Getting testnet keys

bash

stellar keys generate --network testnet <name>
stellar keys address <name>
stellar keys show <name>

Fund an account through friendbot:

bash

curl "https://friendbot.stellar.org/?addr=<G...>"

COMMITMENT_SECRET_HEX is a raw ed25519 seed in hex, not a Stellar S... string — it signs channel commitments directly rather than transactions.

For Base Sepolia, EVM_PRIVATE_KEY is a raw private key, 0x followed by 64 hex characters, from wasit wallet create --role x402 --network eip155:84532, any EVM wallet, or viem's generatePrivateKey(). The payer needs Base Sepolia USDC, from https://faucet.circle.com, and no ETH: the facilitator pays the gas (the exact scheme's EIP-3009 method). A target that uses Permit2 instead needs no ETH either when it offers the eip2612GasSponsoring extension; without it, the payer must approve Permit2 once on-chain, which needs gas, and a run without that approval reports ERROR (setup). A wrong or malformed key is reported at PREFLIGHT before anything is sent, without echoing it.

On Ethereum Sepolia the same key pays in Circle's USDC (0x1c7D4B196Cb0C7B01d743Fbc6116a902379C7238), from https://faucet.circle.com (network Ethereum Sepolia), and again needs no ETH. Wasit's own Ethereum Sepolia fixture runs the SDK's facilitator itself, paying the gas from EVM_FACILITATOR_PRIVATE_KEY, which needs Sepolia ETH; that key is for the fixture only.

For Solana devnet, SVM_PRIVATE_KEY is the base58 encoding of the keypair's 64 bytes (seed, then public key), the form wallets export and wasit wallet create --role x402 --network solana:EtWTRABZaYq6iMfeYKouRu166VU2xqa1 prints. The payer needs devnet USDC of the SDK's default mint, 4zMMC9srt5Ri5X14GAgXhaHii3GnPAEERYPJgZJDncDU, from https://faucet.circle.com (network Solana Devnet), and no SOL: the facilitator signs as fee payer and pays the fee. The payee's USDC token account must exist before the first payment, since the payment's transaction does not create it. A keypair whose public half does not belong to its seed, or any malformed key, is reported at PREFLIGHT without echoing it.