// SCAN REPORT

Mattermost

9 tools. 4 can modify or destroy data without limits.

4 write tools that can modify data. Rate limits recommended.

Last updated: 29 Jun 2026

4 can modify or destroy data

5 read-only

9 tools total

Community server · catalogue entry verified 29/06/2026

How to control Mattermost ↓

TOOL MAP

What Mattermost exposes to your agents

Read (5) Write / Execute (4) Destructive / Financial (0)

Running more than one server? Check your whole stack →

MOST DANGEROUS TOOLS

High Risk

The most dangerous Mattermost tools

Execute · Medium mattermost_run_monitoring This tool triggers execution of a monitoring process whose effects depend on system state and configuration. Write · Low mattermost_add_reaction Adding a reaction is a reversible write operation that creates or associates data (emoji reaction) with a message. Write · Medium mattermost_post_message This tool creates new messages in Mattermost channels, which is a Write operation—it modifies channel state by adding content. Write · Medium mattermost_reply_to_thread This tool creates a new message in an existing thread, which is a reversible write operation.

4 of Mattermost's 9 tools can modify, destroy, or commit something on every call — and an agent calls them with no built-in limits.

POLICY

How to control Mattermost

PolicyLayer is an MCP gateway — it sits between your AI agents and Mattermost, and nothing reaches the server without passing your rules. These are the rules we recommend:

Rate limit write operations

{
  "mattermost_add_reaction": {
    "limits": [
      {
        "counter": "mattermost_add_reaction_per_hour",
        "window": "hour",
        "max": 30,
        "scope": "grant"
      }
    ]
  }
}

Prevents bulk unintended modifications from agents caught in loops.

Cap read operations

{
  "mattermost_get_channel_history": {
    "limits": [
      {
        "counter": "mattermost_get_channel_history_per_minute",
        "window": "minute",
        "max": 60,
        "scope": "grant"
      }
    ]
  }
}

Controls API costs and prevents retry loops from exhausting upstream rate limits.

Create a free account and register Mattermost — nothing to install.
Add these rules — paste them, or build them visually. Tune the limits to your setup.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

ENFORCE POLICY ON MATTERMOST →

Instant setup, no code required.

FULL CATALOGUE

All 9 Mattermost tools

EXECUTE 1 tools

Execute mattermost_run_monitoring Run the topic monitoring process immediately

WRITE 3 tools

Write mattermost_add_reaction Add a reaction emoji to a message Write mattermost_post_message Post a new message to a Mattermost channel Write mattermost_reply_to_thread Reply to a specific message thread in Mattermost

READ 5 tools

Read mattermost_get_channel_history Get messages from a Mattermost channel. By default returns ALL messages. Use limit parameter to restrict the n Read mattermost_get_thread_replies Get all replies in a message thread Read mattermost_get_user_profile Get detailed profile information for a specific user Read mattermost_get_users Get a list of users in the Mattermost workspace with pagination Read mattermost_list_channels List channels in the Mattermost workspace. By default lists public team channels. Set include_private=true to

EXPLORE

Related servers

Other MCP servers with similar tools — same risk classification, starter policies for each.

FAQ

Questions about Mattermost

How do I prevent bulk modifications through Mattermost? +

The Mattermost server has 3 write tools including mattermost_add_reaction, mattermost_post_message, mattermost_reply_to_thread. Set a rate limit in your policy -- for example, 10 calls per hour prevents an agent from making more than 10 modifications per hour. PolicyLayer enforces this at the gateway, before calls reach Mattermost.

How many tools does the Mattermost MCP server expose? +

9 tools across 3 categories: Execute, Read, Write. 5 are read-only. 4 can modify, create, or delete data.

How do I enforce a policy on Mattermost? +

Register the Mattermost MCP server in PolicyLayer, apply the suggested rules above (adjust the limits to your use case), and point your AI client at the PolicyLayer proxy URL instead of the server directly. Your agents keep the same tools; PolicyLayer evaluates every call against policy before it executes. Nothing to install, live in minutes.

Enforce policy on every Mattermost tool call.

Deterministic rules across all 9 Mattermost tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.

ENFORCE POLICY ON MATTERMOST →

Instant setup, no code required.

9 Mattermost tools catalogued and risk-classified — across an index of 43,000+ MCP servers.