Borrowing it
Nothing to install: this file belongs to mjknowles/matrix-mcp-server. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/mjknowles/matrix-mcp-server/main/CLAUDE.mdgit clone --depth 1 https://github.com/mjknowles/matrix-mcp-serverWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/instructions/mjknowles/matrix-mcp-server/claude-md)<a href="https://agentmods.dev/instructions/mjknowles/matrix-mcp-server/claude-md"><img src="https://agentmods.dev/badge/instructions/mjknowles/matrix-mcp-server/claude-md/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/instructions/mjknowles/matrix-mcp-server/claude-md"><img src="https://agentmods.dev/badge/instructions/mjknowles/matrix-mcp-server/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.01505 | $0.01505 |
| Opus 5.5 | $0.00602 | $0.00602 |
| Sonnet 5.5 | $0.00301 | $0.00301 |
| Haiku 4.5 | $0.00151 | $0.00151 |
Grade A, and why
matrix-mcp-server CLAUDE.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 2mo ago.
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.
How it starts
The opening of the file, as written. The whole thing — 181 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.
Repository Overview
This is a Matrix MCP (Model Context Protocol) server implemented in TypeScript that provides secure access to Matrix homeserver functionality. The server acts as a bridge between MCP clients and Matrix homeservers, implementing OAuth 2.0 token exchange with Keycloak for authentication.
Core Architecture
HTTP Server Layer (src/http-server.ts)
- Express-based HTTP server exposing MCP endpoints
- OAuth 2.0 integration with Keycloak authentication provider
- Proxy OAuth provider for token verification and client management
- Serves on port 3000 with
/mcpendpoint for MCP communication
MCP Server Implementation (src/server.ts)
- Core MCP server with Matrix-specific tools
- Implements token exchange flow with Keycloak for Matrix authentication
- Provides tools for Matrix operations: room listing, message retrieval, member management
- Each tool creates ephemeral Matrix clients that authenticate via token exchange
Authentication Flow (src/verifyAccessToken.ts)
- JWT token verification using Keycloak's JWKS endpoint
- Fetches user information from Keycloak userinfo endpoint
- Handles self-signed certificates for local development
Request Routing (src/routes.ts, src/route-handlers.ts)
- Simple Express router handling POST requests for MCP communication
- Uses StreamableHTTPServerTransport for MCP protocol handling
- Returns 405 for non-POST methods
Development Commands
# Install dependencies
npm install
# Build TypeScript to dist/
npm run build
# Development server with hot reload (no OAuth)
npm run dev
# Development server with OAuth enabled
ENABLE_OAUTH=true npm run dev
# Production server
npm start
# Production server with OAuth
ENABLE_OAUTH=true npm start
# Linting
npm run lint
# Testing
npm test
Matrix Tools Available
The server provides these MCP tools (all require matrixUserId parameter):
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.
- 2mo ago First seen · 181 lines · 1,505 tokens per session scan A f9e7baa42308
matrix-mcp-server CLAUDE.md is an instructions file published in the GitHub repository mjknowles/matrix-mcp-server (57 stars, last pushed 1y ago), licensed MIT. It adds 1,505 tokens to every session, about $0.0060 per session on Opus 5.5. 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.
matrix-mcp-server CLAUDE.md compared with instructions from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| matrix-mcp-server CLAUDE.mdmjknowles/matrix-mcp-server | Instructions file | 57 | 1y ago | MIT | A | 1,505 | Claude Code |
| vscode buildNext.instructions.mdmicrosoft/vscode | Instructions file | 195k | yesterday | MIT | A | 9,719 | GitHub Copilot |
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| langchain AGENTS.mdlangchain-ai/langchain | Instructions file | 149k | yesterday | MIT | A | 4,680 | Codex, OpenCode |
| vscode oss-third-party-notices.instructions.mdmicrosoft/vscode | Instructions file | 195k | yesterday | MIT | A | 5,516 | GitHub Copilot |
| vscode copilot-instructions.mdmicrosoft/vscode | Instructions file | 195k | yesterday | MIT | A | 3,093 | GitHub Copilot |
| deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness | Instructions file | 274k | 2d ago | MIT | A | 4,313 | Codex, OpenCode |