# GDAL MCP
**Geospatial AI with epistemic reasoning**
GDAL MCP is a Model Context Protocol (MCP) server that provides AI agents with geospatial analysis capabilities while requiring them to **justify their methodological choices** through a reflection middleware system.
**🎉 v1.1.1 Released (2025-10-26)** — Vector tool parity + cross-domain reflection validated
**🧠 Reflection System** — Domain-based epistemic reasoning that transcends data types
**⚡ 75% Cache Hit Rate** — Methodology reasoning carries across raster ↔ vector operations
[](https://github.com/Wayfinder-Foundry/gdal-mcp/actions/workflows/ci.yml)
[](LICENSE)
[](https://www.python.org/downloads/)
[](https://github.com/jlowin/fastmcp)
[](https://pepy.tech/projects/gdal-mcp)
---
## 📚 Documentation
- **[Quick Start](QUICKSTART.md)** - Installation, setup, and MCP configuration
- **[Tools Reference](TOOLS.md)** - Complete tool documentation with examples
- **[Environment Variables](docs/ENVIRONMENT_VARIABLES.md)** - Runtime configuration and tool surface controls
- **[Vision](docs/VISION.md)** - Long-term roadmap and philosophy
- **[Changelog](CHANGELOG.md)** - Release history and updates
---
## 🧠 The Reflection System
### What Makes GDAL MCP Different?
Most AI tool systems execute operations immediately when requested. GDAL MCP requires the AI to **justify methodological decisions** before execution, creating a conversation about the "why" rather than just executing the "what."
**Traditional AI tool approach:**
```
User: "Reproject this DEM to Web Mercator"
AI: *silently executes operation*
Result: DEM reprojected (but with what resampling? why that CRS? what tradeoffs?)
```
**GDAL MCP with reflection:**
```
User: "Reproject this DEM to Web Mercator for my web map"
AI: *reflection middleware intercepts*
AI: "Before reprojecting to EPSG:3857, let me justify this CRS choice:
Intent: Web Mercator preserves angles (conformal projection),
essential for web tile rendering and navigation
Alternatives considered:
- EPSG:4326 (WGS84) → rejected: not conformal, distorts shapes
- Local UTM → rejected: limited extent, not web-standard
Tradeoffs: Area distortion increases at high latitudes
(acceptable for web visualization)
Confidence: High - this is the standard for web mapping"
*justification stored, operation proceeds*
Result: DEM reprojected with documented methodology
```
### Why This Matters
**1. Utilizes Full MCP Protocol Capabilities**
The Model Context Protocol isn't just about tool execution—it's about **agentic reasoning and interaction**. The reflection system leverages MCP's design to enable:
- Pre-execution prompting (tool dependencies)
- Structured reasoning (schema-validated justifications)
- Stateful workflows (justification caching)
- Human-in-the-loop interaction (advisory prompts)
**2. Prevents Silent Failures**
Geospatial operations can execute successfully while producing **methodologically incorrect results**:
- Nearest-neighbor resampling on continuous elevation data (creates artifacts)
- Web Mercator for area calculations (40%+ distortion possible)
- Bilinear interpolation on categorical data (creates invalid class values)
The reflection system **surfaces these choices** for validation.
**3. Educational, Not Restrictive**
The AI isn't blocked from executing operations—it's **required to demonstrate understanding**:
- First use: Explains reasoning, teaches methodology
- Cached: Instant execution (knowledge persists)
- Result: 75%+ cache hit rates, minimal friction
**4. Creates Audit Trail**
Every methodological decision is documented with:
- Intent (what property must be preserved?)
- Alternatives (what else was considered?)
- Rationale (why this choice?)
- Tradeoffs (what are the limitations?)
- Confidence (high/medium/low)
This enables **reproducible geospatial science**.
## 🎯 Example Workflow
### Multi-Operation Geospatial Analysis
```
User: "I need to reproject this DEM to UTM for accurate slope analysis,
then reproject this vector layer to the same CRS for overlay"
AI Workflow:
1. Inspects DEM metadata (raster_info)
2. REFLECTION: Justifies UTM Zone 10N choice (accurate distance/area)
3. REFLECTION: Justifies cubic resampling (smooth gradients for derivatives)
4. Reprojects DEM (raster_reproject)
5. Inspects vector metadata (vector_info)
6. CACHE HIT: Reuses UTM justification (cross-domain!)
7. Reprojects vector (vector_reproject) - instant, no re-prompting
8. Both datasets now aligned in UTM Zone 10N
Result: 2 operations, 2 reflections (not 3!)
Cache hit rate: 50% → Saves time, maintains methodology
```
**The Key Innovation:** The CRS justification from step 2 is reused in step 6 because the methodology (why UTM Zone 10N?) is **domain-based, not tool-based**. It doesn't matter if you're working with raster or vector data—the projection choice reasoning is the same.
See **[Tools Reference](TOOLS.md)** for detailed examples of all available tools.
## ⚡ Key Features
### 🧠 Reflection Middleware
- Pre-execution reasoning for CRS selection, resampling methods
- Structured justifications (intent, alternatives, choice, tradeoffs, confidence)
- Persistent cache with 75% hit rates in multi-operation workflows
- **Cross-domain cache sharing** - CRS justification works for both raster AND vector
### 🛠️ Comprehensive Toolset
- **Raster tools:** info, convert, reproject, stats
- **Vector tools:** info, reproject, convert, clip, buffer, simplify
- See **[Tools Reference](TOOLS.md)** for complete documentation
### 🛡️ Production Quality
- Full type safety (mypy strict mode)
- 72 passing tests
- Workspace security (path validation middleware)
- Python-native (Rasterio/PyProj/pyogrio)
- Real-time feedback via FastMCP Context API
### 📚 MCP Resources
- Workspace catalog for autonomous file discovery
- Metadata intelligence for format detection
- Reference knowledge base (CRS, resampling methods, compression options)
## 📦 Quick Start
### Install via uvx (Recommended)
```bash
# Run directly from PyPI
uvx --from gdal-mcp gdal --transport stdio
```
### MCP Configuration (Claude Desktop)
Add to `~/Library/Application Support/Claude/claude_desktop_config.json`:
```json
{
"mcpServers": {
"gdal-mcp": {
"command": "uvx",
"args": ["--from", "gdal-mcp", "gdal", "--transport", "stdio"],
"env": {
"GDAL_MCP_WORKSPACES": "/path/to/your/geospatial/data"
}
}
}
}
```
**See [QUICKSTART.md](QUICKSTART.md) for:**
- Alternative installation methods (Docker, local development)
- Detailed MCP client configuration
- Workspace security setup
- Troubleshooting guide
## 🔧 Available Tools
GDAL MCP provides 12 production-ready tools across three categories:
### Raster Operations
- `raster_info` - Inspect metadata (CRS, resolution, bands, nodata)
- `raster_convert` - Format conversion with compression & overviews (COG support)
- `raster_reproject` ⚡ - CRS transformation (with reflection)
- `raster_stats` - Statistical analysis with histograms
### Vector Operations
- `vector_info` - Inspect metadata (CRS, geometry, attributes)
- `vector_reproject` ⚡ - CRS transformation (with reflection)
- `vector_convert` - Format migration (SHP ↔ GPKG ↔ GeoJSON)
- `vector_clip` - Spatial subsetting
- `vector_buffer` - Proximity analysis
- `vector_simplify` - Geometry simplification
### Reflection System
- `store_justification` - Cache epistemic reasoning (used internally)
- Advisory prompts for CRS selection and resampling methods
**⚡ = Reflection-enabled:** These tools require methodological justification on first use, then cache for instant subsequent execution.
**See [TOOLS.md](TOOLS.md) for complete documentation with examples and parameters.**
## 🧪 Testing
```bash
# Run all tests
uv run pytest test/ -v
# With coverage
uv run pytest test/ --cov=src --cov-report=term-missing
```
**Status**: ✅ 72 passing tests including reflection system integration
## 🏗️ Architecture
**Python-Native Stack** (ADR-0017):
- **Rasterio** - Raster I/O and manipulation
- **PyProj** - CRS operations and transformations
- **pyogrio** - High-performance vector I/O (fiona fallback)
- **Shapely** - Geometry operations
- **NumPy** - Array operations and statistics
- **Pydantic** - Type-safe models with JSON schema
**Key Design Decisions** ([26 ADRs](docs/ADR/) guide development):
- ADR-0026: Reflection system and epistemic governance
- ADR-0017: Python-native over CLI shelling for performance
- ADR-0011: Explicit resampling required (prevents silent data corruption)
- ADR-0022: Workspace isolation for security
## 🤝 Contributing
We welcome contributions! See [CONTRIBUTING.md](docs/CONTRIBUTING.md) for:
- Development setup
- Code style guide (Ruff + mypy)
- Testing requirements (pytest + fixtures)
- ADR process
## 📝 License
MIT License - see [LICENSE](LICENSE) for details.
## 🙏 Acknowledgments
- Built with [FastMCP](https://github.com/jlowin/fastmcp)
- Powered by [Rasterio](https://github.com/rasterio/rasterio) and [GDAL](https://gdal.org)
- Inspired by the [Model Context Protocol](https://modelcontextprotocol.io)
## 🗺️ Roadmap
**Current Status: v1.1.1** - Phase 2 Complete ✅
- Reflection middleware operational
- Vector/raster tool parity achieved
- Cross-domain cache sharing validated (75% hit rates)
**Next: Phase 3 - Workflow Intelligence (v2.0+)**
- Formal workflow composition
- Multi-step orchestration
- Analysis pattern libraries
See **[Vision](docs/VISION.md)** for the complete long-term roadmap.
---
**Built with ❤️ for the geospatial AI community**
*Geospatial operations that think, not just execute.*
