MCP Registry Validator

A TypeScript-based validator tool for MCP server.json files to ensure they meet publication criteria for the MCP registry.

Installation

Install globally via npm:

npm install -g mcp-registry-validator

Or use with npx (no installation required):

npx mcp-registry-validator

Usage

Validate in current directory

npx mcp-registry-validator

This will look for server.json in the current directory.

Validate in a specific directory

npx mcp-registry-validator path/to/directory

This will look for server.json in the specified directory.

Validate a specific file

npx mcp-registry-validator path/to/server.json

This will validate the specific file at the given path.

Exit Codes

• 0: Validation successful, no errors found
• 1: Validation failed with errors

What it validates

The validator checks the following:

Required Fields

• $schema
• name
• title
• description
• version
• packages (non-empty array)

Field Length Limits

• title: max 50 characters
• description: max 100 characters
• homepage: max 200 characters

Name Format

Must follow the pattern: io.github.username/server or com.domain/server

Version Format

Must follow semantic versioning (e.g., 1.0.0)

Homepage (if present)

Must be a valid HTTP(S) URL

Package Configuration

Each package must have:

• registryType: one of npm, pypi, nuget, oci, mcpb
• identifier: max 100 characters
• version
• transport.type: one of stdio, sse, streamable-http

Environment Variables (if present)

• Descriptions must be max 200 characters
• Lists required environment variables

Development

Build

npm install
npm run build

Test locally

npm run dev

License

MIT