All 42 articles, sorted alphabetically
AP2 With x402: Agent Stablecoin Payments Over the HTTP 402 Status
How x402 v2 turns HTTP 402 into a machine-readable quote an agent can pay with a signed stablecoin authorization, how the facilitator verifies and settles it, where AP2 mandates fit, and the client and merchant checks that stop replays and overpayment.
Read article →AP2 as an A2A Extension: Carrying Mandates in A2A Messages and Data Parts
How AP2 mandates are carried over A2A: declaring the extension on the agent card with roles and the required flag, activating it per request, carrying mandates as keyed data parts, which role sends which, and what a receiver must validate.
Read article →AP2 Price Changes After Signing: Re-Confirming When the Cart Total Moves
When the total changes between the merchant signing a cart and the payment, the signed cart no longer matches. How AP2 binds payment to the signed checkout hash, when to re-sign and re-confirm, and why a silent rupee tolerance fails.
Read article →3-D Secure architecture
Deep-dive on EMV 3-D Secure (3DS2): the three domains, 3DS Server / Directory Server / issuer ACS, risk-based frictionless vs challenge decisions, dev…
Read article →Agent Payments (AP2) Architecture, in depth: roles, open and closed mandates, hash binding, verification points and reconciliation
The end-to-end architecture of the Agent Payments Protocol as described in the AP2 v0.2 docs: the five roles and the non-agentic trusted surface, open…
Read article →Authorization holds
Deep-dive on the payment authorization-hold lifecycle: authorizing to reserve funds and lower available balance, fulfilment and capture, partial captu…
Read article →AP2 chargebacks -- disputed agent payments and reversals
Deep-dive on AP2 chargebacks: the disputed-agent-payment problem, the chargeback flow (dispute to reversal), the mandate as authorization evidence, li…
Read article →AP2 Chargeback Handling, in depth: the network lifecycle, a case state machine, ledger entries and representment built from mandates
How to operate chargebacks for agent-initiated card payments under AP2: what the protocol provides and what card-network rules govern, the chargeback …
Read article →AP2 Compliance Landscape
The regulatory surface an AP2 agent-payments system touches, described as engineering constraints: payment-institution licensing and the flow-of-funds…
Read article →AP2 Currency Conversion
Cross-currency agent payments: where the conversion actually happens (agent, PSP, card network, or issuer) and how each changes what the user pays, qu…
Read article →AP2 Dispute Architecture, in depth: joining Checkout and Payment Mandates into verifiable evidence, the dispute-time checks and an evidence pipeline
How disputes work for agent payments under AP2 v0.2: which artifacts exist and who holds them, how checkout_hash and transaction_id join the Checkout …
Read article →Double-entry ledger architecture for agent payments
Deep-dive on the double-entry ledger as the system of record for AP2 agent payments: the balancing invariant (debits equal credits), the append-only j…
Read article →Dunning management architecture
Deep-dive on dunning management for recurring payments: how a failed subscription charge enters a retry state machine that recovers involuntary churn …
Read article →AP2 escrow
Escrow for agent payments: when conditional fund holding is the right instrument, the funded-held-released-refunded state machine, writing a machine-c…
Read article →Fraud and risk scoring for agent payments
Deep-dive on fraud detection for agentic payments: mandate-chain verification, online feature stores and velocity counters, rules engines plus ML scor…
Read article →AP2 Fraud Signals, in depth: what the mandate chain proves, what risk_data carries, and how to turn both into decisions
A catalogue of the fraud signals an Agent Payments Protocol (AP2 V2) transaction actually carries: verification verdicts and constraint outcomes, stru…
Read article →AP2 FX conversion architecture
Deep-dive on foreign-exchange conversion in an AP2 agent payment: a rate source plus disclosed spread locked into a quote with an id and expiry, autho…
Read article →Idempotency keys in agent payments
How idempotency keys make agent payments safe to retry: why every transport delivers at least once, who mints the key and why it must be derived from …
Read article →AP2 Payment Intent Architecture in Depth
How an AP2 payment intent is captured: turning an under-specified user request into a bounded, signable authorization, which fields an agent may infer…
Read article →AP2 KYC architecture
How know-your-customer works when an AP2 agent transacts for a user: the onboarding flow and evidence types, risk-based tiering, who counts as the cus…
Read article →AP2 mandate architecture
How AP2 mandates work as an authorization artifact: intent mandates as a bounded spending envelope versus cart mandates for one specific basket, the b…
Read article →AP2 Marketplace Settlement, in depth: from mandate-backed checkout to seller payouts, ledgers, reserves, clawbacks and reconciliation
How a marketplace settles agent-initiated purchases made with the Agent Payments Protocol (AP2): what the v0.2 specification covers and deliberately l…
Read article →AP2 Multi-Party Settlement, in depth: who owes whom after an agent pays, clearing versus settlement, netting, funding lag and tracing every cent back to a mandate
How money actually moves after an AP2 agent payment: the parties on the settlement chain, authorization versus clearing versus settlement versus fundi…
Read article →AP2 multiparty architecture, in depth: roles, mandates, trust boundaries and what breaks between parties
How the Agent Payments Protocol splits one purchase across a shopping agent, trusted surface, credential provider, merchant and payment processor: who…
Read article →Agent Payments Protocol (AP2) Overview
An overview of AP2, Google's Agent Payments Protocol: why an AI agent buying on your behalf breaks the assumptions behind card-present and card-n…
Read article →Agent Payments Protocol Architecture in Depth
AP2 platform architecture in depth: where it sits between agent transport and payment rails, the services you build, deployment models, an agent signi…
Read article →AP2 Payment Flow, in depth: the purchase as a state machine, two hashes, receipts, budgets and the failures in between
How to implement the Agent Payments Protocol (AP2 v0.2) payment flow reliably: a short recap of the human-present and autonomous flows, the difference…
Read article →PCI scope reduction architecture
Deep-dive on shrinking the cardholder data environment: why scope follows data flow, hosted fields and the same-origin boundary, PSP vaults vs network…
Read article →AP2 Pricing Signals
How an autonomous agent works out what something actually costs: structured price feeds versus scraping a rendered page, the tax, shipping, fee and cu…
Read article →AP2 Payment Rail Architecture in Depth
How the choice of payment rail reshapes an AP2 system: card authorization, capture and clearing versus account-to-account and instant credit-push rail…
Read article →AP2 receipts -- verifiable proof of a completed payment
Deep-dive on AP2 receipts: the proof need, receipt contents (amount, parties, mandate reference, settlement), cryptographic signing, verification, lin…
Read article →AP2 payment reconciliation architecture
Deep-dive on reconciling agent-initiated payments: normalizing internal ledger, processor, and bank records into a canonical schema, tiered exact/fuzz…
Read article →AP2 recurring payments architecture
How AP2 handles standing authorization: the recurring mandate versus a one-off cart mandate, the billing-cycle state machine, dunning and smart retry …
Read article →AP2 Refunds: How Agent Payments Protocol Handles Refunds
How AP2 refunds work: refund vs chargeback, linking to the original payment, full and partial refunds, idempotency, settlement reversal, and agent lim…
Read article →AP2 Security
A working threat model for AP2 agent payments: the assets worth stealing and the adversaries who want them, prompt injection that drives an agent to t…
Read article →AP2 split payment architecture
Deep-dive on split payments in an agent commerce protocol: a single buyer authorization and capture fanned into exact per-payee shares by an allocatio…
Read article →AP2 stablecoin architecture
How stablecoins work as a settlement rail for AP2 agent payments: issuance and redemption mechanics, reserve composition and attestation, custody of a…
Read article →Payment tokenization for agents, in depth: network tokens, cryptograms and credentials bound to AP2 mandates
Payment tokenization for AI agents: PSP versus network tokens, EMVCo token roles and cryptograms, how AP2 Payment Mandates scope a credential to one c…
Read article →AP2 Tokens, in depth: SD-JWT mandates, disclosures, key binding and what the payment credential really is
A wire-level guide to the tokens in an Agent Payments Protocol (AP2 v0.2) purchase: the merchant's checkout JWT, open and closed mandates as SD-J…
Read article →Payment velocity limits architecture
Deep-dive on velocity limits for payments: multi-key extraction, windowed atomic counters, sliding windows and distinct-count dimensions, a data-drive…
Read article →AP2 Verification
Runtime verification in AP2 agent payments: separating authentication from authorization, walking the agent's authority chain back to the user, v…
Read article →AP2 wallet architecture
How an AP2 wallet holds signing authority: user-held, custodial and MPC custody models, key generation inside a secure enclave, TEE or HSM, the signin…
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