mcp-server-mattermost AGENTS.md

Project instructions for an MCP server that exposes Mattermost, a team chat platform, through tools for AI assistants.

In plain words
What is it for?
Use them when installing dependencies, testing, linting, type-checking, running, or extending the Mattermost integration.
Why use it?
They describe the server structure, required commands, API references, and coding standards needed to change it safely.

Instructions file for CodexOpenCode

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add instructions/cloud-ru-tech/mcp-server-mattermost/agents-md
Clone the repo
git clone --depth 1 https://github.com/cloud-ru-tech/mcp-server-mattermost

Made for: Codex, OpenCode.

Per session 2,355 This file is loaded in full into every session.
When invoked 2,355 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.02355 $0.02355
Opus 5 $0.01177 $0.01177
Sonnet 5 $0.00471 $0.00471
Haiku 4.5 $0.00235 $0.00235

Measured yesterday against content hash 7e9357daf264, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

mcp-server-mattermost AGENTS.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

AGENTS.md · 267 lines

How it starts

The opening of the file, as written. The whole thing — 267 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

Project Overview

MCP server for Mattermost integration. Exposes Mattermost REST API operations as MCP tools for AI assistants (Claude Desktop, Cursor).

Architecture:

MCP Client (Claude Desktop, Cursor)
    ↓ (stdio JSON-RPC)
FastMCP Server
    ├── Tools Layer (channels, messages, posts, users, teams, files, bookmarks)
    ├── Pydantic Models (validation + schema generation)
    └── MattermostClient (async HTTP with retry)
        ↓ (HTTPS)
Mattermost Server (REST API v4)

Documentation References

Commands

# Install dependencies
uv sync

# Run tests
uv run pytest

# Run specific test file
uv run pytest tests/test_config.py -v

# Lint
uv run ruff check src tests

# Format
uv run ruff format src tests

# Type check
uv run mypy src

# Run the server
uv run mcp-server-mattermost

Code Style

  • Python 3.10+ (use list[], dict[], X | None syntax)
  • 120-character line length
  • Google-style docstrings
  • Type hints required (mypy strict mode)
  • Two blank lines after imports
  • Ruff with ALL rules enabled (see pyproject.toml for exceptions)

Key Source Files

  • src/mcp_server_mattermost/__init__.py - Package entry, exports main() and __version__
  • src/mcp_server_mattermost/server.py - FastMCP instance creation, lifespan, FileSystemProvider
  • src/mcp_server_mattermost/deps.py - Dependency injection providers (get_client)
  • src/mcp_server_mattermost/auth.py - MattermostTokenVerifier for per-client token auth
  • src/mcp_server_mattermost/client.py - Async HTTP client with retry logic
  • src/mcp_server_mattermost/config.py - Settings via pydantic-settings (env vars prefixed MATTERMOST_)
  • src/mcp_server_mattermost/exceptions.py - Exception hierarchy (MattermostMCPError base)
  • src/mcp_server_mattermost/logging.py - Logging setup (stderr per MCP spec)
  • src/mcp_server_mattermost/middleware.py - FastMCP middleware for error handling
  • src/mcp_server_mattermost/enums.py - Capability and ToolTag enums for tool metadata
  • src/mcp_server_mattermost/tools/ - MCP tool implementations by category
  • src/mcp_server_mattermost/models/ - Pydantic models for validation

Read the full file on GitHub · 267 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. yesterday First seen · 267 lines · 2,355 tokens per session scan A 7e9357daf264

Subscribe to this mod's changes

mcp-server-mattermost AGENTS.md is an instructions file published in the GitHub repository cloud-ru-tech/mcp-server-mattermost (42 stars, last pushed 17d ago), licensed MIT. It adds 2,355 tokens to every session, about $0.0118 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.