Repurpose long-form content into social posts via webhook with GPT-4.1 mini

Description

Quick Overview
This workflow exposes a webhook that accepts long-form text and uses OpenAI (via an n8n AI Agent) to repurpose it into a summary, key points, a Twitter thread, a LinkedIn post, and an Instagram caption, returning the results as JSON in the webhook response.

How it works
Receives a POST request on a webhook endpoint containing a content field in the request body.
Sends the incoming content to an OpenAI chat model with instructions to generate multiple social-ready formats as a single JSON object.
Parses the model’s response into structured JSON and returns an error payload if the response is not valid JSON.
Responds to the original webhook request with the generated JSON payload.

Setup
Add an OpenAI credential to the OpenAI Chat Model used by the AI Agent and select the model you want to run.
Copy the webhook’s Production URL and configure your source app to POST JSON with a content field to that endpoint.
If using the included internal test call, paste the Production URL into the HTTP Request step’s YOUR_PRODUCTION_WEBHOOK_URL value before executing the test flow.