Mirror of https://github.com/modelcontextprotocol/registry — A community driven registry service for Model Context Protocol (MCP) servers.
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Filename Latest commit message Latest commit date
Thomas Thomsen d813d2b805
fix(validators): distinguish a missing package from a missing version on PyPI/NPM (#1411)
Fixes #553.

The PyPI and npm validators fetch the version-specific metadata endpoint
(`/pypi/{name}/{version}/json` and the npm equivalent) and report any
non-200 as `<pkg> not found`. That endpoint 404s for two different
reasons though: the package doesn't exist, or it exists and only the
*version* is missing (e.g. a release that hasn't propagated yet). So a
valid package reads as gone:

```diff
- PyPI package 'requests' not found (status: 404)
+ PyPI package 'requests' exists, but version '99.99.99' was not found (status: 404). A newly published release can take a moment to appear on PyPI. Wait and retry, or publish version '99.99.99' before registering it
```

On a version 404 it probes the package-level endpoint
(`/pypi/{name}/json`, `/{name}`) with a `HEAD` to tell the two apart,
and reports 429/5xx as transient rather than "not found". `HEAD` so it
reads a status without pulling the whole packument. The probe carries
its own 3s deadline: it only refines the error message, so a hung probe
must not stretch the validator past the ~10s-per-registry budget the
publish path assumes. Same probe-and-classify shape as the existing
cargo validator.

The fetch is split into `validatePyPIPackage` / `validateNPMPackage`
behind `export_test.go` so the branches are testable with `httptest`,
the same seam cargo uses.

### Testing
- [x] hermetic `httptest` for the status matrix (version-missing,
package-missing, 5xx, 429, inconclusive probe, positive path, scoped
npm); the mocks pin the expected method per endpoint (`GET` fetch,
`HEAD` probe)
- [x] hermetic deadline test: a hung probe is cut off at ~3s and
reported as inconclusive, not "not found"
- [x] existing live package tests still pass, now also hitting the HEAD
probe; on a live 429/5xx they now `t.Skip` as inconclusive instead of
flaking (deliberate: CI runs these against the real registries with no
short-mode gating)
- [x] `gofmt` / `go vet` / `golangci-lint` clean

Out of scope: auto-retry for the propagation race, and SSRF
redirect-pinning parity for the pypi/npm clients (pre-existing, shared
with nuget).
2026-07-12 15:24:34 -04:00
.githooks Add linting documentation and pre-commit hooks (#177) 2025-07-15 09:31:17 -07:00
.github fix(ci): re-validate author association via REST in close-invalid-publish-prs (#1440) 2026-07-12 12:11:04 -04:00
.vscode Move publisher CLI from tools/ to cmd/ (#326) 2025-08-29 14:45:36 +01:00
cmd fix: reject mangled publisher metadata (#1310) 2026-07-12 12:57:45 -04:00
data chore: Release server.json schema version 2025-12-11 (#841) 2025-12-12 09:33:57 -08:00
deploy build(deps): bump github.com/pulumi/pulumi/sdk/v3 from 3.248.0 to 3.251.0 in /deploy (#1431) 2026-07-09 15:53:31 -04:00
docs docs: add polygraph to community projects (#1421) 2026-07-10 18:55:54 -04:00
internal fix(validators): distinguish a missing package from a missing version on PyPI/NPM (#1411) 2026-07-12 15:24:34 -04:00
pkg fix(cargo): harden README fetch, clarify status handling, strengthen tests (#1330) 2026-06-04 17:34:54 -04:00
scripts docs: update API endpoint documentation from /v0/ to /v0.1/ (#802) 2025-12-04 13:02:45 -08:00
tests/integration fix: store tokens in ~/.config/mcp-publisher/ instead of cwd (#1166) 2026-04-15 03:23:07 -04:00
tools feat: add cargo (crates.io) as a package registry type (#1207) 2026-06-03 10:56:43 -04:00
.env.example docs: document GitHub OIDC audience binding for self-hosters and CI users (#1230) 2026-04-29 20:56:53 -04:00
.gitignore Enhanced server.json validation (phase 1) (#636) 2026-01-16 00:49:39 +02:00
.golangci.yml Stop pinning Go to patch versions, use stable in CI (#1137) 2026-04-09 11:57:21 -04:00
.goreleaser.yaml Update Goreleaser and Cosign (#839) 2025-12-11 08:43:57 -08:00
.ko.dockerignore Use ko in favour of docker build (#708) 2025-10-29 15:16:11 +00:00
.ko.yaml Use ko in favour of docker build (#708) 2025-10-29 15:16:11 +00:00
CHANGES.md Added /validate endpoint and modified mcp-publish so that all validation happens there (#896) 2026-02-04 15:52:07 +02:00
CLAUDE.md Add contributing guidelines to prevent seed.json PRs (#1079) 2026-03-22 07:42:18 -07:00
complete.md docs(complete): align publish CLI flags with implementation (closes #767) (#1278) 2026-05-11 09:01:52 -04:00
CONTRIBUTING.md Add contributing guidelines to prevent seed.json PRs (#1079) 2026-03-22 07:42:18 -07:00
docker-compose.yml Use ko in favour of docker build (#708) 2025-10-29 15:16:11 +00:00
go.mod build(deps): bump golang.org/x/crypto from 0.51.0 to 0.52.0 (#1433) 2026-07-10 17:06:10 -04:00
go.sum build(deps): bump golang.org/x/crypto from 0.51.0 to 0.52.0 (#1433) 2026-07-10 17:06:10 -04:00
LICENSE chore: update licensing to Apache 2.0 for new contributions (#887) 2026-01-13 11:11:20 +02:00
Makefile Ensure tests are failing CI (#840) 2025-12-11 09:56:57 +02:00
README.md docs: update maintainer/collaborator matrix in README (#1324) 2026-05-31 03:20:31 -04:00
SECURITY.md Update SECURITY.md to use GitHub Security Advisories (#977) 2026-02-18 23:36:23 -08:00

MCP Registry

The MCP registry provides MCP clients with a list of MCP servers, like an app store for MCP servers.

📤 Publish my MCP server | ⚡️ Live API docs | 👀 Ecosystem vision | 📖 Full documentation

Development Status

2025-10-24 update: The Registry API has entered an API freeze (v0.1) 🎉. For the next month or more, the API will remain stable with no breaking changes, allowing integrators to confidently implement support. This freeze applies to v0.1 while development continues on v0. We'll use this period to validate the API in real-world integrations and gather feedback to shape v1 for general availability. Thank you to everyone for your contributions and patience—your involvement has been key to getting us here!

2025-09-08 update: The registry has launched in preview 🎉 (announcement blog post). While the system is now more stable, this is still a preview release and breaking changes or data resets may occur. A general availability (GA) release will follow later. We'd love your feedback in GitHub discussions or in the #registry-dev Discord (joining details here).

Registry Working Group:

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

Running the server

# Start full development environment
make dev-compose

This starts the registry at localhost:8080 with PostgreSQL. The database uses ephemeral storage and is reset each time you restart the containers, ensuring a clean state for development and testing.

Note: The registry uses ko to build container images. The make dev-compose command automatically builds the registry image with ko and loads it into your local Docker daemon before starting the services.

By default, the registry seeds from the production API with a filtered subset of servers (to keep startup fast). This ensures your local environment mirrors production behavior and all seed data passes validation. For offline development you can seed from a file without validation with MCP_REGISTRY_SEED_FROM=data/seed.json MCP_REGISTRY_ENABLE_REGISTRY_VALIDATION=false make dev-compose.

The setup can be configured with environment variables in docker-compose.yml - see .env.example for a reference.

Alternative: Running a pre-built Docker image

Pre-built Docker images are automatically published to GitHub Container Registry. Note that the image does not bundle PostgreSQL, so you need to run your own and point the registry at it via MCP_REGISTRY_DATABASE_URL (see docker-compose.yml for a working example):

# Run latest stable release
docker run -p 8080:8080 ghcr.io/modelcontextprotocol/registry:latest

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

# Run specific release version
docker run -p 8080:8080 ghcr.io/modelcontextprotocol/registry:v1.0.0

# Run development build from main branch
docker run -p 8080:8080 ghcr.io/modelcontextprotocol/registry:main-20250906-abc123d

Available tags:

  • Releases: latest, v1.0.0, v1.1.0, etc.
  • Continuous: main (latest main branch build)
  • Development: main-<date>-<sha> (specific commit builds)

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!
./bin/mcp-publisher --help

See the publisher guide 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/                    # Documentation
├── internal/                # Private application code
│   ├── api/                 # HTTP handlers and routing
│   ├── auth/                # Authentication (GitHub OAuth, JWT, namespace blocking)
│   ├── config/              # Configuration management
│   ├── database/            # Data persistence (PostgreSQL)
│   ├── 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

Community Projects

Check out community projects to explore notable registry-related work created by the community.

More documentation

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