Showcase · A2A + AP2

Agent negotiation, Midnight-anchored.

The buyer agent and seller agent exchange typed A2A DataParts. Once they agree, the buyer signs an AP2 CartMandate with a Compact witness proof and the server anchors the mandate hash on the Midnight MandateVault contract.

Negotiation transcript

1 · Buyer agent
IntentMandate: I want 2 tickets to `Krump Cypher Vol.1`, budget 20 mUSDC.
2 · Seller agent
CartMandate offer: 2× Krump Cypher Vol.1 @ 8 mUSDC each — total 16 mUSDC. Expires in 5m.
3 · Buyer agent
Sign CartMandate → witness proof (buyerSecret binds to pk = ap2:buyer:v1).
4 · Server
POST /api/public/ap2-anchor { mandateHash, buyer, seller, amount, proof }.
5 · Midnight
anchorMandate(...) → tx 0xSIMULATED — MandateVault.anchored_count += 1.

Contract source: contracts/MandateVault.compact. Deploy with bun run compile on the Undeployed stack, or via the Preview/Preprod deploy script.

The full protocol block for A2A + AP2 is embedded in every prompt tagged with agentic · a2a-ap2.