Your AI agents have 4 identities. They only need one.

MCP, A2A, ANP, AG-UI — every protocol invented its own identity system. Here's how I built a bridge between them. The problem nobody talks about In 2026, AI agents talk to each other using four major protocols: MCP (Anthropic/AAIF) — agent → tool, OAuth tokens A2A (Google/Linux Foundation) — agent → agent, Agent Cards ANP (W3C) — peer-to-peer, DID keys AG-UI — agent → human, no identity at all Each one invented its own identity system. Each one requires separate credentials. Each one has its own discovery mechanism. If your agent talks MCP to your database, A2A to a partner's agent, and ANP to a decentralized peer, it has three separate identities with zero link between them. Try answering these questions: "Which agent executed this transaction?" → Depends on which protocol you check "Revoke this compromised agent." → You need to revoke it in 3 different systems "Show me the complete audit trail." → It doesn't exist. The trace breaks at every protocol boundary This isn't a theoretical