Skip to main content
Gasless SDK modes use a Pimlico-compatible bundler/paymaster endpoint by default. Mainnet: 
https://builder.ostium.io/v1/pimlico/sponsor?chainId=42161
Testnet: 
https://builder.ostium.io/v1/pimlico/sponsor?chainId=421614

​
SDK usage

The default is applied when you create a gasless client without a custom pimlicoUrl. 
const client = await OstiumClient.createDelegatedAndGasless({
  delegatePrivateKey: process.env.DELEGATE_PRIVATE_KEY as `0x${string}`,
  traderAddress: '0xTraderAddress',
});
Override it when you want to use a different ERC-4337 bundler/paymaster endpoint. 
const client = await OstiumClient.createSelfAndGasless({
  traderPrivateKey: process.env.TRADER_PRIVATE_KEY as `0x${string}`,
  pimlicoUrl: 'https://your-bundler.example.com',
});
This endpoint is used internally by the SDK submitter for gasless UserOperations. Non-gasless modes do not call it.