@chainvue/v402-client-fetch

v402 client for AI agents and services. wrapFetchWithPayment(fetch, config) returns a drop-in fetch that handles the 402 handshake transparently: on a 402 it selects an accepted scheme, signs the canonical payload, retries with X-V402-* payment headers, and recovers automatically from price changes (M6). V402Client covers the rest of the facilitator API: signed balance queries, topup info, discovery.

npm install @chainvue/v402-client-fetch

import { wrapFetchWithPayment } from "@chainvue/v402-client-fetch";
import { EnvSigner } from "@chainvue/v402-signer-verus";

const paidFetch = wrapFetchWithPayment(fetch, {
  payer: "v402-agent@",
  signer: new EnvSigner(/* ... */),
});
const res = await paidFetch("https://api.example.com/paid/thing");

Retry semantics follow the normative M5 table: same-requestId auto-retry only for network failures / 503 / 429; endpoint 5xx is not auto-retried (the reservation was rolled back server-side — whether to repeat a possibly side-effectful request is the caller's decision, with a fresh ULID). Node ≥ 22; browser support is on the roadmap (Etappe 2).

License

Apache-2.0