Buying, the safe-and-simple way
Create a fresh wallet, load it with one purchase’s worth of USDC (a digital dollar: 1 USDC is worth 1 US dollar), buy, forget it. No “gas” fees, the extra tokens other crypto apps make you buy first: none needed here, ever. The wallet only ever holds one purchase’s worth, so even the worst day costs exactly that.
The four steps
- Create a throwaway wallet
A wallet is just a pair of codes: an address (like an account number, safe to share) and a private key (like the only key to a safe: whoever holds it owns the money). Generate one right on this page, in your browser, never sent to us, or in any wallet app. Write the recovery phrase down before anything else. - Fund it: send USDC to your new address
Every repo page prints the buyer total (price + checkout402's protocol fee). Send that much USDC plus a little extra (fifty cents covers everything) to your new wallet, on Base or Solana, whichever you prefer. Never send ETH or SOL: this flow only ever uses USDC. - Buy, yourself or through your agent
Paste the repo page URL into Claude (or any AI agent that can pay web links over x402) and give it the key the way it asks: as an environment variable, a note only programs can read, kept out of the chat itself. Chat transcripts are saved, and secrets do not belong in saved things. pip install pay402; pay(url, private_key=…, max_usd=…) does the whole loop with a spending limit you set. - Keep the receipt, then forget the wallet
Save the receipt URL: it is your proof of payment and the place to go if anything needs fixing. Keep the key until the goods arrived and looked right, then the wallet has done its job. It only ever held one purchase's worth, so even the worst case costs exactly that, and no more.
Create a wallet, right here
Generated in your browser by audited, vendored cryptography (the same noble/scure primitives ethers and viem build on). Nothing on this page sends key material anywhere; the only value that can leave is a public address, when you copy it.
Recovery phrase
Addresses
Private keys
Import the recovery phrase into MetaMask or Phantom where you can; one phrase restores both chains. These raw keys are for tooling (a buying agent, for instance).
Why you never need gas
On Base: you never send a transaction at all. You sign a permission slip (an EIP-3009 authorization for the exact amount, to the exact settlement contract, valid for minutes) and checkout402’s facilitator submits it on-chain and pays the gas. A wallet holding only USDC and zero ETH settles fine; the first real sale on this site did exactly that.
On Solana: you sign the transfer, but the fee-payer slot of the transaction belongs to checkout402’s relayer, which co-signs and submits. Zero SOL needed. Different mechanism, same result: USDC is the only thing you ever hold.
Getting USDC onto your new wallet
Never held crypto? Start here (one-time setup)
USDC is bought at an exchange, the same way you would buy a foreign currency: open an account at a centralized exchange (Coinbase, Kraken, Binance, whichever operates in your country), verify your identity when it asks (a legal requirement everywhere; minutes to a day, one time only), then buy USDC with a card or a bank transfer. Buy the buyer total plus a dollar or so of room: card purchases and withdrawals can carry small fees, and some exchanges have a minimum purchase of a few dollars.
That account is the heaviest step of this whole flow, and you only ever do it once. With it in place, every future purchase here is: buy or hold USDC there, withdraw to a fresh wallet, done in minutes.
From an exchange (Coinbase, Kraken, Binance…), on Base: withdraw USDC, not ETH, and when the withdrawal form asks for a network, pick Base deliberately (forms often default to Ethereum: same address format, much higher fees, and funds sent there are NOT on Base). Paste your new wallet's 0x… address, send the exact total.
On Solana: withdraw USDC, not SOL (you do not need SOL for fees here, ever), network Solana, to your new wallet's base58 address.
Send the buyer total from the repo page plus a little buffer (fifty cents covers any quote movement): a wallet funded to the exact cent fails if the total shifts between funding and buying. Leftovers are not lost: the same key moves them anywhere, any time, or funds your next purchase here.
Did the money arrive?
Scan the QR in your exchange’s withdrawal screen instead of pasting, then check the balance here. One click, one lookup, straight from the chain.
Sent it on the wrong network?
USDC on the wrong EVM chain (Ethereum, Arbitrum, Optimism… instead of Base) is not lost: your recovery phrase controls the same 0x address on every EVM chain. Import the phrase into a wallet app, switch it to the chain the money landed on, and move the funds; you will need that chain’s gas token to do it, which is the one time this guide cannot spare you gas.
Across families it cannot happen by accident: an EVM address is not a valid Solana address and vice versa, so exchanges refuse the withdrawal before it leaves. And ETH or SOL sent instead of USDC is also recoverable with the phrase, just useless here: this flow only ever spends USDC.
If an agent buys for you
Your agent will tell you exactly what it needs. A well-behaved one says something like:
“Create a wallet at gitbuyer.com/guide/buying. Send $0.1105 USDC (plus a few cents of room) on Base network to the address. Then set the EVM private key as an environment variable for me. Our chat transcript gets saved, and secrets do not belong in saved logs.”
The amount and chain come from the repo page, which prints the true buyer total. Keys are secrets, and conversation logs persist in history and backups: the key travels as an env var or a file, the same hygiene that keeps secrets out of commit messages. Agents: this page in JSON (same URL, Accept: application/json) and /llms.txt carry the same facts.