# Mastodon MCP server > Connect Claude, ChatGPT or Cursor to Mastodon, on any server. Your agent posts threads and described images within your server's limits. Canonical: https://omnisocials.com/mastodon-mcp | Channel page: https://omnisocials.com/mastodon.md | Mastodon API: https://omnisocials.com/mastodon-api.md | Pricing: https://omnisocials.com/pricing.md | 14-day free trial: https://app.omnisocials.com/signup This is the machine-readable version of [omnisocials.com/mastodon-mcp](https://omnisocials.com/mastodon-mcp), maintained for AI agents. Facts checked against the OmniSocials app on October 16, 2026. - **Server URL:** https://mcp.omnisocials.com - **Auth:** OAuth sign-in, or an API key for agents that run on their own - **Discovery file:** https://omnisocials.com/.well-known/mcp.json - **Docs:** https://docs.omnisocials.com/mcp-server - **With your AI agent:** Connect Claude, ChatGPT or any MCP client to Mastodon with the OmniSocials MCP server. Your agent posts threads and images with descriptions on any Mastodon server, and reads your likes and boosts. - **With your coding agent:** Claude Code and Codex add the OmniSocials MCP server with one command, and agents that run on their own use an API key. Or call the Mastodon API from your own code. ## What your agent does Ask in plain words. Your agent picks the MCP server's tools, within your server's limits. - **Threads that fit your server.** 2 to 25 posts, each within your server's limit, sent as one chain of replies. (`create_post`, `upload_media`) - **Posts that fit your server.** Within your own server's character limit, where a link counts as 23. (`create_post`, `update_post`) - **A description on every image.** Up to 4 images or one video per post, each described in up to 1,500 characters. (`create_post`, `list_media`) - **Know what worked.** Your best post, its likes and boosts, and the best time to post the next one. (`get_recent_platform_posts`, `get_best_times`) ## Setup Connected in a minute. One URL and one sign-in. No API key for chat apps. 1. **Connect Mastodon in OmniSocials.** Type your server's address and sign in there. No app to set up. 2. **Add the server to your agent.** Paste one URL as a custom connector, or run one command. 3. **Sign in and pick a workspace.** OAuth in the browser. Agents that run on their own use an API key. - **Claude:** Customize > Connectors > Add custom connector > Paste the URL. Claude sends you to OmniSocials to sign in. No API key needed. Guide: https://omnisocials.com/claude - **Claude Code:** `claude mcp add --transport http omnisocials https://mcp.omnisocials.com`. Then type /mcp in Claude Code and sign in to OmniSocials. Guide: https://omnisocials.com/claude-code - **Codex:** `codex mcp add omnisocials --url https://mcp.omnisocials.com`. Then run codex mcp login omnisocials to sign in. Guide: https://omnisocials.com/codex - **API key:** `claude mcp add --transport http omnisocials https://mcp.omnisocials.com --header "Authorization: Bearer YOUR_API_KEY"`. For agents that run on their own. Create the key in Settings, API Keys. Docs: https://docs.omnisocials.com/mcp-server ## Tools 19 tools in 4 groups. Your agent picks them from a plain request. ### Publishing Posts, images, video and threads, now or on a schedule. Try asking: "Post the threads launch as a thread Thursday at 9 AM, with a description on the image." - create_post: Schedule a post or a thread, with a description on each image. - create_and_publish_post: Post to Mastodon right away. - update_post: Change the text, thread or time of a scheduled post. - upload_media: Upload images or a video from a URL or the chat. - check_media_compatibility: Check a file's size and format before it goes out. - retry_post: Publish a failed post again. ### Insights What each post did, and when to post the next one. Try asking: "Did my threads do better than my single posts this month?" - get_post_analytics: The numbers Mastodon reports for one post. - get_posts_analytics: The numbers for many posts at once, to compare them. - get_account_analytics: Your followers, following and posts. - get_best_times: Your best days and hours from your own posts, or industry defaults until you have 15. - get_recent_platform_posts: Your latest posts with their likes and boosts, also the ones made in Mastodon. ### Approvals Your team or client signs off before a post goes out. Try asking: "Approve the Mastodon posts that are waiting for me." - list_approval_workflows: The review steps a post can go through. - approve_post: Approve a post that waits for you. - reject_post: Send a post back with what to change. - get_post_approval: Where a post stands in its review. ### Accounts and setup Which account, which workspace, which images. Try asking: "Which workspaces can you post to? Find the threads launch image." - list_accounts: The accounts connected to the workspace. - switch_workspace: Work in another workspace. - list_media: Find an image in your library before uploading it again. - create_webhook: Get an event when a post is scheduled, published, approved, rejected or fails. ## FAQ ### What is the Mastodon MCP server? It is the OmniSocials MCP server with your Mastodon account connected. Your AI agent calls its tools to post, schedule threads and read your numbers. The server lives at https://mcp.omnisocials.com, and the same tools post to your other channels too. ### Does it work with my Mastodon server? Yes, with any Mastodon server. Type its address when you connect Mastodon in OmniSocials and sign in there. OmniSocials registers itself with your server, so there's no app to set up. Your server's character and link limits are read when you connect, and every post is checked against them. Posts go out as public. ### Can my agent post a poll? Not yet. The MCP server doesn't take Mastodon polls. You can add a poll to a Mastodon post in the OmniSocials composer. ### Can it post a thread? Yes. create_post takes 2 to 25 parts, each within your server's character limit (500 by default) and each with up to 4 images and their descriptions. OmniSocials posts them in order, each a reply to the one before. ### Can it answer Mastodon replies? No. Mastodon replies don't come into the Social Inbox, so the MCP server has no reply tools for Mastodon. Your agent can still read how many replies each post got. ### Can it read other people's Mastodon accounts? No. It works with the account you connected: your posts and your numbers. It doesn't scrape other accounts, timelines or followers. ### How do I connect Claude, ChatGPT or Cursor to Mastodon? Connect Mastodon in OmniSocials first. In Claude, open Customize, then Connectors, click Add, choose Add custom connector and paste https://mcp.omnisocials.com. In ChatGPT, add the same URL as a custom MCP server under Plugins; in Cursor, put it in ~/.cursor/mcp.json. Each one sends you to OmniSocials to sign in and pick a workspace. ### Can an AI agent post to Mastodon safely? Yes. Your agent can send a post through an approval workflow: it waits until a teammate or client approves it, and only then goes out at its time. You can also ask your agent to save drafts, or to show you each post before it schedules it. ### Does the Mastodon MCP server need a paid plan? It needs an active OmniSocials plan or the 14-day free trial; without one, the server turns the connection down. The trial needs a card to start, and the MCP server is part of the one plan, like every other feature. ### How much does OmniSocials cost? One plan with every feature included: $10 per seat per month billed annually, or $12 billed monthly. Team members and client seats cost the same. Every account starts with a 14-day free trial. ## Related ### Set up your agent - [Claude](https://omnisocials.com/claude) - [ChatGPT](https://omnisocials.com/chatgpt) - [Claude Code](https://omnisocials.com/claude-code) - [Codex](https://omnisocials.com/codex) - [Cursor](https://omnisocials.com/cursor) - [Every agent](https://omnisocials.com/mcp) ### Mastodon - [Mastodon scheduler](https://omnisocials.com/mastodon) - [Mastodon scheduling tools compared](https://omnisocials.com/blog/mastodon-scheduler) - [Cross-post to Bluesky and Mastodon](https://omnisocials.com/blog/cross-post-bluesky-mastodon) - [Connect Mastodon](https://omnisocials.com/help-center/integrations/mastodon) ### For developers - [MCP server docs](https://docs.omnisocials.com/mcp-server) - [Mastodon API](https://omnisocials.com/mastodon-api) - [CLI](https://omnisocials.com/cli) ## More machine-readable pages - [Mastodon](https://omnisocials.com/mastodon.md) - [Mastodon API](https://omnisocials.com/mastodon-api.md) - [All channels](https://omnisocials.com/channels.md) - [MCP server](https://omnisocials.com/mcp.md) - [REST API](https://omnisocials.com/api.md) - [Pricing](https://omnisocials.com/pricing.md) - [llms.txt](https://omnisocials.com/llms.txt)