AT Protocol (Bluesky PDS)

Bluesky API Errors

AT Protocol errors you'll see when posting through the Bluesky PDS.

Bluesky's AT Protocol uses session-based auth (not OAuth) and grapheme-based length limits, so the error shapes look different from other platforms.

PostPeer Bluesky API View Docs

Authentication3 Rate limit2 Moderation2 Media2 Content1

Authentication

3 errors in this category

invalid tokenHTTP 401Authentication

Bluesky session token is no longer valid.

Why it happens: Bluesky uses short-lived session tokens. Without a recent refresh, calls fail.
How to fix: Reconnect by creating a new session with the user's handle + app password.
How PostPeer handles it: PostPeer refreshes Bluesky sessions on each publish, so this should never surface in normal operation.

expiredHTTP 401Authentication

Session aged past its TTL.

Why it happens: No refresh call hit the session in time.
How to fix: Recreate the session.

unauthorizedHTTP 401Authentication

Bluesky rejected the auth header.

Why it happens: Token revoked, password rotated, or app password deleted.
How to fix: Have the user generate a new app password at bsky.app/settings/app-passwords and reconnect.

Rate limit

2 errors in this category

rate limitHTTP 429Rate limit

Bluesky throttled the request.

Why it happens: Burst of writes against the PDS.
How to fix: Wait a few minutes; spread out batch posting.

too many requestsHTTP 429Rate limit

Per-user or per-IP rate cap hit.

Why it happens: Sustained high request rate.
How to fix: Back off exponentially. PostPeer respects Bluesky's `RateLimit-Reset` header.

Moderation

2 errors in this category

blockedModeration

Bluesky moderation blocked the post.

Why it happens: AT Protocol moderation labellers flagged content as policy-violating.
How to fix: Review Bluesky's community guidelines and rewrite the post.

moderationModeration

Generic moderation rejection.

Why it happens: Content matched a moderation filter (spam, harassment, NSFW without label).
How to fix: If the post is legitimate NSFW, apply the appropriate self-label; otherwise rewrite.

Media

2 errors in this category

blob too largeMedia

Image exceeds Bluesky's 1MB blob cap.

Why it happens: AT Protocol enforces a strict 1MB per blob for images.
How to fix: Compress aggressively — Bluesky is unusually strict here. PostPeer compresses images down to 1MB automatically.

blob invalidMedia

Media file is corrupted or not a supported format.

Why it happens: Bluesky accepts JPG, PNG, and WebP for images.
How to fix: Re-export from the source.

Content

1 error in this category

text too longContent

Post text exceeds 300 graphemes.

Why it happens: Bluesky's 300-character limit is grapheme-based, not byte-based.
How to fix: Trim or chain posts in a thread. PostPeer's SDK exposes a grapheme counter so you can pre-validate.

Quick reference

All 10 Bluesky errors in one table — Ctrl/Cmd-F to find yours.

Code	Category	What it means
invalid token	Authentication	Bluesky session token is no longer valid.
expired	Authentication	Session aged past its TTL.
unauthorized	Authentication	Bluesky rejected the auth header.
rate limit	Rate limit	Bluesky throttled the request.
too many requests	Rate limit	Per-user or per-IP rate cap hit.
blocked	Moderation	Bluesky moderation blocked the post.
moderation	Moderation	Generic moderation rejection.
blob too large	Media	Image exceeds Bluesky's 1MB blob cap.
blob invalid	Media	Media file is corrupted or not a supported format.
text too long	Content	Post text exceeds 300 graphemes.

Other platforms

Instagram errors

33 documented

X (Twitter) errors

12 documented

TikTok errors

25 documented

Facebook errors

15 documented

LinkedIn errors

9 documented

Pinterest errors

8 documented

Threads errors

7 documented

YouTube errors

15 documented

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{ "platforms": ["twitter", "linkedin", "instagram], "content": "Hello world!" }

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