Limits and credits

Per minute

Each API key or connected app can make 60 requests a minute. Over that, 429 rate_limited with Retry-After in seconds.

Per day

Each account has a daily number of actions and of publish actions. The MCP server and the REST API share them, and they reset at 00:00 UTC.

• Actions: every REST action and every MCP tool call.
• Publish actions: each post scheduled or published, each reply sent, and each change to an inbox item or existing post.

Over a daily limit, the REST API answers 429 limit_reached with the reset time, and MCP returns a tool error that says the same:

{
  "ok": false,
  "error": {
    "code": "limit_reached",
    "message": "Daily publish limit reached: 150 of 150 publish actions used today, and this needs 1. It resets at 2026-11-03T00:00:00.000Z (00:00 UTC).",
    "limit": "publishes",
    "max": 150,
    "used": 150,
    "resetsAt": "2026-11-03T00:00:00.000Z"
  }
}

Settings > Developers shows today's usage.

AI credits

There is no fee for the API or the MCP server. AI work, such as images, posters, videos and remixes, uses your AI credits exactly as it does in the app. Some platforms charge Chirpy for each post or reply made through their API (X does), so publishing there through the API also uses AI credits. The response shows creditsCharged. Without enough credits, nothing runs and you get 402 insufficient_credits.