Gas Sponsorship

Send approved token transfers with Para-sponsored gas and track their final outcome

Send supported EVM token transfers from an API-managed wallet without funding that wallet with native gas.

Gas sponsorship requires Para to enroll your partner separately in each environment. Contact Para to confirm production availability and request enrollment. Para enables production partners after internal production validation; Beta enrollment does not enable production sponsorship.

Environment	Chain	USDC contract
Beta	Ethereum Sepolia (11155111)	0x1c7D4B196Cb0C7B01d743Fbc6116a902379C7238
Beta	Base Sepolia (84532)	0x036CbD53842c5426634e7929541eC2318f3dCF7e
Production	Ethereum Sepolia (11155111)	0x1c7D4B196Cb0C7B01d743Fbc6116a902379C7238
Production	Base Sepolia (84532)	0x036CbD53842c5426634e7929541eC2318f3dCF7e
Production pilot	Ethereum mainnet (1)	0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48
Production pilot	Base mainnet (8453)	0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913

Production supports Ethereum Sepolia and Base Sepolia test transfers, plus a native Circle USDC pilot on Ethereum and Base mainnet. Beta supports testnet sponsorship only. Para does not apply a default per-operation gas cap on either Sepolia network. Mainnet sponsorship requires a per-operation gas cap. The listed USDC tokens use 6 decimals: "1000000" transfers 1 USDC. Test USDC has no monetary value. Use env: "PROD" for production and env: "BETA" for Beta when initializing the REST SDK, with the secret key for that environment.

Para manages the sponsorship provider credentials, policy, and gas caps. Your integration uses the Para secret key for the target environment; no Pimlico key or policy ID is required in your requests.

Eligible wallets must belong to your partner, be API-created and unclaimed, and be ready for signing. Each transfer still requires wallet access and passes through permission checks and any configured per-operation gas cap. Enrollment covers eligible wallets created before or afterward. Non-EVM wallets keep their existing transfer behavior.

Send a transfer

Use the existing transfer() method with an idempotency key saved in your payout or job record. Initialize para as shown in REST SDK. Supply your enrolled chain, token contract, and recipient.

sponsored-transfer.ts

const result = await para.transfer(
  walletId,
  { to: recipient, value: "1000000", chainId, tokenAddress, kind: "ERC20" },
  { idempotencyKey: payoutRequestKey },
);

if (result.executionMode === "sponsored") {
  const record = await para.getRestTransaction(walletId, result.transactionId);
  console.log(record.status, record.stage, record.hash);
} else {
  console.log(result.signedTransaction, result.txHash);
}

value is a positive integer in token base units. Omit nonce, transaction type and gas/fee overrides. Omit broadcast or set it to true. Leave recipient screening enabled. Native transfers, unsupported chains or tokens, sign-only requests, and requests with transaction overrides or disabled recipient screening keep the existing transfer path. If Para pauses sponsorship admission while your partner remains enabled, new eligible sponsored requests are rejected. Partners without sponsorship enabled use the existing transfer path, which may require wallet-funded gas.

The sponsored response is HTTP 202, with executionMode: "sponsored", transactionId, and status. Save the tracking ID. Para also returns it in x-transaction-id and provides the lookup path in Location. The response contains no signed transaction bytes. userOperationHash identifies the sponsored operation; txHash in transfer and replay responses and hash in transaction lookup/history identify the on-chain transaction after inclusion.

202 means the request is recorded. Para checks policy, recipient screening, and any configured gas cap afterward. Rejections during preparation appear as tracked failed results; uncertain outcomes remain nonterminal.

Track and resume

Poll getRestTransaction() using the original tracking ID. See Transaction history.

Result	What to do
pending or submitted	Continue tracking. submitted with stage included still awaits receipt verification.
Stage requires_action	Pause for the policy review identified by reviewId. Resume explicitly after approval.
Stage submission_unknown	Submission may have happened. Keep tracking; do not create a replacement transfer.
Stage delivery_unverified	The operation was included, but token delivery needs reconciliation. Keep the tracking ID and contact Para.
confirmed, reverted, or failed	Record the terminal result. Treat unknown future statuses as nonterminal.

resume-transfer.ts

await para.resumeRestTransaction(walletId, transactionId, { reviewId });

Resume continues the same transfer through POST /v1/wallets/{walletId}/transactions/{transactionId}/resume. It accepts the applicable review ID, not a replacement recipient or amount. Later steps can require another review. This supports existing policy reviews. Conditional approval policies are not supported for sponsored transfers in this pilot.

If the transfer response is lost, repeat the original request with the same key. Sponsored keys recover the same operation beyond 24 hours and after sponsorship is disabled. Reusing a key for a different wallet or intent returns 409 IDEMPOTENCY_CONFLICT. Replaying transfer() retrieves status; it does not resume a review.

actualGasCost is the settled cost of the individual operation in native-token base units, including included reverts. Read it as a decimal string or bigint. A timeout does not establish failure, and gas cost does not establish token delivery.

If transaction lookup returns status: "failed" with failureCode: "SPONSORSHIP_PAYMASTER_EXPIRED", Para has proved that the signed gas sponsorship expired without inclusion on-chain. The expired operation has no settled gas cost and is not billed.

Replaying the original idempotency key returns the same terminal record. To retry the transfer after this result, submit a new request with a new idempotency key.

Billing

Production billing requires separate enablement by Para. Confirm the agreed fee rates and billing start time before enabling live billing. Gas sponsorship enrollment alone does not enable customer charging. When enabled, Beta billing uses Stripe test mode. Production Ethereum Sepolia and Base Sepolia transfers are excluded from live gas billing.

The Developer Portal’s Billing page shows sponsored operations and their saved USD estimates. Each estimate uses the operation’s settled native gas cost, a saved exchange-rate quote, and the configured provider and Para fees. The estimate is separate from Pimlico’s provider invoice. Reverted operations included on-chain still consume gas; operations that were never submitted do not incur sponsored execution gas.

Wallet delegation

Sponsorship uses EIP-7702 while keeping the wallet’s address. Once applied on-chain, delegation persists until another authorization replaces or clears it. A reverted transfer or disabled sponsorship does not remove that delegation. Signing an authorization alone does not change the account. See EIP-7702.