Post to Mastodon with Claude
Mastodon has no single API to sign up for. Every instance is its own server with its own app registration, its own tokens, and its own limits. RobinReach handles that per-instance setup once, so Claude can write and schedule your posts through one MCP URL, whichever server you call home.
- No Mastodon API setup
- No code, one MCP URL
- Works with ChatGPT and Codex too
One network, thousands of servers
The Mastodon API is a pleasure to read and a chore to run.
Every instance is a new integration
There is no central developer portal. You register an application on your own server, collect a client id and secret, and repeat the whole dance for every instance you post from.
Media that is not ready yet
Upload a video and Mastodon accepts it, then keeps processing it in the background. Attach it too early and the post fails. You have to poll until it is done.
No scheduling in the app
Mastodon itself has no post scheduler for normal accounts. Anything time-based means writing a job runner and keeping it alive.
Why Claude can't post to Mastodon on its own
Claude writes brilliant posts, but out of the box it has no account access, no publishing rights, and no scheduler. RobinReach's MCP server is the missing pair of hands.
Claude by itself
- Cannot log in to Mastodon or hold OAuth tokens for your account.
- Cannot publish, schedule, or upload media. The draft dies in the chat window.
- The workaround is the Mastodon API: developer registration, reviews, token refresh, and format rules, all maintained by you.
- You end up as the copy-paste middleman for every single post.
Claude + RobinReach over MCP
- RobinReach holds the official, compliant Mastodon connection. You authorize it once with a normal OAuth click.
- One MCP URL gives Claude real tools: draft, validate, attach media, schedule, and publish.
- RobinReach handles tokens, rate limits, media processing, and Mastodon's format rules for you.
- The same connector covers all 13 RobinReach networks, so one setup unlocks every channel.
Connect Claude to Mastodon in 3 steps
No developer account, no app review, no code, no API key. If you can paste a URL and sign in, you are qualified.
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1
Copy the MCP URL
Create a free RobinReach account and connect Mastodon with one OAuth click. Then copy the RobinReach MCP URL. It is the same for everyone and has no API key in it.
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2
Add it to Claude
In Claude, open Settings, then Connectors, click Add custom connector, name it RobinReach, paste the URL and click Add. It works the same in Claude Desktop, with no config file.
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3
Click Connect and sign in
A RobinReach window opens. Sign in, keep your whole account selected or pick one brand under "Or connect a single brand", and click Connect. No API key needed.
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โ
Say "Hi Robin"
Claude discovers RobinReach's tools on its own. Ask it to write and schedule your first Mastodon post and watch it appear on your calendar.
# In Claude: Settings, then Connectors, # then Add custom connector Name: RobinReach URL: https://robinreach.com/mcp/v1/messages # Then click Connect and sign in to RobinReach. # Pick your whole account or a single brand. No API key.
Coming soon to the Claude directory
The same URL works in ChatGPT, with the same sign-in. For now you add it through developer mode on a paid ChatGPT plan. ChatGPT app coming soon.
Using Claude Code? Run claude mcp add --transport http robinreach https://robinreach.com/mcp/v1/messages, then run /mcp, select robinreach and choose Authenticate. Full instructions for every AI client, including the tools that use an API key, are on the AI setup guide.
What posting to Mastodon from Claude looks like
You describe the outcome in plain language. Claude uses RobinReach's tools to do the rest.
More example prompts for planning, writing, and scheduling live on the AI setup guide.
Everything Claude can publish on Mastodon
RobinReach exposes Mastodon's formats and rules to Claude as tools, so posts come out platform-native, not copy-pasted.
Text posts
Conversational posts inside the 500 character limit, written for an audience with no algorithm to game.
Image posts
Up to four images per post, uploaded and attached with the processing wait handled for you.
Video posts
One MP4 or WEBM per post, uploaded and held until the instance finishes transcoding it.
Reply threads
Up to ten connected replies under the main status, each with its own image if you want one.
Any instance
mastodon.social, your company server, or a niche community. Connect the domain and RobinReach does the rest.
Real scheduling
Mastodon has no built-in scheduler. Claude plus RobinReach gives you one, driven by plain language.
Posting to Mastodon with Claude, answered
How do I post to Mastodon with Claude?
Which Mastodon instances are supported?
Can Claude post threads on Mastodon?
What is the character limit?
Can I attach images and video?
Does Mastodon have a built-in scheduler?
Can I use ChatGPT instead of Claude?
Can I connect Claude to just one client's brand?
Keep exploring
Mastodon Scheduling
See how RobinReach connects any Mastodon instance and schedules posts, images, and reply threads alongside your other networks.
Explore the schedulerPost with Claude on every network
One connector covers LinkedIn, X, Instagram, TikTok, and more. See every platform Claude can publish to.
All AI integrationsThe full AI setup guide
Step-by-step instructions for Claude, ChatGPT, Codex, and the API, plus every MCP tool RobinReach exposes.
Open the guideComparing AI posting tools for Mastodon?
Give Claude publishing hands on Mastodon
Free account, one OAuth click, one MCP URL. Your first AI-scheduled Mastodon post is about three minutes away.