v4: every page and API URL follows one of two rules, written down in API.md — pages are a hierarchy where @name is a user and any other root word a category or an app page, tabs and views are plain segments and a default view is the bare path; API resources are /api/<plural>/<key>, a user's key being an id or @name, the caller's things under /api/me, media a sub-resource, lookups by another key a query filter. ~ is gone: the feed is /, /hot, /new, /journal, /follow and /music/hot, a profile /@bob with its overview and the tabs dumps, upvoted, playlists (her own only), follow (users, and /follow/playlists), invitees and manage (role and name, for user:manage), which replace the separate UserDumps, UserUpvoted and UserPlaylists pages; /settings holds the account (now with the username) and /manage the category manager, both linked from the user menu and one's profile. Dumps and playlists live under their owner, /@bob/dumps/<slug> and /@bob/playlists/<slug>, named by slug alone: migration 0021 re-slugs them to the bare slugify(title), unique per owner and kind (the oldest keeps it, clashes get -2), renames the categories whose slug v4 reserves (hot, follow, settings…), and rewrites this site's v3 links in dump notes, comments, chat, and playlist and profile descriptions. A slug changes only when edited, through the edit forms' new link field, which proposes slugify(title) as the title changes; a username changes from /settings or, for user:manage, from /@name/manage. Every slug or name left behind stays an alias of its item or user for good (dump_slug_aliases, playlist_slug_aliases, user_aliases), so old links redirect without chaining and nobody else can take one; slugs change 3 times a day per item, names once in 30 days, moderators exempt. An alias, or a name in another case, answers the item with its current path: the pages put it in their URL (useCanonicalPath, without fetching again), and the OG middleware answers a 301. shared/paths.ts builds and parses every page path, for the client's links, the emails' (digest-service lost its own builders and its id fallbacks, and links /follow and /settings) and the server's matchers (OG tags, self previews, backlinks, self-url); shared/slug.ts holds slugify and the format categories share. Dumps and playlists carry ownerUsername and a required slug, and notifications join their users' current names and their items' paths each time they are sent or read, so renames reach them and a deleted item's has no link. The API was renamed per the plan's table: POST /api/users and /api/sessions, /api/password-resets, /api/me (with settings, password, avatar, media-token, playlists?contains=, follow, feed?from=, notifications), /api/users/:key/{dumps,upvoted,playlists,follow/users,follow/playlists,invitees,avatar} and by path /api/users/:key/{dumps,playlists}/:slug, /api/dumps?url= and ?category=, /api/dumps/:id/{file,thumbnail,metadata}, /api/playlists/:id/cover, /api/remote/{preview,image,bandcamp,youtube} (one router), and /api/unsubscribe, the v3 POST /api/users/unsubscribe staying for the digests already sent. A stored default feed tab "followed" reads as "follow" once. dumps.slug and playlists.slug stay nullable, since SQLite can't add NOT NULL without rebuilding tables others reference; every writer sets them and unique (user_id, slug) indexes hold them. 254 backend tests (new: migration 0021 on a v3 fixture, slug aliases, swaps and rate limits, username renames, aliases and limits, reads by path and their privacy, the OG 301s, both unsubscribe paths, v4-shaped digest links with no ids, notification joins, shared paths and slugs) and 668 frontend tests (new: the profile's tabs and follow views, Settings, Manage, the link field, canonical URLs on the dump, playlist and profile pages, bare default feed paths) pass, and tsc, eslint, deno check, deno lint, deno fmt and doc:lint are clean; the migration was also run on a copy of the development database.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

api/services/digest-service.ts

@@ -22,7 +22,12 @@ import {
   type DigestCadence,
 } from "../../shared/settings.ts";
 import { SETTINGS_COLUMNS } from "../model/settings.ts";
-import type { NotificationType } from "../../shared/notification.ts";
+import type {
+  DumpRef,
+  NotificationType,
+  PlaylistRef,
+} from "../../shared/notification.ts";
+import { dumpPath, feedPath, playlistPath } from "../../shared/paths.ts";
 import {
   type ActivityKind,
   type DigestContent,
@@ -35,6 +40,7 @@ import { createUnsubscribeToken } from "../lib/jwt.ts";
 import { isEmailEnabled, sendEmail } from "./email-service.ts";
 import { getSettings } from "./settings-service.ts";
 import { dumpFileVersion } from "./dump-service.ts";
+import { withCurrentRefs } from "./notification-service.ts";
 
 const DAY_MS = 86_400_000;
 /** How long each cadence's period lasts. */
@@ -67,11 +73,6 @@ interface Window {
   to: string;
 }
 
-const dumpUrl = (row: { id: string; slug: string | null }) =>
-  `${FRONTEND_URL}/dumps/${encodeURIComponent(row.slug ?? row.id)}`;
-const playlistUrl = (row: { id: string; slug: string | null }) =>
-  `${FRONTEND_URL}/playlists/${encodeURIComponent(row.slug ?? row.id)}`;
-
 /** Flattens Markdown into a short line of text for a quote. */
 function quoteOf(markdown: string | undefined | null): string | undefined {
   if (!markdown) return undefined;
@@ -95,7 +96,7 @@ const DUMP_COLS = `d.id, d.slug, d.title, d.kind, d.url, d.user_id,
 
 interface DumpRow {
   id: string;
-  slug: string | null;
+  slug: string;
   title: string;
   kind: string;
   url: string | null;
@@ -126,7 +127,7 @@ function thumbnailOf(row: DumpRow): string | null {
       createdAt: new Date(row.created_at),
       updatedAt: row.updated_at ? new Date(row.updated_at) : undefined,
     });
-    return `${PUBLIC_URL}/api/thumbnails/${row.id}?v=${version}`;
+    return `${PUBLIC_URL}/api/dumps/${row.id}/thumbnail?v=${version}`;
   }
   let thumbnailUrl: unknown;
   try {
@@ -139,7 +140,7 @@ function thumbnailOf(row: DumpRow): string | null {
   if (typeof thumbnailUrl !== "string") return null;
   if (thumbnailUrl.startsWith("https://")) return thumbnailUrl;
   if (thumbnailUrl.startsWith("http://")) {
-    return `${PUBLIC_URL}/api/proxy-image?url=${
+    return `${PUBLIC_URL}/api/remote/image?url=${
       encodeURIComponent(thumbnailUrl)
     }`;
   }
@@ -157,7 +158,9 @@ function toDigestDump(row: DumpRow, readerId: string): DigestDump {
   }
   return {
     title: row.title,
-    url: dumpUrl(row),
+    url: `${FRONTEND_URL}${
+      dumpPath({ ownerUsername: row.poster, slug: row.slug })
+    }`,
     poster: row.poster,
     domain,
     thumbnail: thumbnailOf(row),
@@ -205,7 +208,7 @@ function activityOf(
   }[];
   const highlights = rows.flatMap((row) => {
     try {
-      const h = highlightOf(row.type, JSON.parse(row.data));
+      const h = highlightOf(row.type, withCurrentRefs(JSON.parse(row.data)));
       return h ? [{ ...h, at: new Date(row.created_at) }] : [];
     } catch {
       return [];
@@ -219,24 +222,35 @@ function activityOf(
 const commentBody = (id: string) =>
   (db.prepare(`SELECT body FROM comments WHERE id = ? AND deleted = 0;`)
     .get(id) as { body: string } | undefined)?.body;
-const dumpTarget = (id: string, fallbackTitle: string) => {
-  const row = db.prepare(`SELECT id, slug, title FROM dumps WHERE id = ?;`)
-    .get(id) as { id: string; slug: string | null; title: string } | undefined;
-  return row ? { title: row.title, url: dumpUrl(row) } : {
-    title: fallbackTitle,
-    url: `${FRONTEND_URL}/dumps/${encodeURIComponent(id)}`,
-  };
-};
-const playlistTarget = (id: string, fallbackTitle: string) => {
-  const row = db.prepare(`SELECT id, slug, title FROM playlists WHERE id = ?;`)
-    .get(id) as { id: string; slug: string | null; title: string } | undefined;
-  return row ? { title: row.title, url: playlistUrl(row) } : {
-    title: fallbackTitle,
-    url: `${FRONTEND_URL}/playlists/${encodeURIComponent(id)}`,
-  };
-};
+/**
+ * Returns a highlight's dump, titled `title`, linked where the notification's
+ * joined ref says it is now, or unlinked once it is deleted.
+ */
+const dumpTarget = (ref: DumpRef, title: string) => ({
+  title,
+  url: ref.dumpSlug && ref.dumpOwnerUsername
+    ? `${FRONTEND_URL}${
+      dumpPath({ ownerUsername: ref.dumpOwnerUsername, slug: ref.dumpSlug })
+    }`
+    : null,
+});
+/** Returns a highlight's playlist as {@link dumpTarget} does its dump. */
+const playlistTarget = (ref: PlaylistRef, title: string) => ({
+  title,
+  url: ref.playlistSlug && ref.playlistOwnerUsername
+    ? `${FRONTEND_URL}${
+      playlistPath({
+        ownerUsername: ref.playlistOwnerUsername,
+        slug: ref.playlistSlug,
+      })
+    }`
+    : null,
+});
 
-/** Returns the highlight a notification makes, or null for another kind. */
+/**
+ * Returns the highlight a notification makes, from its data with the refs
+ * joined, or null for another kind.
+ */
 function highlightOf(
   type: NotificationType,
   // deno-lint-ignore no-explicit-any
@@ -249,20 +263,20 @@ function highlightOf(
           return {
             kind: "mentionComment",
             who: data.mentionerUsername,
-            target: dumpTarget(data.dumpId, data.contextTitle),
+            target: dumpTarget(data, data.contextTitle),
             quote: quoteOf(commentBody(data.contextId)),
           };
         case "dump":
           return {
             kind: "mentionDump",
             who: data.mentionerUsername,
-            target: dumpTarget(data.contextId, data.contextTitle),
+            target: dumpTarget(data, data.contextTitle),
           };
         case "playlist":
           return {
             kind: "mentionPlaylist",
             who: data.mentionerUsername,
-            target: playlistTarget(data.contextId, data.contextTitle),
+            target: playlistTarget(data, data.contextTitle),
           };
         case "chat":
           return {
@@ -279,14 +293,14 @@ function highlightOf(
       return {
         kind: "comment",
         who: data.commenterUsername,
-        target: dumpTarget(data.dumpId, data.dumpTitle),
+        target: dumpTarget(data, data.dumpTitle),
         quote: quoteOf(commentBody(data.commentId)),
       };
     case "playlist_followed":
       return {
         kind: "playlistFollow",
         who: data.followerUsername,
-        target: playlistTarget(data.playlistId, data.playlistTitle),
+        target: playlistTarget(data, data.playlistTitle),
       };
     case "user_followed":
       return { kind: "userFollow", who: data.followerUsername };
@@ -294,7 +308,7 @@ function highlightOf(
       return {
         kind: "commentLike",
         who: data.likerUsername,
-        target: dumpTarget(data.dumpId, data.dumpTitle),
+        target: dumpTarget(data, data.dumpTitle),
         quote: quoteOf(commentBody(data.commentId)),
       };
   }
@@ -393,7 +407,7 @@ function communityOf(readerId: string, w: Window): DigestContent["community"] {
       ORDER BY dumps DESC, p.created_at DESC;`,
   ).all(w.from, w.to) as {
     id: string;
-    slug: string | null;
+    slug: string;
     title: string;
     owner: string;
     dumps: number;
@@ -432,7 +446,9 @@ function communityOf(readerId: string, w: Window): DigestContent["community"] {
     membersMore: Math.max(0, members.length - MEMBERS_MAX),
     playlists: playlists.slice(0, PLAYLISTS_MAX).map((p) => ({
       title: p.title,
-      url: playlistUrl(p),
+      url: `${FRONTEND_URL}${
+        playlistPath({ ownerUsername: p.owner, slug: p.slug })
+      }`,
       owner: p.owner,
       dumps: p.dumps,
     })),
@@ -473,11 +489,9 @@ export function buildDigest(
     community,
     links: {
       notifications: `${FRONTEND_URL}/notifications`,
-      followed: `${FRONTEND_URL}/~/followed`,
+      followed: `${FRONTEND_URL}${feedPath(undefined, "follow")}`,
       chat: `${FRONTEND_URL}/?chat=open`,
-      settings: `${FRONTEND_URL}/users/${
-        encodeURIComponent(reader)
-      }/~/settings`,
+      settings: `${FRONTEND_URL}/settings`,
       unsubscribe: `${FRONTEND_URL}/unsubscribe?token=${
         encodeURIComponent(token)
       }`,
@@ -567,7 +581,7 @@ export async function sendDueDigests(now: Date = new Date()): Promise<number> {
           to: row.email,
           ...email,
           headers: {
-            "List-Unsubscribe": `<${PUBLIC_URL}/api/users/unsubscribe?token=${
+            "List-Unsubscribe": `<${PUBLIC_URL}/api/unsubscribe?token=${
               encodeURIComponent(token)
             }>`,
             "List-Unsubscribe-Post": "List-Unsubscribe=One-Click",