chp-adapter-mcp 0.10.0

CHP capability adapter — wraps Model Context Protocol (MCP) server tools as governed CHP capabilities

chp-adapter-mcp

The inbound MCP bridge for the Capability Host Protocol. Connects to an external Model Context Protocol server, discovers its tools, and registers each one as a governed CHP capability (chp.adapters.mcp.<server>.<tool>) with full execution evidence.

This complements the TypeScript outbound bridges (@auxo/chp-runtime-mcp), which expose CHP capabilities as MCP tools. Together they make CHP and MCP interoperate in both directions:

• outbound (TS): CHP capability → MCP tool
• inbound (this package): MCP tool → CHP capability

Install

pip install chp-adapter-mcp

Usage

from chp_core import LocalCapabilityHost, register_adapter
from chp_adapter_mcp import MCPAdapter, MCPServerConfig

host = LocalCapabilityHost()
adapter = MCPAdapter(MCPServerConfig(
    name="filesystem",
    command="npx",
    args=["-y", "@modelcontextprotocol/server-filesystem", "/tmp"],
))
register_adapter(host, adapter)

# Every tool the server exposes is now a CHP capability:
result = host.invoke("chp.adapters.mcp.filesystem.read_file", {"path": "/tmp/x"})

The MCP tool's own JSON Schema becomes the capability input_schema, so chp-core validates arguments before the tool runs and emits a full evidence chain (execution_started → mcp_tool_called → mcp_tool_result → execution_completed, or execution_failed).

Design notes

• Each MCPAdapter owns one MCP server connection on a dedicated background thread + event loop (_ThreadedMCPSession), because the host runs handlers via asyncio.run (a fresh loop per call) and an MCP session is loop-bound.
• The session is abstracted behind a small protocol so it can be faked in tests without spawning a subprocess.
• MCPAdapter requires a server config, so register it manually with register_adapter(host, MCPAdapter(config)). It is also declared under the chp.adapters entry-point group for discovery/introspection.