# 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`)

   ```typescript
   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

```typescript
// 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.