Extract structured JSON from web pages via a webhook API with Gaffa

Quick overview

This workflow exposes a secured webhook that accepts a URL and a field schema, then uses Gaffa to load the web page and return structured JSON for the requested fields, with caching support and clear 400/502 error responses.

How it works

1. Receives a POST request on a webhook endpoint secured with Header Auth.
2. Validates the JSON body (url, optional selector, and a non-empty fields schema with supported types) and returns HTTP 400 with an error message if validation fails.
3. Builds a Gaffa parse_json extraction request, including a configurable max_cache_age to allow cached results.
4. Sends the request to Gaffa to render the page and extract the requested fields into structured JSON.
5. Returns HTTP 200 with the extracted data and a from_cache flag when extraction succeeds, or HTTP 502 with Gaffa’s error message when it fails.

Setup

1. Install the community node @gaffa-dev/n8n-nodes-gaffa in your n8n instance.
2. Create a Gaffa account, generate an API key, and add it in n8n as a Gaffa API credential.
3. Create a Header Auth credential (for example, X-API-Key) and select it on the webhook so callers must include the secret header.
4. Deploy the workflow and configure your client to POST JSON to the production webhook URL with Content-Type: application/json, including url, fields, and optional selector.