Overview
AGP is the governance layer, not the transport — integrate it with MCP, A2A, AP2, UCP, and microservices.
Other agentic protocols handle talking, coordinating, and paying. AGP handles accountability. It sits orthogonally across MCP, A2A, AP2, and UCP — adding verifiable authority, deterministic policy enforcement, and an immutable evidence chain to every transaction those protocols make.
| Protocol | What it does | AGP governs |
|---|---|---|
| MCP | Tool Connectivity — model-to-tool transport and context passing | Tool Governance — capability scopes, policy evaluation, signed audit envelope per tool call |
| A2A | Agent Messaging — coordination between orchestrators and worker agents | Liability Delegation — sub-token issuance, scoped inheritance, cascade revocation across the full agent graph |
| AP2 | Payment Mandates — IntentMandates and CartMandates for agentic payments | Transactional Guardrails — capability tokens map to IntentMandates, action envelopes map to CartMandates, every dispute is resolvable from an immutable ledger |
| UCP | Commerce Sessions — checkout orchestration across merchants and platforms | Spend Authority — policy evaluated before any UCP request reaches a merchant; spend limits and human approval requirements enforced deterministically |
MCP — Tool Governance
MCP handles the conversation between a model and its tools. AGP governs every tool call that conversation triggers — capability scope, policy clearance, and a signed audit envelope. Any MCP tool invocation becomes a governed, ledger-recorded action.
Microservices
AGP as a gateway or sidecar for your existing APIs. Downstream services verify the action envelope before processing any agent-initiated request — no agent can call a protected endpoint without a signed, policy-cleared artifact.
A2A — Liability Delegation
A2A handles the coordination between orchestrators and workers. AGP governs the liability chain. Sub-token delegation, scoped capability inheritance, and cascade revocation ensure every node in the agent graph is accountable — not just the orchestrator.
UCP — Spend Authority
UCP handles the checkout session. AGP governs the spend authority. Policy is evaluated before any UCP request reaches a merchant — spend limits, capability scope, and human approval requirements enforced at the protocol layer, not by the shopping agent.
AP2 — Transactional Guardrails
AP2 handles the payment mandate. AGP governs the evidence chain. IntentMandates map to capability tokens; CartMandates map to action envelopes. Every payment dispute is resolvable from an immutable, cryptographically linked audit record.