fix: AP inbox reliability — PeerTube View skip, raw body digest, signature window, trailing slash

federation-bridge.js:
- Buffer application/activity+json and ld+json bodies that Express
  doesn't parse (inbox POSTs from Mastodon, PeerTube, etc.)
- Store original bytes in req._rawBody and pass them verbatim to Fedify
  so HTTP Signature Digest verification passes; JSON.stringify reorders
  keys which caused every Mastodon Like/Announce/Create to be silently
  rejected
- Short-circuit PeerTube View (WatchAction) activities with 200 before
  Fedify's JSON-LD parser throws on Schema.org extensions

federation-setup.js:
- Accept signatures up to 12 hours old (Mastodon retries with the
  original signature hours after a failed delivery)
- Look up AP object URLs with $in [url, url+"/"] to tolerate trailing
  slash differences between stored posts and AP object URLs

inbox-listeners.js:
- Register a no-op .on(View) handler so Fedify doesn't log noisy
  "Unsupported activity type" errors for PeerTube watch events

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

lib/federation-bridge.js

@@ -35,8 +35,11 @@ export function fromExpressRequest(req) {
     // Express body parser already consumed the stream — reconstruct
     // so downstream handlers (e.g. @fedify/debugger login) can read it.
     const ct = req.headers["content-type"] || "";
-    if (ct.includes("application/json")) {
+    // Handle activity+json and ld+json bodies (PeerTube, Mastodon, etc.).
-      body = JSON.stringify(req.body);
+    // Use original raw bytes when available (set by the buffer guard below)
+    // so Fedify's HTTP Signature Digest check passes.
+    if (ct.includes("application/json") || ct.includes("activity+json") || ct.includes("ld+json")) {
+      body = req._rawBody || JSON.stringify(req.body);
     } else if (ct.includes("application/x-www-form-urlencoded")) {
       body = new URLSearchParams(req.body).toString();
     } else {
@@ -129,6 +132,40 @@ async function sendFedifyResponse(res, response, request) {
 export function createFedifyMiddleware(federation, contextDataFactory) {
   return async (req, res, next) => {
     try {
+      // Buffer application/activity+json and ld+json request bodies ourselves —
+      // Express's JSON body parser only handles application/json, so req.body
+      // is otherwise undefined for AP inbox POSTs. We need the body to:
+      //   1. Detect and short-circuit PeerTube View (WatchAction) activities
+      //      before Fedify's JSON-LD parser chokes on Schema.org extensions.
+      //   2. Preserve original bytes in req._rawBody so fromExpressRequest()
+      //      can pass them to Fedify verbatim, keeping HTTP Signature Digest
+      //      verification intact (JSON.stringify reorders keys, breaking it).
+      const _apct = req.headers["content-type"] || "";
+      if (
+        req.method === "POST" &&
+        !req.body &&
+        req.readable &&
+        (_apct.includes("activity+json") || _apct.includes("ld+json"))
+      ) {
+        const _chunks = [];
+        for await (const _chunk of req) {
+          _chunks.push(Buffer.isBuffer(_chunk) ? _chunk : Buffer.from(_chunk));
+        }
+        const _raw = Buffer.concat(_chunks);
+        req._rawBody = _raw; // preserve for Fedify Digest check
+        try {
+          req.body = JSON.parse(_raw.toString("utf8"));
+        } catch {
+          req.body = {};
+        }
+      }
+      // Silently accept PeerTube View (WatchAction) — return 200 to prevent
+      // retries. Fedify's vocab parser throws on PeerTube's Schema.org
+      // extensions before any inbox handler is reached.
+      if (req.method === "POST" && req.body?.type === "View") {
+        return res.status(200).end();
+      }
+
       const request = fromExpressRequest(req);
       const contextData = await Promise.resolve(contextDataFactory(req));
 

lib/federation-setup.js

@@ -135,6 +135,10 @@ export function setupFederation(options) {
   const federation = createFederation({
     kv,
     queue,
+    // Accept signatures up to 12 h old.
+    // Mastodon retries failed deliveries with the original signature, which
+    // can be hours old by the time the delivery succeeds.
+    signatureTimeWindow: { hours: 12 },
   });
 
   // --- Actor dispatcher ---
@@ -659,7 +663,11 @@ function setupObjectDispatchers(federation, mountPath, handle, collections, publ
   async function resolvePost(ctx, id) {
     if (!collections.posts || !publicationUrl) return null;
     const postUrl = `${publicationUrl.replace(/\/$/, "")}/${id}`;
-    const post = await collections.posts.findOne({ "properties.url": postUrl });
+    // Match with or without trailing slash — AP object URLs omit the slash
+    // but posts are stored with one, so an exact match would fail.
+    const post = await collections.posts.findOne({
+      "properties.url": { $in: [postUrl, postUrl + "/"] },
+    });
     if (!post) return null;
     if (post?.properties?.["post-status"] === "draft") return null;
     if (post?.properties?.visibility === "unlisted") return null;

lib/inbox-listeners.js

@@ -24,6 +24,7 @@ import {
   Remove,
   Undo,
   Update,
+  View,
 } from "@fedify/fedify/vocab";
 
 import { logActivity as logActivityShared } from "./activity-log.js";
@@ -822,7 +823,13 @@ export function registerInboxListeners(inboxChain, options) {
       } catch (error) {
         console.warn("[ActivityPub] Flag handler error:", error.message);
       }
-    });
+    })
+    // ── View (PeerTube watch) ─────────────────────────────────────────────
+    // PeerTube broadcasts View (WatchAction) activities to all followers
+    // whenever someone watches a video. Fedify has no built-in handler for
+    // this type, producing noisy "Unsupported activity type" log errors.
+    // Silently accept and discard.
+    .on(View, async () => {});
 }
 
 /**