Bluesky MCP Server

Your AI agent writes, publishes and schedules Bluesky posts with images or video through the official Bluesky API.

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No credit card
3 min setup

Updated Nov 5, 2026

Connect in a minute

In Claude, open Customize → Connectors → Add custom connector and paste:
Connector URL
```
https://postonce.to/mcp
```
Choose Register automatically, select Add, then Connect and sign in to PostOnce.
Ask your agent:
Prompt
```
Show my connected PostOnce accounts.
```

Claude guide →

Turn on Developer mode, then create an app in Plugins with this URL:
Server URL
```
https://postonce.to/mcp
```
Choose OAuth with automatic registration and sign in to PostOnce.
Ask your agent:
Prompt
```
Show my connected PostOnce accounts.
```

ChatGPT guide →

Install the plugin. It adds the server and the skills below.

Terminal

claude plugin marketplace add postoncehq/plugins
claude plugin install bluesky-mcp@postoncehq

Run /mcp, pick the postonce server, choose Authenticate and sign in to PostOnce.
Ask your agent:
Prompt
```
Show my connected PostOnce accounts.
```

Claude Code guide →

Add the server:

Terminal

codex mcp add postonce --url https://postonce.to/mcp

Sign in to PostOnce in the browser that opens:
Terminal
```
codex mcp login postonce
```
Ask your agent:
Prompt
```
Show my connected PostOnce accounts.
```

Codex guide →

Merge into ~/.cursor/mcp.json:

~/.cursor/mcp.json

{
  "mcpServers": {
    "postonce": {
      "url": "https://postonce.to/mcp"
    }
  }
}

In Cursor Settings → MCP, select Connect next to postonce and sign in to PostOnce.
Ask your agent:
Prompt
```
Show my connected PostOnce accounts.
```

Cursor guide →

Add a remote server:

Connection

URL: https://postonce.to/mcp
Transport: Streamable HTTP
Auth: OAuth (sign in with PostOnce)

No OAuth in your client? Send Authorization: Bearer with a key from Preferences → API keys (paid plans only).
Ask your agent:
Prompt
```
Show my connected PostOnce accounts.
```

All integrations →

What your agent can do

Ask your agent toHow it works

Publish a text post now (up to 300 characters)create_post on your connected Bluesky account

Schedule a post for latercreate_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 @mentionsThey're turned into clickable rich text when the post is published

Save a draft to finish latercreate_draft

Check whether a post went out, and get its URLget_post

Change or cancel a scheduled postupdate_post, cancel_post

Post the same thing to Bluesky and other platformsAdd 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.

Bluesky skills

Your agent writes for the platform before it posts. In the plugin, free on GitHub.

bluesky-post-writerWrites Bluesky posts that fit in 300 characters and sound like a person, with links, hashtags and mentions that become clickable.
bluesky-bio-generatorWrites a 256-character Bluesky bio, display name and pinned post idea for you to paste into your profile.
bluesky-custom-domain-handleWalks you through using your own domain as your Bluesky handle, with the DNS TXT record or the /.well-known file.
bluesky-content-calendarPlans 1–4 weeks of Bluesky posts from your goals or a source you want to repurpose, drafts each one and schedules them on approval.
postoncePublishing workflow: pick the right account, upload media, schedule, and confirm the post actually went live.

bluesky-mcp on GitHub

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.

Can I post to Bluesky from my own code?

Yes. The same publishing works through the PostOnce social media posting API with an API key on any paid plan.

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