x402 skill

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.
• 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".

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.

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. BROWSERUSEAPI_KEY in the environment
2. a BROWSERUSEAPI_KEY= line in ./.env
3. the key browser-use login stored (browser-use auth status says whether there is one)
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 . 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.

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 BROWSERUSEX402PRIVATEKEY= 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):

BROWSERUSEX402PRIVATEKEY=

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

Say:

Got it: . 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):

BROWSERUSEX402PRIVATEKEY=

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