Quick Start

Users can directly interact with our bundler via API endpoints—enabling actions like sending UserOperations, estimating gas, and more. Learn more about how to use the bundler endpoints here.

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Examples

1. Clone the repository

git clone https://github.com/gelatodigital/how-to-use-bundler-api-endpoints.git

2. Install dependencies

pnpm install

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How to use the Bundler API Endpoints?

There are various methods of payments that can be used with Gelato Bundler, lets go through them one by one.

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1. Sponsoring gas with 1Balance

Gelato’s 1Balance is a powerful alternative to traditional onchain paymasters. It acts as a cross-chain gas tank, allowing you to sponsor gas fees across any supported EVM-compatible chain — using just a single balance.

Instead of maintaining balances on multiple chains, you only need to deposit funds in one place, and you’re ready to sponsor gas anywhere.

To start sponsoring transactions with 1Balance, follow these steps:

1. Create a Sponsor API Key : Check out our How-To Guide for detailed instructions on generating a sponsor API key.
2. Use the API Key in Your Requests : When calling Gelato API endpoints, make sure to include the sponsorAPIKey as a query parameter.
3. Configure the UserOperation Parameters :
   • Set maxFeePerGas, maxPriorityFeePerGas, and preVerificationGas to 0 (0x0). This allows transaction fees to be settled after execution, rather than through the EntryPoint.
   • Leave all paymaster-related fields empty (i.e paymaster, paymasterData, paymasterPostOpGasLimit, paymasterVerificationGasLimit).

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2. Onchain Paymasters

This is the standard method of sponsoring gas or paying gas fees with ERC-20 tokens using onchain paymasters.

To use features like gas sponsorship, ERC-20 token payments, or other custom payment methods via onchain paymasters, follow these steps:

1. Include Paymaster Fields : You must pass all required paymaster-related fields along with the standard UserOperation parameters.
2. sponsorAPIKey is not required for this method
3. Fetch Gas Parameters from Gelato APIs : Use the following endpoints to retrieve gas-related values:
   • maxFeePerGas and maxPriorityFeePerGas can be fetched from eth_getUserOperationGasPrice API Endpoint.
   • callGasLimit, verificationGasLimit, preVerificationGas & paymasterVerificationGasLimit can be fetched from eth_estimateUserOperationGas API Endpoint.

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3. Paying Gas with Native Tokens

This is the standard method where users pay gas fees directly using their native tokens (like ETH, MATIC, etc.).

To use this method, follow these steps:

1. Keep Paymaster Fields Empty : Do not include any paymaster-related fields in the UserOperation parameters. This ensures the transaction is treated as a self-sponsored native token payment.
2. sponsorAPIKey is not required for this method
3. Fetch Gas Parameters from Gelato APIs : Use the following endpoints to retrieve gas-related values:
   • maxFeePerGas and maxPriorityFeePerGas can be fetched from eth_getUserOperationGasPrice API Endpoint.
   • callGasLimit, verificationGasLimit, preVerificationGas can be fetched from eth_estimateUserOperationGas API Endpoint.

Now that you’ve learned about the required parameters for different payment methods with the Gelato Bundler, let’s move on to the next step: exploring the Bundler API Endpoints.