Adobe Sign Webhook Handler with Header Passthrough

Adobe Sign Webhook Handler with Header Passthrough

This workflow provides a dual-endpoint webhook receiver for Adobe Sign (or any service sending similar payloads). It accepts both POST and GET requests on the same path (test1), extracts the x-adobesign-clientid header from the incoming request, and responds with that header value in the response. It then captures the full request body and extracts key agreement fields such as agreement ID, participant sets, and status. This is particularly useful for building custom webhook integrations with Adobe Sign, where you need to validate the client ID and quickly store or forward the agreement data.

The workflow is designed to be a starting point for handling e-signature events — you can easily extend it by adding database storage, Slack notifications, or other downstream processing.

Nodes and Their Roles

1. POST (Webhook) — No auth

   • Listens for incoming POST requests at the path test1. When a request arrives, it triggers the workflow. No authentication is configured, but you can add basic auth or a header check in the Function node if needed.

2. reg-GET (Webhook) — No auth

   • Listens for incoming GET requests at the same path test1. This allows the webhook to also respond to verification requests (e.g., Adobe Sign challenge requests). Both webhooks feed into the same processing logic.

3. Function (n8n Function node) — No auth

   • Contains custom JavaScript that extracts the x-adobesign-clientid header from the first input item's JSON. It then sets myNewField to 1 (a placeholder) and clientID to the extracted header value for all items. This ensures the client ID is available later for the response.

4. webhook-response (Respond to Webhook) — No auth

   • Sends an immediate HTTP response back to the webhook caller. It configures a response header named x-adobesign-clientid with the value obtained from the Function node's output (clientID). The response body is empty by default, but you can modify the options to include a body if needed.

5. SetWebhookData (Set node) — No auth

   • Receives the webhook response’s body (which contains the original incoming payload) and creates new fields: webhookData (the full body), agreement_ID (from body.agreement.id), all_participants (from body.agreement.participantSetsInfo), and agreement_status (from body.agreement.status). The node is configured to keep only these fields (keepOnlySet: true), discarding original data. This cleanly prepares the data for further processing.

Setup Instructions

• Adobe Sign account – You need an Adobe Sign account to generate webhook URLs. In Adobe Sign, go to Account > Webhooks and create a new webhook pointing to your n8n endpoint. Use the production URL of your n8n instance followed by /webhook/test1 (or the correct path based on your n8n webhook ID). Both POST and GET methods should be enabled (Adobe Sign sends a GET challenge on creation and POST for events).
• n8n instance – This workflow uses two webhook nodes; ensure your n8n is publicly accessible (e.g., via ngrok, cloud tunnel, or a hosted instance).
• No external credentials are required inside n8n – the workflow does not authenticate to any external service.

Use Cases and Variations

• E-signature event processing – Use this as a base to handle Adobe Sign agreement events (signed, declined, etc.). Add nodes to save the data to a database (e.g., Airtable, PostgreSQL) or to send notifications via Slack/email.
• Custom validation – Modify the Function node to verify the client ID against a stored list before allowing further processing.
• Adapt to other services – Replace the header name and data structure to work with DocuSign, HelloSign, or any webhook service that sends similar metadata.
• Multi-step workflows – After SetWebhookData, add logic to fetch agreement details from Adobe Sign API using the agreement_ID and OAuth2 credentials.

{
  "nodes": [
    {
      "name": "Function",
      "type": "n8n-nodes-base.function",
      "position": [
        -280,
        -80
      ],
      "parameters": {
        "functionCode": "// Code here will run only once, no matter how many input items there are.\n// More info and help: https://docs.n8n.io/nodes/n8n-nodes-base.function\n\n// Loop over inputs and add a new field called 'myNewField' to the JSON of each one\nc_id = items[0].json.headers['x-adobesign-clientid'];\n\nfor (item of items) {\n  item.json.myNewField = 1;\n  item.json.clientID = c_id;\n}\n\nreturn items;"
      },
      "typeVersion": 1
    },
    {
      "name": "POST",
      "type": "n8n-nodes-base.webhook",
      "position": [
        -540,
        -160
      ],
      "webhookId": "dfe2a7a8-c0f7-41e1-9bf7-15e2b6e98741",
      "parameters": {
        "path": "test1",
        "options": {},
        "httpMethod": "POST",
        "responseMode": "responseNode"
      },
      "typeVersion": 1
    },
    {
      "name": "reg-GET",
      "type": "n8n-nodes-base.webhook",
      "position": [
        -540,
        20
      ],
      "webhookId": "5356a36b-1090-4470-ad87-7cfdb6c18daf",
      "parameters": {
        "path": "test1",
        "options": {},
        "responseMode": "responseNode"
      },
      "typeVersion": 1
    },
    {
      "name": "webhook-response",
      "type": "n8n-nodes-base.respondToWebhook",
      "position": [
        -100,
// ... truncated (copy to see full JSON)