402rates.com
testnet · building in public

Cross-chain settlement intelligence

Rate data your agent can buy by the call.

Settlement costs, staking yields and tokenized treasury rates, normalised across chains, served over HTTP 402 and settled in USDC. No account, no API key, no subscription.

Specimen
What one USDC transfer costs 27 Jul 2026 · 22:08 UTC
ChainCost per transfer, USDTimes the cheapest
xdc0.00002691 ×
base0.00075528 ×
polygon0.0013550 ×
arbitrum0.0025494 ×
ethereum0.00814303 ×
Execution gas only. One sampled response, not a live quote. Every paid call carries its own sources, a freshness proof and its own caveats.

The exchange

An agent asks, gets a price, pays inside the same request, and receives the data. No signup stands between the question and the answer.

Live handshake · api.402rates.com fetching… 
connecting…

Rate sheet

CapabilityWhat you getStatusUSDC
settlement.costs Estimated execution gas cost of a USDC transfer per chain, cheapest first. Live gas, verified chain heads. Live 0.01
staking.yields Native staking and validator economics across chains, normalised to comparable terms. Building 0.01
rwa.yields Tokenized treasury yields by issuer and chain, measured rather than quoted. Building 0.03
rwa.compare Side by side product comparison, including who is eligible to hold each instrument. Building 0.05

Pay on any of these

  • Base
  • Polygon
  • Arbitrum
  • Solana
  • XDC

One endpoint, several rails. The 402 response lists every network it accepts and your agent picks one, including XDC, where the same transfer settles for a fraction of the others. That number is not a claim on this page. It is what settlement.costs measures on every call.

First call

See the payment terms for yourself. This costs nothing:

curl -i https://api.402rates.com/v1/settlement/costs

Read the machine readable description of every endpoint, its parameters and its price:

curl https://api.402rates.com/v1/manifest

To buy the data, point any x402 capable client or agent framework at the same URL. It reads the terms from the 402, pays in USDC, and retries. Gas is sponsored, so your agent only needs the stablecoin.

Where this stands

This is being built in the open, so here is the honest state of it rather than a roadmap that flatters us.

Running on testnet. The payment rails, the freshness guards and the idempotency handling are implemented and covered by tests. Mainnet follows once the first paid calls are proven end to end on both rails.

One endpoint is live. The rest of the rate sheet is being built in the order shown. Nothing is listed here as available before it is.