Mattermost

Let your agents work in your Mattermost workspace: read teams, channels, posts and users, search messages, post and reply in threads, send direct messages, create channels and add reactions.

Connection

Authentication: API key (Mattermost personal access token).
Required settings:
- Mattermost server domain — The domain of your Mattermost server, without https:// nor path (e.g. chat.example.com or yourteam.cloud.mattermost.com). Mattermost must be served over HTTPS at the root of this domain.

Personal access tokens must first be enabled by a System Admin in System Console → Integrations → Integration Management (“Enable Personal Access Tokens”). By default only System Admins may create one: for another account, go to System Console → User Management → Users, open the account’s dropdown → Manage Roles, select “Allow this account to generate personal access tokens” and Save. Then, signed in as that account: Profile → Security → Personal Access Tokens → Create Token, enter a description, Save, and copy the access token (it is shown only once). The agents act with this user’s permissions and only see the teams and channels it belongs to: a dedicated non-admin account is recommended.See Mattermost’s documentation.

Read actions (10)

Action	Description
`get_channel`	Get a channel by id (name, display name, type O public / P private / D direct / G group, purpose, header).
`get_channel_by_name`	Find a channel of a team by its name, the handle shown in the channel URL (e.g. town-square), not its display name. include_deleted: optional boolean to also find archived channels.
`get_me`	Get the Mattermost user behind the token (id, username, names, locale). Its id is the user_id that create_direct_channel and add_reaction require.
`get_post`	Get a single post by id (message, channel_id, user_id, root_id of its thread, create_at in Unix milliseconds).
`get_user_by_username`	Get a user by username (without the leading @). Returns its id, needed to open a direct message.
`list_channel_posts`	List posts of a channel, newest first, as { order: [post ids], posts: { id: post } }. page (from 0) and per_page (1-200, default 60) paginate; before / after: a post id to page around it; since: Unix time in milliseconds, returns posts modified after it and cannot be combined with page, per_page, before or after.
`list_my_channels`	List the channels the token user is a member of in a team (team_id from list_my_teams). include_deleted: optional boolean to include archived channels.
`list_my_teams`	List the teams the token user belongs to (id, name, display_name, type, description). A team id is needed to list, find or create channels and to search posts. Team invite codes are removed.
`search_posts`	Search posts in a team (read-only query sent as a POST body), results as { order, posts }. terms: string (required) — words to find, “from:username” and “in:channel-name” narrow it; is_or_search: boolean (required) — true matches any word, false all words; time_zone_offset: optional integer, seconds from UTC for on:/before:/after: dates; include_deleted_channels: optional boolean for archived channels; page / per_page: optional integers (only honored by servers using Elasticsearch/OpenSearch).
`search_users`	Search users by username, full name, nickname or email (read-only query sent as a POST body). term: string (required); team_id / in_channel_id: optional ids to restrict the search; allow_inactive: optional boolean; limit: optional integer 1-100 (default 100).

Write actions (4)

Action	Description
`add_reaction`	Add an emoji reaction to a post. Arguments: user_id: the token user’s own id string (from get_me — Mattermost refuses any other user); post_id: post id string; emoji_name: string, the emoji name without colons (e.g. “thumbsup”, “white_check_mark”).
`create_channel`	Create a channel in a team. Arguments: team_id: team id string (from list_my_teams); name: string, the URL handle, 2-64 lowercase letters, digits, ”-” or ”_”, starting and ending with a letter or digit; display_name: string shown in the UI (1-64 characters); type: “O” (public) or “P” (private); purpose: optional plain-text string (max 250); header: optional Markdown string (max 1024). The token user needs the create_public_channel or create_private_channel permission.
`create_direct_channel`	Open (or get, if it already exists) the direct message channel between the token user and another user, then post in it with create_post. Arguments: user_ids: array of exactly 2 user id strings — the token user’s own id (from get_me) and the other user’s id (from get_user_by_username or search_users). Returns the channel; its id is the channel_id for create_post.
`create_post`	Post a message in a channel, or reply in a thread. Arguments: channel_id: channel id string (from list_my_channels, get_channel_by_name or create_direct_channel); message: Markdown string (1-16383 characters); root_id: optional post id string of the thread’s first post to reply in that thread (for a reply, use the root_id of the post you answer if it has one, else its id). The token user needs the create_post permission in the channel.

Permissions

Every action above must be explicitly granted to an agent before it can be used. See Permissions for the grant model and Security for how credentials are protected.

Last reviewed against the provider API: September 2026.

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Connection

Read actions (10)

Write actions (4)

Permissions

​Connection

​Read actions (10)

​Write actions (4)

​Permissions

Connection

Read actions (10)

Write actions (4)

Permissions