Overview
The HN front page is a firehose. This n8n workflow pulls the top 30 posts hourly, filters against your keyword and domain list, uses GPT-4o-mini to rank relevance and add a one-line summary, and posts a Slack digest twice a day. It's the fastest way to stop missing launches in your category.
How it works
- Cron trigger every 30 minutes.
- Fetch HN top stories via Firebase API.
- Function node dedupes against Postgres/Notion.
- For matches, GPT-4o-mini writes: 1-line summary + relevance score (0-10).
- Slack digest posts at 9am and 4pm with score >= 6 grouped by topic.
Benefits
- Never miss a competitor launch by more than a few hours.
- Signal-to-noise beats browsing HN yourself.
- Runs on free tiers — HN API is public, GPT-4o-mini costs pennies.
Use cases
- Founders in a fast-moving category (AI tools, dev tools, no-code).
- PMMs monitoring category trends.
- Investors watching batches from YC, S24, W25.
Step-by-step guide
Step 1: Load your keyword list
Include product names, category phrases, and 'Show HN' filters for a broad sweep.
Step 2: Fetch and de-dupe
Store item.id in a small table; skip anything seen in the last 7 days.
Step 3: Rank with GPT-4o-mini
Prompt: 'Given this HN title + URL description, rate 0-10 relevance to {my keywords} and write one line on why.'
Step 4: Slack digest formatting
Group by topic; include HN link and score. Keep under 10 items per digest.
Step 5: Tune weekly
Add a thumbs-up/thumbs-down reaction on Slack posts. Weekly, feed those back to refine the ranking prompt.
Example
Digest: '[9/10] Show HN: Semantic search over your inbox (competitor to us) — clean UX, YC S25.'