What is mcp-rust-proxy CLAUDE.md?

Repository instructions for a Rust server that connects clients to multiple Model Context Protocol servers. Rust is a programming language, and MCP is a standard for connecting software agents to tools and data sources.

Use it when developing or reviewing the proxy, its server management, transport and protocol layers, shared state, or Yew-based web interface.

It explains how the proxy routes requests, manages server health and connections, supports transport methods, and keeps the project organized across branches.

mcp-rust-proxy CLAUDE.md — Instructions file by zach-source

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/zach-source/mcp-rust-proxy/claude-md

Clone the repo

git clone --depth 1 https://github.com/zach-source/mcp-rust-proxy

Per session 3,279 This file is loaded in full into every session.

When invoked 3,279 The same file — it is already loaded in full.

Security scan A 1 finding. 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.

Model	Per session	Once invoked
Fable 5	$0.03279	$0.03279
Opus 5	$0.01639	$0.01639
Sonnet 5	$0.00656	$0.00656
Haiku 4.5	$0.00328	$0.00328

Measured 3d ago against content hash fd65ac0c02c4, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

mcp-rust-proxy CLAUDE.md scanned grade A with 1 finding 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 3d 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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

3. Use `curl http://localhost:3001/api/logs/{server}/stream` for raw SSE stream

CLAUDE.md · 339 lines

How it starts

The opening of the file, as written. The whole thing — 339 lines — stays where its author put it; the contents beside it link to each section on GitHub.

MCP Rust Proxy - Claude Development Guide

Project Overview

MCP Rust Proxy is a high-performance Model Context Protocol (MCP) proxy server built in Rust. It provides connection pooling, health monitoring, and a web UI for managing multiple MCP servers.

Project Structure

This is a git work tree folder structure, the root folder has no code; the sub folders are of branches, create branches and merge to main when tested and ready
Main development happens in feature branches (e.g., feature/rust-mcp-proxy)

Key Components

Core Architecture

Proxy Server (src/proxy/): Handles incoming MCP requests and routes them to appropriate backend servers
Server Management (src/server/): Manages MCP server lifecycle, health checks, and restarts
Transport Layer (src/transport/): Supports stdio, HTTP-SSE, and WebSocket transports
State Management (src/state/): Centralized state using DashMap for thread-safe concurrent access
Protocol Version Support (src/protocol/): Multi-version MCP protocol support with automatic translation
Web UI (yew-ui/): Rust/WASM frontend built with Yew framework

Protocol Version Support

Supported Versions: 2024-11-05, 2025-03-26, 2025-06-18
Auto-Detection: Protocol version detected during initialize handshake
Bidirectional Translation: Automatic message translation between any version pair
Zero-Copy Optimization: Pass-through mode when versions match
API Integration: Protocol version visible in /api/servers and /api/servers/{name} responses
Structured Logging: Version negotiation logged with structured fields (server_name, protocol_version)
Deprecation Warnings: Logs WARN for servers using 2024-11-05 (deprecated)

Aggregator Plugin (Claude Agent SDK Integration)

Plugin Location: src/plugins/official/aggregator-plugin.js
Rust Integration: src/proxy/aggregator_tools.rs
Purpose: Intelligent multi-server context aggregation using Claude to query multiple MCP servers
Key Features:
- Uses @anthropic-ai/claude-agent-sdk to orchestrate queries across multiple MCP servers
- Enforces MCP tool usage over training data with explicit tool use: [servers] directives
- Intelligent server selection based on query keywords:
  - context7: Default for documentation/library information
  - serena: Auto-selected for code-related queries (function, class, method, etc.)
  - filesystem: Auto-selected for file operations (file, directory, path, etc.)
  - fetch: Auto-selected for web operations (url, website, http, etc.)
- Comprehensive logging for debugging tool usage and server selection
- Tracks aggregation statistics (response sizes, processing time, tool calls)

Read the full file on GitHub · 339 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.

3d ago First seen · 339 lines · 3,279 tokens per session scan A fd65ac0c02c4

Subscribe to this mod's changes

mcp-rust-proxy CLAUDE.md is an instructions file published in the GitHub repository zach-source/mcp-rust-proxy (5 stars, last pushed 10mo ago), licensed MIT. It adds 3,279 tokens to every session, about $0.0164 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

vscode buildNext.instructions.md

Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).

microsoft/vscode · 6,785 tokens

mcp-rust-proxy CLAUDE.md