The map

When an agent pays a tenth of a cent for some data, several companies can be involved, each doing one job. This lesson draws the whole stack once, with one real example on each layer, so every name in the rest of the track has a place to sit.

Picture an AI agent that needs this morning’s rainfall for one field. It finds a weather service in a catalogue and asks for the data. The service answers 402 with a price of $0.001. The agent signs a payment from its wallet, sends the request again and gets the reading back.

The map

From the agent’s side that took two requests. Behind them, at least five separate parties did a job: one wrote the rules, one held the agent’s money, one moved it, one was paid, and one made the service findable. A sixth group sells a different way to do the whole thing. Every number in this lesson is dated, because this market changes month to month.

The protocol

x402 is the rulebook. It says what a 402 response must contain and how the buyer signs a payment. On its own it moves no money.

Example: the x402 Foundation. Coinbase announced x402 on 6 May 2025, and on 2 April 2026 the Linux Foundation launched the x402 Foundation to hold it. The code lives in one public repository, which logged about 20 commits a week in the six months to October 2026. The protocol is still version 2 (14 Oct) source, released on 11 December 2025 and extended since through small software releases.

Facilitators

A facilitator checks the buyer’s signed payment and settles it on the blockchain, so the seller never has to run blockchain software.

Example: Coinbase’s facilitator, part of the Coinbase Developer Platform (CDP). In the six months to 11 October 2026 it settled 91% of all x402 transactions on Base, according to x402scan. It charges sellers nothing for the first 1,000 settlements each month and $0.001 for each one after that (14 Oct) source.

Dozens of other facilitators exist. Their prices run from free to a percentage of each payment, and several are run by token projects. Lesson 3 sorts the serious ones from the rest.

Wallets

This is the buyer side. An agent can pay only if someone has put money, usually USDC, into a wallet it is allowed to use, with limits on what it may spend.

Example: Crossmint, a funded wallet and checkout company. Its docs show an agent paying an x402 endpoint from a Crossmint wallet with USDC on Base. x402 is one of several ways its agent wallets pay; cards and checkouts are others. Most established companies treat x402 this way, as one rail among several.

Sellers

A seller is anyone who puts a price on an API, a dataset or a tool.

Example: Venice, a private AI app that raised a $65M Series A at a $1 billion valuation on 1 July 2026. A wallet can top up a Venice balance through x402 and spend it on chat and image calls with no account and no API key. Venice also shows how small this market still is. By 11 October 2026 it had taken $5,279 of x402 top-ups in total, from 201 wallets, while the company said in July 2026 that its API handles 2 million calls a day.

Discovery

An agent can’t pay for a service it can’t find.

Example: the Bazaar, a catalogue of paid endpoints that Coinbase runs and its own docs describe as “in early development (14 Oct) source”. A service gets listed after a facilitator processes a paid request for it. On 11 October 2026 the Bazaar held 32,169 resources, and the median one drew 2 calls in 30 days. One endpoint took 43.8% of all calls; lesson 4 explains why.

Discovery

People use a different tool: x402scan, an explorer built by Merit Systems. Most usage numbers in this track come from it. It counts USDC transfers sent by the facilitators it knows about, on Base, Solana and Polygon (14 Oct) source.

Rivals

x402 isn’t the only way a machine can pay.

Example: the Machine Payments Protocol (MPP) from Stripe and Tempo. Cloudflare’s docs call it backwards-compatible with x402, and Stripe’s docs say machine payments on Stripe work best with MPP (14 Oct) source. Rival chains count too: on 25 August 2026 Solana passed Base on daily x402 transactions. Lesson 5 covers both.

Above the stack

A small group of large companies shapes every layer. Coinbase, Cloudflare and Stripe (14 Oct) source hold the seats on the protocol’s technical steering committee, and AWS and Circle have shipped x402 products of their own. Lesson 2 takes them one at a time.

Two things the map shows

One company can sit on several layers. Coinbase created the protocol, holds a steering-committee seat, runs the biggest facilitator and runs the Bazaar. When people call x402 “open”, that is true of the code and the governance, and the money still flows mostly through Coinbase.

Many names you’ll see on x402 lists sit on no layer at all. The official x402 directory had 206 entries when it was taken down on 7 July 2026, and the researchers found that 116 of them showed no activity on Base. A logo on a list tells you a project wanted to be associated with x402. It doesn’t tell you anyone pays it.

Two things the map shows

Every project on this map, with its rating and its live activity, is in the players directory.