HTTP/1.1 402 PAYMENT REQUIRED agent402.base.eth · BASE · SOLANA · POLYGON · ARBITRUM · MONAD · CELO · AVALANCHE · STELLAR · ALGORAND · ROBINHOOD · USDC · USDG
Agent402 / tools / uuid

UUID generator

FREE with proof-of-work · or $0.001 in USDC · GET /api/uuid

Generate UUIDs. ?version=4 (default, random) or 7 (time-ordered), ?count=1..100.

Input

FieldTypeDescription
versionstring4 (random) or 7 (time-ordered)
countstringHow many (1-100, default 1)

Example output

{
  "version": 7,
  "uuids": [
    "0190a1b2-…"
  ]
}

Try it - see the 402 challenge (free)

curl -i "https://agent402.tools/api/uuid?version=7&count=3"

The response is HTTP 402 Payment Required with exact payment requirements. Any x402 v2 client pays automatically and retries:

Paid call (JavaScript agent)

import { wrapFetchWithPayment } from "@x402/fetch";
import { x402Client } from "@x402/core/client";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

const client = new x402Client();
registerExactEvmScheme(client, { signer: privateKeyToAccount(KEY) });
const payFetch = wrapFetchWithPayment(fetch, client);

const res = await payFetch("https://agent402.tools/api/uuid?version=7&count=3");

No wallet? Pay with compute

This is a pure-CPU tool, so an agent without a wallet can pay with proof-of-work instead of USDC: fetch a challenge, solve the sha256 puzzle (16 leading zero bits - a fraction of a second of CPU, no money, no AI tokens), and resend with the X-Pow-Solution header.

import { createHash } from "node:crypto";
const lz = (b) => { let t = 0; for (const x of b) { if (!x) { t += 8; continue; } t += Math.clz32(x) - 24; break; } return t; };
const c = await (await fetch("https://agent402.tools/api/pow/challenge?slug=uuid")).json();
let n = 0;
while (lz(createHash("sha256").update(c.challenge + ":" + n).digest()) < c.difficulty) n++;
await fetch("https://agent402.tools/api/uuid", { method: "GET", headers: { "X-Pow-Solution": c.token + ":" + n } });

Part of these workflows

This tool is one step in 2 curated multi-tool workflows - agents can fetch the whole sequence as an MCP prompt or call https://agent402.tools/api/skill-packs/{slug}/prompt.

Related tools

ULID generator

FREE w/ compute · or $0.001 · GET /api/ulid

Generate ULIDs (sortable, timestamp-prefixed identifiers). ?count=1..100.

Password generator

FREE w/ compute · or $0.001 · GET /api/password

Generate cryptographically random passwords. ?length=8..128 (default 24), ?symbols=true|false (default true), ?count=1..…

Random

FREE w/ compute · or $0.001 · GET /api/random

Cryptographically secure randomness. ?bytes=1..1024 returns hex; or ?min=&max= returns a uniform integer; ?count=1..100.