Self + Gasless

createSelfAndGasless() keeps custody with the trader EOA but submits trades through a Safe smart account.

the trader EOA owns USDC and positions
the trader EOA signs the underlying trade action
the trader’s Safe submits the transaction as a sponsored user operation

When to use it

consumer apps that want a gasless UX
embedded trading flows where the user should not need ETH after setup
client-side apps that already have a Safe execution path

One-time setup

The trader must do two EOA-signed transactions once:

await client.approveUsdc('max');
await client.setupGaslessDelegation();

After that, trading calls can be sent gaslessly through the Safe.

Submit-capable client

const client = await OstiumClient.createSelfAndGasless({
  traderPrivateKey: process.env.TRADER_PRIVATE_KEY as `0x${string}`,
  pimlicoUrl: 'https://builder.prod.bedrock.ostium.io/v1/pimlico/sponsor?chainId=42161',
});

If you already know the Safe address for this trader key and chain, pass safeAddress to skip the SDK’s smart-account derivation call during construction:

const client = await OstiumClient.createSelfAndGasless({
  traderPrivateKey: process.env.TRADER_PRIVATE_KEY as `0x${string}`,
  safeAddress: '0xSafeAddress',
});

Build-only client

const client = await OstiumClient.createSelfAndGasless({
  traderAddress: '0xTraderAddress',
  safeAddress: '0xSafeAddress',
});

const tx = client.getOpenTradeTx({
  pairId: 0,
  buy: true,
  price: '65000',
  collateral: '100',
  leverage: '5',
  type: OrderType.Market,
});

In build-only mode, get*Tx() returns a Safe-style request with safeAddress and calls.

Parameters

Field	Type	Required	Notes
`traderPrivateKey`	`0x${string}`	Submit-capable	Trader EOA key. A Safe is derived from it to relay trades gaslessly.
`traderAddress`	`0x${string}`	Build-only	Trader EOA address.
`safeAddress`	`0x${string}`	Build-only; optional submit-capable	Required for build-only. Optional with `traderPrivateKey` when you already know the deterministic Safe address and want to skip derivation.
`pimlicoUrl`	`string`	Optional	Bundler/paymaster URL. Defaults to the Ostium sponsor URL (chain-aware).
`rpcUrl`	`string`	Optional	RPC URL for reads/simulation. Defaults to the public RPC.
`sponsorshipPolicyId`	`string`	Optional	Pimlico sponsorship policy ID.

Plus the shared options (testnet, slippageBps, builder, subgraphUrl, builderApiUrl, alchemyApiKey). See Client Configuration.

SDK

Client Modes

Helpers

Read Methods

Write Methods

Builder API

Builder

Trader

Legacy

Self + Gasless

When to use it

One-time setup

Submit-capable client

Build-only client

Parameters

​When to use it

​One-time setup

​Submit-capable client

​Build-only client

​Parameters

When to use it

One-time setup

Submit-capable client

Build-only client

Parameters