The Webhook Egress plugin acts as a bridge between Flatfile and external systems by sending workbook data to webhook endpoints. When a user triggers a specific action in the Flatfile UI (like a “Submit” button), this plugin gathers all data from all sheets within the current workbook, packages it into a single JSON payload, and sends it via an HTTP POST request to a pre-configured webhook URL. This plugin is ideal for integrating Flatfile with custom backends, serverless functions, or third-party services that accept data via webhooks. Common use cases include triggering data processing pipelines, updating databases, or pushing data into CRM systems once users have finished cleaning and preparing their data in Flatfile.

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Installation

Install the plugin using npm: 
npm install @flatfile/plugin-webhook-egress

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Configuration & Parameters

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Parameters

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job
string
required
The name of the job or event that will trigger the egress process. This must correspond to an operation name defined in an action in your workbook configuration (e.g., ‘workbook:submitActionFg’).
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webhookUrl
string
The URL of the webhook endpoint where the workbook data will be sent. If not provided, the plugin will use the value from the WEBHOOK_SITE_URL environment variable.

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Default Behavior

When the webhookUrl parameter is not provided during initialization, the plugin will look for an environment variable named WEBHOOK_SITE_URL and use its value as the destination for the data. If neither the parameter nor the environment variable is set, the request will fail. The plugin sends data as a JSON payload in an HTTP POST request with Content-Type: application/json.

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Usage Examples

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Basic Usage

// listener.js
import { listener } from '@flatfile/listener';
import { webhookEgress } from '@flatfile/plugin-webhook-egress';

listener.use(webhookEgress('workbook:submitActionFg'));

// You also need to define the action in your workbook config
// workbook.config.js
const workbookConfig = {
  name: 'My Workbook',
  sheets: { /* ... */ },
  actions: [
    {
      operation: 'submitActionFg',
      mode: 'foreground',
      label: 'Submit Data',
      description: 'Send data to our system.',
      primary: true,
    },
  ],
};

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Explicit Webhook URL Configuration

// listener.js
import { listener } from '@flatfile/listener';
import { webhookEgress } from '@flatfile/plugin-webhook-egress';

const MY_WEBHOOK_URL = 'https://api.myapp.com/data-ingest';

listener.use(webhookEgress('workbook:submitActionFg', MY_WEBHOOK_URL));

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Webhook Response with Rejections

The plugin can process responses from your webhook that contain data rejections. If your webhook performs validation and finds errors, it can return them in a specific JSON format, and the plugin will display these errors in the Flatfile UI. 
// Example webhook endpoint response format
// POST https://api.myapp.com/data-ingest
/*
{
  "rejections": {
    "id": "wb_abc123", // The workbook ID
    "sheets": [
      {
        "sheetId": "us_sh_xyz456", // The sheet ID
        "rejectedRecords": [
          {
            "id": "dev_rc_123", // The record ID
            "values": [
              {
                "field": "email",
                "message": "This email address is already in use."
              }
            ]
          }
        ]
      }
    ]
  }
}
*/

// No special client-side configuration needed for rejections
import { listener } from '@flatfile/listener';
import { webhookEgress } from '@flatfile/plugin-webhook-egress';

listener.use(webhookEgress('workbook:submit', 'https://webhook.site/your-unique-url'));

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Troubleshooting

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Common Error Messages

“Failed to submit data to [webhook]”
  • Check that the webhook URL is correct
  • Verify the server is running and accessible
  • Ensure the webhook is not returning error status codes (4xx or 5xx)
“Error posting data to webhook”
  • Check for network connectivity issues
  • Verify DNS resolution for the webhook URL
  • Confirm the webhook URL is properly formatted
“Request succeeded but failed to parse response from webhook”
  • Your webhook returns a 200 OK status but the response body is not valid JSON
  • Ensure your endpoint returns Content-Type: application/json
  • Return at least an empty JSON object {} if no specific response is needed

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Error Handling Patterns

The plugin handles errors internally and reports them as job outcomes:
  • Non-200 HTTP status codes: The job completes with a failure message showing the status code
  • Network errors: The job fails with a generic “Error posting data to webhook” message
  • Invalid JSON responses: The job completes with a success status but warns about parsing issues

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Notes

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Requirements and Limitations

  • An action must be configured in the workbook with an operation that matches the job string passed to the plugin
  • The webhook endpoint must accept POST requests with Content-Type: application/json
  • The entire workbook’s data (all sheets and all records) is sent in a single request, which may result in large payloads for extensive workbooks

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Dependencies

  • The plugin depends on @flatfile/plugin-job-handler for job lifecycle management (bundled with the plugin)
  • Uses @flatfile/util-response-rejection for processing webhook rejection responses
  • Utilizes @flatfile/util-common for error logging

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Validation Flow

The plugin supports a two-way validation flow where your webhook can return validation errors in the rejections format. These errors are automatically processed and displayed in the Flatfile UI, allowing users to see and correct data issues identified by your backend systems.