Monetize your API.
Per call. Any chain.
List endpoints, charge USDC per request, settle on Solana, Base, SKALE, Avalanche and more. Built on x402 — no subscriptions, no API keys to handle, no billing logic in your stack.
GET /v1/forecast?city=:cAPIs charge per month.
Agents call once.
The agent economy moves at HTTP speed. Subscriptions, signups, key rotation — every hop slows it down or breaks it outright. The marketplace removes them all: the agent just calls the URL, the price is settled in the request itself.
- API keys to provision and rotate
- Subscription tiers to negotiate
- Stripe accounts and tax filings
- Free-tier abuse + API key leaks
x402 changes that
One HTTP request. One USDC settlement.
No accounts in between.
Provider or buyer. Same protocol.
Whether you ship the endpoint or call it, the marketplace removes the parts you don't want to build — billing, signups, key rotation, multi-chain wallets.
Four steps. One rail.
The whole loop is HTTP-native — no off-platform billing, no proprietary auth headers, no out-of-band invoices.
Provider registers an endpoint, sets a USDC price + a chain. The marketplace mints a /relay/:apiId/* URL.
Buyer (human or agent) finds the listing or hits the /relay URL directly. No signup required.
First call returns 402. The client signs an x402 challenge, retries — the facilitator validates + settles USDC.
Once settled, the relay forwards to the upstream and pipes the response back. The provider sees a normal request.
The protocol does the work.
x402 turns “Payment Required” into a first-class part of the request loop — no off-channel billing, no manual invoicing, no human in the middle.
The 402 status code is part of HTTP. No custom auth headers, no proprietary SDK lock-in. Any client that can fetch a URL can pay.
Charge per request, not per month. Prices down to fractions of a cent. Revenue scales linearly with usage.
Solana, Base, SKALE, Avalanche, Polygon, SEI, peaq — switch the network on the listing, the same client keeps working.
One line on each side. Done.
Server: wrap a route. Client: wrap an axios instance. The marketplace handles the 402 → sign → settle → upstream loop in between.
server.tsimport { relai } from "@relai-fi/x402"
app.use({
price: "0.005", // USDC per call
network: "base-sepolia",
facilitator: relai.facilitator,
})X-PAYMENT header.agent.tsimport { withPaymentInterceptor } from "x402-axios"
const api = withPaymentInterceptor(axios, wallet)
const res = await api.get(
"https://api.relai.fi/relay/wxr-92/v1/forecast"
)await.Built for usage-shaped revenue.
Anywhere the natural unit is a request, not a seat. The marketplace gives that request a price, a settlement chain, and an audit trail.
LLM agents budget per-call instead of per-month — only spend on the calls that actually fire.
Sell market intelligence per query: OI, liquidations, on-chain risk. Charge for the value, not the seat.
Per-token pricing without provisioning keys. Buyers pay only for the completions they consume.
Articles, podcasts, datasets — gate any URL and charge cents per access. No subscription required.
GPU seconds, rendering jobs, scrape runs — meter the resource directly, not via a billing portal.
Chain APIs together: each one settles independently. The composer pays the marketplace, the marketplace pays each leg.
Need privacy? Need facilitator?
The marketplace shares its rail with two sister products. Different problem, same settlement, same SDKs.
Common questions.
Yes — you connect a wallet on the chain you want to be paid on. Your USDC lands in that wallet directly; we never custody funds.
They need a funded wallet on the same chain as the API they call. The x402 client handles signing the payment header on every request.
Stripe still requires accounts, signups, monthly cycles, and a credit-card relationship. x402 is account-less and chain-native — every call is its own settlement.
Pick the chain your buyers already hold USDC on. Solana is fast and cheap; Base is the EVM default; SKALE is gas-free; Avalanche / Polygon / SEI / peaq are also live.
Listing is free during the multichain beta. We take a small protocol fee on settled payments — full pricing details in the docs.
Ship your first paid endpoint today.
List an API in minutes or run an agent against an existing one. No accounts, no signups, no key rotation. Just calls.