Only MCP

🚀 Only_mcp

A simple implementation of MCP v0.2 client and server for my MCP learning.

This is not a complete implementation and should not be used in a production environment.

🚧 Current Progress

I spent time last weekend implementing MCP v0.2 - it was as interesting as expected! Now the agent can use authenticated tools, although there is still room for improvement.

Key Observations:

• Protocol Changes: MCP v0.2 differs significantly from v0.1. Most notably, the SSE endpoint has been removed. It also relies on the .well-known OAuth flow for authentication. The introduction of application/json requests simplifies some interactions but eliminates the possibility of server push via SSE.
• SDK and Tool Gaps: The current Python SDK for quickly building MCP servers is still at v0.2, with limited authentication support. This forced me to build a Falcon-based scaffold server compatible with both standards. The development toolchain lags - for example, Claude integration still requires a local stdio-based setup. The promising mcp-proxy tool does not yet support v0.2, leading to unexpected obstacles during implementation.
• Interoperability Issues: MCP's tooling solution differs from OpenAI's chat completion standard, increasing implementation complexity. Function call chains (e.g., getting a schema first and then performing an update) also pose challenges - the tool call workflow could be more seamless.
• Long-Term Task Support: Although direct support is still incomplete, MCP v0.2 introduces event IDs for task status polling, a welcome improvement, though I haven't tested it in my setup.
• Deployment and Strategy: MCP endpoints should ideally be hosted alongside REST APIs and integrated with the OAuth flow, making them suitable for handling specialized proxy traffic. Cloudflare has emerged as a reliable hosting option, although self-hosting may become more popular once the toolchain matures. When considering building an independent MCP gateway, founders may need to reevaluate its long-term viability.

Overall, MCP v0.2 is progressing well, but it will take a few more iterations to perfect the tools and SDK maturity.

🛠️ Developer's Guide

Pre-commit Hooks

pre-commit install

Development in Containers

We only develop within containers.

docker compose up --build

Frontend Dependencies

Frontend dependencies are managed locally. If you need to manually run eslint, execute:

npm --prefix frontend install && npx eslint