Incoming Webhooks

Trigger FlowX processes when an external system sends an HTTP POST. Secure with API keys, event-driven, no polling.

Available starting with FlowX.AI 5.6.0

Incoming Webhooks require the webhook-gateway microservice to be deployed.

What is an incoming webhook?

A webhook is an HTTP endpoint that an external system calls to notify FlowX when an event happens. Instead of FlowX polling for updates, the third-party system sends an HTTP POST the moment something occurs — and FlowX starts a process in response. Common uses include receiving events from payment processors, CRMs, ERPs, or CI/CD pipelines.

Overview

Incoming Webhooks allow external systems to trigger FlowX processes by sending HTTP POST requests to a generated URL. Each webhook gets a unique, cryptographically secure API key for authentication — no IMAP setup, no polling, just a direct HTTP call.

Use webhooks when you need to:

• Receive events from third-party platforms (payment processors, CRMs, ERPs) that support outbound webhooks
• Trigger processes from CI/CD pipelines or internal tools via simple HTTP calls
• Replace polling-based integrations with event-driven process starts

API key authentication

Each webhook gets a unique, secure API key included in the URL

JSON payload forwarding

Webhook body and HTTP headers are forwarded to the process instance as variables

Manage Triggers UI

Activate, deactivate, and manage webhook URLs from Runtime Settings

Zero configuration

No server settings needed — create the data source, connect to a process, activate

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How it works

1. Create an Incoming Webhook data source

   In Integration Designer, create a new data source and select Incoming Webhook. Provide a name and optional description. No connection settings are required.

2. Connect to a Message Start Event

   In your process definition, add a Message Start Event node. Set the Trigger Type to Incoming Webhook and select your webhook data source.

3. Commit and activate

   Commit the version, then go to Runtime → Manage Triggers. The webhook appears as Deactivated. Click the action menu and select Activate.

4. Get the webhook URL

   From the trigger’s action menu, select Get URL. Copy the generated URL (includes the API key as a query parameter) and configure it in your external system.

5. External system sends POST request

   When the external system POSTs JSON to the webhook URL, the webhook-gateway service validates the API key, publishes the event to Kafka, and the process engine starts a new process instance.

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Creating a webhook data source

1. Navigate to Data Sources

   Go to Integrations → Data Sources in your project.

2. Add a new data source

   Click + and select Incoming Webhook as the data source type.

3. Configure basic information

   Field	Required	Description
   Name	Yes	A unique name for the webhook (3–50 characters, letters, numbers, [] () . _ -)
   Description	No	Purpose or context for this webhook

4. Create

   Click Create. The webhook data source is ready to be connected to a process.

Incoming Webhooks accept POST requests with JSON payloads (max 1 MB). No connection settings, credentials, or polling configuration is needed.

When deleting a webhook data source, deactivate it first and remove the URL from any third-party systems that use it. Deleting the webhook in FlowX does not notify external systems — they will continue sending requests that return errors.

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Connecting to a Message Start Event

To use the webhook, connect it to a Message Start Event node in your process definition.

1. Open your process definition

   Open the process in the Process Designer.

2. Add a Message Start Event node

   Drag a Message Start Event from the Start Events section of the node palette onto the canvas.

3. Configure the Process Trigger

   In the node configuration panel, under Process Trigger:

   • Set Trigger Type to Incoming Webhook
   • In Select Webhook, choose your webhook data source from the dropdown
4. Save the node

   Click Save to persist the configuration.

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Managing webhooks at runtime

Activating a webhook

For a webhook to appear in Manage Triggers:

1. The webhook data source must be created
2. The webhook must be connected to a Message Start Event node
3. The version must be committed

Navigate to Runtime → Manage Triggers to view and control webhooks:

Column	Description
State	Active or Deactivated
Trigger Type	Webhook
Event Name	The webhook data source name
Location	Project and branch information

Use the action menu (three-dot icon) to:

• Activate — Start accepting webhook requests
• Deactivate — Stop accepting requests. The API key and URL are preserved, so you can reactivate later without reconfiguring external systems.
• Get URL — View and copy the webhook URL with API key

A single webhook can trigger multiple processes — add the same webhook data source to Message Start Event nodes in different process definitions. Each incoming request starts all connected processes.

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Webhook URL and API key

When you activate a webhook and select Get URL, a modal displays:

• Webhook URL — The full URL including the API key as a flowxApiKey query parameter
• Copy button — Copies the URL to clipboard
• Reset API Key — Generates a new API key (invalidates the previous URL)

URL format:

https://{services-host}/webhooks/incoming/{orgId}/{workspaceId}/{appId}/{resourceDefinitionId}?flowxApiKey={apiKey}

Available starting with FlowX.AI 5.8.0 — webhook registrations using a non-generic provider (for example, Slack) get a provider-segmented URL: /webhooks/incoming/{provider}/{ids}/{resourceDefinitionId}. The provider segment is slack for Slack registrations. Generic registrations continue to use the URL without a provider segment.

Resetting the API key creates a new webhook URL. Update the URL in all third-party systems that use it, or they will receive 401 Unauthorized errors.

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Provider adapters

Available starting with FlowX.AI 5.8.0

Webhook registrations now select an inbound provider: either GENERIC (the default, no signature validation) or SLACK (HMAC-SHA256 verification of the Slack signing secret). Future providers can be added without changing the URL contract.

When a webhook is created in the Integration Designer, the Settings tab now exposes:

• Provider — GENERIC or SLACK. Once saved, the provider becomes immutable; create a new webhook to switch.
• Provider secret — the signing secret obtained from the provider (for example, the Slack app’s signing secret). Stored encrypted; can be rotated independently of the API key.

For SaaS-hosted secrets you can also reference a config parameter using the ${configParam.name} placeholder syntax — placeholders are resolved at registration time the same way LLM provider secrets are.

Generic provider

The default. No signature validation is performed; authentication relies on the FlowX flowxApiKey and HTTPS. Use GENERIC for systems that do not sign their webhooks, or where signature validation is handled inside the process via a business-rule action on the raw headers.

Slack provider

Performs Slack’s standard signature check on every incoming request:

Header	Purpose
X-Slack-Signature	HMAC-SHA256 signature of the version, timestamp, and raw body, prefixed with v0=.
X-Slack-Request-Timestamp	Unix timestamp; rejected if more than 5 minutes out of skew.

Requests that fail signature verification, that miss either header, or that arrive without a configured signing secret are rejected with 401 Unauthorized.

Slack’s URL-verification handshake is handled automatically — a url_verification POST with a challenge field receives the challenge value back as JSON, before the request is forwarded to the process. No process configuration is required for the handshake.

Path / provider mismatch

If a request hits the URL for one provider but the webhook registration is configured with a different provider, the gateway returns 400 Bad Request. Always use the URL shown in the Get URL modal — it carries the correct provider segment for the registration.

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Webhook payload

When an external system POSTs to the webhook URL, the following data is available in the process instance:

{
  "webhookMessage": {
    "dateTime": "2026-03-23T15:30:00Z",
    "payload": {
      "orderId": "ORD-12345",
      "status": "completed",
      "amount": 299.99
    },
    "headers": {
      "Content-Type": ["application/json"],
      "X-Custom-Header": ["value"]
    }
  }
}

Field	Type	Description
dateTime	string (ISO 8601)	Ingestion time at FlowX — when webhook-gateway received the request. If the provider includes its own event timestamp in the payload, use that for the original event time.
payload	object or string	The POST request body (parsed as JSON if valid, raw string otherwise)
headers	object	All HTTP headers from the incoming request. Each header maps to an array of values — access the first value with webhookMessage.headers.Content-Type[0] in process variables

headers includes values added by the FlowX ingress in addition to what the caller sent — typically X-Forwarded-For, X-Real-IP, X-Request-ID, X-Forwarded-Host, X-Forwarded-Proto. These are useful for logging and tracing but should not be confused with provider-supplied headers.

The maximum payload size is 1 MB. Requests exceeding this limit are rejected.

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Authentication

Webhook authentication uses API keys:

• Each webhook registration gets a unique 32-byte, base64-URL-encoded API key
• The key is passed as the flowxApiKey query parameter in the webhook URL
• Validation uses constant-time comparison to prevent timing attacks
• Invalid or missing keys return 401 Unauthorized
• Inactive webhooks return 404 Not Found

FlowX validates provider signatures only for providers with a built-in adapter. For the GENERIC provider — and for any third-party signature scheme without a dedicated adapter (Stripe-Signature, X-Hub-Signature-256, etc.) — signature headers are forwarded to the process in webhookMessage.headers but no validation is performed. Authentication for GENERIC registrations relies on the FlowX API key and HTTPS. The raw request body is not preserved after JSON parsing, which makes in-process HMAC verification impractical — for unsupported providers, design integrations assuming API key + HTTPS is the only authentication layer, or request a built-in adapter.

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Error handling

HTTP Status	Cause	Resolution
200 OK	Webhook accepted and published to Kafka	—
400 Bad Request	Malformed payload (not valid JSON)	Verify the POST body is valid JSON
401 Unauthorized	Invalid or missing API key	Check the flowxApiKey parameter matches the active webhook URL
404 Not Found	Webhook registration not found or deactivated	Verify the webhook is activated in Manage Triggers
413 Payload Too Large	Request body exceeds 1 MB	Reduce the payload size or split into multiple requests
500 Internal Server Error	Processing error	Check webhook-gateway service logs

Failed webhook events appear in Runtime → Failed Triggers with details about the failure cause.

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Best practices

Use HTTPS

Always use HTTPS URLs in production to protect the API key in transit

Validate payloads in your process

Add validation logic in your process to handle unexpected or malformed payloads gracefully

Monitor Failed Triggers

Regularly check the Failed Triggers section for webhook processing errors

Rotate keys periodically

Use the Reset API Key feature to rotate webhook credentials, then update the URL in external systems

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Related resources

Message Start Event

Configure message-based and webhook process triggers

Email Trigger

Start processes from incoming emails via IMAP

Integration Designer

Build integration workflows and manage data sources

Webhook Gateway setup

Deploy and configure the webhook-gateway microservice