Add hashtag preference schema and feature flag

docs/nostr-event-schemas.md

@@ -147,6 +147,7 @@ import { updateWatchHistoryListWithDefaultClient } from "./nostrWatchHistoryFaca
 | Watch history chunk (`NOTE_TYPES.WATCH_HISTORY_CHUNK`) | `WATCH_HISTORY_KIND` (default `30079`, clients also read legacy `30078`) | `['d', <snapshotId:index>]`, `['encrypted','nip04']`, `['snapshot', <id>]`, `['chunk', <index>, <total>]`, optional leading `['head','1']` on the first chunk, pointer tags for each item, plus schema append tags | NIP-04 encrypted JSON chunk (`{ version, snapshot, chunkIndex, totalChunks, items[] }`) |
 | Subscription list (`NOTE_TYPES.SUBSCRIPTION_LIST`) | `30002` | `['d', 'subscriptions']` | NIP-04 encrypted JSON `{ subPubkeys: string[] }` |
 | User block list (`NOTE_TYPES.USER_BLOCK_LIST`) | `30002` | `['d', 'user-blocks']` | NIP-04 encrypted JSON `{ blockedPubkeys: string[] }` |
+| Hashtag preferences (`NOTE_TYPES.HASHTAG_PREFERENCES`) | `30005` | `['d', 'bitvid:tag-preferences']` plus schema-appended `['encrypted','nip44_v2']` | NIP-44 encrypted JSON `{ version, interests: string[], disinterests: string[] }` |
 | Admin moderation list (`NOTE_TYPES.ADMIN_MODERATION_LIST`) | `30000` | `['d', 'bitvid:admin:editors']`, repeated `['p', <pubkey>]` entries | Empty content |
 | Admin blacklist (`NOTE_TYPES.ADMIN_BLACKLIST`) | `30000` | `['d', 'bitvid:admin:blacklist']`, repeated `['p', <pubkey>]` entries | Empty content |
 | Admin whitelist (`NOTE_TYPES.ADMIN_WHITELIST`) | `30000` | `['d', 'bitvid:admin:whitelist']`, repeated `['p', <pubkey>]` entries | Empty content |
@@ -157,6 +158,17 @@ If you introduce a new Nostr feature, add its schema to
 `js/nostrEventSchemas.js` so that the catalogue stays complete and so existing
 builders inherit the same debugging knobs.
 
+### Hashtag preference lists
+
+Hashtag preference events (`NOTE_TYPES.HASHTAG_PREFERENCES`) live on a
+replaceable `30005` list with a stable identifier tag of
+`['d','bitvid:tag-preferences']`. The builder appends `['encrypted','nip44_v2']`
+so downstream clients can detect that the payload is encrypted. The `content`
+field must be a NIP-44 ciphertext representing the JSON shape
+`{ version, interests: string[], disinterests: string[] }`, allowing clients to
+share their preferred and muted hashtags without exposing the raw preferences on
+relays.
+
 ### NIP-71 rollout
 
 bitvid now emits a paired NIP-71 event (kind `21` for long-form, `22` for short

js/constants.js

@@ -147,6 +147,7 @@ const DEFAULT_FLAGS = Object.freeze({
   VIEW_FILTER_INCLUDE_LEGACY_VIDEO: false,
   FEATURE_WATCH_HISTORY_V2: true,
   FEATURE_PUBLISH_NIP71: false,
+  FEATURE_HASHTAG_PREFERENCES: false,
   FEATURE_TRUST_SEEDS: true, // Rollback: disable to drop baseline trust seeds without code changes.
   FEATURE_TRUSTED_HIDE_CONTROLS: true,
   TRUSTED_MUTE_HIDE_THRESHOLD: DEFAULT_TRUSTED_MUTE_HIDE_THRESHOLD,
@@ -167,6 +168,7 @@ const runtimeFlags = (() => {
       DEFAULT_FLAGS.VIEW_FILTER_INCLUDE_LEGACY_VIDEO,
     FEATURE_WATCH_HISTORY_V2: DEFAULT_FLAGS.FEATURE_WATCH_HISTORY_V2,
     FEATURE_PUBLISH_NIP71: DEFAULT_FLAGS.FEATURE_PUBLISH_NIP71,
+    FEATURE_HASHTAG_PREFERENCES: DEFAULT_FLAGS.FEATURE_HASHTAG_PREFERENCES,
     FEATURE_TRUST_SEEDS: DEFAULT_FLAGS.FEATURE_TRUST_SEEDS,
     FEATURE_TRUSTED_HIDE_CONTROLS: DEFAULT_FLAGS.FEATURE_TRUSTED_HIDE_CONTROLS,
     TRUSTED_MUTE_HIDE_THRESHOLD: DEFAULT_FLAGS.TRUSTED_MUTE_HIDE_THRESHOLD,
@@ -204,6 +206,11 @@ export let FEATURE_PUBLISH_NIP71 = coerceBoolean(
   DEFAULT_FLAGS.FEATURE_PUBLISH_NIP71
 );
 
+export let FEATURE_HASHTAG_PREFERENCES = coerceBoolean(
+  runtimeFlags.FEATURE_HASHTAG_PREFERENCES,
+  DEFAULT_FLAGS.FEATURE_HASHTAG_PREFERENCES
+);
+
 export let FEATURE_TRUST_SEEDS = coerceBoolean(
   runtimeFlags.FEATURE_TRUST_SEEDS,
   DEFAULT_FLAGS.FEATURE_TRUST_SEEDS
@@ -292,6 +299,20 @@ Object.defineProperty(runtimeFlags, "FEATURE_PUBLISH_NIP71", {
   },
 });
 
+Object.defineProperty(runtimeFlags, "FEATURE_HASHTAG_PREFERENCES", {
+  configurable: true,
+  enumerable: true,
+  get() {
+    return FEATURE_HASHTAG_PREFERENCES;
+  },
+  set(next) {
+    FEATURE_HASHTAG_PREFERENCES = coerceBoolean(
+      next,
+      DEFAULT_FLAGS.FEATURE_HASHTAG_PREFERENCES
+    );
+  },
+});
+
 Object.defineProperty(runtimeFlags, "FEATURE_TRUST_SEEDS", {
   configurable: true,
   enumerable: true,
@@ -367,6 +388,7 @@ runtimeFlags.ACCEPT_LEGACY_V1 = ACCEPT_LEGACY_V1;
 runtimeFlags.VIEW_FILTER_INCLUDE_LEGACY_VIDEO = VIEW_FILTER_INCLUDE_LEGACY_VIDEO;
 runtimeFlags.FEATURE_WATCH_HISTORY_V2 = FEATURE_WATCH_HISTORY_V2;
 runtimeFlags.FEATURE_PUBLISH_NIP71 = FEATURE_PUBLISH_NIP71;
+runtimeFlags.FEATURE_HASHTAG_PREFERENCES = FEATURE_HASHTAG_PREFERENCES;
 runtimeFlags.FEATURE_TRUST_SEEDS = FEATURE_TRUST_SEEDS;
 runtimeFlags.FEATURE_TRUSTED_HIDE_CONTROLS = FEATURE_TRUSTED_HIDE_CONTROLS;
 runtimeFlags.WSS_TRACKERS = WSS_TRACKERS;
@@ -407,6 +429,11 @@ export function setTrustedHideControlsEnabled(next) {
   return FEATURE_TRUSTED_HIDE_CONTROLS;
 }
 
+export function setHashtagPreferencesEnabled(next) {
+  runtimeFlags.FEATURE_HASHTAG_PREFERENCES = next;
+  return FEATURE_HASHTAG_PREFERENCES;
+}
+
 export function resetRuntimeFlags() {
   setUrlFirstEnabled(DEFAULT_FLAGS.URL_FIRST_ENABLED);
   setAcceptLegacyV1(DEFAULT_FLAGS.ACCEPT_LEGACY_V1);
@@ -414,6 +441,7 @@ export function resetRuntimeFlags() {
     DEFAULT_FLAGS.VIEW_FILTER_INCLUDE_LEGACY_VIDEO
   );
   setWatchHistoryV2Enabled(DEFAULT_FLAGS.FEATURE_WATCH_HISTORY_V2);
+  setHashtagPreferencesEnabled(DEFAULT_FLAGS.FEATURE_HASHTAG_PREFERENCES);
   setTrustSeedsEnabled(DEFAULT_FLAGS.FEATURE_TRUST_SEEDS);
   setTrustedHideControlsEnabled(DEFAULT_FLAGS.FEATURE_TRUSTED_HIDE_CONTROLS);
   setTrustedMuteHideThreshold(DEFAULT_FLAGS.TRUSTED_MUTE_HIDE_THRESHOLD);

js/nostrEventSchemas.js

@@ -22,6 +22,7 @@ export const NOTE_TYPES = Object.freeze({
   WATCH_HISTORY_CHUNK: "watchHistoryChunk",
   SUBSCRIPTION_LIST: "subscriptionList",
   USER_BLOCK_LIST: "userBlockList",
+  HASHTAG_PREFERENCES: "hashtagPreferences",
   ADMIN_MODERATION_LIST: "adminModerationList",
   ADMIN_BLACKLIST: "adminBlacklist",
   ADMIN_WHITELIST: "adminWhitelist",
@@ -313,6 +314,21 @@ const BASE_SCHEMAS = {
       description: "Encrypted JSON: { blockedPubkeys: string[] }.",
     },
   },
+  [NOTE_TYPES.HASHTAG_PREFERENCES]: {
+    type: NOTE_TYPES.HASHTAG_PREFERENCES,
+    label: "Hashtag preferences",
+    kind: 30005,
+    identifierTag: {
+      name: "d",
+      value: "bitvid:tag-preferences",
+    },
+    appendTags: [["encrypted", "nip44_v2"]],
+    content: {
+      format: "nip44-json",
+      description:
+        "NIP-44 encrypted JSON: { version, interests: string[], disinterests: string[] }.",
+    },
+  },
   [NOTE_TYPES.ADMIN_MODERATION_LIST]: {
     type: NOTE_TYPES.ADMIN_MODERATION_LIST,
     label: "Admin moderation list",
@@ -1133,6 +1149,28 @@ export function buildBlockListEvent({
   };
 }
 
+export function buildHashtagPreferenceEvent({
+  pubkey,
+  created_at,
+  content,
+}) {
+  const schema = getNostrEventSchema(NOTE_TYPES.HASHTAG_PREFERENCES);
+  const tags = [];
+  const identifierName = schema?.identifierTag?.name || "d";
+  const identifierValue = schema?.identifierTag?.value || "bitvid:tag-preferences";
+  if (identifierName && identifierValue) {
+    tags.push([identifierName, identifierValue]);
+  }
+  appendSchemaTags(tags, schema);
+  return {
+    kind: schema?.kind ?? 30005,
+    pubkey,
+    created_at,
+    tags,
+    content: typeof content === "string" ? content : String(content ?? ""),
+  };
+}
+
 function resolveAdminNoteType(listKey) {
   switch (listKey) {
     case "moderation":