MCP Registry

Warning

The registry is under active development. The registry API spec is unstable and the official MCP registry database may be wiped at any time.

📖 API Documentation | 📚 Technical Docs

What is the registry?

The registry will provide MCP clients with a list of MCP servers. Like an app store for MCP servers. (In future it might do more, like also hosting a list of clients.)

There are two parts to the registry project:

1. 🟦 The MCP registry spec: An API specification that allows anyone to implement a registry.
2. 🟥 The Official MCP registry: A hosted registry following the MCP registry spec at registry.modelcontextprotocol.io. This serves as the authoritative repository for publicly-available MCP servers. Server creators publish once, and all consumers (MCP clients, aggregators, marketplaces) reference the same canonical data. This is owned by the MCP open-source community, backed by major trusted contributors to the MCP ecosystem such as Anthropic, GitHub, PulseMCP and Microsoft.

The registry is built around the server.json format - a standardized way to describe MCP servers that works across discovery, initialization, and packaging scenarios.

In time, we expect the ecosystem to look a bit like this:

Note that MCP registries are metaregistries. They host metadata about packages, but not the package code or binaries. Instead, they reference other package registries (like NPM, PyPi or Docker) for this.

Additionally, we expect clients pull from subregistries. These subregistries add value to the registry ecosystem by providing curation, or extending it with additional metadata. The Official MCP registry expects a lot of API requests from ETL jobs from these subregistries.

Development Status

2025-08-26 update: We're targeting a 'preview' go-live on 4th September. This may still be unstable and not provide durability guarantees, but is a step towards being more solidified. A general availability (GA) release will follow later.

Current key maintainers:

• Adam Jones (Anthropic) @domdomegg
• Tadas Antanavicius (PulseMCP) @tadasant
• Toby Padilla (GitHub) @toby

Contributing

We use multiple channels for collaboration - see modelcontextprotocol.io/community/communication.

Often (but not always) ideas flow through this pipeline:

• Discord - Real-time community discussions
• Discussions - Propose and discuss product/technical requirements
• Issues - Track well-scoped technical work
• Pull Requests - Contribute work towards issues

Quick start:

Pre-requisites

• Docker
• Go 1.24.x
• golangci-lint v2.4.0

Running the server

# Start full development environment
make dev-compose

This starts the registry at localhost:8080 with PostgreSQL and seed data. It can be configured with environment variables in docker-compose.yml - see .env.example for a reference.

Alternative: Local setup without Docker

Prerequisites:

• PostgreSQL running locally
• Go 1.24.x installed

# Build and run locally
make build
make dev-local

The service runs on localhost:8080 by default. This can be configured with environment variables in .env - see .env.example for a reference.

Alternative: Running a pre-built Docker image

Pre-built Docker images are automatically published to GitHub Container Registry:

# Run latest from main branch
docker run -p 8080:8080 ghcr.io/modelcontextprotocol/registry:latest

# Run specific commit build
docker run -p 8080:8080 ghcr.io/modelcontextprotocol/registry:main-20250806-a1b2c3d

Available tags: latest, main-<date>-<sha>

Publishing a server

To publish a server, we've built a simple CLI. You can use it with:

# Build the latest CLI
make publisher

# Use it!
./cmd/publisher/bin/mcp-publisher --help

See the publisher README for more details.

Other commands

# Run lint, unit tests and integration tests
make check

There are also a few more helpful commands for development. Run make help to learn more, or look in Makefile.

Architecture

Project Structure

├── cmd/                     # Application entry points
│   └── publisher/           # Server publishing tool
├── data/                    # Seed data
├── deploy/                  # Deployment configuration (Pulumi)
├── docs/                    # Technical documentation
│   ├── server-json/         # server.json specification & examples
│   └── server-registry-api/ # API specification
├── internal/                # Private application code
│   ├── api/                 # HTTP handlers and routing
│   ├── auth/                # Authentication (GitHub OAuth, JWT, namespace blocking)
│   ├── config/              # Configuration management
│   ├── database/            # Data persistence (PostgreSQL, in-memory)
│   ├── service/             # Business logic
│   ├── telemetry/           # Metrics and monitoring
│   └── validators/          # Input validation
├── pkg/                     # Public packages
│   ├── api/                 # API types and structures
│   │   └── v0/              # Version 0 API types
│   └── model/               # Data models for server.json
├── scripts/                 # Development and testing scripts
├── tests/                   # Integration tests
└── tools/                   # CLI tools and utilities
    └── validate-*.sh        # Schema validation tools

Authentication

Publishing supports multiple authentication methods:

• GitHub OAuth - For publishing by logging into GitHub
• GitHub OIDC - For publishing from GitHub Actions
• DNS verification - For proving ownership of a domain and its subdomains
• HTTP verification - For proving ownership of a domain

The registry validates namespace ownership when publishing. E.g. to publish...:

• io.github.domdomegg/my-cool-mcp you must login to GitHub as domdomegg, or be in a GitHub Action on domdomegg's repos
• me.adamjones/my-cool-mcp you must prove ownership of adamjones.me via DNS or HTTP challenge

More documentation

See the docs folder for more details if your question has not been answered here!