Auto-Generate Social Posts from GitHub README/CHANGELOG Updates with GPT-4o and OAuth

Description

Generate social posts from GitHub pushes to Twitter and LinkedIn
On each GitHub push, this workflow checks if the commit set includes README.md and CHANGELOG.md, fetches both files, lets an LLM generate a Twitter and LinkedIn post, then publishes to Twitter and LinkedIn (Person).
Apps & Nodes
Trigger:** Webhook
Logic:** IF, Merge, Aggregate
GitHub:** Get Repository File (×2)
Files:** Extract from File (text) (×2)
AI:** OpenAI Chat Model → LLM Chain (+ Structured Output Parser)
Publish:** Twitter, LinkedIn (Person)
Prerequisites
GitHub:** OAuth2 or PAT with repo read.
OpenAI:** API key.
Twitter:* OAuth2 app with *Read and Write; scopes tweet.read tweet.write users.read offline.access.
LinkedIn (Person):* OAuth2 credentials; *required scope:** w_member_social, openid.
Setup
GitHub Webhook: Repo → Settings → Webhooks

Payload URL: https://<your-n8n-domain>/webhook/github/push
Content type: application/json • Event: Push • Secret (optional) • Branches as needed.
Credentials: Connect GitHub, OpenAI, Twitter, and LinkedIn (Person).
How it Works
Webhook receives GitHub push payload.
IF checks that README and CHANGELOG appear in added/modified.
GitHub (Get Repository File) pulls README.md and CHANGELOG.md.
Extract from File (text) converts both binaries to text.
Merge & Aggregate combines into one item with both contents.
LLM (OpenAI + Parser) returns a JSON with twitter and linkedin.
Twitter posts the tweet.
LinkedIn (Person) posts the LinkedIn text.