kicad-mcp-rs

kicad-mcp-rs is a local-first MCP server for KiCad, written in Rust. It talks to KiCad through the official Protobuf-over-NNG IPC API and does not rewrite an open design as text. Version 0.2.1 implements the M0 to M6 surface with post-audit security hardening, and KiCad 10.0.6 is the primary target; KiCad 11 support is built from a pinned development schema and remains preview until tested against a released KiCad 11 build.

The safety model is strict: MCP uses stdio with diagnostics on stderr only, reads are bounded and paginated, the KiCad API token is never returned or logged, mutations require both KICAD_MCP_ALLOW_WRITE true and KICAD_MCP_PROJECT_ROOT set, update and delete operations require a content revision, mutation tools default to dry-run and return structured receipts, and mutations never save automatically (save_active_board is explicit).

The tool surface covers inspection and validation (status, project, board summary, footprints, nets, selection, DRC, ERC, export), PCB mutation (move footprint, set footprint property, create and update tracks, create vias, delete items), and a KiCad 11 preview surface (schematic hierarchy, netlist, place symbol, native STEP export) that stays hidden unless KiCad 11 or newer is detected at startup. DRC, ERC, and exports run through kicad-cli, and a KiCad plugin action adds an IPC probe.