# TypeHandlerRegistry Implementation Summary
## Objective
Wire all handlers (directive, script, knowledge) via a central `TypeHandlerRegistry` to provide unified routing for all MCP operations.
## Solution
### 1. TypeHandlerRegistry Core (`kiwi_mcp/handlers/registry.py`)
**Core Responsibility:** Route operations by `item_type` to appropriate handler.
**Key Methods:**
```python
async def search(item_type, query, **kwargs) → Dict[str, Any]
async def load(item_type, item_id, **kwargs) → Dict[str, Any]
async def execute(item_type, action, item_id, **kwargs) → Dict[str, Any]
```
**Routing Logic:**
- Maps `item_type` to handler: `directive`, `script`, `knowledge`
- Handles missing dependencies gracefully
- Supports project_path for local operations
- Returns structured errors for unknown types
**Interface Methods:**
- `get_supported_types()` → list of registered types
- `get_handler_info()` → handler metadata and operations
### 2. Tool Dispatch Integration
#### SearchTool (`kiwi_mcp/tools/search.py`)
```python
async def execute(self, arguments):
# Dispatch to registry
result = await self.registry.search(
item_type=arguments["item_type"],
query=arguments["query"],
source=arguments.get("source", "local"),
limit=arguments.get("limit", 10)
)
return self._format_response(result)
```
#### LoadTool (`kiwi_mcp/tools/load.py`)
```python
async def execute(self, arguments):
# Dispatch to registry
result = await self.registry.load(
item_type=arguments["item_type"],
item_id=arguments["item_id"],
destination=arguments.get("destination", "project"),
version=arguments.get("version")
)
return self._format_response(result)
```
#### ExecuteTool (`kiwi_mcp/tools/execute.py`)
```python
async def execute(self, arguments):
# Dispatch to registry
result = await self.registry.execute(
item_type=arguments["item_type"],
action=arguments["action"],
item_id=arguments["item_id"],
parameters=arguments.get("parameters", {}),
project_path=arguments.get("project_path")
)
return self._format_response(result)
```
#### HelpTool (`kiwi_mcp/tools/help.py`)
- Updated to accept registry parameter for consistency
- Can access handler info if needed
### 3. Server Integration (`kiwi_mcp/server.py`)
```python
class KiwiMCP:
def __init__(self, project_path=None):
# 1. Create registry with all handlers
self.registry = TypeHandlerRegistry(project_path=project_path)
# 2. Initialize tools with registry reference
self.tools = {
"search": SearchTool(registry=self.registry),
"load": LoadTool(registry=self.registry),
"execute": ExecuteTool(registry=self.registry),
"help": HelpTool(registry=self.registry),
}
# 3. Register MCP handlers
self._setup_handlers()
```
## Dispatch Flow
```
┌─────────────────────────────────────────────────────────────────┐
│ MCP Client Call │
│ tool: "search" │
│ args: {item_type: "directive", query: "...", source: "local"} │
└─────────────────────┬───────────────────────────────────────────┘
│
↓
┌─────────────────────────────────────────────────────────────────┐
│ SearchTool.execute(arguments) │
│ ├─ Validates item_type and query │
│ └─ Calls registry.search(...) │
└─────────────────────┬───────────────────────────────────────────┘
│
↓
┌─────────────────────────────────────────────────────────────────┐
│ TypeHandlerRegistry.search() │
│ ├─ Checks item_type in handlers dict │
│ ├─ Returns error if unknown │
│ └─ Dispatches to directive_handler.search() │
└─────────────────────┬───────────────────────────────────────────┘
│
↓
┌─────────────────────────────────────────────────────────────────┐
│ DirectiveHandler.search() │
│ ├─ Calls SearchTool from context-kiwi │
│ ├─ Passes all parameters │
│ └─ Returns results │
└─────────────────────┬───────────────────────────────────────────┘
│
↓
┌─────────────────────────────────────────────────────────────────┐
│ MCP Response │
│ { │
│ "error": "...", or │
│ "directives": [...], or │
│ ... │
│ } │
└─────────────────────────────────────────────────────────────────┘
```
## Handlers
### DirectiveHandler
- **Module:** `kiwi_mcp/handlers/directive/handler.py`
- **Class:** `DirectiveHandler`
- **Upstream:** context-kiwi library
- **Methods:**
- `async search(query, source, ...)`
- `async load(directive_name, destination, ...)`
- `async execute(action, directive_name, parameters, ...)`
### ScriptHandler
- **Module:** `kiwi_mcp/handlers/script/handler.py`
- **Class:** `ScriptHandler`
- **Upstream:** script-kiwi library
- **Methods:**
- `async search(query, source, ...)`
- `async load(script_name, destination, ...)`
- `async execute(action, script_name, parameters, ...)`
### KnowledgeHandler
- **Module:** `kiwi_mcp/handlers/knowledge/handler.py`
- **Class:** `KnowledgeHandler`
- **Upstream:** knowledge-kiwi library
- **Methods:**
- `async search(query, source, ...)`
- `async load(zettel_id, destination, ...)`
- `async execute(action, zettel_id, parameters, ...)`
## Testing & Verification
### Unit Verification
```bash
# Test registry loads with all 3 handlers
python -c "from kiwi_mcp.handlers.registry import TypeHandlerRegistry; \
r = TypeHandlerRegistry(); \
print(f'Registry loaded: {r.get_supported_types()}')"
# Output: Registry loaded: ['directive', 'script', 'knowledge']
```
### Server Verification
```bash
# Test server has registry and tools are wired
python -c "from kiwi_mcp.server import KiwiMCP; \
m = KiwiMCP(); \
print(f'Server registry: {type(m.registry).__name__}'); \
print(f'Tools wired: {all(t.registry is m.registry for t in m.tools.values())}')"
# Output:
# Server registry: TypeHandlerRegistry
# Tools wired: True
```
### Full Verification
```bash
# Run comprehensive verification script
python verify_registry_wiring.py
# All tests pass ✓
```
## Error Handling
### Unknown Type Error
```python
await registry.search(item_type="invalid", query="test")
# Returns:
# {
# "error": "Unknown item_type: invalid",
# "supported_types": ["directive", "script", "knowledge"]
# }
```
### Missing Required Parameters
```python
await registry.search(item_type="directive") # Missing query
# Returns:
# {
# "error": "item_type and query are required"
# }
```
### Uninitialized Registry in Tool
```python
tool = SearchTool() # Without registry
await tool.execute({"item_type": "directive", "query": "test"})
# Returns:
# {
# "error": "Registry not initialized",
# "message": "SearchTool requires registry instance"
# }
```
## Architecture Benefits
1. **Centralized Routing**
- All type routing in one place
- Easy to understand dispatch flow
- Single point for validation
2. **Extensibility**
- Add new type → Add handler → Register in registry
- No tool code changes needed
- Consistent interface for all types
3. **Separation of Concerns**
- Registry handles routing
- Handlers handle domain logic
- Tools handle MCP protocol
4. **Error Handling**
- Structured error responses
- Graceful fallback for missing dependencies
- Validation before dispatch
5. **Introspection**
- Registry provides handler metadata
- Tools can query capabilities
- Support for dynamic help content
## Files
### New
- `kiwi_mcp/handlers/registry.py` - TypeHandlerRegistry implementation
- `verify_registry_wiring.py` - Comprehensive verification
- `REGISTRY_WIRING_REPORT.md` - Detailed report
- `IMPLEMENTATION_SUMMARY.md` - This file
### Modified
- `kiwi_mcp/server.py` - Create registry, pass to tools
- `kiwi_mcp/tools/search.py` - Dispatch via registry
- `kiwi_mcp/tools/load.py` - Dispatch via registry
- `kiwi_mcp/tools/execute.py` - Dispatch via registry
- `kiwi_mcp/tools/help.py` - Accept registry parameter
## Verification Results
✓ Registry initialization with 3 handlers
✓ Handler instances created correctly
✓ Tools wired to registry
✓ Dispatch flow functional
✓ Error handling working
✓ No import errors
✓ Project path support included
## Status
**Complete and Verified** ✓
All success criteria met:
- TypeHandlerRegistry class exists
- All 3 types registered (directive, script, knowledge)
- Server instantiates with registry
- No import errors
Ready for integration with kiwi libraries.
