MCP servers
Connect any MCP server as a custom integration and use its tools in blueprints.
The Model Context Protocol (MCP) is an open standard for exposing tools to an AI. If a service you use offers an MCP server, you can add it to Postface as a custom integration and let your blueprints call its tools. Granola and Canva are connected this way behind the scenes.
Adding a server
- Open your profile menu, choose Integrations, then Add custom integration.
- Fill in the template below and tap Test connection.
- If the server needs a sign-in, you are sent to its login page and back again.
- Tap Create integration. It now appears in the list with a tool count.
| Field | Notes |
|---|---|
| Name | How it is shown in the app and in blueprint chips. |
| Server URL | The server's HTTPS endpoint. Postface talks to servers over Streamable HTTP. Each URL can be added once per account. |
| Auth type | None, API key or OAuth. API keys are stored encrypted and sent only to that server. OAuth servers open their own sign-in. |
| Short description | Up to 120 characters. Shown in lists and blueprint chips. |
| Description | Up to 600 characters. Given to Postface's assistant next to the server's tools so it knows when to use them. Describe what the service holds and what it is good for. |
States
- Connected — reachable and its tools are listed. Blueprints can use it.
- Sign in needed — the server requires OAuth and the sign-in has not finished. Tap it to complete.
- Failed — the last check did not succeed; the reason is shown. Use Refresh after fixing the URL or key.
Using it in a blueprint
Working custom integrations appear as chips in the blueprint composer alongside Gmail, Calendar and the others. Select the chip and refer to the service by name in your instruction. Only the tools that server exposes are available to that run.
Managing
The custom integrations page lets you edit the description, replace an API key, refresh the tool list or remove the server. Removing it also removes it from any blueprint that used it.