roam402

Client SDK for Roam402 — 2,349 routes across 751 verified x402 services, payable in USDC on Algorand mainnet. One merchant, dual-chain receipts, trust tiers from the Agents-Trust census.

npm i roam402            # algosdk optional (only for signerFromMnemonic)

import { createRoamClient, signerFromMnemonic } from "roam402";

const roam = createRoamClient({
  signer: await signerFromMnemonic(process.env.ALGO_MNEMONIC!),
  network: "mainnet",
});

const catalog = await roam.catalog();                       // free, paged (25/page)
const page2   = await roam.catalog({ offset: 25 });         // …walk it with total/next
const found   = await roam.catalog({ q: "speech", maxPrice: 0.01, method: "POST" });

// Or just say what you need ($0.0005) — returns candidates, never buys them:
const { candidates } = await roam.resolve("transcribe an audio file", { limit: 3 });
const inputs = await roam.schema(candidates[0].path);       // free: what it expects
const trust   = await roam.trust("blockrun.ai");            // $0.0005
const check   = await roam.precheck("https://…/endpoint");  // $0.0002
const scan    = await roam.call("quickintel-scan-full", {   // wrapped route
  query: { chain: "base", tokenAddress: "0x…" },
});

• roam.fetch — a payment-enabled fetch: hand it to any HTTP client (OpenAI SDK fetch option, axios adapter, LangChain tool) and that code transparently answers 402 challenges with signed Algorand payments.
• Signers — anything implementing { address, signTransactions } (use-wallet / Pera adapters work), or signerFromMnemonic server-side.
• Receipts — paid responses carry PAYMENT-RESPONSE (Algorand settlement), X-Roam-Origin-Chain / X-Roam-Origin-Tx (origin-chain settlement), and an EdDSA-signed JWS receipt verifiable offline against the did:jwk in its own key id.

Payments settle through the GoPlausible facilitator; the buyer needs only USDC on Algorand — no account, no API key, no gas (fee abstraction).

Concurrency

Paid calls can run in parallel. The client serialises only the few milliseconds of payment construction, because two payments built by one wallet in the same millisecond are byte-identical and Algorand rejects the duplicate — an agent firing four calls at once would see three fail with an unexplained 402.

Give each agent its own wallet: the guard covers one client, so two processes sharing a mnemonic can still collide.