Claude Code drafts it. You approve it. PostDelegate posts it.Mastodon: Posts and threads on mastodon.social, with images or a video.
How to post to Mastodon from Claude Code
- Add PostDelegate to Claude Code. Add the PostDelegate MCP server with the command below. Run /mcp inside Claude Code and authenticate the postdelegate server. Your browser opens to sign in.
Terminal
claude mcp add postdelegate --transport http "https://app.postdelegate.com/mcp-oauth-dynamic" - Connect Mastodon in PostDelegate. On the calendar page choose Add Channel, then Mastodon. Sign in to your mastodon.social account and approve the permissions PostDelegate asks for: reading your profile, publishing posts and uploading media.
- Ask Claude Code for a draft. Describe the post in plain words. Claude Code checks your Mastodon channel's rules, creates the post and sends back a preview link.
Teach Claude Code the posting rules
Save the PostDelegate skill to ~/.claude/skills/postdelegate/SKILL.md. Call it with /postdelegate, or just ask for a post and Claude Code loads it. Agent files has the steps.
What to ask Claude Code
Mention any Mastodon setting in plain words and Claude Code fills it in. Claude Code can also read text files in your project, such as a changelog or a draft in Markdown.
- Draft a Mastodon post about our open-source release, under 500 characters, with two relevant hashtags.
- Which Mastodon posts do I have scheduled next week? Move nothing, just list them.
- Summarise the README’s “Why” section as a Mastodon thread and save it as a draft.
What Claude Code can do on your Mastodon channel
- Check the rules first. Before writing, it reads your Mastodon channel's length limit (500 characters) and required settings.
- Draft, schedule or post. It creates a draft, a scheduled post or an immediate post, and runs the same checks as the app.
- Use your media. It attaches files from your media library or adds one from a public link.
- Review and fix. It lists what is scheduled, changes the Mastodon settings of a post that has not gone out, and deletes posts you no longer want.
A Mastodon post is up to 500 characters with up to four images or one video. PostDelegate keeps the text and media together with the planned post, publishes it as a public post at the time you pick, and turns extra entries into a thread of replies.
Before you start
- PostDelegate connects accounts on mastodon.social. Accounts on other Mastodon servers cannot be connected yet.
- Posts are published as public posts, limited to 500 characters with up to four images or one video.
The Mastodon channel guide has every field, and MCP tools lists exactly what an assistant can and cannot do.
Questions
Will Claude Code publish to Mastodon without asking me?
Do I need an API key to connect Claude Code?
Does it cost extra to use Claude Code with PostDelegate?
Can Claude Code attach images or video to a Mastodon post?
Can I connect an account on another Mastodon server?
Can I schedule a Mastodon thread?
Mastodon from other assistants
Other networks from Claude Code
- YouTube
- Bluesky
- Google Business Profile
- Telegram
- Discord
- Slack
- Tumblr
- Lemmy
- Nostr
- Twitch
- Kick
- Dribbble
- DEV.to
- Medium
- WordPress
- Hashnode
- Listmonk (email)
Prefer to plan Mastodon posts yourself? See the Mastodon scheduler.