[kishore7snehil]

📋 Changes

Adds auth0-ai-mcp, a library that secures Model Context Protocol (MCP) servers with Auth0. It is built on auth0-api-python and ships no MCP framework of its own, so each framework gets a thin adapter around it. Guides and a runnable example follow in separate PRs.

✨ Features

• Verifies the bearer token on each request and builds the verified caller as a Principal.
• Auth0AsgiMiddleware wraps any ASGI app. It answers 401 for a missing, malformed or invalid token and 503 when Auth0 cannot be reached, before the MCP handler runs. A bearer value with whitespace inside is rejected without calling Auth0. The 401 challenge carries scope when scopes_supported is set, and 401 and 503 responses send Cache-Control: no-store. It also serves protected resource metadata.
• scopes_supported must be a list of single-value strings, otherwise ConfigurationError is raised at startup.
• Request context accessors give tool code the verified caller and a request-scoped client that never exposes the raw token.
• require_scopes and with_required_scopes gate tools on the caller's scopes.
• Token exchange for downstream calls with On-Behalf-Of, client credentials and Token Vault, including downscope and expiry checks (a token with no usable expiry and one that is already expired raise separate messages), with an optional token_store for caching through the core SDK.
• Organization policy options on create_mcp_client.
• test.yml runs the tests and ruff on Python 3.10 to 3.14, and dependabot.yml gets a pip entry for the package.

🔧 API Changes

New public API exported from auth0_ai_mcp, with Auth0AsgiMiddleware imported from auth0_ai_mcp.middleware. Nothing existing changes.

📖 Documentation

Adds a short README.md and CONTRIBUTING.md. The guides and examples are added in follow-up PRs.

🧪 Testing

The package has 273 unit tests that stub the core client, so they need no Auth0 tenant. pytest, ruff check . and poetry build pass locally.

auth0-api-python is pinned to a commit SHA until the release that includes the token caching, malformed-token and client_info changes is published. This PR stays a draft until the pin is replaced with a released version.

• This change adds unit test coverage
• This change adds integration test coverage
• This change has been tested on the latest version of the platform/language or why not

Contributor Checklist

• I have read the Auth0 general contribution guidelines
• I have read the Auth0 Code of Conduct

[rmad17]

This call doesn't pass request_url or request_headers, so a domains resolver on a prebuilt multi-domain api_client receives None for both. Separately, if the resolver fails, the middleware answers 503 with Retry-After rather than 401.

Is that intentional? In particular:

• Is a request-aware resolver meant to be supported in this release?
• Is 503 the expected response when the resolver fails, including for an unrecognized issuer?

[kishore7snehil]

A request-aware domains resolver isn't supported in this release. A static multi-domain list works, create_mcp_client has no resolver option, and a resolver on a prebuilt api_client receives None for the URL and headers. The 503 only happens when the resolver itself fails (it raises or returns an invalid list). A token from an unrecognized issuer is a 401, because core raises VerifyAccessTokenError for it. We can add request context later if a real use case comes up.