Ink Paymaster SDKPrepaid stablecoins or native-gas sponsorship

TypeScript and Viem clients for ERC-4337 UserOperations on Ink Mainnet.

Two explicit modes

Use public prepaid USDC, USD₮0, or USDG reimbursement, or authenticated native-gas sponsorship, without confusing their policies.

Viem-native

Plug either paymaster implementation into a Viem Bundler Client and submit calls normally.

ERC-7677 compatible

The sponsored client calls pm_getPaymasterStubData and pm_getPaymasterData with EntryPoint v0.7 UserOperations.

The SDK supports pinned public prepaid-token deployments for EntryPoint v0.7 and v0.8 on Ink Mainnet, plus a separate authenticated sponsored paymaster on v0.7. Alto is the ERC-4337 bundler behind each public RPC; it is not a paymaster.

Use INK_PUBLIC_PAYMASTER_V08 for EIP-7702 accounts. The original INK_PUBLIC_PAYMASTER constant remains pinned to v0.7; see EIP-7702 accounts for the integration flow.

What it handles

Requests and validates prepaid USDC, USD₮0, or USDG quotes.
Creates an authenticated Viem ERC-7677 Paymaster Client for native-gas sponsorship.
Integrates both modes with Viem's Bundler Client paymaster hooks.
Reads the selected reimbursement token's balance, allowance, and refund credit.
Encodes reimbursement-token approvals and refund claims.
Estimates, sends, and waits for v0.7 and EIP-7702 v0.8 UserOperations.

What your wallet handles

Your application supplies a compatible smart account or EIP-7702 EOA, its signing mechanism, and a reliable Ink RPC URL. Before the first prepaid operation, that account must hold an enabled reimbursement token and execute a finite, owner-paid approval for that token. Sponsored mode instead requires a sponsorship-enabled API key held by trusted backend infrastructure.