The Transaction API is a unified relayer that dispatches transactions on EVM chains with gas sponsorship, fee abstraction, batching, and parallel processing. It manages nonces, estimates optimal gas, and resubmits transactions when needed, so you can focus on your business logic.
For endpoint details, see the API reference: Transactions API. For SDK usage, see TypeScript SDK and Go SDK. A full server example is in Building a Relaying Transaction Server.

​
Core capabilities

  • Gas sponsorship — sponsor user interactions at the project, contract, token, or address level.
  • Fee abstraction — users can pay fees in supported ERC-20s (e.g., USDC), or you can sponsor entirely.
  • Batching — group multiple calls into one on-chain transaction.
  • Parallel processing — send multiple independent transactions concurrently.
  • Compatible with any EVM contract — no contract changes required.

​
When to use it

  • You want production-grade dispatch with retries, correct gas pricing, and nonces managed.
  • You need free or token-denominated gas for users.
  • You’re building server-triggered actions (e.g., mints, rewards) or client-triggered meta-transactions.

​
Minimal client example (TypeScript)

import { Session } from '@0xsequence/auth'
import { ethers } from 'ethers'

const chainId = 8453 // Base mainnet, for example

// Create a Sequence session for the current user or service signer
const session = await Session.singleSigner({ signer: myEOA, projectAccessKey: '<ACCESS_KEY>' })
const signer = session.account.getSigner(chainId)

// Call any contract function
const erc20 = new ethers.Contract('0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48', ['function transfer(address to, uint256 amount)'], signer)
const tx = await erc20.transfer('0xRecipient', 10n ** 6n) // 1 USDC
await tx.wait()

​
Gas Sponsorship and Fee Tokens

Use Builder to configure gas sponsorship for your project. You can also have the end user pay the relayer directly by including a fee payment transaction in the bundle. See accepted fee tokens via /rpc/Relayer/FeeTokens on the network relayer. More details are available in the API reference.

​
References