How AI agents pay: the emerging protocols (ACP, AP2, x402), agent identity and verifiable mandates, checkout and card-network flows, fraud and disputes, and how merchants become agent-ready.
How AI agents that discover, choose, and pay on your behalf break the assumptions baked into every checkout, and the protocol stack rushing in to fix them.
What agentic commerce is: AI agents that discover, select, and pay on a user's behalf.
Four protocols, four jobs: how tools, agent-to-agent messaging, and payment rails compose into one buying flow.
How the layers compose: MCP gives an agent tools and context; A2A lets agents talk to each other; AP2/ACP/x402 are the payment rails those agents call when money must move.
How Stripe and OpenAI turned "buy it for me" into an open standard — product feeds, delegated payment tokens, and OAuth consent.
The Agentic Commerce Protocol co-developed by Stripe and OpenAI that powers Instant Checkout in ChatGPT.
How three cryptographically signed mandates turn an agent's purchase into a non-repudiable audit trail.
Google's open Agent Payments Protocol (AP2).
How Coinbase revived a dormant status code so software agents can pay for what they use, one request at a time.
Coinbase's x402 revives the dormant HTTP 402 Payment Required status code so agents pay for resources machine-to-machine.
A clear-eyed look at trust models, who signs what, rails, credential handling, and settlement — and why these four overlap more than they compete.
A clear-eyed comparison across trust model, who signs what, payment rails supported, credential handling, settlement, and best-fit use cases.
When software spends money on your behalf, the merchant has to answer two questions before the charge clears: which agent is this, and what did the human actually let it do.
How a merchant verifies WHICH agent is acting and WHAT it may do.
When an AI agent spends your money, "the user said so" is not evidence. A signed mandate chain is.
A deep dive on the mandate chain as evidence: verifiable credentials (VCs), signing, the non-repudiable Intent→Cart→Payment chain, revocation and expiry, and why this replaces 'trust me, the user said so' with cryptograp…
How an AI agent turns a shopper's intent into a settled purchase, and where ACP and AP2 plug into the same eight-stage skeleton.
A complete walkthrough: product discovery via an AI surface → cart assembly → user approval/mandate → delegated payment token → merchant checkout → authorization → fulfillment → receipts/webhooks.
How Visa and Mastercard are reshaping tokenization so an AI agent can pay on your behalf — with scoped credentials, agent-aware identity, and the network doing what it has always done: authenticate, authorize, tokenize.
How the card networks are adapting tokenization for agents.
When software holds the card and clicks "buy," the old questions — was this the cardholder, did they mean to, who pays if not — all get harder to answer.
The new fraud surface: prompt injection turning a shopping agent into an attacker's buyer, hijacked delegated credentials (Visa saw ~450% more dark-web 'AI Agent' chatter in H1 2026), and disputes when an agent acted on…
The surface a store must expose when the buyer is an AI agent, not a browser — and why it is the fintech reliability playbook wearing a new hat.
What a store must expose to sell to agents: a machine-readable product feed/catalog, agentic checkout endpoints, acceptance of delegated payment tokens, idempotency keys for retried agent calls, webhooks for async status…
This series is part of a larger body of work by Pratik Dhanave, an Agentic AI Architect writing about production AI systems, distributed systems, and cloud-native engineering. Explore all course series, browse every post, or find topics via the tag index.