The Agent Payments Tracker
Agent payments are the protocols and card-network programs that let software pay, or buy, on someone’s behalf. This page tracks the main ones: who backs each, what it does, who holds the money when something goes wrong, how far it has shipped, and what public evidence exists that anyone is using it. I keep it because most comparisons of these protocols are written by companies with a product in the race, and because “announced” and “live” get blurred more often than they should.
Last updated: 2026-10-23. Updated weekly. Sources checked 23 October 2026. A few could not be re-read, and the change log says which. Each name in the first table links to the backer’s own material.
Recent changes (5 October to 23 October 2026)
- 14 Oct: Chainalysis counted “over 138 million x402 transactions” on Base in a review period ending September 2026. It doesn’t say whether wash or test activity was excluded.
- 15 Oct: Google launched Universal Cart in the US, in Search and the Gemini app, with checkout “powered by the Universal Commerce Protocol (UCP)” through Google Pay. No transaction figures.
- 20 Oct: Mastercard opened Agent Pay for Machines Early Access: first-version APIs and a sandbox for developers, after pilots with Cloudflare, Coinbase, Base, BVNK and others. It “builds on x402.” No general-availability date.
- 20 Oct: Visa, BILL and Billtrust launched a live pilot in which AI agents pay approved invoices through supplier portals, using Visa Intelligent Commerce and Trusted Agent Protocol. No transaction counts.
Earlier (24 September to 2 October 2026)
- 24 Sep: Block joined the x402 Foundation and is contributing Bitcoin Lightning support to x402. Block describes the Lightning work as ongoing, not shipped.
- 30 Sep: Cloudflare put its Monetization Gateway into closed beta for eligible US sellers and buyers. It charges agents over HTTP 402 and settles in USDC on Base through Coinbase’s x402 facilitator. I wrote about it here.
- 30 Sep: Mastercard added trust services to Agent Pay, including a score for how likely it is that an AI agent started a transaction. It is “rolling out for testing in the U.S.”
- 30 Sep: OUSD, the stablecoin co-owned by Visa, Mastercard, Stripe, Shopify and Coinbase, went live. It isn’t an agent protocol, but Stripe’s machine-payments docs list OUSD and USDC for stablecoin balances. Background: When the Card Networks Co-Own the Stablecoin.
The tracker
| Name | Backers | Layer | Status (date) |
|---|---|---|---|
| x402 | Created by Coinbase; now the x402 Foundation at the Linux Foundation, 40 members at launch and “more than 50 active members” by 1 Oct 2026, incl. Cloudflare, Google, Stripe, Visa, Mastercard | Pay per HTTP request, mostly stablecoins | Live since 2025; spec v2; foundation launched 14 Jul 2026 |
| MPP | Stripe and Tempo | Pay per HTTP request, stablecoins or cards | Live since 18 Mar 2026; IETF Internet-Draft |
| ACP | OpenAI and Stripe | Checkout inside an AI app | Spec in beta, latest 17 Apr 2026; ChatGPT Instant Checkout moved to apps, Mar 2026 |
| AP2 | Google; 60+ orgs at launch; donated to FIDO Alliance | Signed proof of what the user authorised | Spec v0.2; in FIDO standardisation since 28 Apr 2026 |
| UCP | Google, with Shopify, Etsy, Wayfair, Target, Walmart | Checkout in Google AI Mode and Gemini | US checkout announced 11 Jan 2026; rolling out in the US in Universal Cart since 15 Oct 2026; Canada, Australia, UK announced 20 May 2026 |
| Visa Intelligent Commerce | Visa; Trusted Agent Protocol with Cloudflare | Tokenised cards for agents | Live: “hundreds” of transactions by 18 Dec 2025; Connect in pilot since 8 Apr 2026; B2B invoice pilot with BILL and Billtrust live since 20 Oct 2026 |
| Mastercard Agent Pay | Mastercard; Verifiable Intent with Google | Tokenised cards for agents | Live: US issuers from Sep 2025, Latin America by Mar 2026; Agent Pay for Machines in developer early access since 20 Oct 2026, no general-availability date |
| Name | Who holds the money, and the dispute path | Public usage evidence | Watch for |
|---|---|---|---|
| x402 | Seller’s wallet, via a facilitator. The v2 spec has no refund or dispute flow | TRM Labs: $52.7M settled; 0.6–7.5% of screened commerce looks agentic. Visa/Artemis: ~$15.0M adjusted, May 2025 to 21 Apr 2026. Chainalysis: 138M+ transactions on Base, filters not stated | Lightning support; a dated public counter |
| MPP | Through Stripe: settles to the Stripe balance in fiat; refunds via Stripe | None published | Volume figures; rails beyond Tempo and Solana |
| ACP | The merchant stays merchant of record; the AI app passes a payment token, not card details | None published | Which AI apps implement it after Instant Checkout |
| AP2 | Moves no money; produces signed mandates as evidence. Liability not assigned | None published | Whether FIDO turns it into a standard networks honour in disputes |
| UCP | Retailer stays seller of record; pays with Google Pay, PayPal “soon” | None published | Merchant counts; non-US launch dates |
| Visa IC | Card rails; Visa says it can “help to manage disputes” | “Hundreds” of agent transactions (Dec 2025) | Any figure since then |
| Mastercard Agent Pay | Card rails; Verifiable Intent gives “a clear audit trail” for disputes | None published | Proof all US cardholders were enabled; a date for Agent Pay for Machines beyond early access |
How to read this table
The seven rows don’t all compete. x402 and MPP answer how a piece of software pays for a single request without an account. ACP and UCP answer how an AI app completes a purchase from a merchant. AP2, Verifiable Intent and Trusted Agent Protocol answer how a merchant or a network can tell that the user authorised what the agent did. Visa’s and Mastercard’s programmes put card credentials into all of that. A single purchase could touch three of these rows.
“Live” means a backer says real payments can be made in production, at least for some users. “Pilot” means live only with named partners or in a closed beta. “Spec” means documents and sample code, with no production claim from the backer. “None published” means I found no figure from a named source. It doesn’t mean nobody is using it.
The money column matters most to a merchant. Card-based rows inherit the networks’ dispute rules. The x402 spec has none, so recourse depends on whoever sits between the buyer and the seller. Stripe offers refunds on machine payments it processes, but that is Stripe’s own feature. The protocol itself has no refund step.
What isn’t known
Neither card network has published volume for its agent programme. Visa’s last number is “hundreds” of transactions, from December 2025, and its October pilot announcements gave no counts. In September 2025 Mastercard said all US cardholders would be enabled for Agent Pay by mid-November. I haven’t found a later primary source confirming that it happened.
x402 is the only rail with independent data, and the data says less than the counters. TRM’s screening found that between 0.6% and 7.5% of the likely commerce looked like agents, and couldn’t tell the rest apart from scripts. I covered that in detail. Visa and Artemis put adjusted volume at about $15.0 million across 109.6 million transactions, after removing wash and test activity. Chainalysis counted over 138 million on Base without saying whether it removed wash or test activity, so the two counts can’t be compared directly. On 2 October the x402.org counter showed 75.41 million transactions and $24.24 million for the “Last 30 Days”, undated; I couldn’t re-read it for this update. Daniel McGlynn reported in September that the counter had shown the same figures for months. Treat it as unverified.
Nobody has said who pays when an agent buys the wrong thing. AP2 and Verifiable Intent produce evidence of what the user authorised, and none of the documents I read assigns the loss. That gap is where I think merchants should press their providers, along with the questions in agentic checkout is being built faster than anyone trusts it. On the payer side, the record of what each agent spent is a separate problem, and I wrote about it in Most Agent Payments Won’t Run on Cards.
Change log
- 2026-10-04: First version. Seven rows: x402, MPP, ACP, AP2, UCP, Visa Intelligent Commerce, Mastercard Agent Pay. Sources checked 2026-10-02.
- 2026-10-23: x402: Chainalysis count (14 Oct) added to usage evidence; status unchanged. The homepage counter and GitHub repo couldn’t be re-read, so the counter sentence is now dated 2 October. Sources checked 2026-10-23.
- 2026-10-23: UCP: US checkout now rolling out in Universal Cart (15 Oct). Visa IC: live BILL and Billtrust invoice pilot (20 Oct), no new figure. Mastercard: Agent Pay for Machines moved to developer early access (20 Oct), still no usage figures. Sources checked 2026-10-23.
- 2026-10-23: Correction: the x402 row said “40 members”, the figure at the July launch. The Linux Foundation said “more than 50 active members” on 1 Oct 2026; the cell now shows both. Sources checked 2026-10-23.
- 2026-10-23: MPP, ACP, AP2: checked 2026-10-23, no change (Stripe machine-payments docs, ACP README still beta with 17 Apr 2026 latest, ap2-protocol.org still v0.2 in FIDO). Sources checked 2026-10-23.