Modelcontextprotocol MCP

What Modelcontextprotocol MCP does

Modelcontextprotocol MCP operates the official MCP Registry, a catalog that lets MCP clients find available MCP servers. The repository contains both the registry API and the mcp-publisher command-line application used to submit server metadata from a server's own project.

The registry is intended to provide a shared discovery layer rather than a pull-request-based directory. Adding files to this repository does not publish a server. Publishers use the CLI and the registry's publishing workflow instead.

The project also exposes live API documentation and versioned public API types. Its implementation includes HTTP handlers, validation, authentication, PostgreSQL persistence, seed-data import, and telemetry components.

How it works

A registry deployment runs as a Go service backed by PostgreSQL. The local development environment is started with Docker Compose and is available at localhost:8080. Development startup normally seeds the database from a filtered subset of the production API, allowing local behavior and validation to resemble the deployed registry while keeping startup data smaller.

For offline development, seed data can come from a local file by setting MCP_REGISTRY_SEED_FROM and disabling registry validation with MCP_REGISTRY_ENABLE_REGISTRY_VALIDATION=false. The development database uses ephemeral storage, so its contents are reset when the containers restart.

Publishing includes namespace ownership checks. Supported verification paths include GitHub OAuth, GitHub OIDC for GitHub Actions, DNS ownership checks, and HTTP ownership checks. For example, GitHub namespaces are associated with the relevant GitHub account or workflow, while domain-based namespaces require control of the corresponding domain.

The registry API reached an API freeze for v0.1 on October 24, 2025. The project had previously launched as a preview, so integrations should account for the documented API lifecycle and deployment state.

Setup and configuration

Local development requires Docker, Go, ko, and golangci-lint. Run make dev-compose to build the registry image with ko, start the registry and PostgreSQL, and expose the service on port 8080.

A pre-built image is available from GitHub Container Registry. The image does not include PostgreSQL, so a separate database must be provided through MCP_REGISTRY_DATABASE_URL.

To build the publishing CLI, run make publisher, then use ./bin/mcp-publisher --help. Use make check to run linting, schema validation, and tests; this command also stops an active development environment. make help lists additional Make targets.

Configuration values are illustrated in docker-compose.yml and .env.example. The registry can be seeded from a local JSON file for offline work, or from the production API for a filtered development dataset.

Tools and capabilities

• Registry HTTP API for publishing and discovering MCP server entries.
• mcp-publisher CLI for submitting a server from its own project.
• PostgreSQL-backed persistence for registry data.
• Namespace validation using GitHub, DNS, and HTTP ownership mechanisms.
• Seed-data import for production-derived or local development datasets.
• Local containerized development through Docker Compose.