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Agentic commerce for builders
A guided path for developers and technical teams: the full protocol stack, each standard in depth, how agents pay, and how to query this reference from your own agent.
- 1 What Is Agentic Commerce?
Orient quickly, then go deep.
A plain-language explanation of agentic commerce: AI agents that browse, choose, and pay on a person's behalf. How a transaction flows, why it is happening now, what is actually live, and who the players are.
- 2 The Agentic Commerce Protocol Stack: ACP vs AP2 vs UCP vs MCP vs x402 vs MPP
The full stack and how the layers fit.
A neutral, plain-language comparison of the protocols behind agentic commerce: ACP, AP2, UCP, MCP, A2A, x402, and MPP. What each one does, who backs it, and how they fit together.
- 3 ACP Explained: The Agentic Commerce Protocol
The agent-to-merchant checkout standard.
A neutral guide to the Agentic Commerce Protocol (ACP): what it is, who maintains it, how payment flows through a Shared Payment Token, what is actually live, and how it relates to AP2, MCP, and UCP.
- 4 AP2 Explained: The Agent Payments Protocol
Proving the user authorized the purchase.
A neutral guide to the Agent Payments Protocol (AP2): how it proves a user authorized an agent's purchase, the mandate model, its move to the FIDO Alliance, and how it relates to ACP, A2A, MCP, and x402.
- 5 UCP Explained: The Universal Commerce Protocol
The other commerce-layer standard.
A neutral guide to the Universal Commerce Protocol (UCP): Google's open standard for the full agentic shopping journey, who governs it, how it relates to ACP and AP2, and what is actually live.
- 6 MCP Explained: The Model Context Protocol in Agentic Commerce
The discovery layer agents use to find tools.
A neutral guide to the Model Context Protocol (MCP) and its role in agentic commerce: the discovery layer agents use to find and call a merchant's tools, how it composes with the commerce protocols, and how it shows up in payments.
- 7 How AI Agents Pay
Tokenization, mandates, and the network rails.
How AI agents actually pay: tokenization, signed mandates, passkeys and delegated authority, and the network products from Visa, Mastercard, American Express, PayPal, Stripe, and the x402 stablecoin rail. What is live versus announced.
- 8 MPP Explained: The Machine Payments Protocol
The settlement layer: agents paying for APIs, compute, and services.
A neutral guide to the Machine Payments Protocol (MPP): the open standard from Stripe and Tempo that lets AI agents pay for APIs, compute, and services programmatically, how it works, what it settles in, and how it relates to x402, ACP, and AP2.
- 9 Query the Atlas over MCP
Connect this reference to your own AI agent.
- 10 How to Implement ACP: A Merchant Integration Walkthrough
Build capstone: integrate ACP as a merchant, with the real endpoints and the Shared Payment Token flow.
A practical builder's guide to integrating the Agentic Commerce Protocol as a merchant: the three responsibilities (product feed, the Agentic Checkout API, and accepting a Shared Payment Token), the real endpoints and payloads, and how the payment flows without your store ever seeing a card.
- 11 How to Build a Remote MCP Server: A Worked Example
Build capstone: ship your own remote MCP server, using ours as the worked example.
A practical builder's guide to shipping a remote Model Context Protocol server, using the Agentic Commerce Atlas's own Cloudflare Worker as the worked example: the Streamable HTTP transport, the JSON-RPC methods you must implement, how to define and serve tools, and how to deploy and test it.
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