Questions about AI agent payments

Agentic commerce is trade where an AI agent finds a service and pays for it, inside limits a person sets. That includes paid APIs, metered sessions, and checkout an agent runs. See agentic commerce and What is the agent economy?.

The agent economy is that commerce taken together. An AI agent is the software that acts. A tool protocol such as MCP moves context, not money. A payment protocol moves the dollars. The essay is What is the agent economy?.

Agent GDP is the dollars AI agents paid, counted from public payment records. Today that includes x402 (pay per web request) and MPP (pay for a session on Tempo). The live total is on Agent GDP.

No. Gross domestic product measures a national economy. Agent GDP adds up AI agent payments from public records. Card, bank, and Lightning payments stay out when there is no public record to read. The distinction is on the measurement page.

The service names a price. The agent authorizes that amount. A payment then settles. x402 does this for a web request. MPP meters a session. AP2 signs a permission to pay. ACP runs a merchant checkout. L402 pairs a web challenge with a Lightning invoice. The paths are in How agent payments work.

x402 is a way for an AI agent to pay for a web request. The server answers with HTTP 402 and a price. The agent signs the payment. A facilitator (a company that settles the payment on a blockchain) checks it and sends USDC, a digital dollar. Agent GDP counts the USDC transfer the payer authorized when a known facilitator wallet submits it. A router hop counts once. A transfer that pays the facilitator, or that pays the sender, is left out. The flow is in How agent payments work.

The agent requests a page or API. The server answers with HTTP 402 and a price. The agent signs a payment and tries again. A facilitator checks the signature. The server does the work. The facilitator sends the payment on a blockchain. The server then returns the result. That is the usual x402 flow, explained in How agent payments work.

A facilitator is a company that settles an agent payment on a blockchain. It checks the x402 payment, submits it, and waits for confirmation. Some services do those steps themselves. This site names a facilitator by the wallet that sends the USDC. Rankings are on Facilitators.

x402 payments are on Base, Polygon, Solana, and Arc. MPP sessions are on Tempo. Arc history starts on 16 September 2026, the public mainnet date. x402 history starts on 6 May 2025, the date of Coinbase's launch post. Chain pages are on Chains. The rules are in How we measure Agent GDP.

Usually, no. The agent signs a USDC authorization. The facilitator submits it and pays the network fee. That pattern is called gas sponsorship. See How agent payments work.

x402 sets the rules for paying for a web request on a blockchain. MPP sets the rules for a machine payment, including a metered session on Tempo. AP2 is a signed permission to pay. ACP is merchant checkout inside an agent. L402 pairs a web challenge with a Lightning invoice. The map is Agent payment protocols compared.

x402 payments on the chains we read, and MPP sessions on Tempo. AP2, ACP, and L402 are real standards, and we explain them. Their payments are not in the total, because we cannot read one public record for them. The list is on Protocols.

A blank means we do not have a public payment record to add. It does not mean the standard is unused. AP2 pays on whatever rail its permission names. ACP pays through the merchant's processor. L402 pays a Lightning invoice. We list them on Protocols so you can see what is missing.

Not here. AP2 and ACP can sit on top of another rail. If that rail is an x402 USDC transfer from a known facilitator, we count the transfer once, as x402. We do not add the permission or the checkout again. The rule is in Agent payment protocols compared.

MPP, the Machine Payments Protocol, is a way for a machine to pay. A Tempo session locks a deposit, signs vouchers, and settles the amount used. Agent GDP counts that Tempo settlement, and only the amount that actually moved. A quote that never settles adds nothing. Card charges under the MPP name are not in this total.

The size we publish is the live dollar total on Agent GDP, for the period you pick. This page does not copy that number, because it changes. Quote the figure with the time printed beside it. The total is x402 and MPP payments only.

An x402 payment is the USDC transfer a known facilitator wallet submits for the payer. The payer is the address that authorized it. The seller is the address that received the payment. A second hop in the same transaction is not a second payment. An MPP payment is the amount settled on Tempo, priced one dollar per token. A price quote, a permission to pay, an open checkout, and an unpaid invoice are not payments. The rules are on Methodology and in How we measure Agent GDP.

Raw volume is every payment we can attribute, including facilitator fees. Organic volume keeps a seller only when, in that period, settled volume is at least $100, there are at least 3 different payers, the average payment is at least $0.001, and the seller is not a facilitator wallet. Organic is a filter. It is not proof against wash trading. Both series are published so you can see the filter.

The site and the API read hourly and daily totals. Rankings refresh about once an hour. A page may be cached for about five minutes. The time next to a figure is when that total was built. x402 history starts on 6 May 2025. Arc history starts on 16 September 2026. Individual payments stay queryable for 180 days. Older charts use the totals. If a live read times out, the page keeps the last successful figures and shows when they were read. Details are in How we measure Agent GDP.

No. A figure is read from public payment records and labeled with the time it was counted. Standards without a public record are left out. Sample rows are practice data, and the page says so. If we have no successful read, the page says the figure is unavailable.

Use cases come from the Bazaar catalog: inference, search, data, and the other categories on Use cases. A category total is settled volume whose seller matched a classified service. Unclassified payments stay in Agent GDP and stay out of the named categories. The explainer is Agent payment use cases.

The site and the free API need no key. Free reads are about 60 requests a minute per IP. Each response says how to cite it. Bulk payment rows and a few exports are paid per call. The guide is the API page. The contract is OpenAPI.

CC BY 4.0. You may copy a figure if you credit Agent GDP, link the license, and keep the time printed next to the number. The license link is in the footer. Each JSON response repeats that credit line. The rules page is Methodology.

Send GET to a /api/v1 route. Free routes need no key. You can filter by period or payment standard. Every JSON body includes a credit line: title, the exact URL, publisher, license, and the time it was read. The contract is OpenAPI. Agents can also read llms.txt.

Paid bulk reads use x402 on Base. A request without payment gets HTTP 402 and a price. Pay that price and the route returns one response. Prices are on each paid route in OpenAPI. Those routes currently span $0.001 to $0.25 per successful response. The overview and the rankings stay free. Details are on the API page.

No. Facilitators, services, sellers, chains, and use cases sort by settled volume, payments, payers, or the change in those numbers. Nothing is for sale. A logo names a network. It is not an endorsement. The tables start at Facilitators.

Cite the page URL and the time printed next to the figure. Name the period. Do not add chain totals on top of protocol totals, or add organic volume on top of the full total. A missing standard is not a measured zero. If this FAQ and the methodology disagree, the methodology page wins. The same text is at /api/v1/methodology.