---

name: x402 description: Set up Browser Use Cloud payments with x402 — pay per request from a crypto wallet (USDC on Base mainnet), no signup or API key. Two setups it works out up front — "just use it" (set up a wallet so you or Claude Code can run cloud browser tasks paid from the wallet — Claude writes and runs throwaway scripts, nothing touches your codebase) or "build it in" (install the SDK and write the key + code into your project). Walks through wallet setup, funding, .env, and a ~$1 test run. Use when the user asks about x402, pay-per-use, USDC payments, or wants Browser Use Cloud without an API key. For the free-tier signup (reverse-CAPTCHA → API key), use browser-use cloud signup or the cloud skill instead. allowed-tools: Bash, Read, Write, Edit

Browser Use Cloud — pay with x402 (crypto wallet)

This is a scripted flow. Follow the steps in order. x402 only works through the SDK (browser-use-sdk for Python, the browser-use npm package for TS) — there is no browser-use CLI command for it, so every step runs a short SDK script.

How to use this script

• Lines under Say: are spoken to the user word for word. Don't paraphrase, add, or drop anything.
• <like this> inside a Say block is a fill-in — replace it with the real value, keep the rest exact.
• Lines under Ask: use the AskUserQuestion tool. Use the question and option text exactly as written.
• To show an explanation before a question, put it inside the AskUserQuestion question field (it renders above the options). Don't send it as separate chat text before calling the tool — that text gets dropped when the question UI opens. So: explanation + the actual question both go in the question field, in one tool call.
• Lines under Do: are your actions. Don't read them out.
• Track two facts as you go: SETUP (A or B, from Step 1) and MODE (A or B, from Step 2).
• SETUP, MODE, and the Path A/B/C names are internal labels for you only. Never say them to the user. Describe choices in plain words instead (e.g. "top up your account" / "accountless wallet"), never "Mode B" or "Path A".

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Step 1 — Open and pick the setup

Ask: (header: Use x402) — put the explanation and the question both in the question field, exactly:

x402 is a protocol from Coinbase that, instead of presenting an API key, allows you to use crypto to pay for API requests. x402 lets you pay Browser Use per request from a crypto wallet with USDC on Base — no signup, API key, or credit card needed, just a wallet. Setup takes a few minutes: get or make a wallet, add funds, save the key in .env, and test it.

How do you want to use x402?

• Just use it — Run Browser Use tasks, paid from your wallet, here in terminal by asking me. I set up the wallet and key.
• Build it in — You're coding an app and want x402 in it. I will help you install the SDK, save the key to your project's .env, and add code.

Do: "Just use it" → SETUP = A. "Build it in" → SETUP = B.

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Step 2 — Find the account (check before asking)

Do: Look for an existing Browser Use API key, in this order. Don't say anything yet.

1. BROWSER_USE_API_KEY in the environment
2. a BROWSER_USE_API_KEY= line in ./.env
3. ~/.browser-use/config.json (saved by browser-use cloud login / signup)
4. browser-use doctor output, if the CLI is installed

If no key is found anywhere:

Say:

No Browser Use key found, so I'll set this up accountless: the wallet is your identity, and the first payment makes a project named after it.

Do: MODE = A. Go to Step 3.

If a key is found:

Ask: (header: Account) — question: I found a Browser Use API key in <location>. Where should the USDC credits go?

• Top up that account — Credits go to your existing API key's project. Good if your free credits ran out, or you'd rather pay with crypto than a card.
• Accountless wallet — The wallet is a separate identity. The first payment makes a fresh project named after the wallet, apart from your existing account.

Do: "Top up that account" → MODE = B. "Accountless wallet" → MODE = A.

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Step 3 — Wallet

Ask: (header: Wallet) — question: Do you have a wallet ready, or should I set one up?

• I have a funded wallet — An EVM wallet (MetaMask, Rabby, Coinbase Wallet, Frame, Phantom, …) with USDC on Base mainnet.
• Walk me through it — I'll guide you through making a wallet, adding Base, and buying USDC.
• Make a fresh one — I'll generate a throwaway wallet for automation. You'll still need to fund it.

Branch on the answer.

Path A — "I have a funded wallet"

Do: Check .env is in .gitignore; add it if missing.

Ask: (header: Add key) — put the note and the question both in the question field:

Your wallet's private key needs to go into .env. You can paste it here and I'll add it for you, or add it yourself. Heads up: anything pasted in chat is saved in the transcript, so for a high-value wallet, adding it yourself is a bit safer. How do you want to do it?

• Paste it here — Paste your private key in the chat and I'll write it to .env for you.
• I'll add it myself — You add it to .env, then send me just your public address.

If "Paste it here":

Do: Write BROWSER_USE_X402_PRIVATE_KEY=<pasted key> to .env (create the file if needed; make sure .env is gitignored). Never echo the key back or print it anywhere.

Say:

Saved your key to .env — I won't print it back.

Do: Go to Step 4.

If "I'll add it myself":

Say:

Add this line to your .env, then send me your wallet's public address (the 0x… one — safe to share):

BROWSER_USE_X402_PRIVATE_KEY=<your private key>

Do: When they send the address, check it matches ^0x[0-9a-fA-F]{40}$.

Say:

Got it: <address>. That's a valid address.

Do: Go to Step 4.

Path B — "Walk me through it"

Say:

1. Install MetaMask (or Rabby, Coinbase Wallet, Frame, Trust Wallet, Phantom, …) from the official site only: https://metamask.io. Make a wallet, save the seed phrase offline, set a password.
2. Add Base as a network. Open https://chainlist.org/chain/8453 → "Connect Wallet" → "Add to MetaMask", then approve it in your wallet.
3. Click "Buy" in your wallet. Pick USDC, network Base, pay with card / Apple Pay / bank. The USDC lands straight in your wallet.
4. Get the private key: account menu → Account details → Show private key → enter password → copy.
5. Add it to your .env (make sure .env is gitignored):

BROWSER_USE_X402_PRIVATE_KEY=<your private key>

6. Send me your wallet's public address (the 0x… one) so I can check it.

Do: Then follow Path A from the address check onward.

Path C — "Make a fresh one"

Do: Generate a wallet. Save the key to .env. Show the address only.

Python:

pip install eth-account

from eth_account import Account
acc = Account.create()
print("Address:", acc.address)
print("Private key:", acc.key.hex())

TypeScript:

npm install viem

import { generatePrivateKey, privateKeyToAccount } from "viem/accounts";
const key = generatePrivateKey();
console.log("Address:", privateKeyToAccount(key).address);
console.log("Private key:", key);

Say:

Made a fresh wallet. Your public address is <address>, and I've saved the private key to .env. Now it needs funds.

Do: Go to Step 4 (funding).

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Step 4 — Add funds

If Path A or B (already funded):

Say:

Your wallet's already funded, so we'll skip ahead to the test.

Do: Go to Step 5.

If Path C:

Say:

Two ways to get USDC into your wallet on Base:

• In-wallet Buy button (easiest): click "Buy", pick USDC, set the network to Base, pay with a card. No exchange needed.
• From an exchange: send USDC to <address> and pick "Base" as the network — not Ethereum, which costs $5–$20 in fees.

Add at least $20: that covers the $1 test plus a few real tasks. I'll watch the balance and tell you when it lands.

Do: Check the on-chain balance every 5s with Base's public RPC:

PADDED=$(printf "%064s" "${WALLET_ADDR:2}" | tr ' ' '0')
curl -s https://mainnet.base.org \
  -H "Content-Type: application/json" \
  -d "{\"jsonrpc\":\"2.0\",\"method\":\"eth_call\",\"params\":[{\"to\":\"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913\",\"data\":\"0x70a08231${PADDED}\"},\"latest\"],\"id\":1}"

Read result as a hex number; divide by 1_000_000 (USDC has 6 decimals). Stop once it's $20 or more.

Say:

Funded — I see $<amount> on Base. Next, a quick test.

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Step 5 — Test run (~$1)

Do: If SETUP = A, make sure the SDK is installed where you'll run scripts (default Python). If SETUP = B, install it into the project in the project's language — work out the language from the cwd (package.json/tsconfig.json → TypeScript; pyproject.toml/requirements.txt/*.py → Python; ask only if you can't tell):

# Python (needs 3.10+ for the x402 extra)
pip install "browser-use-sdk[x402]"
# TypeScript
npm install browser-use-sdk @x402/fetch @x402/evm viem

Ask: (header: Test run) — question: Ready to test? This spends exactly $1 USDC from your wallet to check payment + run work end to end.

• Use the default task — "Go to example.com and tell me the heading text." (~5 seconds, cheap)
• I'll give you a task — Tell me a short task to run instead.
• Skip the test — Skip the test and go straight to using x402.

Do:

• "I'll give you a task" → Say: What's the task? Keep it short. Wait for it.
• "Skip the test" → go to Step 6.
• Otherwise use the default task.

Do: Run the test. Use the raw x402 client with max_value of $1.50 so it pays $1, not the $5 the SDK uses by default:

import asyncio, os
from decimal import Decimal
from x402 import x402Client
from x402.http.clients import x402HttpxClient
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client
from eth_account import Account

async def main():
    client = x402Client()
    register_exact_evm_client(
        client,
        EthAccountSigner(Account.from_key(os.environ["BROWSER_USE_X402_PRIVATE_KEY"])),
    )
    # max_value caps the spend per request — picks the $1 option over the $5 default.
    async with x402HttpxClient(client, max_value=Decimal("1.5"), timeout=180.0) as http:
        resp = await http.post(
            "https://x402.api.browser-use.com/api/v3/sessions",
            json={"task": "<the task>"},
        )
        print(resp.status_code, resp.json())

asyncio.run(main())

If MODE = B, add the API key header, or the $1 goes to a new wallet project instead of the one being topped up:

async with x402HttpxClient(
    client, max_value=Decimal("1.5"), timeout=180.0,
    headers={"X-Browser-Use-API-Key": os.environ["BROWSER_USE_API_KEY"]},
) as http:
    ...

If the installed x402 lib has no max_value, Say: That x402 version can't force a $1 charge, so the test will cost $5 instead. Want me to go ahead? — wait for a yes before running.

Say:

Paid. On-chain proof: https://basescan.org/address/<address>#tokentxns — look for a USDC transfer out of exactly $1.000000.

Do: Read the balance. If MODE = A (needs browser-use-sdk ≥ 3.8.0; if older, say to run pip install -U "browser-use-sdk[x402]" or skip this):

import asyncio, os
from browser_use_sdk.v3 import get_wallet_balance

async def main():
    bal = await get_wallet_balance(os.environ["BROWSER_USE_X402_PRIVATE_KEY"])
    print(bal['total_credits_usd'])

asyncio.run(main())

If MODE = B, skip get_wallet_balance (it returns 404 — the credits sit in the API key's project, that's normal, don't show it as an error) and read it the normal way:

from browser_use_sdk.v3 import AsyncBrowserUse
client = AsyncBrowserUse(api_