Universal Commerce Protocol (UCP) & Agent Payments (AP2) Demo
UCP is the standardized language for AI agents to discover, negotiate, and execute transactions autonomously. Paired with AP2 — the trust layer using Verifiable Digital Credentials and cryptographic checkout-hash binding — agents can securely pay merchants across REST, MCP, and A2A transports without custom integrations.
What are UCP & AP2?
The Universal Commerce Protocol (UCP) and Agent Payments Protocol (AP2) together form a complete standard for autonomous AI commerce — from product discovery to cryptographically secured payment.
Universal Commerce Protocol (UCP)
- • Standardized Language: A common protocol for AI agents to discover, negotiate, and execute transactions autonomously
- • Transport Agnostic: Runs across REST, MCP, and A2A protocols
- • Machine-Readable Discovery:
/.well-known/ucpprofile lets any agent find merchant capabilities - • Server-Selects Architecture: Businesses dictate protocol version and capabilities
- • Minor Units: All monetary amounts represented in cents to avoid floating-point errors
Agent Payments Protocol (AP2)
- • Trust Layer: Secures agent-led transactions using Verifiable Digital Credentials (VDCs)
- • Checkout Hash: Cryptographically signed payment authorizations tied to specific cart states
- • Signature Algorithms: Supports ES256, ES384, and ES512
- • Mandates Extension: Session becomes “Security Locked” once negotiated — no modifications allowed
- • Non-Repudiation: Every authorization is verifiable and tamper-proof
Why This Matters
As AI agents increasingly handle purchasing, booking, and supply-chain transactions on behalf of humans and organizations, a universal commerce standard prevents fragmentation and ensures trust. UCP gives agents a shared language; AP2 ensures every dollar is accounted for with cryptographic proof.
- • No more one-off API integrations per merchant
- • Agents can transact across any UCP-compliant storefront
- • Payment authorization is tied to exact cart state — no bait-and-switch
Key Features at a Glance
Transport Agnostic
Works over REST, MCP, and A2A — plug into existing infrastructure without rewrites.
Server-Selects
Merchants control which UCP version and capabilities they expose. Agents adapt accordingly.
Verifiable Digital Credentials
AP2 uses VDCs to prove agent identity and payment authority without sharing raw secrets.
Checkout Hash Binding
Payment authorization is cryptographically bound to the exact cart state — tamper-evident by design.
Mandates Extension
Once an AP2 mandate is negotiated the session locks. No items can be added, removed, or repriced.
Minor Unit Amounts
All monetary values in cents (e.g., $59.98 = 5998) to eliminate floating-point rounding issues.
Add autonomous commerce to your AI agents
We help teams implement UCP and AP2 so their agents can discover, negotiate, and pay — securely and at scale.
Plan your commerce integrationBusiness Applications
How UCP and AP2 unlock autonomous commerce across industries
Agent-Led Purchasing
- • Procurement: Agents compare suppliers, negotiate pricing, and authorize purchases without human approval loops
- • Travel & Booking: Personal AI assistants book flights, hotels, and rentals across UCP-enabled providers
- • SaaS Subscriptions: Agents evaluate, trial, and subscribe to software tools on behalf of teams
Trust & Compliance
- • Audit Trail: Every AP2 authorization is cryptographically signed — complete non-repudiation
- • Spending Limits: VDCs encode authority boundaries so agents cannot exceed delegated budgets
- • Supply Chain: Multi-agent supply networks transact with verifiable credentials at each hop
Developer Experience
- • Single Standard: Implement UCP once and reach every compliant merchant
- • Transport Freedom: Use the transport you already have — REST, MCP, or A2A
- • Open Specs: Published at ucp.dev and ap2-protocol.org
Ecosystem
- • UCP Hub: ucphub.ai — registry for discovering UCP-enabled merchants
- • Interoperability: Designed to compose with A2A, MCP, and existing payment rails
- • Open Source: Reference implementations and SDKs available for rapid adoption
