API and MCP server — cometpost

Connect an assistant

The server is hosted at https://mcp.cometpost.app/mcp and speaks Streamable HTTP. Sign in to the dashboard and connect a social account first: an assistant can only reach Channels that exist.

Claude and ChatGPT: add it by URL

Claude: Settings, Connectors, Add custom connector, paste the URL.
ChatGPT: turn on developer mode, then add a connector with the same URL.

The assistant sends you to Google to sign in, then to a consent page where you choose which Channels it may use and whether it may schedule posts itself. Scheduling is off by default, so the assistant creates drafts and you publish them. No key to copy.

Claude Code, Cursor and scripts: use a key

Create a credential in the dashboard under New credential, choose its Channels and whether it may schedule, and send it as a bearer token. The secret is shown once.

{
  "mcpServers": {
    "cometpost": {
      "url": "https://mcp.cometpost.app/mcp",
      "headers": { "Authorization": "Bearer cp_live_..." }
    }
  }
}

You can revoke a key or an assistant at any time in the dashboard; it takes effect on the next request.

What an assistant can do

The server offers 15 tools, grouped here by job.

Find out what is possible: list your Channels, list platforms with their caption limits, media rules and options, and ask one Channel what it can do right now.
Media: list reusable media, upload from a public URL (up to 64 MiB), send a small image inline (up to 5 MiB), or start and complete a direct upload for files up to 512 MiB.
Posts: validate a post without saving it, create a post, edit it, list and search posts, read one post's status per destination, cancel a post, and re-arm a post whose schedule failed to start.
Timing: reschedule a single destination of a post.

Creating a post is safe to repeat: every call carries an idempotency key, so a retry after a lost reply does not post twice. Posts are checked against each platform's limits before they are accepted, and a refusal says what to change.

What stays with you

Releasing a draft, retrying a failed delivery, deleting a post or media, disconnecting an account, billing and managing credentials all need you signed in to the dashboard. A key or an assistant that asks for one of them is refused, whatever its settings. An assistant cannot approve its own draft.

Publishing is final. Once a post has gone live, cometpost cannot recall it. Each key and each connected assistant gets 1000 requests per UTC day.

Platform status

An assistant can only publish where cometpost is live. Today:

Platform	Status	What works
Threads	Live	Text posts, with one image or video. Details.
Instagram	Live	Feed images (JPEG) and image carousels on professional accounts. No Reels or video. Details.
YouTube	Limited release	You can connect a channel. Until Google completes its audit of our API access, videos uploaded through cometpost stay private.
Facebook Pages	In review	Not available yet. It is waiting on Meta's app review.
TikTok	Coming soon	Not available yet. Planned: send a video to your TikTok drafts, where you add the caption and finish posting.
X	Coming soon	Not available yet.

Each platform goes live only after that platform approves cometpost's API access. That is the platform's decision.

The HTTP API

The MCP server uses the same public API as the dashboard, so anything it can do, a script can do directly. Everything is under https://api.cometpost.app/v1, with the same bearer credentials.

OpenAPI 3.1 description (/v1/openapi.json), no key needed to fetch it.
llms.txt, a short plain-text guide written for agents.

Connecting a social account needs a person in a browser; it is not part of the API. Questions or a missing tool? Email hello@cometpost.app.