> ## Documentation Index
> Fetch the complete documentation index at: https://docs.b3os.org/llms.txt
> Use this file to discover all available pages before exploring further.

# Thirdweb Engine: Write Contract

Execute a write transaction on a smart contract via your Thirdweb Engine. Queues the transaction and returns a queueId for tracking. Use get-transaction-status to poll for confirmation. Ideal for: state-changing contract calls, token transfers, minting.

![Thirdweb Engine: Write Contract logo](https://ai-icon.b3.fun/logo/thirdweb-engine)
Catalog action Integrations thirdweb-engine

Execute a write transaction on a smart contract via your Thirdweb Engine. Queues the transaction and returns a queueId for tracking. Use get-transaction-status to poll for confirmation. Ideal for: state-changing contract calls, token transfers, minting.


## At a Glance

| Field | Value |
| --- | --- |
| Action ID | `thirdweb-engine-write-contract` |
| Category | Integrations |
| Connector | `thirdweb-engine` |
| Requires gas | No |
| Funds movement | None declared |
| Tags | `smart-contract`, `integration`, `contract`, `write`, `transaction`, `onchain` |

## Payload Schema

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `chain` | `string` | Yes | Chain ID \(e.g. '8453' for Base, '1' for Ethereum\) |
| `contractAddress` | `string` | Yes | Contract address to write to |
| `functionName` | `string` | Yes | Solidity function name or full signature \(e.g. "transfer" or "function transfer\(address to, uint256 amount\)"\) |
| `args` | `array` | Yes | Function arguments |
| `backendWalletAddress` | `string` | No | Backend wallet to send from \(overrides connector default\) |
| `value` | `string` | No | Native currency amount in wei to send with the transaction |

## Result Schema

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `queueId` | `string` | Yes | Engine queue ID for tracking the transaction |

## Examples

**Workflow node**

```json
{
  "type": "thirdweb-engine-write-contract",
  "payload": {
    "chain": "8453",
    "contractAddress": "0x0000000000000000000000000000000000000000",
    "functionName": "example-functionName",
    "args": []
  },
  "children": [],
  "connector": {
    "type": "thirdweb-engine",
    "id": "conn_thirdweb_engine"
  }
}
```
  **Test with API**

```bash
curl -X POST "https://api.b3os.org/v1/actions/thirdweb-engine-write-contract/test" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "inputs": {
    "chain": "8453",
    "contractAddress": "0x0000000000000000000000000000000000000000",
    "functionName": "example-functionName",
    "args": []
  }
}'
```

**Use expressions for dynamic values**

Payload fields can use workflow expressions such as `{{$trigger.body.amount}}`, `{{$nodes.fetch.result.price}}`, and `{{$props.asset}}` when the value should come from a trigger, prior node, or reusable workflow prop.