MCP Identity & Auth Engineering: OAuth2, PKCE & mTLS

Prerequisite: Familiarity with the concepts introduced in Part 2 — Build. Review it first if the terminology in this part is unfamiliar. Part 3 — Identity & Authentication: OAuth2, PKCE & mTLS Answer-first: Hardcoding static API keys in AI agent code creates severe security liabilities. Production MCP architectures enforce Zero Trust authentication using OAuth 2.1 with PKCE for user identity propagation and SPIFFE/SPIRE mTLS X.509 certificates for workload-to-workload identity verification across microservice meshes. ...

June 6, 2026 · 6 min · Lê Tuấn Anh