Mastodon posting API
yeetpost posts to Mastodon with one HTTP call: POST the text to /api/v2/post/mastodon with an API key. It works on any instance and checks the text against that instance's own character limit, read when you connect.
Post with curl
curl -X POST https://api.yeetpost.com/api/v2/post/mastodon \
-H "x-api-key: $YEETPOST_API_KEY" \
-d 'new release is out, notes are on the blog'The body is the post. The slug in the path is your connection's slug; GET /api/v2/connections lists yours. For several connections, scheduling, drafts and idempotency use POST /api/v2/posts, see the posting guide.
Post from an agent over MCP
claude mcp add --transport http \
--header 'Authorization: Bearer ${YEETPOST_API_KEY}' \
yeetpost https://api.yeetpost.com/api/v2/mcp
# then ask Claude: post this to my Mastodon accountThe hosted MCP server also accepts an OAuth login, so claude.ai can add it as a custom connector with no key. See MCP for agents.
Mastodon limits
| Text | The instance's own limit, read when you connect (500 by default). A link counts 23, a mention its local part |
|---|---|
| Images | Up to 4 per post (png, jpeg, gif, webp), alt text sent |
| Threads | Yes, up to 24 replies under the head status |
| First comment | No |
| Delete | Yes |
| Metrics read back | Yes |
A post over a text limit is refused whole with 400 text_too_long and a field naming the part to shorten, before anything is sent.
Connecting Mastodon
Type your instance's host in the yeetpost dashboard and approve the request on your instance. yeetpost registers itself on the instance the first time, so you need no developer app of your own.
Fees
Posting to Mastodon is free. Billing is per connected account: the first 2 are free.
Posts are unlimited on every plan. See pricing.
Docs
Last verified 2026-10-29