EPSG MCP Server

EPSG MCP Server

日本語版 README

An MCP server that provides specialized knowledge and decision support for Coordinate Reference Systems (CRS) worldwide.

Global coverage through a 3-layer fallback:

1. Country Packs (Japan, US State Plane, UK National Grid, etc.) for expert-level recommendations
2. Automatic UTM zone calculation when no pack is available
3. Safe defaults (WGS84 / Web Mercator) as the final fallback

Coordinate transformation execution is delegated to mcp-server-proj, focusing on knowledge provision and decision support.

Features

• CRS Search: Search CRS by EPSG code, name, region, or prefecture
• Detailed Information: Get detailed information on geodetic datum, projection method, area of use, accuracy characteristics, and more
• Regional Listings: List CRS available in Japan/Global with purpose-specific recommendations
• CRS Recommendation: Recommend the optimal CRS for each purpose and location (with multi-zone support for Hokkaido and Okinawa)
• Usage Validation: Verify the validity of CRS selection and present issues with suggestions for improvement
• Transformation Routing: Propose optimal transformation paths using BFS graph search (with reverse transformation support)
• CRS Comparison: Compare CRS from 7 perspectives (datum, projection, accuracy, distortion, compatibility, etc.)
• Best Practices: CRS usage guidance on 10 topics (surveying, web mapping, data exchange, etc.)
• Troubleshooting: Diagnose CRS problems by symptoms (coordinate shifts, calculation errors, etc.)
• Country Pack System: Extensible regional expertise (Japan, US, UK available; easily add more)
• Offline Operation: Local database requires no external API
• Internationalized: Tool definitions and parameter descriptions in English (usable by AI agents in any language)
• Graceful Degradation: Works anywhere via UTM fallback even without region-specific packs

Installation

npm install @shuji-bonji/epsg-mcp

Or run directly:

npx @shuji-bonji/epsg-mcp

Usage

Claude Desktop

Add to claude_desktop_config.json:

{
	"mcpServers": {
		"epsg": {
			"command": "npx",
			"args": ["@shuji-bonji/epsg-mcp"]
		}
	}
}

Enabling Additional Country Packs

By default, only the Japan pack is loaded. To enable additional packs (e.g., US, UK), set the EPSG_PACKS environment variable:

{
	"mcpServers": {
		"epsg": {
			"command": "npx",
			"args": ["@shuji-bonji/epsg-mcp"],
			"env": {
				"EPSG_PACKS": "jp,us,uk"
			}
		}
	}
}

Available packs: jp (Japan), us (United States), uk/gb (United Kingdom)

Language Settings

By default, output is in English. To get Japanese output, set the EPSG_LANG environment variable:

{
	"mcpServers": {
		"epsg": {
			"command": "npx",
			"args": ["@shuji-bonji/epsg-mcp"],
			"env": {
				"EPSG_LANG": "ja"
			}
		}
	}
}

MCP Inspector

npx @anthropic-ai/mcp-inspector npx @shuji-bonji/epsg-mcp

Tools

search_crs

Search CRS by keyword.

// Input
{
  query: string;           // Search keyword (e.g., "JGD2011", "4326", "Tokyo")
  type?: "geographic" | "projected" | "compound" | "vertical" | "engineering";
  region?: "Japan" | "Global";
  limit?: number;          // Default: 10
}

// Output
{
  results: CrsInfo[];
  totalCount: number;
}

Usage Examples:

• "Search for CRS related to JGD2011"
• "Find projected coordinate systems available in Tokyo"
• "Get information about EPSG code 6677"

get_crs_detail

Get detailed CRS information by EPSG code.

// Input
{
  code: string;  // "EPSG:6677" or "6677"
}

// Output
{
  code: string;
  name: string;
  type: CrsType;
  datum?: DatumInfo;
  projection?: ProjectionInfo;
  areaOfUse: AreaOfUse;
  accuracy?: AccuracyInfo;
  remarks?: string;
  useCases?: string[];
  // ...
}

Usage Examples:

• "Tell me the details of EPSG:6677"
• "What are the characteristics of Web Mercator (3857)?"

list_crs_by_region

Get available CRS list and recommendations by region.

// Input
{
  region: "Japan" | "Global";
  type?: CrsType;
  includeDeprecated?: boolean;  // Default: false
}