Constant lookup

Look up a physical constant by its key (e.g. "speed-of-light"), symbol (e.g. "c") or exact name. Returns the CODATA 2018 recommended value, unit, relative standard uncertainty (0 for values that are exact by SI definition) and category.

Open endpoint ↗

Price per call: $0.004
Chain: Base
Method: POST
Paid calls · 30 days: 1

Call it from code

This API is run by its own provider and paid directly through x402. We list it so you can find it; we don't route or hold the payment.

import { x402Client, wrapFetchWithPayment } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";

const client = new x402Client();
registerExactEvmScheme(client, { signer: agentAccount });

const pay = wrapFetchWithPayment(fetch, client);
const res = await pay("https://physics.openverbs.com/v1/constant", { method: "POST" });
console.log(await res.json());

https://physics.openverbs.com/v1/constant