splice-cad/splice-cad-mcp

Generate a harness assembly from a plan by selecting which nodes and bundles to include. Returns the created harness ID. The assembly appears in Splice as an editable harness linked to the project.

List all legacy harnesses owned by the authenticated user. These are standalone harnesses not associated with a project.

Create a new legacy harness. Provide the full WorkingHarness JSON with BOM and connection data. Read the harness_schema resource first. Returns the harness with harness_id and revision_id set.

Load a legacy harness with its full BOM (hydrated parts) and connection data. Use this to inspect or modify an existing harness.

Save (overwrite) a legacy harness. The harness_data must include harness_id and revision_id from the loaded harness. Use get_harness first to load current state, modify it, then save.

Get a structured summary of a legacy harness: connectors, wires, cables, connections, and validation warnings. More concise than get_harness.

Check which browser tabs are connected via the WebSocket bridge. Returns connected namespaces — project:<uuid> for plans, harness:<uuid> for assemblies. Use the namespace value with execute_command/get_live_state to target a specific tab.

Execute a single command through the live WebSocket bridge. Works for both plan mode (project:* namespace) and assembly/harness mode (harness:* namespace). PREFER execute_commands (plural) for batching — much faster. Canvas updates immediately, action added to undo history.

PREFERRED over execute_command. Execute multiple commands in a single call — much faster than calling execute_command repeatedly. All commands run atomically and undo as one action. Works for both plan (project:*) and assembly (harness:*) namespaces.

Undo the last command in the Splice frontend.

Redo the last undone command in the Splice frontend.

Get or set live frontend state. Reflects all unsaved changes, including for assemblies (harness:* namespace). Use setComponentState to update the Component Creator form fields.

Search the Splice connector parts database. Only use this when the user asks you to find a part in the database, or when you need a sourcePartId for linking. For most cases, prefer creating BOM entries directly with the MPN/manufacturer you already know (from datasheets, user input, or web research)…

Search the Splice wire parts database. Only use when the user asks to find a wire in the database. For most cases, create wire BOM entries directly with gauge/color you already know. Supports "22 awg red", "18 awg black white stripe".

Search the Splice cable parts database. Only use when the user asks to find a cable in the database. For most cases, create cable BOM entries directly. Supports "4 core shielded 20 awg", "belden 2 conductor".

Get full details for a specific part by ID, including its specification (pin count, gauge, etc.).

Create a component in the Splice parts database with full specs, images, and pin labels. Use lookup_part first to get image/datasheet URLs. Categories: "connector" (default), "circuit_breaker", "fuse", "relay", "contactor", "switch", "push_button", "motor", "pcb", "power_supply", "battery", "diode",…

Get default properties, specs, and SVG templates for all component categories (fuse, relay, circuit breaker, etc.). Use this to discover what category-specific fields are available when creating components.

Look up a real-world part on DigiKey by MPN. Returns image URL, datasheet URL, specs, and parameters. Use this to enrich components before creating them with create_component.

Create a custom multi-conductor cable in the parts database. Use when a cable is not found via search — e.g. from a datasheet. Returns a part ID for BOM entries.

Get PlanData for a project. WARNING: Can be very large for complex plans. PREFER get_plan_summary to understand plan state. Use node_ids/link_ids to fetch specific elements instead of the full plan.

Save (overwrite) the PlanData JSON for a project. The plan_data must be a complete, valid PlanData object. Read the plan_schema resource first to understand the structure. Use get_plan to fetch the current state before modifying.

PREFERRED way to read plan state. Returns components (with positions, pins, connection status, MPN), bundles, conductors, branch points, unconnected pins, and warnings. Much smaller than get_plan — use this first, only fetch full plan if you need raw data for specific elements.

Validate a project's plan for structural issues: orphan nodes, dangling conductors, missing parts, invalid references, mating compatibility, terminal point wiring, and shape/category consistency. Returns structured findings — each with a machine code, severity, involved node/conductor/link/mate IDs,…

List all projects owned by the authenticated user.

Create a new Splice project. Returns the project ID and details.

Get a project with its plan and assembly list.