---
title: Chat Trigger
description: Start a workflow from a chat deployment
---

import { Callout } from 'fumadocs-ui/components/callout'
import { Image } from '@/components/ui/image'

## Overview

The Chat trigger creates a conversational interface for your workflow. Deploy your workflow as a chat and users can interact with it through a shareable URL. Each message starts a new workflow execution using your latest deployment.

## Runtime Outputs

<div className='flex justify-center my-6'>
  <Image
    src='/static/triggers/chat-trigger-light.png'
    alt='Chat deployment conversation'
    width={400}
    height={250}
    className='rounded-xl border border-border shadow-sm'
  />
</div>

The trigger writes three fields that downstream blocks can reference:

| Reference | Description | Type |
|-----------|-------------|------|
| `<chat.input>` | Latest user message | string |
| `<chat.conversationId>` | Conversation thread ID | string |
| `<chat.files>` | Optional uploaded files | files array |

### File Properties

Access individual file properties using array indexing:

| Property | Description | Type |
|----------|-------------|------|
| `<chat.files[0].url>` | Signed download URL | string |
| `<chat.files[0].name>` | Original filename | string |
| `<chat.files[0].size>` | File size in bytes | number |
| `<chat.files[0].type>` | MIME type | string |
| `<chat.files[0].uploadedAt>` | Upload timestamp (ISO 8601) | string |
| `<chat.files[0].expiresAt>` | URL expiry timestamp (ISO 8601) | string |

## Usage Notes

1. Add one Chat Trigger block per workflow.
2. Deploy the workflow in chat mode.
3. Share the deployment link—every reply reuses the conversation ID so the workflow can keep context.

<Callout type="info">
The builder blocks multiple Chat Trigger blocks in the same workflow.
</Callout>
