diff --git a/src/lib/api/feed/custom.ts b/src/lib/api/feed/custom.ts
index 75c4a62..6f3f690 100644
--- a/src/lib/api/feed/custom.ts
+++ b/src/lib/api/feed/custom.ts
@@ -52,16 +52,30 @@ export class CustomFeedAPI implements FeedAPI {
     cursor: string | undefined
     limit: number
   }): Promise<FeedAPIResponse> {
-    // Only use the microcosm batch path when there's no session. Personalized
-    // feeds (e.g. For You) require a service-auth JWT forwarded to the feed
-    // generator, which the batch path doesn't yet mint — without it the
-    // generator rejects the request. Logged-in always uses the AppView path
-    // below, which forwards auth correctly.
-    if (MICROCOSM_ENABLED && !this.agent.did) {
+    // Microcosm batch path: Slingshot proxies the feed generator's skeleton and
+    // fetches all post records in one request. For personalized feeds we forward
+    // a service-auth token (aud = the feed generator's DID) so the generator can
+    // identify the viewer — same as the AppView would.
+    if (MICROCOSM_ENABLED) {
       try {
         const page = await buildCustomFeed(this.params.feed, {
+          viewerDid: this.agent.did,
           limit,
           cursor,
+          getAuthorization: this.agent.did
+            ? async (feedGenDid: string) => {
+                try {
+                  const {data} =
+                    await this.agent.com.atproto.server.getServiceAuth({
+                      aud: feedGenDid,
+                      lxm: 'app.bsky.feed.getFeedSkeleton',
+                    })
+                  return data.token
+                } catch {
+                  return undefined
+                }
+              }
+            : undefined,
         })
         if (page.feed.length) {
           return {cursor: page.cursor, feed: page.feed}
diff --git a/src/lib/microcosm/feed.ts b/src/lib/microcosm/feed.ts
index 7a30b8c..562f37b 100644
--- a/src/lib/microcosm/feed.ts
+++ b/src/lib/microcosm/feed.ts
@@ -153,14 +153,34 @@ async function resolveFeedGenDid(
  */
 export async function buildCustomFeed(
   feedUri: string,
-  opts: {viewerDid?: string; limit?: number; cursor?: string} = {},
+  opts: {
+    viewerDid?: string
+    limit?: number
+    cursor?: string
+    /**
+     * Mint a service-auth token scoped to the feed generator (aud = its DID,
+     * lxm = app.bsky.feed.getFeedSkeleton). Called after the gen DID is known.
+     * Required for personalized feeds; omit when logged out.
+     */
+    getAuthorization?: (feedGenDid: string) => Promise<string | undefined>
+  } = {},
   signal?: AbortSignal,
 ): Promise<FollowingFeedPage & {cursor?: string}> {
   const feedGenDid = await resolveFeedGenDid(feedUri, signal)
   if (!feedGenDid) return {feed: []}
 
+  const authorization = opts.getAuthorization
+    ? await opts.getAuthorization(feedGenDid).catch(() => undefined)
+    : undefined
+
   const batch = await hydrateFeedSkeleton(
-    {feedGenDid, feed: feedUri, limit: opts.limit ?? 30, cursor: opts.cursor},
+    {
+      feedGenDid,
+      feed: feedUri,
+      limit: opts.limit ?? 30,
+      cursor: opts.cursor,
+      authorization,
+    },
     signal,
   ).catch(() => undefined)
   if (!batch) return {feed: []}
diff --git a/src/lib/microcosm/slingshot.ts b/src/lib/microcosm/slingshot.ts
index 816873f..8ff15da 100644
--- a/src/lib/microcosm/slingshot.ts
+++ b/src/lib/microcosm/slingshot.ts
@@ -117,6 +117,11 @@ export async function hydrateFeedSkeleton(
     feed: string
     limit?: number
     cursor?: string
+    /**
+     * Service-auth token whose `aud` matches the feed generator DID. Required
+     * for personalized feeds; forwarded to the generator by Slingshot.
+     */
+    authorization?: string
   },
   signal?: AbortSignal,
 ): Promise<{
@@ -127,6 +132,7 @@ export async function hydrateFeedSkeleton(
   const payload = {
     xrpc: 'app.bsky.feed.getFeedSkeleton',
     atproto_proxy: `${args.feedGenDid}#bsky_fg`,
+    ...(args.authorization ? {authorization: args.authorization} : {}),
     params: {
       feed: args.feed,
       limit: args.limit ?? 30,