What MCP is

MCP (Model Context Protocol) is an open standard that lets an AI assistant use tools in other apps. An MCP server is the part of an app that offers those tools. Postra has one, so an assistant such as Claude Code, Cursor or Codex can work in your Postra workspace when you ask it to.

What your assistant can do in Postra

List your connected channels.
Write posts and schedule them, save them as drafts or publish them now.
Make AI images and videos, or a caption with a matching branded graphic.
Copy an image or video from a public link into your media library, or find files already there.
Show what is planned in your calendar, including posts that failed and why.
Read analytics for a channel.
Pass a whole request to Postra’s own assistant in plain words, with the ask_postra tool.

The full list is on the Tools page.

Server address

https://app.postra.co.uk/api/mcp

The server uses streamable HTTP. Every request needs an Authorization header.

How it signs in

Credential	Who uses it	Header
Your API key	You, for your own workspace	`Authorization: Bearer YOUR_API_KEY`
An OAuth access token (starts with `pos_`)	An app that a Postra user has approved through Sign in with Postra	`Authorization: Bearer pos_ACCESS_TOKEN`

Your API key is in Settings → Developers → Access. Only owners and admins see this tab. The key gives full access to the workspace, so keep it private. If it leaks, choose Rotate Key: the old key stops working straight away.

Step-by-step setup for each assistant is on Connect your assistant.

Limits

Limit	Value
Plan	Every paid plan. Without an active subscription the server answers `401 No subscription found`.
Requests	120 requests every 5 minutes per workspace. After that the server answers `429 Too many requests` until the 5 minutes are up.
Questions in one request	At most 5 `ask_postra` questions in one batched request.
Assistant questions a month	2,200 per workspace, the same on every plan. It is shared with the assistant inside Postra and resets with your next billing month.

The monthly limit counts questions to ask_postra only. The other tools do not use it, but AI images and videos use your plan’s monthly AI image and video allowance, and scheduled posts count towards your plan’s monthly posts. Drafts do not count.

Scheduling through `ask_postra`

Your assistant has already checked the request with you, so Postra does not ask again.

If the request names the channel, the date and time and the text, Postra schedules it and replies with exactly what it scheduled: channel, date and time with time zone, text and attachments.
If any of these is missing or unclear, nothing is scheduled. Postra replies with what is missing, so you can send the request again in one message.

Each question to ask_postra stands on its own. Postra does not remember earlier questions, so put everything it needs in one message.

Moving and deleting posts

Moving or deleting a post is never done through MCP. Your assistant can only ask for it, and there is no Approve button outside Postra. To move or delete a post, open Postra and do it in the calendar, or ask the assistant inside Postra, which shows an Approve button.

Errors you may see

Answer	Meaning
`401 Missing Authorization header`	The request had no `Authorization` header.
`401 Invalid API Key or OAuth token`	The key or token is wrong, was rotated or was revoked.
`401 No subscription found`	The workspace has no active paid plan.
`429 Too many requests`	More than 120 requests in 5 minutes. Wait and try again.
“Ask at most 5 questions in one request.”	Too many `ask_postra` calls in one batch.
“You have reached this month’s fair-use limit for the AI assistant”	The 2,200 questions for this month are used.