Architecture explanation

KiCad MCP Pro is organized around a small number of boundaries that keep the tool safe, testable, and honest about what it can automate.

Core idea

The MCP server exposes agent-facing tools, but KiCad-facing behavior is isolated behind adapter seams. Pure domain logic remains testable without KiCad; live KiCad or KiCad CLI/IPC integration is treated as an explicit runtime dependency.

Why this matters

• Agent clients need predictable tool contracts.
• KiCad file formats and IPC APIs can change between KiCad releases.
• Destructive operations must remain explicit and auditable.
• Heuristic SI/PI/EMC/thermal checks must not be marketed as solver-grade signoff.

Main layers

1. Transport and MCP protocol handling.
2. Tool registration and profile routing.
3. Orchestration and workflow helpers.
4. KiCad adapter seam for CLI, IPC, and S-expression files.
5. Pure domain logic and validation helpers.

More detail

• High-level architecture: ARCHITECTURE.md
• Development architecture: docs/development/architecture.md
• ADRs: docs/adr/README.md
• Security threat model: docs/security/threat-model.md
• Input validation: docs/security/input-validation.md