Bluesky + PostOnce
Bluesky MCP Server
Bluesky MCP server for Claude, ChatGPT, Cursor and Codex. Your AI agent can write, publish and schedule Bluesky posts with images or video through the official Bluesky API, with no scraping and no browser automation. You connect with a Bluesky app password you can revoke any time.
Requires a PostOnce account, API access, and your own API key.
https://postonce.to/mcpWhat your agent can do on Bluesky
Publish a text post now (up to 300 characters)
create_post on your connected Bluesky account
Schedule a post for later
create_post with publish_at
Post up to 4 images, or 1 video (up to 3 minutes, 100 MB)
create_upload_url, upload, then create_post with media
Use links, #hashtags and @mentions
They're turned into clickable rich text when the post is published
Save a draft to finish later
create_draft
Check whether a post went out, and get its URL
get_post
Change or cancel a scheduled post
update_post, cancel_post
Post the same thing to Bluesky and other platforms
Add more targets to create_post (LinkedIn, Instagram, TikTok, YouTube, X, Threads, Facebook, Pinterest)
Not supported: threads and replies, quote posts, link preview cards, image alt text, reading your feed or notifications, analytics, DMs, and editing or deleting posts that are already published. Text over 300 characters is cut off, not rejected. This server publishes; it doesn't browse Bluesky for you.
Connect Bluesky to your agent
You need a PostOnce account with your Bluesky account connected. Try it free for 7 days without entering a card.
Claude and ChatGPT
Add a custom connector with this URL and sign in with PostOnce. No API key.
https://postonce.to/mcpClaude Code
Install the plugin for the connection and the Bluesky skills, then set POSTONCE_API_KEY.
claude plugin marketplace add postoncehq/plugins
claude plugin install bluesky-mcp@postoncehqCursor, Codex and other clients
Point any MCP client at the URL above over Streamable HTTP with the header Authorization: Bearer and your PostOnce API key. Never paste the key into chat.
Bluesky skills included
The plugin ships these Agent Skills so your agent knows what works on Bluesky before it posts. They work in Claude Code, Codex, Cursor and any client that reads Agent Skills.
- bluesky-post-writer
Writes Bluesky posts that fit in 300 characters and sound like a person, with links, hashtags and mentions that become clickable.
- bluesky-bio-generator
Writes a 256-character Bluesky bio, display name and pinned post idea for you to paste into your profile.
- bluesky-custom-domain-handle
Walks you through using your own domain as your Bluesky handle, with the DNS TXT record or the /.well-known file.
- bluesky-content-calendar
Plans 1–4 weeks of Bluesky posts from your goals or a source you want to repurpose, drafts each one and schedules them on approval.
- postonce
Publishing workflow: pick the right account, upload media, schedule, and confirm the post actually went live.
Try these prompts
Write a Bluesky post about our new release with the repo link and schedule it for Thursday at 9am.
Post this screenshot to Bluesky with a short caption.
Plan a week of Bluesky posts from our changelog and schedule them.
Bluesky MCP questions
Is there an official Bluesky MCP server?
This server uses Bluesky's official API (the AT Protocol) through PostOnce, and adds scheduling, drafts and posting to other platforms from the same request.
Can Claude post to Bluesky?
Yes, once it's connected to an MCP server that can publish, like this one. Claude writes the post, then calls create_post. It can post now or schedule for later.
Is it safe for my Bluesky account?
Yes. PostOnce connects with a Bluesky app password, not your main password. An app password can't change your password or delete your account, and you can revoke one in Bluesky at any time, which cuts off access immediately. Posts go through Bluesky's official API. Many MCP servers on GitHub drive a logged-in browser session or ask for your main password instead; avoid giving any tool your main password.
Do I need a Bluesky developer account or API key?
No. You create an app password in Bluesky's settings and enter it in PostOnce. There's no developer app to register.
Can it post Bluesky threads?
No. Each post is published on its own; replies and threads aren't supported. For something longer than 300 characters, split it into standalone posts or post the first part and add replies yourself in the Bluesky app.
Does it show link previews?
Links become clickable, but this server doesn't attach a link preview card. If the visual matters, add an image to the post.
Is it free?
The skills are free and MIT-licensed on GitHub. Publishing runs through a PostOnce account, which you can try free for 7 days without entering a card. After that, see pricing.
MCP servers for other platforms
The same connection publishes everywhere PostOnce supports. Each platform has its own skills: LinkedIn MCP, Instagram MCP, TikTok MCP, YouTube MCP, Facebook MCP, X (Twitter) MCP, Threads MCP, Pinterest MCP.
Let your agent post to Bluesky
Requires a PostOnce account, API access, and your own API key.