tweets_user_id_fkey",
             type: :uuid,
             prefix: "public"
-          ), null: false
+          ),
+          null: false
 
       add :state, :text, null: false, default: "drafted"
     end

priv/repo/migrations/20260330173403_add_posts_media_s3.exs

@@ -22,7 +22,8 @@ defmodule Mixer.Repo.Migrations.AddPostsMediaS3 do
             name: "media_tweet_id_fkey",
             type: :uuid,
             prefix: "public"
-          ), null: false
+          ),
+          null: false
     end
   end
 

priv/repo/migrations/20260330174801_add_user_id_to_media_and_allow_null_tweet_id.exs

@@ -17,7 +17,8 @@ defmodule Mixer.Repo.Migrations.AddUserIdToMediaAndAllowNullTweetId do
             name: "media_user_id_fkey",
             type: :uuid,
             prefix: "public"
-          ), null: false
+          ),
+          null: false
     end
   end
 

priv/repo/migrations/20260331182608_add_tweet_likes.exs

@@ -17,7 +17,8 @@ defmodule Mixer.Repo.Migrations.AddTweetLikes do
             name: "tweet_likes_tweet_id_fkey",
             type: :uuid,
             prefix: "public"
-          ), null: false
+          ),
+          null: false
 
       add :user_id,
           references(:users,
@@ -25,7 +26,8 @@ defmodule Mixer.Repo.Migrations.AddTweetLikes do
             name: "tweet_likes_user_id_fkey",
             type: :uuid,
             prefix: "public"
-          ), null: false
+          ),
+          null: false
     end
 
     create unique_index(:tweet_likes, [:tweet_id, :user_id],

priv/repo/migrations/20260406180126_add_tweet_comments.exs

@@ -0,0 +1,30 @@
+defmodule Mixer.Repo.Migrations.AddTweetComments do
+  @moduledoc """
+  Updates resources based on their most recent snapshots.
+
+  This file was autogenerated with `mix ash_postgres.generate_migrations`
+  """
+
+  use Ecto.Migration
+
+  def up do
+    alter table(:tweets) do
+      add :parent_tweet_id,
+          references(:tweets,
+            column: :id,
+            name: "tweets_parent_tweet_id_fkey",
+            type: :uuid,
+            prefix: "public",
+            on_delete: :delete_all
+          )
+    end
+  end
+
+  def down do
+    drop constraint(:tweets, "tweets_parent_tweet_id_fkey")
+
+    alter table(:tweets) do
+      remove :parent_tweet_id
+    end
+  end
+end

priv/repo/migrations/20260408035350_add_user_profile_fields.exs

@@ -0,0 +1,29 @@
+defmodule Mixer.Repo.Migrations.AddUserProfileFields do
+  @moduledoc """
+  Updates resources based on their most recent snapshots.
+
+  This file was autogenerated with `mix ash_postgres.generate_migrations`
+  """
+
+  use Ecto.Migration
+
+  def up do
+    alter table(:users) do
+      add :username, :text
+      add :display_name, :text
+      add :avatar_url, :text
+    end
+
+    create unique_index(:users, [:username], name: "users_unique_username_index")
+  end
+
+  def down do
+    drop_if_exists unique_index(:users, [:username], name: "users_unique_username_index")
+
+    alter table(:users) do
+      remove :avatar_url
+      remove :display_name
+      remove :username
+    end
+  end
+end

priv/resource_snapshots/repo/tweets/20260406180127.json

@@ -0,0 +1,154 @@
+{
+  "attributes": [
+    {
+      "allow_nil?": false,
+      "default": "fragment(\"gen_random_uuid()\")",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": true,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "id",
+      "type": "uuid"
+    },
+    {
+      "allow_nil?": false,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "content",
+      "type": "text"
+    },
+    {
+      "allow_nil?": false,
+      "default": "0",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "likes",
+      "type": "bigint"
+    },
+    {
+      "allow_nil?": false,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": {
+        "deferrable": false,
+        "destination_attribute": "id",
+        "destination_attribute_default": null,
+        "destination_attribute_generated": null,
+        "index?": false,
+        "match_type": null,
+        "match_with": null,
+        "multitenancy": {
+          "attribute": null,
+          "global": null,
+          "strategy": null
+        },
+        "name": "tweets_user_id_fkey",
+        "on_delete": null,
+        "on_update": null,
+        "primary_key?": true,
+        "schema": "public",
+        "table": "users"
+      },
+      "scale": null,
+      "size": null,
+      "source": "user_id",
+      "type": "uuid"
+    },
+    {
+      "allow_nil?": false,
+      "default": "fragment(\"(now() AT TIME ZONE 'utc')\")",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "inserted_at",
+      "type": "utc_datetime_usec"
+    },
+    {
+      "allow_nil?": false,
+      "default": "fragment(\"(now() AT TIME ZONE 'utc')\")",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "updated_at",
+      "type": "utc_datetime_usec"
+    },
+    {
+      "allow_nil?": false,
+      "default": "\"drafted\"",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "state",
+      "type": "text"
+    },
+    {
+      "allow_nil?": true,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": {
+        "deferrable": false,
+        "destination_attribute": "id",
+        "destination_attribute_default": null,
+        "destination_attribute_generated": null,
+        "index?": false,
+        "match_type": null,
+        "match_with": null,
+        "multitenancy": {
+          "attribute": null,
+          "global": null,
+          "strategy": null
+        },
+        "name": "tweets_parent_tweet_id_fkey",
+        "on_delete": "delete",
+        "on_update": null,
+        "primary_key?": true,
+        "schema": "public",
+        "table": "tweets"
+      },
+      "scale": null,
+      "size": null,
+      "source": "parent_tweet_id",
+      "type": "uuid"
+    }
+  ],
+  "base_filter": null,
+  "check_constraints": [],
+  "create_table_options": null,
+  "custom_indexes": [],
+  "custom_statements": [],
+  "has_create_action": true,
+  "hash": "090E928120B2CFAA2B8D5D2EB43AD6E782ABB552AFC211BB6173D6337F487218",
+  "identities": [],
+  "multitenancy": {
+    "attribute": null,
+    "global": null,
+    "strategy": null
+  },
+  "repo": "Elixir.Mixer.Repo",
+  "schema": null,
+  "table": "tweets"
+}

priv/resource_snapshots/repo/users/20260408035351.json

@@ -0,0 +1,133 @@
+{
+  "attributes": [
+    {
+      "allow_nil?": false,
+      "default": "fragment(\"gen_random_uuid()\")",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": true,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "id",
+      "type": "uuid"
+    },
+    {
+      "allow_nil?": false,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "email",
+      "type": "citext"
+    },
+    {
+      "allow_nil?": true,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "hashed_password",
+      "type": "text"
+    },
+    {
+      "allow_nil?": true,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "confirmed_at",
+      "type": "utc_datetime_usec"
+    },
+    {
+      "allow_nil?": true,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "username",
+      "type": "text"
+    },
+    {
+      "allow_nil?": true,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "display_name",
+      "type": "text"
+    },
+    {
+      "allow_nil?": true,
+      "default": "nil",
+      "generated?": false,
+      "precision": null,
+      "primary_key?": false,
+      "references": null,
+      "scale": null,
+      "size": null,
+      "source": "avatar_url",
+      "type": "text"
+    }
+  ],
+  "base_filter": null,
+  "check_constraints": [],
+  "create_table_options": null,
+  "custom_indexes": [],
+  "custom_statements": [],
+  "has_create_action": true,
+  "hash": "E57BFA1141A2F4D237E6B3C8FE4BAD93772015179B56AEC9FA1F762C4FF5B6B8",
+  "identities": [
+    {
+      "all_tenants?": false,
+      "base_filter": null,
+      "index_name": "users_unique_email_index",
+      "keys": [
+        {
+          "type": "atom",
+          "value": "email"
+        }
+      ],
+      "name": "unique_email",
+      "nils_distinct?": true,
+      "where": null
+    },
+    {
+      "all_tenants?": false,
+      "base_filter": null,
+      "index_name": "users_unique_username_index",
+      "keys": [
+        {
+          "type": "atom",
+          "value": "username"
+        }
+      ],
+      "name": "unique_username",
+      "nils_distinct?": true,
+      "where": null
+    }
+  ],
+  "multitenancy": {
+    "attribute": null,
+    "global": null,
+    "strategy": null
+  },
+  "repo": "Elixir.Mixer.Repo",
+  "schema": null,
+  "table": "users"
+}

test/mixer/accounts/follow_test.exs

@@ -0,0 +1,172 @@
+defmodule Mixer.Accounts.FollowTest do
+  use Mixer.DataCase, async: true
+
+  require Ash.Query
+
+  alias Mixer.Accounts.Follow
+  alias Mixer.Accounts.User
+
+  describe "follow" do
+    test "a user can follow another user" do
+      alice = user_fixture("alice@example.com", "alice")
+      bob = user_fixture("bob@example.com", "bob")
+
+      assert {:ok, follow} =
+               Follow
+               |> Ash.Changeset.for_create(:follow, %{following_id: bob.id}, actor: alice)
+               |> Ash.create()
+
+      assert follow.follower_id == alice.id
+      assert follow.following_id == bob.id
+    end
+
+    test "following the same user twice is a noop (upsert)" do
+      alice = user_fixture("alice2@example.com", "alice2")
+      bob = user_fixture("bob2@example.com", "bob2")
+
+      assert {:ok, _} =
+               Follow
+               |> Ash.Changeset.for_create(:follow, %{following_id: bob.id}, actor: alice)
+               |> Ash.create()
+
+      assert {:ok, _} =
+               Follow
+               |> Ash.Changeset.for_create(:follow, %{following_id: bob.id}, actor: alice)
+               |> Ash.create()
+
+      assert count_follows(alice.id, bob.id) == 1
+    end
+
+    test "a user cannot follow themselves" do
+      alice = user_fixture("alice3@example.com", "alice3")
+
+      assert {:error, error} =
+               Follow
+               |> Ash.Changeset.for_create(:follow, %{following_id: alice.id}, actor: alice)
+               |> Ash.create()
+
+      assert Exception.message(error) =~ "cannot follow yourself"
+    end
+
+    test "guests cannot follow" do
+      bob = user_fixture("bob3@example.com", "bob3")
+
+      assert {:error, _error} =
+               Follow
+               |> Ash.Changeset.for_create(:follow, %{following_id: bob.id})
+               |> Ash.create()
+    end
+  end
+
+  describe "unfollow" do
+    test "a user can unfollow someone they follow" do
+      alice = user_fixture("alice4@example.com", "alice4")
+      bob = user_fixture("bob4@example.com", "bob4")
+
+      Follow
+      |> Ash.Changeset.for_create(:follow, %{following_id: bob.id}, actor: alice)
+      |> Ash.create!()
+
+      assert count_follows(alice.id, bob.id) == 1
+
+      assert :ok =
+               Follow
+               |> Ash.ActionInput.for_action(:unfollow, %{following_id: bob.id}, actor: alice)
+               |> Ash.run_action()
+
+      assert count_follows(alice.id, bob.id) == 0
+    end
+
+    test "unfollowing when not following is a noop" do
+      alice = user_fixture("alice5@example.com", "alice5")
+      bob = user_fixture("bob5@example.com", "bob5")
+
+      assert :ok =
+               Follow
+               |> Ash.ActionInput.for_action(:unfollow, %{following_id: bob.id}, actor: alice)
+               |> Ash.run_action()
+
+      assert count_follows(alice.id, bob.id) == 0
+    end
+
+    test "guests cannot unfollow" do
+      bob = user_fixture("bob6@example.com", "bob6")
+
+      assert {:error, error} =
+               Follow
+               |> Ash.ActionInput.for_action(:unfollow, %{following_id: bob.id})
+               |> Ash.run_action()
+
+      assert Exception.message(error) =~ "forbidden"
+    end
+  end
+
+  describe "follower/following counts" do
+    test "follower_count and following_count reflect current follows" do
+      alice = user_fixture("alice6@example.com", "alice6")
+      bob = user_fixture("bob7@example.com", "bob7")
+      carol = user_fixture("carol@example.com", "carol")
+
+      Follow
+      |> Ash.Changeset.for_create(:follow, %{following_id: bob.id}, actor: alice)
+      |> Ash.create!()
+
+      Follow
+      |> Ash.Changeset.for_create(:follow, %{following_id: carol.id}, actor: alice)
+      |> Ash.create!()
+
+      Follow
+      |> Ash.Changeset.for_create(:follow, %{following_id: bob.id}, actor: carol)
+      |> Ash.create!()
+
+      alice_loaded = User |> Ash.get!(alice.id, load: [:follower_count, :following_count], authorize?: false)
+      bob_loaded = User |> Ash.get!(bob.id, load: [:follower_count, :following_count], authorize?: false)
+
+      assert alice_loaded.following_count == 2
+      assert alice_loaded.follower_count == 0
+      assert bob_loaded.follower_count == 2
+      assert bob_loaded.following_count == 0
+    end
+
+    test "am_i_following reflects the actor's follow status" do
+      alice = user_fixture("alice7@example.com", "alice7")
+      bob = user_fixture("bob8@example.com", "bob8")
+
+      not_following =
+        User |> Ash.get!(bob.id, actor: alice, load: [:am_i_following], authorize?: false)
+
+      refute not_following.am_i_following
+
+      Follow
+      |> Ash.Changeset.for_create(:follow, %{following_id: bob.id}, actor: alice)
+      |> Ash.create!()
+
+      following =
+        User |> Ash.get!(bob.id, actor: alice, load: [:am_i_following], authorize?: false)
+
+      assert following.am_i_following
+    end
+  end
+
+  # ── fixtures ──────────────────────────────────────────────────────────────
+
+  defp user_fixture(email, username) do
+    User
+    |> Ash.Changeset.for_create(:register_with_password, %{
+      email: email,
+      password: "password1234",
+      password_confirmation: "password1234",
+      username: username
+    })
+    |> Ash.create!(authorize?: false)
+  end
+
+  defp count_follows(follower_id, following_id) do
+    Follow
+    |> Ash.Query.filter(
+      Ash.Expr.expr(follower_id == ^follower_id and following_id == ^following_id)
+    )
+    |> Ash.read!(authorize?: false)
+    |> length()
+  end
+end

test/mixer/posts/tweet_like_test.exs

@@ -2,6 +2,7 @@ defmodule Mixer.Posts.TweetLikeTest do
   use Mixer.DataCase, async: true
 
   import Ash.Expr
+  require Ash.Query
 
   alias Mixer.Accounts.User
   alias Mixer.Posts.Tweet
@@ -24,14 +25,14 @@ defmodule Mixer.Posts.TweetLikeTest do
         Tweet
         |> Ash.get!(tweet.id, actor: user, load: [:liked_by_me], authorize?: false)
 
-      refute Ash.ForbiddenField.forbidden?(tweet_for_actor.liked_by_me)
+      refute match?(%Ash.ForbiddenField{}, tweet_for_actor.liked_by_me)
       assert tweet_for_actor.liked_by_me
 
       tweet_without_actor =
         Tweet
         |> Ash.get!(tweet.id, load: [:liked_by_me], authorize?: false)
 
-      refute Ash.ForbiddenField.forbidden?(tweet_without_actor.liked_by_me)
+      refute match?(%Ash.ForbiddenField{}, tweet_without_actor.liked_by_me)
       refute tweet_without_actor.liked_by_me
     end
 
@@ -93,13 +94,17 @@ defmodule Mixer.Posts.TweetLikeTest do
   end
 
   defp user_fixture(email) do
+    username =
+      email |> String.split("@") |> List.first() |> String.replace(~r/[^a-zA-Z0-9_]/, "_")
+
     User
     |> Ash.Changeset.for_create(:register_with_password, %{
       email: email,
       password: "password1234",
-      password_confirmation: "password1234"
+      password_confirmation: "password1234",
+      username: username
     })
-    |> Ash.create!()
+    |> Ash.create!(authorize?: false)
   end
 
   defp tweet_fixture(user, content) do

test/mixer/posts/tweet_test.exs

@@ -0,0 +1,220 @@
+defmodule Mixer.Posts.TweetTest do
+  use Mixer.DataCase, async: true
+
+  require Ash.Query
+
+  alias Mixer.Accounts.User
+  alias Mixer.Posts.Tweet
+
+  describe "tweet creation" do
+    test "a user can create a tweet" do
+      user = user_fixture("poster@example.com", "poster")
+
+      assert {:ok, tweet} =
+               Tweet
+               |> Ash.Changeset.for_create(:create, %{content: "hello world"}, actor: user)
+               |> Ash.create()
+
+      assert tweet.content == "hello world"
+      assert tweet.user_id == user.id
+      assert tweet.state == :posted
+      assert tweet.likes == 0
+    end
+
+    test "tweet content cannot be blank" do
+      user = user_fixture("blank@example.com", "blankuser")
+
+      assert {:error, error} =
+               Tweet
+               |> Ash.Changeset.for_create(:create, %{content: nil}, actor: user)
+               |> Ash.create()
+
+      assert Exception.message(error) =~ "content"
+    end
+
+    test "guests cannot create tweets" do
+      assert {:error, _error} =
+               Tweet
+               |> Ash.Changeset.for_create(:create, %{content: "spam"})
+               |> Ash.create()
+    end
+
+    test "all users can read tweets" do
+      user = user_fixture("readable@example.com", "readable")
+
+      Tweet
+      |> Ash.Changeset.for_create(:create, %{content: "public post"}, actor: user)
+      |> Ash.create!()
+
+      tweets = Tweet |> Ash.read!(authorize?: false)
+      assert length(tweets) >= 1
+    end
+  end
+
+  describe "tweet update" do
+    test "owner can edit their tweet" do
+      user = user_fixture("editor@example.com", "editor")
+      tweet = tweet_fixture(user, "original content")
+
+      assert {:ok, updated} =
+               tweet
+               |> Ash.Changeset.for_update(:update, %{content: "edited content"}, actor: user)
+               |> Ash.update()
+
+      assert updated.content == "edited content"
+    end
+
+    test "non-owner cannot edit a tweet" do
+      owner = user_fixture("owner@example.com", "tweetowner")
+      other = user_fixture("other@example.com", "otheruser")
+      tweet = tweet_fixture(owner, "owner's post")
+
+      assert {:error, error} =
+               tweet
+               |> Ash.Changeset.for_update(:update, %{content: "hacked"}, actor: other)
+               |> Ash.update()
+
+      assert Exception.message(error) =~ "forbidden"
+    end
+  end
+
+  describe "tweet deletion" do
+    test "owner can delete their tweet" do
+      user = user_fixture("deleter@example.com", "deleter")
+      tweet = tweet_fixture(user, "to be deleted")
+
+      assert :ok =
+               tweet
+               |> Ash.Changeset.for_destroy(:destroy, %{}, actor: user)
+               |> Ash.destroy()
+
+      assert {:ok, nil} = Tweet |> Ash.get(tweet.id, authorize?: false, not_found_error?: false)
+    end
+
+    test "non-owner cannot delete a tweet" do
+      owner = user_fixture("owner2@example.com", "owner2")
+      other = user_fixture("other2@example.com", "other2")
+      tweet = tweet_fixture(owner, "protected post")
+
+      assert {:error, error} =
+               tweet
+               |> Ash.Changeset.for_destroy(:destroy, %{}, actor: other)
+               |> Ash.destroy()
+
+      assert Exception.message(error) =~ "forbidden"
+    end
+  end
+
+  describe "comments (replies)" do
+    test "a user can reply to a tweet" do
+      author = user_fixture("author@example.com", "author")
+      replier = user_fixture("replier@example.com", "replier")
+      parent = tweet_fixture(author, "parent post")
+
+      assert {:ok, comment} =
+               Tweet
+               |> Ash.Changeset.for_create(
+                 :create,
+                 %{content: "great post!", parent_tweet_id: parent.id},
+                 actor: replier
+               )
+               |> Ash.create()
+
+      assert comment.parent_tweet_id == parent.id
+      assert comment.user_id == replier.id
+    end
+
+    test "comment_count reflects number of replies" do
+      author = user_fixture("countauthor@example.com", "countauthor")
+      replier = user_fixture("countreplier@example.com", "countreplier")
+      parent = tweet_fixture(author, "tweet with replies")
+
+      Tweet
+      |> Ash.Changeset.for_create(:create, %{content: "reply 1", parent_tweet_id: parent.id}, actor: replier)
+      |> Ash.create!()
+
+      Tweet
+      |> Ash.Changeset.for_create(:create, %{content: "reply 2", parent_tweet_id: parent.id}, actor: replier)
+      |> Ash.create!()
+
+      loaded = Tweet |> Ash.get!(parent.id, load: [:comment_count], authorize?: false)
+      assert loaded.comment_count == 2
+    end
+
+    test "tweet owner can delete a comment on their tweet" do
+      author = user_fixture("tweetowner3@example.com", "tweetowner3")
+      replier = user_fixture("commenter@example.com", "commenter")
+      parent = tweet_fixture(author, "parent tweet")
+
+      comment =
+        Tweet
+        |> Ash.Changeset.for_create(
+          :create,
+          %{content: "a comment", parent_tweet_id: parent.id},
+          actor: replier
+        )
+        |> Ash.create!()
+
+      # Tweet owner (author) can delete someone else's comment on their post
+      assert :ok =
+               comment
+               |> Ash.Changeset.for_destroy(:destroy, %{}, actor: author)
+               |> Ash.destroy()
+    end
+
+    test "a third party cannot delete a comment they don't own" do
+      author = user_fixture("tweetowner4@example.com", "tweetowner4")
+      replier = user_fixture("commenter2@example.com", "commenter2")
+      bystander = user_fixture("bystander@example.com", "bystander")
+      parent = tweet_fixture(author, "parent tweet 2")
+
+      comment =
+        Tweet
+        |> Ash.Changeset.for_create(
+          :create,
+          %{content: "a comment", parent_tweet_id: parent.id},
+          actor: replier
+        )
+        |> Ash.create!()
+
+      assert {:error, error} =
+               comment
+               |> Ash.Changeset.for_destroy(:destroy, %{}, actor: bystander)
+               |> Ash.destroy()
+
+      assert Exception.message(error) =~ "forbidden"
+    end
+
+    test "guests cannot post comments" do
+      author = user_fixture("tweetowner5@example.com", "tweetowner5")
+      parent = tweet_fixture(author, "parent post 3")
+
+      assert {:error, _error} =
+               Tweet
+               |> Ash.Changeset.for_create(
+                 :create,
+                 %{content: "spam comment", parent_tweet_id: parent.id}
+               )
+               |> Ash.create()
+    end
+  end
+
+  # ── helpers ───────────────────────────────────────────────────────────────
+
+  defp user_fixture(email, username) do
+    User
+    |> Ash.Changeset.for_create(:register_with_password, %{
+      email: email,
+      password: "password1234",
+      password_confirmation: "password1234",
+      username: username
+    })
+    |> Ash.create!(authorize?: false)
+  end
+
+  defp tweet_fixture(user, content) do
+    Tweet
+    |> Ash.Changeset.for_create(:create, %{content: content}, actor: user)
+    |> Ash.create!()
+  end
+end

test/mixer_web/controllers/page_controller_test.exs

@@ -1,8 +1,32 @@
 defmodule MixerWeb.PageControllerTest do
   use MixerWeb.ConnCase
 
-  test "GET /", %{conn: conn} do
+  test "GET / redirects to /feed when logged in", %{conn: conn} do
+    user =
+      Mixer.Accounts.User
+      |> Ash.Changeset.for_create(
+        :register_with_password,
+        %{
+          email: "test@example.com",
+          password: "Password1!",
+          password_confirmation: "Password1!",
+          username: "testuser"
+        },
+        authorize?: false
+      )
+      |> Ash.create!()
+
+    conn =
+      conn
+      |> Plug.Test.init_test_session(%{})
+      |> AshAuthentication.Plug.Helpers.store_in_session(user)
+      |> get(~p"/")
+
+    assert redirected_to(conn) == ~p"/feed"
+  end
+
+  test "GET / renders the home page for unauthenticated users", %{conn: conn} do
     conn = get(conn, ~p"/")
-    assert html_response(conn, 200) =~ "Peace of mind from prototype to production"
+    assert html_response(conn, 200) =~ "Mixer"
   end
 end