$ man util.beauty-start

start

Fund a wallet, pick an on-ramp, call an endpoint. No signup, no dashboard, no API key required. Self-serve path is x402 (USDC on Base). Prepaid keys are early access for teams.

§ 0 · wallet

You need an EVM private key holding USDC on Base (chain 8453, token 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913). No ETH for gas: payments use EIP-3009 transferWithAuthorization; the facilitator submits the tx. A dollar of USDC covers hundreds of calls (utilities run about $0.001–$0.007).

§ I · Claude Code skill

Installs catalog discovery + payment recipe into Claude Code.

mkdir -p ~/.claude/skills/util-beauty && \
  curl -fsSL https://util.beauty/skill.md \
  -o ~/.claude/skills/util-beauty/SKILL.md

§ II · any agent

Paste into the system prompt of any harness that can run shell or Node.

curl https://util.beauty/prompt.txt

§ III · code (~60s)

npm i @x402/fetch @x402/evm viem

import { wrapFetchWithPayment, x402Client } from "@x402/fetch";
import { ExactEvmScheme, toClientEvmSigner } from "@x402/evm";
import { privateKeyToAccount } from "viem/accounts";
import { createPublicClient, http } from "viem";
import { base } from "viem/chains";

const account = privateKeyToAccount(process.env.X402_PRIVATE_KEY);
const signer = toClientEvmSigner(
  account,
  createPublicClient({ chain: base, transport: http("https://mainnet.base.org") }),
);
const client = new x402Client().register("eip155:8453", new ExactEvmScheme(signer));
const paidFetch = wrapFetchWithPayment(fetch, client);

const res = await paidFetch("https://util.beauty/v1/crypto/hash", {
  method: "POST",
  headers: {
    "Content-Type": "application/json",
    "Idempotency-Key": crypto.randomUUID(),
  },
  body: JSON.stringify({ function: "sha256", input: "hello" }),
});
console.log(await res.json());

First request gets 402; the wrapper signs and retries. Settlement tx hash returns in X-PAYMENT-RESPONSE. If the library cannot parse util.beauty’s 402 body, use the raw flow in the API docs or the in-repo scripts/x402-payer.mjs.

§ IV · MCP

Three thin tools: list_utilities → describe_utility → call_utility. Schemas load on demand — not at connect time.

# see https://util.beauty/mcp for install configs
export X402_PRIVATE_KEY=0x...
npx -y util-beauty-mcp

§ V · prepaid (early access)

Team API keys are not self-serve yet. Request access if you need a ledger and volume credits. Agents should use x402 today.