> For the complete documentation index, see [llms.txt](https://dev.ada-anvil.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://dev.ada-anvil.io/guides/transaction/create-custom-transaction.md).

# Create Custom Transaction

## Introduction

This guide demonstrates how to create a **custom transaction** that sends ADA and assets to multiple recipient addresses in a single transaction. This powerful feature allows you to efficiently distribute funds and tokens to several wallets at once, reducing transaction costs and improving throughput. Simply include **multiple outputs** in the payload to each recipient, and define what ADA and assets to send, and Anvil API will handle building the transaction for you.

For more information on **transactions**, please refer to the [Transaction Overview](https://github.com/Cardano-Forge/anvil-api/blob/main/docs/guides/transaction/transaction/README.md).

## Key Features

* Send different amounts of ADA to multiple recipients
* Distribute different native assets to different addresses
* Customize each output independently
* Handle complex transactions in a single API call

## Requirements

* A Cardano wallet with sufficient ADA
* Native assets in your wallet (if sending assets)
* Recipient wallet addresses
* Valid API key for authentication

## Full Examples

### Using Bash and cURL

{% content-ref url="/pages/CYJa1JzvztabyqOES1AF" %}
[Bash & cURL](/guides/transaction/create-custom-transaction/bash-and-curl.md)
{% endcontent-ref %}

### Using TS/JS Fetch

{% content-ref url="/pages/LYTHGUePMPudmg8XfRpX" %}
[Deno & Fetch](/guides/transaction/create-custom-transaction/node-and-fetch.md)
{% endcontent-ref %}

***

## **Specifications**

### API Endpoint

```
POST /transactions/build
```

### Request Structure

```json
{
  "changeAddress": "<sender_address>",
  "outputs": [
    {
      "address": "<receiver_address_1>",
      "lovelace": <lovelace_amount>,
      "assets": [
        {
          "policyId": "<policy_id>",
          "assetName": "<asset_name>",
          "quantity": <lovelace_amount>
        }
      ]
    },
    {
      "address": "<receiver_address_2>",
      "lovelace": <lovelace_amount>,
      "assets": [
        {
          "policyId": "<policy_id>",
          "assetName": "<asset_name>",
          "quantity": <lovelace_amount>
        }
      ]
    }
    // Add as many outputs as needed
  ],
  // Optional bounds that determine when the transaction is valid. 
  // False can be used to disable a bound.
  // If transactions are submitted outside of the validity interval, they will be rejected.
  "validityInterval": {
    "start": <posix_timestamp_or_slot_number>, // Optional, default: current slot
    "end": <posix_timestamp_or_slot_number>    // Optional, default: current slot + 2 hours
  }
}
```

## Best Practices

* Always verify recipient addresses before submitting transactions
* Include sufficient ADA in each output (minimum 2 ADA if sending native assets)
* Test transactions on testnet before moving to mainnet
* Consider transaction fees when planning outputs
* Keep your API key secure and never expose it in client-side code