Crate cairn_mcp_server 

Cairn MCP server — a thin JSON-RPC transport over cairn_core::edit.

It holds no logic of its own (docs/design.md Section 7): every tool call dispatches to the one Editor in Core, and every commit returns the one Core Report. The MCP subset implemented is the minimum to drive authoring: initialize, tools/list, tools/call. Resources, prompts, and capability negotiation beyond a tools declaration are out of v0.1.

Tools exposed are exactly those that work: the Section 6 worked-session loop, run/run_module, the version-control surface, the stored-tree tools query_type, find_references, replace_node, fill_hole, and the v0.2 editor substrate render_addressed/node_at/put_expr (projection + hash↔span index + the node-construction primitive, so an out-of-process editor turns a cursor into a node hash and mints replacements). tools/list reflects exactly the working surface.

Structs

Session

One authoring session: a store, the single Core editor over it, and a per-session SQLite file run_handler drives so a web handler’s load/persist round-trip persists across calls (POST in one call, GET it back in the next — the verification an i64 run_module cannot give).

Functions

serve_stdio

Read JSON-RPC messages line-by-line from stdin, write responses to stdout.