When an autonomous agent buys something on a human's behalf, every payment needs cryptographic authorization that's independently verifiable — not platform trust, not a card-network rule, not a chargeback waiting to happen. This demo runs the full flow: soft-reject, magic-link authorization, bilateral handshake, settlement, receipt, and the Bitcoin maxi delegation policy that lets a human supervise their agent's spend at runtime.
Scenario · Martina is in Buenos Aires. Martina asked her AI agent Vickyto find her a women's bike no more than $250 USD that would fit her, comes from a reliable vendor, preferably new and can arrive this week. Vicky found the perfect bike for Martina, an Overtech R29 Q5 mountain bike on Mercado Libre: ARS 253.999, 49% off, ≈ 235 USDT via x402.
Martina hasn't configured a delegation policy yet (a new chargeback prevention requirement for agentic payments on Mercado Libre), so Vicky's purchase attempt soft-rejects, Vicky doesn't have authorization to spend on her behalf. Martina has to tap.
One page, scroll-paced, with real screenshots from each step of the flow. Built for screen-share — pause on any beat, point at any element.
WDK provides the wallet, payment, and cryptographic primitives. Observer Protocol provides the trust handshake, soft-reject escalation, bilateral verification, and chargeback-resistant receipts. Together they enable verified human-supervised agentic commerce — including in markets like Argentina where stablecoin settlement and crypto-native dispute resolution remove real friction. Mercado Libre handles ~20% of LatAm e-commerce; agent-supervised purchases on platforms like this are the natural wedge for crypto-native chargeback prevention.
Merchant DID shown in the demo is illustrative — Mercado Libre would publish their own DID at this endpoint if they integrated. The protocol architecture is identical regardless of merchant identity.