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VISION

The A2A Stack: Agent-to-Agent Commerce

Agents calling agents, paying for API access, and verifying each other's outputs. This is agent-to-agent commerce, and it needs new infrastructure.

The Problem: Agents Can't Coordinate

AI agents are already calling APIs, browsing websites, and executing code. But when Agent A needs to use Agent B's service, fundamental questions arise:

?How to discover AI policy and pricing?
?How to pay without human intervention?
?How to verify work was performed?
?How to maintain audit trails?

The A2A Stack

The A2A (Agent-to-Agent) stack describes the layers needed for autonomous agent commerce. Each layer addresses a specific coordination problem:

LAYER 1
AI Policy Discovery

Agents discover bot policy, crawling rules, and terms at /.well-known/peac.txt

LAYER 2
Access Control (HTTP 402)

Gated endpoints return 402 with payment instructions (x402, Stripe)

LAYER 3
Receipts (PEAC-Receipts)

Every transaction returns a signed, verifiable receipt as proof

LAYER 4
Provenance

Chain of receipts + C2PA creates auditable lineage for compliance

An A2A Transaction Flow

Here's how a complete agent-to-agent transaction works with PEAC:

1
Policy check: Agent A fetches /.well-known/peac.txt to discover crawling policy and payment options
2
Access request: Agent A calls Agent B's API endpoint
3
402 response: Agent B returns HTTP 402 with payment details
4
Payment: Agent A pays via configured method (x402/Stripe)
5
Receipt: Agent B processes request and returns PEAC-Receipt in headers
6
Verification: Agent A or operator verifies receipt at verify endpoint

Why Receipts Matter

In human-to-business transactions, receipts are obvious: email confirmations, PDF invoices, bank statements. Agent-to-agent transactions need the same thing, but machine-readable.

Proof of Service

Cryptographic evidence of work performed

Audit Trail

Operators review agent spending

Dispute Resolution

Shows exactly what was delivered

Compliance

Bundled for regulatory reporting

What's Shipping vs. Planned

SHIPPINGAI policy discovery, HTTP 402 patterns, PEAC-Receipt format, x402/Stripe integration
IN DEVMCP tool bindings, ACP integration, automated agent wallet management
PLANNEDMulti-agent receipt chains, provenance dashboards, compliance bundle exports

Getting Started

If you're building agent infrastructure:

Start with Originary Declare to publish your AI access policy
Add HTTP 402 to paid endpoints - see What is HTTP 402?
Return PEAC-Receipts from your API responses
Use the Verify API for receipt verification