Crate grex_mcp 

grex-mcp — MCP-native server for grex (M7).

Stage 5 wires the rmcp framework: the server speaks the MCP 2025-06-18 wire protocol over any rmcp::transport (stdio in production, tokio::io::duplex in tests). The handshake + tools/list (returning empty) + transport-close shutdown are live; the 11 tool handlers land in Stage 6, and cancellation in Stage 7.

Stdout discipline

The MCP stdio transport multiplexes only JSON-RPC bytes on stdout. All diagnostics MUST go to stderr. GrexMcpServer::run installs a tracing_subscriber::fmt writer pinned to stderr — idempotently, so test reuse and serve-from-CLI both work. The no_println_lint.rs integration test enforces zero println! / print! macros under src/ to prevent regressions.

Re-exports

pub use error::CancelledExt;

pub use error::REQUEST_CANCELLED;

pub use tools::VERBS_EXPOSED;

Modules

error

Error mapping from grex-core failure types to MCP error envelopes.

tools

Tool registry surface for the grex MCP server.

Structs

GrexMcpServer

The grex MCP server. One instance per grex serve invocation; one instance per integration test. Cheap to construct; all state behind Arc so ServerHandler impls can clone onto handler tasks for free.

ServerState

Shared, immutable-after-build state every tool handler reads.