The gateway approach (OAuth + RBAC) solves the perimeter problem — who can connect. protect-mcp solves a different layer — what can they do once connected, and how do you prove it.
It wraps any MCP server as a stdio proxy. Per-tool policies (block, rate-limit, require human approval). Every decision gets an Ed25519-signed receipt that's verifiable offline — no callbacks, no accounts.
The two layers stack: your gateway authenticates the caller, protect-mcp constrains which tools they can call and signs the evidence.
npx protect-mcp -- node your-server.js
MIT licensed. The receipts protocol has an IETF Internet-Draft: https://datatracker.ietf.org/doc/draft-farley-acta-signed-re...
https://github.com/PanosSalt/MCP-Gateway
OAuth 2.1 + PKCE, Microsoft Entra SSO, per-tool RBAC, full audit trail on every tool call. The gateway sits in front of your tools so auth and access control are solved once at the platform level rather than per-server. Self-hostable with Docker.
First open source project — built it after seeing exactly the pattern described here in enterprise MCP deployments.