n8n 04 — HTTP & Webhooks

The HTTP Request node can call any REST API — GET, POST, PUT, PATCH, DELETE. It handles JSON, form data, binary files, and more.

Header Auth (most common for API keys)

Name:  Authorization
Value: Bearer eyJhbGciOiJIUzI1NiJ9...

# Or for X-API-Key style:
Name:  X-API-Key
Value: your-api-key-here

Basic Auth

Username: myuser
Password: mypassword
# n8n auto-encodes as Base64 in Authorization header

OAuth2

1. Create OAuth2 credential (Client ID + Secret)
2. Set Authorization URL and Token URL from the service docs
3. Add required scopes (e.g. "read:users write:repos")
4. Click "Connect" — browser opens for user consent
5. n8n stores and auto-refreshes the token

# POST with JSON body (key-value mode)
Method: POST
URL: https://api.example.com/users
Body Content Type: JSON
Body Parameters:
  name  = {{ $json.name }}
  email = {{ $json.email }}
  role  = "viewer"

# POST with raw JSON (full control)
Body Content Type: JSON
Body (raw):
{
  "name": "{{ $json.name }}",
  "email": "{{ $json.email }}",
  "metadata": {
    "source": "n8n-automation",
    "createdAt": "{{ $now.toISO() }}"
  }
}

Many APIs return paginated results. Enable "Pagination" in the HTTP Request node options:

# Offset-based pagination (page 1, 2, 3...)
Pagination Type: Update a parameter in each request
Parameter: page
Start value: 1
Increment by: 1
Continue while: {{ $response.body.data.length > 0 }}

# Cursor-based pagination (next_cursor token)
Pagination Type: Response contains next URL
Next URL path: $.meta.next_page_url

# Max pages safety limit: set "Max Requests" = 20

# 1. Add Webhook node as trigger
# 2. Copy the "Test URL" shown in the node panel
# 3. Click "Execute Workflow" (puts n8n in listen mode)
# 4. Send a request from curl:

curl -X POST https://your-n8n.com/webhook-test/abc123 \
  -H "Content-Type: application/json" \
  -H "X-Api-Key: mysecret" \
  -d '{
    "event": "form_submitted",
    "name": "Alice",
    "email": "alice@example.com"
  }'

# In Postman:
# Method: POST
# URL: (paste test URL)
# Body: raw / JSON
# Send — n8n captures the request

By default, n8n returns 200 OK with { "message": "Workflow was started" } immediately. For custom responses, use the Respond to Webhook node.

# Respond to Webhook node settings:
Respond When: Last node finishes
Response Code: 200
Response Body: JSON
Response Data:
{
  "status": "success",
  "id": "{{ $('Save to DB').item.json.inserted_id }}",
  "message": "Record created"
}

# To return an error:
Response Code: 400
Response Body:
{
  "error": "Validation failed",
  "field": "email"
}

Full example: receive a form POST, validate it, append to Google Sheets, return a confirmation.

1. Webhook (POST /form-submit)
      ↓
2. Code Node — validate required fields
   const body = $input.first().json.body;
   if (!body.email) throw new Error('Email required');
   return [{ json: body }];
      ↓
3. Google Sheets — Append Row
   Sheet: "Leads"
   Columns: name, email, message, timestamp
      ↓
4. Respond to Webhook
   Code: 200
   Body: { "success": true, "message": "Thanks!" }

Retry on Fail

# In HTTP Request node → Options tab:
Retry On Fail: ON
Max Tries: 3
Wait Between Tries: 1000ms (1 second)

Check HTTP status code

# Enable "Include Response Headers and Status"
# Then in the next IF node:
{{ $json.statusCode }} equals 200   → success branch
{{ $json.statusCode }} not equals 200 → error branch

# Or check for specific error
{{ $json.statusCode }} >= 400  → handle error

On Error setting (per node)

Continue (ignore errors)     → workflow keeps running
Stop Workflow                → stops this branch
Continue With Error Output   → error data goes to next node