Chains Supported

Method	Description	Ethereum	Polygon	Arbitrum	Optimism	Base	Zora	Fraxtal	Astar	Solana
eth_sendUserOperation	Sends a user operation to the given EVM network.	All Networks	All Networks	All Networks	All Networks	All Networks	All Networks	All Networks	Unsupported	Unsupported
eth_estimateUserOperationGas	Estimates the gas values for a `UserOperation`.	All Networks	All Networks	All Networks	All Networks	All Networks	All Networks	All Networks	Unsupported	Unsupported
eth_supportedEntryPoints	Returns an array of the `entryPoint` addresses supported by the client.	All Networks	All Networks	All Networks	All Networks	All Networks	All Networks	All Networks	Unsupported	Unsupported
eth_getUserOperationByHash	Return a `UserOperation` based on a hash (`userOpHash`).	All Networks	All Networks	All Networks	All Networks	All Networks	All Networks	All Networks	Unsupported	Unsupported
eth_getUserOperationReceipt	Get the `UserOperationReceipt` based on the `userOpHash` value.	All Networks	All Networks	All Networks	All Networks	All Networks	All Networks	All Networks	Unsupported	Unsupported
rundler_maxPriorityFeePerGas	Returns a fee per gas that is an estimate of how much users should set as a priority fee in `UOs` for Rundler endpoints.	All Networks	All Networks	All Networks	All Networks	All Networks	All Networks	All Networks	Unsupported	Unsupported

What exactly is the Bundler API?

The Bundler APIs are a collection of ERC-4337 compliant JSON-RPC endpoints, making it possible for users to work with user operations.