--- title: "Protocols and programs for agent payments | Agent Ready Checkout" description: "Protocols and programs in the agent checkout matrix: ACP, UCP, AP2, Visa TAP, Visa IC, Mastercard Agent Pay. Dated, sourced profiles." canonical: https://agentreadycheckout.com/protocols site: "Agent Ready Checkout" last_updated: 2026-11-04 section: "Protocols" --- # Protocols and programs for agent payments | Agent Ready Checkout > Protocols and programs in the agent checkout matrix: ACP, UCP, AP2, Visa TAP, Visa IC, Mastercard Agent Pay. Dated, sourced profiles. Source: https://agentreadycheckout.com/protocols Site: Agent Ready Checkout Last reviewed: 2026-11-04 Reference # Protocols and programs In short 12 protocols are profiled here, each with the matrix cells that describe it, the facts behind them and a source and read date for every claim. Together they hold 23 live cells, 12 pilot and 57 announced as of 4 Nov 2026. Live cells sit on ACP, UCP, Visa IC, Mastercard Agent Pay, x402. ## Protocols and programs in the matrix | Name | Operator | What it is | Stated cells | | --- | --- | --- | --- | | Agentic Commerce Protocol (ACP) | OpenAI, Stripe and Meta (lead maintainers) | An Apache 2.0 checkout protocol between an AI agent, a merchant and a payment provider; first shipped in ChatGPT Instant Checkout on 29 Sep 2025 and now used mainly for product feeds in ChatGPT. | 3 live, 2 pilot, 7 announced | | Universal Commerce Protocol (UCP) | UCP Tech Council (Google, Shopify, Etsy, Target, Wayfair, Amazon, Meta, Microsoft, Salesforce, Stripe and others) | An Apache 2.0 protocol for discovery, cart, checkout and orders between agents and businesses, announced by Google and Shopify in January 2026; powers checkout in Google AI Mode and Gemini and Microsoft Copilot onboarding. | 10 live, 4 pilot, 6 announced | | Agent Payments Protocol (AP2) | FIDO Alliance (donated by Google, April 2026) | A mandate-based protocol in which signed verifiable credentials record what the user authorised, giving issuers, merchants and networks an audit trail for human-present and human-not-present agent payments. | 0 live, 1 pilot, 10 announced | | Visa Trusted Agent Protocol (TAP) | Visa | Visa's agent identity scheme: an agent signs each HTTP request with HTTP Message Signatures (Web Bot Auth) so a merchant or its CDN can tell a registered agent from a bot and receive consented user and payment identifiers. | 0 live, 1 pilot, 5 announced | | Visa Intelligent Commerce (incl. Intelligent Commerce Connect) | Visa | Visa's program for agent payments: tokenised credentials for agents, cardholder-defined payment instructions, and since April 2026 Intelligent Commerce Connect, a single acceptance integration for TAP, MPP, ACP and UCP traffic. | 1 live, 1 pilot, 6 announced | | Mastercard Agent Pay | Mastercard | Mastercard's agentic payments program: registered agents transact with Mastercard agentic tokens, merchants verify agents through Web Bot Auth at the CDN, and since 30 Sep 2026 issuers can test a probability score for AI-initiated transactions. | 1 live, 1 pilot, 8 announced | | Mastercard Agent Pay for Machines (AP4M) | Mastercard | Mastercard's machine-to-machine payment service for agents buying digital services, built on x402 with MPP compatibility, settling across cards, accounts and stablecoins; Early Access opened 20 Oct 2026. | 0 live, 1 pilot, 7 announced | | American Express Agentic Commerce Experiences (ACE) | American Express | American Express's developer kit for agent payments (agent registration, account enablement, intent, payment credentials, cart context), with Amex Agent Purchase Protection announced for agent errors. | 0 live, 0 pilot, 6 announced | | x402 | x402 Foundation (Linux Foundation) | An HTTP 402 payment protocol: a server answers 402 with payment requirements, the client pays (mostly stablecoins on EVM chains and Solana, Lightning since Sep 2026) and retries; governed by the x402 Foundation. | 3 live, 0 pilot, 1 announced | | Machine Payments Protocol (MPP) | Tempo and Stripe | An HTTP 402 protocol co-authored by Tempo and Stripe with challenge, credential and receipt messages and one-time, session and subscription intents, settling on Tempo stablecoins, Stripe tokens, cards or Lightning. | 2 live, 0 pilot, 0 announced | | Stripe Link for agents (Link Agent Wallet) | Stripe | Stripe's consumer wallet exposed to agents: the agent creates a spend request, the user approves it, and Link returns a one-time credential or a saved Link payment at Link merchants; Meta Muse uses it. | 3 live, 0 pilot, 1 announced | | Verifiable Intent (VI) | Mastercard, with Google; contributed to FIDO Alliance | An open SD-JWT credential format that chains credential provider, user and agent, binding user constraints (amount, merchants, items) so every party can prove what the agent was allowed to buy. | 0 live, 1 pilot, 0 announced | See also [the full matrix](https://agentreadycheckout.com/matrix) and [the head-to-heads](https://agentreadycheckout.com/compare). ## Sources 1. [agenticcommerce.dev/](https://www.agenticcommerce.dev/), read 4 Nov 2026 2. [Stripe: Developing an open standard for agentic commerce](https://stripe.com/blog/developing-an-open-standard-for-agentic-commerce), read 4 Nov 2026 3. [ucp.dev/](https://ucp.dev/), read 4 Nov 2026 4. [shopify.com/news/ai-commerce-at-scale](https://www.shopify.com/news/ai-commerce-at-scale), read 4 Nov 2026 5. [AP2 protocol site](https://ap2-protocol.org/), read 4 Nov 2026 6. [cloud.google.com/blog/products/ai-machine-learning/announcing-agents-to-payments-ap2-protocol](https://cloud.google.com/blog/products/ai-machine-learning/announcing-agents-to-payments-ap2-protocol), read 4 Nov 2026 7. [Visa Trusted Agent Protocol repository](https://github.com/visa/trusted-agent-protocol), read 4 Nov 2026 8. [Visa Introduces Trusted Agent Protocol](https://usa.visa.com/about-visa/newsroom/press-releases.releaseId.21716.html), read 4 Nov 2026 9. [Visa Intelligent Commerce](https://www.visa.com/en-us/solutions/intelligent-commerce), read 4 Nov 2026 10. [Find and Buy with AI: Visa Unveils New Era of Commerce](https://usa.visa.com/about-visa/newsroom/press-releases.releaseId.21361.html), read 4 Nov 2026 11. [Mastercard Agent Pay](https://www.mastercard.com/us/en/business/artificial-intelligence/mastercard-agent-pay.html), read 4 Nov 2026 12. [mastercard.com/us/en/news-and-trends/press/2025/april/mastercard-unveils-agent-pay-pioneering-agentic-payments-technolog](https://www.mastercard.com/us/en/news-and-trends/press/2025/april/mastercard-unveils-agent-pay-pioneering-agentic-payments-technology-to-power-commerce-in-the-age-of-ai.html), read 4 Nov 2026 13. [ap4m.build/info](https://ap4m.build/info), read 4 Nov 2026 14. [Mastercard launches Agent Pay for Machines](https://www.mastercard.com/us/en/news-and-trends/press/2026/june/mastercard-launches-agent-pay-for-machines.html), read 4 Nov 2026 15. [Amex Agentic Commerce Experiences](https://www.americanexpress.com/en-us/company/agentic-commerce/), read 4 Nov 2026 16. [x402.org](https://www.x402.org/), read 4 Nov 2026 17. [Machine Payments Protocol](https://mpp.dev/), read 4 Nov 2026 18. [Stripe Link Agent Wallet docs](https://docs.stripe.com/agentic-commerce/agents/link-agent-wallet), read 4 Nov 2026 19. [verifiableintent.dev](https://verifiableintent.dev/), read 4 Nov 2026 20. [mastercard.com/us/en/news-and-trends/stories/2026/verifiable-intent.html](https://www.mastercard.com/us/en/news-and-trends/stories/2026/verifiable-intent.html), read 4 Nov 2026 Last reviewed 4 Nov 2026 ## Edition Matrix edition of 4 Nov 2026. Reviewed 4 Nov 2026, [20 sources](#sources-h). ## Method [How cells, sources and read dates are defined](https://agentreadycheckout.com/method)