Testnet faucet (try x402 free)

Fund any address with testnet money via the Coinbase faucet - USDC (1) or ETH (0.0001) on Base Sepolia, USDC (1) or SOL on Solana devnet - everything an agent needs to rehearse the complete x402 payment loop safely before moving real money. Send POST /api/testnet-fund with the required field address and pay $0.001 per call over x402 or MPP (there is no free tier). It returns a JSON object with funded, network, token, transactionHash and explorer.

A tenth of a cent buys a full testnet dollar. Limits: 2 drips per address per day; CDP enforces its own rolling caps on top.

Category: Wallet operations · Tags: cdp coinbase wallet onboarding x402 agent-wallet faucet testnet

TRY IN PLAYGROUND →

Parameters

Example request

curl -i -X POST https://agent402.tools/api/testnet-fund \
  -H "Content-Type: application/json" \
  -d '{"address":"0xaBF4FAbd7c416fB67202E5f9002389Fc75e2a9D0","token":"usdc"}'

Without payment this returns HTTP 402 Payment Required with the exact price for testnet-fund; any x402 v2 or MPP client pays it and retries.

Example response

{
  "funded": true,
  "network": "base-sepolia",
  "token": "usdc",
  "transactionHash": "0xabc123…",
  "explorer": "https://sepolia.basescan.org/tx/0xabc123…"
}

From an MCP client

catalog.call {
  "slug": "testnet-fund",
  "params": {
    "address": "0xaBF4FAbd7c416fB67202E5f9002389Fc75e2a9D0",
    "token": "usdc"
  }
}

The hosted connector at https://agent402.tools/mcp needs a payment for testnet-fund; the stdio package pays it from a wallet or from AGENT402_CREDITS_KEY. Local install: npx -y agent402-mcp.

Errors and behavior

• address is required. An input the tool rejects returns an HTTP 4xx whose body carries error, tool, expected, required and example, so the caller can correct it.
• A paid call that ends in any status of 400 or above is not charged: settlement is cancelled when the tool fails.
• Wallet-only: this tool reaches the network or stored state, so it has no proof-of-work tier. A prepaid card-credits key (Authorization: Bearer a402_...) also pays it.
• A GET or HEAD to /api/testnet-fund returns the same 402 quote, so the price can be read without a body.
• An Idempotency-Key header makes a retried paid call replay the first 200 instead of charging again.

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();
client.setSpendControls?.(false); // keep your own spending ceiling in code
registerExactEvmScheme(client, { signer: privateKeyToAccount(KEY) });
const payFetch = wrapFetchWithPayment(fetch, client);

const res = await payFetch("https://agent402.tools/api/testnet-fund", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
    "address": "0xaBF4FAbd7c416fB67202E5f9002389Fc75e2a9D0",
    "token": "usdc"
  }),
});

Related tools