GLEIF MCP Server

GLEIF MCP Server

Verify any company's legal identity in one question. Look up LEI codes, validate counterparties, and trace corporate ownership structures using the official GLEIF database. Covers 2.8M+ entities across 200+ jurisdictions.

12 tools for LEI lookup, entity search, BIC/SWIFT cross-referencing, corporate ownership, and batch validation. Works with Claude Desktop, Claude Code, Cursor, VS Code, Windsurf, and other MCP-compatible tools.

Use Cases

• KYC & Onboarding: Verify counterparty identities before signing contracts
• Compliance Checks: Validate LEIs for MiFID II, EMIR, or DORA reporting
• Due Diligence: Research corporate ownership chains and ultimate parents
• Financial Analysis: Cross-reference securities (ISIN) and banks (BIC/SWIFT) with their legal entities
• Data Enrichment: Batch-process company lists to add LEI data

What is LEI?

The Legal Entity Identifier (LEI) is a 20-character alphanumeric code that uniquely identifies legal entities participating in financial transactions worldwide. It's mandated by 200+ regulations including MiFID II, EMIR, Dodd-Frank, and DORA.

LEI Format (ISO 17442):

• Characters 1-4: LOU (Local Operating Unit) prefix
• Characters 5-18: Entity-specific identifier
• Characters 19-20: Check digits (mod 97 validation)

Example: HWUPKR0MPOU8FGXBT394 (Apple Inc.)

Features

Core Capabilities

• LEI Lookup: Get full entity details by LEI code
• Batch Lookup: Look up multiple LEIs in a single request (up to 100)
• Entity Search: Find companies by name with fuzzy matching and pagination
• LEI Validation: Verify format, check digits (ISO 17442), and registration status

Financial Identifiers

• BIC/SWIFT Lookup: Find bank LEIs from BIC codes
• ISIN Lookup: Find security issuer LEIs from ISIN codes
• Country Browse: List entities by jurisdiction

Relationships & Compliance

• Corporate Ownership: Parent companies, subsidiaries, ultimate parents
• Fund Relationships: Fund managers, umbrella funds, sub-funds
• Reporting Exceptions: Level 2 data exceptions with reasons
• LEI Issuers: List and details of all Local Operating Units (LOUs)

Performance & Reliability

• Fast Responses: Results are cached locally, so repeat queries return instantly
• No API Key Needed: Works out of the box with GLEIF's public API
• Handles Errors Gracefully: Automatic retries on timeouts or temporary failures
• Stays Within Limits: Built-in rate limiting prevents hitting GLEIF's quotas

Installation

Download Binary

Pre-built binaries for all platforms on the releases page:

Platform	Binary
macOS (Apple Silicon)	gleif-mcp-server-darwin-arm64
macOS (Intel)	gleif-mcp-server-darwin-amd64
Linux (x64)	gleif-mcp-server-linux-amd64
Linux (ARM64)	gleif-mcp-server-linux-arm64
Windows (x64)	gleif-mcp-server-windows-amd64.exe

# macOS/Linux - download and make executable
chmod +x gleif-mcp-server-darwin-arm64

Build from Source

Requires Go 1.25+:

git clone https://github.com/olgasafonova/gleif-mcp-server.git
cd gleif-mcp-server
go build -o gleif-mcp-server .

Install via Go

go install github.com/olgasafonova/gleif-mcp-server@latest

AI Agent Setup

Quickest start: Using Claude Desktop? Just add the config below and restart. Using an IDE like Cursor? Same idea, different config file. Pick your tool below.

Claude Desktop

Step 1: Download the binary

Go to the releases page and download the binary for your system:

• Mac (Apple Silicon M1/M2/M3/M4): gleif-mcp-server-darwin-arm64
• Mac (Intel): gleif-mcp-server-darwin-amd64
• Windows: gleif-mcp-server-windows-amd64.exe

Step 2: Mac only - allow the file to run

macOS blocks downloaded files. Open Terminal and run:

chmod +x ~/Downloads/gleif-mcp-server-darwin-arm64
xattr -d com.apple.quarantine ~/Downloads/gleif-mcp-server-darwin-arm64

Step 3: Open the config file

Mac: Open Finder, press Cmd + Shift + G, paste this path:

~/Library/Application Support/Claude/

Windows: Press Win + R, paste this path:

%APPDATA%\Claude

Open claude_desktop_config.json. If it doesn't exist, create it.

Step 4: Add the config

Mac (replace YOUR_USERNAME with your actual username):

{
  "mcpServers": {
    "gleif": {
      "command": "/Users/YOUR_USERNAME/Downloads/gleif-mcp-server-darwin-arm64"
    }
  }
}

Windows (replace YOUR_USERNAME - note the double backslashes):

{
  "mcpServers": {
    "gleif": {
      "command": "C:\\Users\\YOUR_USERNAME\\Downloads\\gleif-mcp-server-windows-amd64.exe"
    }
  }
}

To find your username: Mac - open Terminal and type whoami. Windows - look at C:\Users\.

Step 5: Restart Claude Desktop

Quit completely (Cmd + Q on Mac) and reopen.

Step 6: Test it

Type in Claude Desktop:

Look up Apple's LEI using GLEIF

You should see Claude call the GLEIF tool and return company data.

Claude Code (CLI)

# Add the server
claude mcp add gleif /path/to/gleif-mcp-server

# Or with scope for all projects
claude mcp add --scope user gleif /path/to/gleif-mcp-server

Cursor IDE

Add to .cursor/mcp.json in your project or ~/.cursor/mcp.json for global config:

{
  "mcpServers": {
    "gleif": {
      "command": "/path/to/gleif-mcp-server"
    }
  }
}

VS Code with Continue Extension

Add to .continue/config.json:

{
  "experimental": {
    "modelContextProtocolServers": [
      {
        "name": "gleif",
        "transport": {
          "type": "stdio",
          "command": "/path/to/gleif-mcp-server"
        }
      }
    ]
  }
}

Windsurf

Add to ~/.codeium/windsurf/mcp_config.json:

{
  "mcpServers": {
    "gleif": {
      "command": "/path/to/gleif-mcp-server"
    }
  }
}

Cline (VS Code Extension)

Add via Cline's MCP settings or in .vscode/cline_mcp_settings.json:

{
  "mcpServers": {
    "gleif": {
      "command": "/path/to/gleif-mcp-server",
      "args": []
    }
  }
}

Antigravity

Add to ~/.antigravity/mcp.json:

{
  "mcpServers": {
    "gleif": {
      "command": "/path/to/gleif-mcp-server"
    }
  }
}

Not working? Tell us what made it hard — even one sentence helps.

Tools Reference

Core Lookup Tools

Tool	Description	Parameters
lei_lookup	Get full details for a specific LEI	lei (required): 20-char LEI code
validate_lei	Check format, check digits, and status	lei (required): LEI to validate
batch_lei_lookup	Look up multiple LEIs at once	leis (required): Comma-separated LEIs (max 100)

Search Tools

Tool	Description	Parameters
search_entity	Search by company name	query (required), limit (default 20), page (default 1), fuzzy (default true)
search_by_bic	Find LEI from BIC/SWIFT	bic (required): 8 or 11 char code
search_by_isin	Find issuer LEI from ISIN	isin (required): 12-char ISIN
search_by_country	List entities by country	country (required): ISO 2-letter code, limit (default 20)
autocomplete	Entity name suggestions	prefix (required): min 2 chars, limit (default 10)

Relationship Tools

Tool	Description	Parameters
get_relationships	Get corporate/fund relationships	lei (required), type: direct-parent, ultimate-parent, children, fund-manager, umbrella-fund, sub-funds

LEI Issuer Tools

Tool	Description	Parameters
get_lei_issuer	Get details about an LOU	issuer_id (required): LOU identifier
list_lei_issuers	List all LOUs worldwide	None

Compliance Tools

Tool	Description	Parameters
get_reporting_exceptions	Get Level 2 reporting exceptions	lei (required): LEI to check

Usage Examples

Basic LEI Lookup

Prompt: "Look up LEI HWUPKR0MPOU8FGXBT394"

Returns: Full entity details for Apple Inc. including legal name, headquarters address, jurisdiction (US-CA), entity status, registration status, managing LOU, and next renewal date.

Company Search with Pagination

Prompt: "Search for Deutsche Bank, show page 2"

Tool call:

{
  "name": "search_entity",
  "arguments": {
    "query": "Deutsche Bank",
    "limit": 20,
    "page": 2,
    "fuzzy": true
  }
}

Returns: List of matching entities with pagination info (total results, current page, has more).

Batch LEI Lookup

Prompt: "Look up these LEIs: HWUPKR0MPOU8FGXBT394, 5493006MHB84DD0ZWV18, 549300GKFG0RYRRQ1414"

Returns: Summary of all three entities with LEI, legal name, country, city, and status.

Find Bank by BIC

Prompt: "Find the LEI for BIC DEUTDEFF"

Returns: Deutsche Bank AG's LEI record with full details.

Find Security Issuer

Prompt: "Who issued ISIN US0378331005?"

Returns: Apple Inc. (the issuer of AAPL stock).

Corporate Structure

Prompt: "Who is the ultimate parent of this subsidiary?"

Tool call:

{
  "name": "get_relationships",
  "arguments": {
    "lei": "549300GKFG0RYRRQ1414",
    "type": "ultimate-parent"
  }
}

LEI Validation

Prompt: "Is LEI HWUPKR0MPOU8FGXBT394 valid?"

Returns:

{
  "lei": "HWUPKR0MPOU8FGXBT394",
  "valid": true,
  "status": "ISSUED",
  "entityStatus": "ACTIVE",
  "nextRenewal": "2025-08-15"
}

Check Reporting Exceptions

Prompt: "Why is parent info missing for this company?"

Tool call:

{
  "name": "get_reporting_exceptions",
  "arguments": {
    "lei": "5493006MHB84DD0ZWV18"
  }
}

Returns: Exception categories and reasons (e.g., NON_CONSOLIDATING, NATURAL_PERSONS).

List All LEI Issuers

Prompt: "Show me all LEI issuers"

Returns: Complete list of LOUs (Local Operating Units) with name, country, status, and number of sponsored LEIs.

Response Format

All tools return JSON with relevant fields. Example entity record:

{
  "lei": "HWUPKR0MPOU8FGXBT394",
  "legalName": "Apple Inc.",
  "country": "US",
  "city": "Cupertino",
  "status": "ACTIVE",
  "regStatus": "ISSUED"
}

Search results include pagination:

{
  "count": 20,
  "results": [...],
  "pagination": {
    "currentPage": 1,
    "perPage": 20,
    "total": 156,
    "lastPage": 8
  },
  "hasMore": true
}

Error Handling

The server returns structured errors:

Error Code	Description	Retryable
not_found	LEI/entity not in GLEIF database	No
invalid_format	Invalid LEI/BIC/ISIN format	No
rate_limited	GLEIF API rate limit exceeded	Yes
timeout	Request timed out	Yes
server_error	GLEIF API error	Depends on status
network_error	Connection failed	Yes

Example error response:

{
  "code": "not_found",
  "message": "LEI not found in GLEIF database",
  "statusCode": 404,
  "retryable": false
}

Architecture

gleif-mcp-server/
├── main.go                 # Entry point, MCP server setup
├── internal/gleif/
│   ├── client.go          # GLEIF API client with caching & rate limiting
│   ├── client_test.go     # Client and validation tests
│   ├── cache.go           # LRU cache with TTL
│   ├── types.go           # Data structures for API responses
│   └── errors.go          # Structured error types
└── tools/
    ├── definitions.go     # Tool metadata and parameter specs
    ├── handlers.go        # MCP tool implementations
    └── handlers_test.go   # Handler tests with mock server

Technical Details

For developers who want the specifics:

Setting	Value
Cache duration	15 minutes
Cache capacity	1000 entities, 500 searches
Rate limit	50 req/min (GLEIF allows 60)
Retry strategy	3 attempts with exponential backoff
Connection pool	100 max idle, 10 per host

API Reference

This server wraps the public GLEIF API:

• Base URL: https://api.gleif.org/api/v1
• Authentication: None required
• Rate Limit: 60 requests/minute
• Documentation: https://www.gleif.org/en/lei-data/gleif-api

Troubleshooting

Server won't start

• Check the binary has execute permissions: chmod +x gleif-mcp-server
• Verify the path in your MCP config is absolute, not relative

"Rate limit exceeded" errors

• The server automatically handles rate limiting with retries
• If persistent, reduce concurrent requests or wait a few minutes

"LEI not found" for valid LEI

• The GLEIF database updates daily; recently issued LEIs may not appear immediately
• Verify the LEI format (exactly 20 alphanumeric characters)

Slow responses

• First requests may be slower (cache warming)
• GLEIF API occasionally has latency spikes; retries handle this automatically

Claude Desktop doesn't show the server

• Restart Claude Desktop after editing config
• Check JSON syntax in config file
• Verify the binary path exists and is executable

Development

# Run tests
go test ./...

# Run tests with coverage
go test -coverprofile=coverage.out ./...
go tool cover -html=coverage.out

# Run tests with race detector
go test -race ./...

# Build
go build -o gleif-mcp-server .

Contributing

Contributions welcome. Please open an issue first to discuss proposed changes.

License

MIT License - see LICENSE for details.

More MCP Servers

Check out my other MCP servers:

Server	Description	Stars
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nordic-registry-mcp-server	Access Nordic business registries. Look up companies across Norway, Denmark, Finland, Sweden.
productplan-mcp-server	Talk to your ProductPlan roadmaps. Query OKRs, ideas, launches.
tilbudstrolden-mcp	Nordic grocery deal hunting. Find offers, plan meals, track spending.

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Acknowledgments

• GLEIF for the public LEI API
• Model Context Protocol for the MCP specification