runtime-mcp 0.1.0

MCP Runtime client for accessing cloud-based MCP capabilities

MCP STDIO Proxy Client

Project Role

• Transparent MCP client that reads JSON-RPC requests from STDIN, sends them to a remote MCP Engine via HTTP, and writes responses back to STDOUT without modification.
• No embeddings, databases, caching, or local model logic; every capability lives entirely in the remote MCP Engine.

Relationship With the MCP Engine

• Acts purely as a byte-level transport bridge for JSON-RPC messages.
• Any MCP-conformant engine reachable over HTTP can be used; the proxy never inspects business semantics.

Quick Start

1. Install (optional):

   pip install -e .
   

2. Configure environment variables:

   export SERVER_URL=http://127.0.0.1:14501
   export RPC_PATH=/mcp/rpc
   export AUTHORIZATION=0123456789ABCDEF
   export HTTP_TIMEOUT=30
   

   When SERVER_URL is omitted the proxy defaults to https://runtime.lincloud.cn, and AUTHORIZATION can be unset if the remote engine does not require it.
3. Launch via runtime or python -m runtime.main.
4. Send JSON-RPC over STDIN, e.g.:

   echo '{"jsonrpc":"2.0","id":1,"method":"tools/list"}' | runtime
   

Authorization Forwarding

Priority order for the HTTP Authorization header:

1. params.authorization when present and exactly 16 characters.
2. Environment variable AUTHORIZATION if set.
3. No header when neither source exists.

Error Handling

• Invalid JSON input -> code: -32700.
• HTTP/network failures or remote non-JSON responses -> code: -32000 with the specific proxy error message.
• The proxy always echoes the original id whenever possible and preserves jsonrpc: "2.0".

Process Lifecycle

• Produces no extra STDOUT noise; only raw JSON-RPC responses are emitted.
• Terminates gracefully on EOF, Ctrl+C, or startup configuration errors.

Development

• Requires Python 3.9 or later and no additional dependencies.
• Layout:

  runtime/
    config.py
    http_client.py
    main.py