402rates.com

A payment integration check for 0.001 USDC, with no external data lookup. Returns time, transport rail, network mode and a catalogue of free and paid capabilities. HTTP payment options can include Base, Polygon, Arbitrum and XDC; the challenge lists currently available networks for each transport. The settlement receipt identifies the paid network and transaction.

What a USDC transfer actually costs on Base, Polygon, Arbitrum, Ethereum and XDC, measured rather than assumed: gas units simulated per chain against live prices and fresh chain heads, plus the rollup L1 data fee where it applies. Every figure ships with its inputs and the block it was read at, so you can recompute it. Cheapest first; a chain that cannot be measured is excluded, never estimated.

Realised 30-day yields for 13 tokenized treasury funds: BUIDL, BENJI, OUSG, USDY, USTB, USYC, VBILL, mTBILL, TBILL, cUSDO, EUTBL, USTBL and UKTBL. Measured rows use NAV, price or verified passive-holder balance series under the published Open Treasury Yield Basis. Each carries its observations, sources and dates, plus an issuer figure and difference where available. Quoted and unavailable rows stay explicit; free coverage names every gap.