Paymaster as a Service · EIP-7702 · gasless

Your users transact without gas. You sponsor it; they never learn what gas is.

You prepay a deposit and VKX pays your users' gas via EIP-7702. A single deposit covers every EVM network. Just npm install @vkx/gas — no wallet migration, no "you need gas".

Create account / Access panel View documentation
Deposit Just one covers every EVM network
User wallet No migration the EOA itself delegates (7702)
Integration npm install @vkx/gas
Why VKX

It is not just paying the gas. It is the gas working back for you.

Other paymaster providers only charge. Here, part of what you pay returns as credit and subsidizes your next transactions. Add a single deposit for every network and an integration that takes minutes.

Cashback that subsidizes

Part of what you pay returns as credit, consumed before your deposited balance. The more you use it, the cheaper it gets: your balance works back for you.

One deposit, every network

You deposit native currency once into the treasury and the same balance pays gas on BSC, Polygon, Base, Arbitrum and Ethereum. No per-network balance to manage.

Real simplicity

API + npm install @vkx/gas. Your users never see the phrase "you need gas" — the transaction simply happens.

Truly gasless (7702)

The user's own EOA delegates via EIP-7702. No migrating to a new smart wallet: anyone who already has a wallet keeps it.

On cheap networks (BSC, Polygon, Base, Arbitrum) gas costs cents per transaction — what is at stake is converting non-crypto users, not saving cents.

Use cases

Where "you need gas" stops your user cold.

If your users are not crypto-native, gas is the point where they give up. See if you recognize yourself in any of these scenes.

Games / GameFi

The player wants to claim an item or NFT and gets stuck because they have no gas. With VKX, they click and receive — the gas is yours, not theirs.

Claim item gasless

NFT / mint

Gasless mint for people who have never used crypto. The user mints the NFT without buying native currency first.

Gasless mint

Fintech / payments

The user pays in stablecoin without knowing what gas is. You sponsor the fee and the experience becomes "just pay".

Pay in stablecoin

dApps / loyalty / cashback

An on-chain loyalty program where redeeming points cannot require the user to understand gas.

On-chain loyalty

On-ramps

The user just bought crypto and their first transaction would already fail for lack of gas. You sponsor it and keep the flow going.

First transaction
Pricing

You pay the real gas + a markup per network. And part comes back.

Simple: the network's real gas plus a per-network markup. On BNB Chain, Polygon, Base and Arbitrum each transaction costs cents — and part of what you pay comes back as credit.

Pricing US$ 0.0094 One simple transaction on BNB Chain less than 1 cent — measured on-chain
Cents per transaction On BNB Chain, Polygon, Base and Arbitrum, each transaction costs cents. You sponsor it without feeling it.
Scale without surprises 1,000 transactions on BNB Chain cost a few dollars. The cost tracks your volume, not your revenue.
Part comes back to you A fraction of what you pay becomes credit and is used first on your next transactions — your balance works back.

How the cashback works

Part of what you pay returns as cashback credit in your account. That credit is used FIRST, before the balance you deposited. In practice, as you use the service, you build up credit that subsidizes your next transactions — your balance works back for you. Unlike other paymaster providers, which only charge and give nothing back.

The markup applies to the network's real gas, not to the user's transaction amount — which is why the cost per transaction stays in cents on BNB Chain, Polygon, Base and Arbitrum. A single native-currency deposit covers every EVM network.

How to integrate

Install, set the key, sponsor. In minutes.

Install @vkx/gas, use your vkx_gas_... key and call prepare() to sponsor your user's operation. The key stays in an environment variable and never reaches client code.

1 Install the packageNode >= 18 
npm install @vkx/gas
2 Set the keyVKX_GAS_KEY in the environment 
export VKX_GAS_KEY=vkx_gas_...
3 Sponsorprepare() returns what to submit 
await gas.prepare({ network: 'BSC', userOp })

Straight into your Node code

You prepare the sponsorship for the operation (7702); the user signs the userOpHash and you submit the op. The balance is debited from your prepaid deposit — cashback first.

index.js@vkx/gas 
import { GasSponsor } from '@vkx/gas';

const gas = new GasSponsor({ apiKey: process.env.VKX_GAS_KEY });

// prepare the sponsorship for your user's operation (7702)
const sponsored = await gas.prepare({ network: 'BSC', userOp });

// your user signs sponsored.userOpHash and you submit the op
console.log(sponsored.userOpHash, sponsored.estimatedDebitUsd);

API reference

All endpoints use the header Authorization: Bearer vkx_gas_.... The base host comes from configuration — in the examples: https://api.vkxtech.com.br

Endpoint What it does
POST /security/gas/prepare Prepares the sponsorship of an operation (7702). Body { network, userOp }; returns userOpHash, paymasterAndData and the gas limits, plus estimatedDebitUsd and cashbackTagPct.
GET /security/gas/balance Reads the prepaid balance and available cashback credit — per network and consolidated.
GET /security/gas/history Lists the history of sponsored operations, with the debit and cashback applied to each.
POST /security/gas/deposit/claim Credits a deposit made into the treasury. Body { network, txHash } — confirms the on-chain top-up in your balance.
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FAQ

Questions before integrating.

Straight answers for anyone evaluating a paymaster as a service to take gas out of the user's way.

You install @vkx/gas, prepay a deposit in native currency and call prepare({ network, userOp }). VKX returns the paymaster data; the user signs the userOpHash and you submit the operation. The gas comes from your prepaid balance (cashback first), and the user transacts without needing native currency.
No. We use EIP-7702: the user's own EOA delegates the behavior. Anyone who already has a wallet keeps the same address — no new smart wallet, no migration.
No. A single native-currency deposit into the treasury covers every supported EVM network (BSC, Polygon, Base, Arbitrum and Ethereum). You do not manage a balance per network.
Part of what you pay returns as cashback credit in your account. That credit is consumed before the balance you deposited, so as you use the service it subsidizes your next transactions. It is the opposite of providers that only charge and give nothing back.
You pay the network's real gas plus a per-network markup, charged in absolute terms. On networks like BNB Chain, Polygon, Base and Arbitrum the cost per transaction is cents — one simple transaction on BNB Chain cost US$ 0.0094 in an on-chain test. And part of what you pay comes back as credit, used first on your next transactions.

Take gas out of your user's way.

Sign in with your Google account, create your gas key and report your deposit — no form, no waiting.

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