> ## Documentation Index
> Fetch the complete documentation index at: https://sequence-0fb8d9e6-api_docs.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Transaction API

> Send transactions via a unified relayer with gas sponsorship, batching, and parallel processing. Works with any EVM contract and any Sequence or external wallet.

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.

<Info>
  For endpoint details, see the API reference: [Transactions API](/api-references/transactions/overview). For SDK usage, see [TypeScript SDK](/sdk/typescript/overview) and [Go SDK](/sdk/go/overview). A full server example is in [Building a Relaying Transaction Server](/guides/building-relaying-server).
</Info>

## 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)

```ts theme={null}
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](/api-references/transactions/overview).

## References

* [API Reference](/api-references/transactions/overview)
* [TypeScript SDK](/sdk/typescript/overview)
* [Go SDK](/sdk/go/overview)
* [Relaying Transaction Server Guide](/guides/building-relaying-server)
* [Sidekick Dockerized Backend](/solutions/infrastructure/sidekick)