feat: Implement n8n-MCP Enhancement Plan v2.1 Final

- Implement simple node loader supporting n8n-nodes-base and langchain packages
- Create parser handling declarative, programmatic, and versioned nodes
- Build documentation mapper with 89% coverage (405/457 nodes)
- Setup SQLite database with minimal schema
- Create rebuild script for one-command database updates
- Implement validation script for critical nodes
- Update MCP server with documentation-focused tools
- Add npm scripts for streamlined workflow

Successfully loads 457/458 nodes with accurate documentation mapping.
Versioned node detection working (46 nodes detected).
3/4 critical nodes pass validation tests.

Known limitations:
- Slack operations extraction incomplete for some versioned nodes
- One langchain node fails due to missing dependency
- No AI tools detected (none have usableAsTool flag)

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

docs/report.md

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+# n8n-MCP Implementation Report
+
+## Summary
+
+Successfully implemented the n8n-MCP Enhancement Plan v2.1 Final, delivering a functional MVP that provides accurate n8n node documentation through the Model Context Protocol (MCP).
+
+## Achievements
+
+### Week 1: Core Implementation ✅
+
+1. **Node Loader** (`src/loaders/node-loader.ts`)
+   - Loads nodes from both `n8n-nodes-base` and `@n8n/n8n-nodes-langchain`
+   - Handles both array and object formats for node configurations
+   - Successfully loads 457 out of 458 nodes
+
+2. **Simple Parser** (`src/parsers/simple-parser.ts`)
+   - Parses both declarative and programmatic nodes
+   - Detects versioned nodes (both VersionedNodeType and inline versioning)
+   - Extracts node metadata, properties, and operations
+   - Handles instantiation of nodes to access instance properties
+
+3. **Documentation Mapper** (`src/mappers/docs-mapper.ts`)
+   - Maps nodes to their documentation files
+   - Handles both file and directory documentation structures
+   - Includes known fixes for problematic node names
+   - Achieves 89% documentation coverage (405/457 nodes)
+
+4. **Database Schema** (`src/database/schema.sql`)
+   - Simple SQLite schema optimized for the MVP
+   - Stores all essential node information
+   - Includes indexes for performance
+
+5. **Rebuild Script** (`src/scripts/rebuild.ts`)
+   - One-command database rebuild (`npm run rebuild`)
+   - Provides clear progress and error reporting
+   - Completes in under 30 seconds
+
+### Week 2: Testing and Integration ✅
+
+1. **Validation Script** (`src/scripts/validate.ts`)
+   - Tests critical nodes (HTTP Request, Code, Slack, Agent)
+   - Validates documentation coverage
+   - Provides database statistics
+   - 3 out of 4 critical nodes pass all tests
+
+2. **MCP Server Updates** (`src/mcp/server-update.ts`)
+   - Implements all planned MCP tools:
+     - `list_nodes` - Filter and list nodes
+     - `get_node_info` - Detailed node information
+     - `search_nodes` - Full-text search
+     - `list_ai_tools` - List AI-capable nodes
+     - `get_node_documentation` - Fetch node docs
+     - `get_database_statistics` - Database stats
+
+## Key Metrics
+
+- **Nodes Loaded**: 457/458 (99.8%)
+- **Documentation Coverage**: 405/457 (88.6%)
+- **Versioned Nodes Detected**: 46
+- **AI Tools**: 0 (none marked with usableAsTool flag)
+- **Triggers**: 10
+- **Packages Supported**: 2
+
+## Known Limitations
+
+1. **Slack Operations**: Unable to extract operations from some versioned nodes due to complex structure
+2. **AI Tools Detection**: No nodes currently have the `usableAsTool` flag set
+3. **One Failed Node**: One node from langchain package fails to load due to missing dependency
+
+## Usage
+
+```bash
+# Setup
+git clone https://github.com/n8n-io/n8n-docs.git n8n-docs
+npm install
+
+# Build
+npm run build
+
+# Rebuild database
+npm run rebuild
+
+# Validate
+npm run validate
+
+# Start MCP server
+npm start
+```
+
+## Next Steps (Post-MVP)
+
+1. Improve operations extraction for complex versioned nodes
+2. Add real-time monitoring capabilities
+3. Implement version history tracking
+4. Add support for community nodes
+5. Create web UI for browsing documentation
+
+## Conclusion
+
+The implementation successfully achieves the MVP goals:
+- ✅ Accurate node-to-documentation mapping
+- ✅ Coverage of official n8n packages
+- ✅ Fast rebuild process (<30 seconds)
+- ✅ Simple one-command operations
+- ✅ Reliable processing of standard nodes
+- ✅ Working MCP server with documentation tools
+
+The system is ready for use and provides a solid foundation for future enhancements.