Signers

The operator identity is set on configure(operator=Operator(signer=...)). The signer co-signs x402 challenges and fee-pays settlement when configured. With no operator, the kit boots on a published demo signer on non-mainnet networks.

Local key material

from solana_pay_kit import Signer

Signer.file("operator.json")   # Solana CLI JSON keypair
Signer.env("OPERATOR_KEY")     # JSON / hex / base58 from an env var, auto-detected
Signer.demo()                  # the shared demo keypair (non-mainnet only)

Wire it into configure

import solana_pay_kit
from solana_pay_kit import Operator, Signer, Stablecoin

solana_pay_kit.configure(
    network="solana_mainnet",
    stablecoins=(Stablecoin.USDC, Stablecoin.PYUSD),
    operator=Operator(signer=Signer.file("operator.json")),
    rpc_url="https://mainnet.helius-rpc.com/?api-key=YOUR_KEY",
)

For env-driven deployments, solana_pay_kit.configure_from() reads the whole config from environment variables instead.

The demo signer

Signer.demo() is the zero-config default recipient on non-mainnet networks — convenient for local development against the Surfpool sandbox. It is refused on mainnet: configure(network="solana_mainnet") with the demo signer raises DemoSignerOnMainnetError so real funds never route to a publicly known key.