KiCAD-MCP-Server/docs/ROUTER_IMPLEMENTATION_STATUS.md

Router Implementation Status

✅ Phase 1 Complete: Foundation & Infrastructure

Date: December 28, 2025

What Was Implemented

1. Tool Registry (src/tools/registry.ts)

• ✅ Complete tool categorization (59 tools → 7 categories)
• ✅ Direct tools list (12 high-frequency tools)
• ✅ Category lookup maps for O(1) access
• ✅ Tool search functionality
• ✅ Registry statistics and metadata

2. Router Tools (src/tools/router.ts)

• ✅ list_tool_categories - Browse all categories
• ✅ get_category_tools - View tools in a category
• ✅ execute_tool - Execute any routed tool
• ✅ search_tools - Search tools by keyword

3. Server Integration (src/server.ts)

• ✅ Router tools registered at server startup
• ✅ All tools remain functional (backwards compatible)
• ✅ Logging added for router pattern status

4. Documentation

• ✅ TOOL_INVENTORY.md - Complete tool catalog
• ✅ ROUTER_ARCHITECTURE.md - Design specification
• ✅ ROUTER_IMPLEMENTATION_STATUS.md - This file

Current State

Status: ✅ Router Infrastructure Complete

Build: ✅ Compiles successfully (npm run build)

Tool Count:

• Total Tools: 59 (ALL still registered and visible)
• Direct Tools: 12
• Routed Tools: 47
• Router Tools: 4
• Currently Visible to Claude: 63 tools (59 + 4 router)

Token Impact:

• Current: ~42K tokens (still showing all tools)
• Target: ~12K tokens (Phase 2 optimization)
• Potential Savings: ~30K tokens (71% reduction)

🔄 Phase 2: Token Optimization (Next Step)

Objective

Hide routed tools from Claude's context while keeping them accessible via execute_tool.

Two Approaches

Option A: Registration Filtering (Recommended)

Modify tool registration to conditionally register tools based on whether they're in the direct list.

Changes needed:

1. Update each register*Tools function to check isDirectTool()
2. Only call server.tool() for direct tools
3. Routed tools remain accessible via execute_tool calling callKicadScript

Pros:

• Clean separation
• True token savings
• No behavior changes

Cons:

• Requires modifying 9 tool files

Option B: MCP Filter (If Supported)

If MCP SDK supports tool filtering/hiding, use that instead.

Pros:

• No tool file changes
• Centralized control

Cons:

• May not be supported by SDK
• Needs investigation

Implementation Plan for Phase 2

1. Create Helper Function (src/tools/conditional-register.ts)

   export function registerToolConditionally(
     server: McpServer,
     toolName: string,
     definition: ToolDefinition,
     handler: Function
   ) {
     if (isDirectTool(toolName)) {
       // Register with MCP (visible to Claude)
       server.tool(toolName, definition, handler);
     } else {
       // Register handler for execute_tool (hidden from Claude)
       registerToolHandler(toolName, handler);
     }
   }
   

2. Update Tool Registration Functions Modify each register*Tools function to use conditional registration.

3. Test

   • Verify direct tools work normally
   • Verify routed tools work via execute_tool
   • Verify token count reduction

4. Measure Impact Count tools visible to Claude before/after.

📊 Categories & Distribution

Category	Tools	Description
board	9	Board configuration, layers, zones, visualization
component	8	Advanced component operations
export	8	Manufacturing file generation
drc	9	Design rule checking & validation
schematic	9	Schematic editor operations
library	4	Footprint library access
routing	3	Advanced routing (vias, copper pours)
TOTAL	47	Routed tools
direct	12	Always visible tools
router	4	Discovery tools

🧪 Testing the Router

Test 1: List Categories

User: "What tool categories are available?"

Expected: Claude calls list_tool_categories
Result: Returns 7 categories with descriptions

Test 2: Browse Category

User: "What export tools are available?"

Expected: Claude calls get_category_tools({ category: "export" })
Result: Returns 8 export tools

Test 3: Search Tools

User: "How do I export gerber files?"

Expected: Claude calls search_tools({ query: "gerber" })
Result: Finds export_gerber in export category

Test 4: Execute Tool

User: "Export gerbers to ./output"

Expected: Claude calls execute_tool({
  tool_name: "export_gerber",
  params: { outputDir: "./output" }
})
Result: Executes via router, returns gerber export result

📝 Benefits Achieved (Phase 1)

1. ✅ Foundation Ready: All infrastructure in place
2. ✅ Organized: 59 tools categorized into logical groups
3. ✅ Discoverable: Tools easily found via search/browse
4. ✅ Backwards Compatible: All existing tools still work
5. ✅ Extensible: Easy to add new tools and categories
6. ✅ Documented: Complete architecture and usage docs

🚀 Next Actions

1. Optional: Complete Phase 2 (Token Optimization)

   • Implement conditional registration
   • Hide routed tools from context
   • Achieve 71% token reduction

2. Or: Ship Phase 1 As-Is

   • Router tools work perfectly now
   • Users can discover and execute tools
   • Optimization can be done later
   • No breaking changes

📚 Related Files

• src/tools/registry.ts - Tool registry and categories
• src/tools/router.ts - Router tool implementations
• src/server.ts - Server integration
• docs/TOOL_INVENTORY.md - Complete tool list
• docs/ROUTER_ARCHITECTURE.md - Design specification
• docs/mcp-router-guide.md - Original implementation guide

💡 Usage Example

// User: "I need to export gerber files"

// Claude's interaction:
// 1. Sees "export" and "gerber" keywords
// 2. Calls search_tools({ query: "gerber" })
//    → Returns: { category: "export", tool: "export_gerber", ... }
// 3. Calls execute_tool({
//      tool_name: "export_gerber",
//      params: { outputDir: "./gerbers" }
//    })
//    → Executes and returns result
// 4. "I've exported your Gerber files to ./gerbers/"

Status Summary

✅ Router Pattern: IMPLEMENTED ✅ Build: PASSING ✅ Backwards Compatible: YES ⏳ Token Optimization: PENDING (Phase 2)

The router infrastructure is complete and functional. The system now supports tool discovery and organized access to all 59 tools. Phase 2 optimization (hiding routed tools) can be implemented when ready for maximum token savings.