rnv-mcp-identity

An identity and authorization layer for MCP servers. On every tool call it asks one question, is this caller who it claims to be, and is this action within what it's allowed to do?, and answers with exactly one of three outcomes:

• allow: identity resolved, verified, and the action is in scope.

• deny: verified, but out of scope; or an identity was presented and failed verification.

• unknown: identity could not be established at all. The call is refused.

An unknown caller never acts. That rule is the whole project: resolve or refuse, never guess.

Status: reference implementation, pre-1.0, Apache-2.0. This is the reference-implementation arm of AIII, the Artificial Intelligence Identification Initiative. It composes on existing standards (the MCP authorization model, WIMSE workload identity, RFC 7800 key confirmation, RFC 7638 thumbprints, EAT attestation) rather than replacing them.

Live demo: Identity Gate on Hugging Face Spaces, running this engine on the released v0.1.0.

What's here

• src/rnv_mcp_identity/ — the library: a framework-agnostic decision engine (L1 identity, L2 verification, L3 authorization) plus a FastMCP middleware adapter. The core has no runtime dependencies.

• examples/ — a runnable FastMCP server guarded by the layer, an in-process test, and an HTTP client. Start here to watch it allow one call and refuse three.

• SPEC.md — the normative spec: the decision sequence, the capability and policy model, the threat model, and the v0 wire format.

• AAIF-READINESS.md — an honest dossier on whether this belongs in a foundation, and what's missing before it would.

Related MCP server: Agent Identity MCP Server

Quickstart

pip install -e ".[dev,verify,fastmcp]"
python -m pytest -q                                # the full suite
python -m pytest -q tests/test_demo_inprocess.py   # just the guarded-server demo

Run the demo over real HTTP:

python examples/demo_server.py        # terminal 1
python examples/demo_client_http.py   # terminal 2

The wire format (v0)

The identity token rides in the mcp-agent-identity header and a holder-of-key proof in mcp-agent-proof. The proof binds to the exact token, so a stolen token alone can't act. The reference client in examples/ is the normative example; see SPEC.md section 10.

Docs

• SPEC.md — the specification

• ROADMAP.md — where this is going

• PRIOR-ART.md — what it builds on, and the gap it fills

• GOVERNANCE.md — how decisions are made

• CONTRIBUTING.md — how to help

• SECURITY.md — how to report vulnerabilities

• AAIF-READINESS.md — foundation-readiness assessment

License

Apache-2.0. See LICENSE.

A note on affiliation

This project aspires to become a foundation-hosted project and is not affiliated with, endorsed by, or accepted into the AAIF or the Linux Foundation. See AAIF-READINESS.md for an honest account of where it stands.

Verifying a release

Each GitHub release carries the build artifacts, a SHA256SUMS manifest, a Sigstore signature over that manifest (SHA256SUMS.sigstore.json), and a CycloneDX SBOM (sbom.cdx.json).

Check integrity (hashes):

sha256sum -c SHA256SUMS

Verify authenticity and the signer's identity (keyless Sigstore):

pip install sigstore
python -m sigstore verify identity \
  --cert-identity "https://github.com/RNVizion/rnv-mcp-identity/.github/workflows/release.yml@refs/tags/v0.1.0" \
  --cert-oidc-issuer "https://token.actions.githubusercontent.com" \
  --bundle SHA256SUMS.sigstore.json \
  SHA256SUMS

A valid result proves the manifest was produced by this repository's release workflow under GitHub's OIDC, not by a third party. Replace the tag in --cert-identity with the release you are verifying.