Bluesky API: How to Post to Bluesky via API

The official Bluesky API

A Bluesky post is a repository record of type app.bsky.feed.post, created with com.atproto.repo.createRecord on the account's PDS. The record needs text and a createdAt timestamp. Mentions, links and hashtags are rich-text facets that point at byte ranges in the UTF-8 text. Images are uploaded as blobs and referenced from an embed.

What posting requires

1. For your own account: create an app password in Bluesky settings and start a session with com.atproto.server.createSession.
2. For other people's accounts: implement atproto OAuth, which uses PKCE, PAR and DPoP, with client metadata published at a URL that serves as your client_id.
3. No developer registration, app review or API key is required.
4. Post with createRecord, calculate facet byte offsets for links and mentions, and upload images as blobs before referencing them.

Cost: Free. Bluesky does not charge for API access; the limits below are the only constraints.

Official limits

Common gotchas

• Facets use UTF-8 byte offsets, not character positions. Emoji and non-Latin text shift the offsets and break links if you count characters.
• Links and hashtags in plain text are not clickable until you add the facets yourself.
• createSession is limited to 300 per day per account, so a script that logs in on every run should reuse and refresh its session.
• The 300 limit counts graphemes, so a JavaScript string length check is not the same thing.
• Other atproto hosts can set different rate limits than Bluesky's own PDS.

Post to Bluesky via API

curl -X POST https://api.publora.com/api/v1/create-post \
  -H "Content-Type: application/json" \
  -H "x-publora-key: sk_YOUR_API_KEY" \
  -d '{
    "content": "Our analytics view now shows reposts and quotes side by side. Details: https://example.com/changelog #buildinpublic",
    "platforms": ["bluesky-did:plc:abc123xyz"],
    "scheduledTime": "2026-10-07T16:00:00.000Z",
    "mediaUrls": ["https://example.com/images/analytics-view.png"]
  }'
# { "success": true, "postGroupId": "...", "scheduledTime": "2026-10-07T16:00:00.000Z" }

import requests

response = requests.post(
    "https://api.publora.com/api/v1/create-post",
    headers={
        "Content-Type": "application/json",
        "x-publora-key": "sk_YOUR_API_KEY",
    },
    json={
        # Must fit in 300 characters; longer text is rejected, not split.
        "content": "Our analytics view now shows reposts and quotes side by side. #buildinpublic",
        "platforms": ["bluesky-did:plc:abc123xyz", "mastodon-109876543210"],
        "scheduledTime": "2026-10-07T16:00:00.000Z",
    },
)
print(response.json())  # {'success': True, 'postGroupId': '...', 'scheduledTime': '...'}

Or let an AI agent post

Connect any MCP client to mcp.publora.com:

• “Shorten this announcement to under 280 characters and schedule it to my Bluesky and Mastodon accounts for Thursday at 16:00 UTC.”
• “Pull post stats for my Bluesky posts from last week and tell me which ones got the most reposts.”
• “Schedule a Bluesky post with this screenshot URL tomorrow at 10:00 UTC, with the link and #opensource in the text.”