OAuth 2.1

← Part 2: Build a Production Server | Next Chapter: Part 4: MCP Gateway Architecture → Prerequisite: Complete Part 2: Build a Production Server with Go to understand server concurrency, connection pooling, and handler mechanics. Answer-first: Securing Non-Human Identities (NHI) in agentic MCP ecosystems demands replacing ambient API keys with OAuth 2.1 PKCE authorization code flows, Client Identity Metadata Documents, and SPIFFE/SPIRE cryptographic workload identities. This zero-trust security model enforces downscoped ephemeral tokens, fine-grained Open Policy Agent authorization, and mandatory human-in-the-loop approvals for high-risk write tools, preventing confused deputy privilege escalation across multi-tenant environments. ...

📖 Bản tiếng Việt (Vietnamese Edition) Series Navigation: This is Part 6 of the Core Banking Systems Architecture Masterclass. For interbank rails, read Part 5: ISO 20022 Payment Gateways. FAPI 2.0 Security: DPoP, mTLS & Sender-Constrained Tokens Answer-first: Financial-Grade API (FAPI) 2.0 establishes the zero-trust security baseline for open banking and payment initiation services by completely eliminating bearer token vulnerabilities. By mandating sender-constrained tokens via Demonstrating Proof-of-Possession (DPoP, RFC 9449) or mutual TLS certificate binding (RFC 8705), alongside Pushed Authorization Requests (PAR) and Hardware Security Module (HSM) attestation, financial platforms ensure that intercepted access tokens cannot be replayed by adversaries, guaranteeing cryptographically provable non-repudiation across all external and internal API interactions. ...