Configuration

mm-mcp reads its configuration from its environment, which an MCP client sets in the server's env block. No setting is a command-line flag that carries a secret (ADR-019).

Environment variables

MM_URL

Required. The address you open Mattermost at, such as https://chat.example.com. An http or https address, without a query.

MM_TOKEN

Required. The credential mm-mcp acts with: a personal access token, a bot token, or a session token. The server acts as whoever owns it.

MM_MCP_ALLOW_WRITES

Optional, false by default. true offers the tools that post and change things in Mattermost. A change others see, such as a post, a reply, an edit, a deletion, a reaction or a pin, asks you before it acts. A change that is yours alone or gone in seconds does not: following a thread, saving a post, setting a reminder, saving a draft, and showing that you are typing (ADR-021). Accepts true, false, 1, 0, yes, no, on and off.

MM_MCP_MARK_AI_GENERATED

Optional, true by default. Every post and edit the model writes carries Mattermost's own marker for text written with AI, which its web app shows beside the post's time (ADR-031). false leaves it out.

MM_MCP_DOWNLOAD_DIR

Optional. The directory save_file writes attachments to, when the server runs over stdio on your own machine. Your Downloads directory by default. An existing file is never overwritten (ADR-029).

MM_MCP_BLOCK_EXTERNAL_NETWORK

For mm-mcp's own tests. While it is 1, mm-mcp refuses to reach any address but the loopback ones (ADR-006). Leave it unset.

Command line

mm-mcp serve

Runs the server over stdio, for a client that starts it as a process.

mm-mcp serve --transport http [--host 127.0.0.1] [--port 8765]

Runs it over Streamable HTTP, on a loopback address only.

mm-mcp version

Prints the installed version.

mm-mcp help

Prints the commands and where the configuration comes from. --help and -h do the same.

A configuration error exits with status 2 and says which setting is wrong.