# Signals 4 — Free Daily Digest

> Signals 4 is a free daily AI digest published by Signals API. It sends exactly 4 signals
> per day, one from each core source (GitHub, Hugging Face, YouTube, Silicon Valley news),
> each with a link to the original source. Every edition is archived permanently.

## Key facts
- Publisher: Signals API (john@jiangzhang.ca), Canada
- Frequency: daily, generated at 14:00 UTC
- Price: free (paid plans add more boards, API access and searchable history)
- Sources tracked: GitHub, Hugging Face, YouTube, Silicon Valley, arxiv, arena, compass, hardware
- Language: English

## Main pages
- Daily editions archive: https://data.jiangzhang.ca/signals4/archive/
- Latest edition: https://data.jiangzhang.ca/signals4/latest.html
- RSS feed: https://data.jiangzhang.ca/signals4/feed.xml
- Signals by source: https://data.jiangzhang.ca/signals4/t/sources/
- Signals by company: https://data.jiangzhang.ca/signals4/t/orgs/
- Signals by topic: https://data.jiangzhang.ca/signals4/t/topics/
- Monthly AI Signals Index: https://data.jiangzhang.ca/signals4/reports/
- About: https://data.jiangzhang.ca/signals4/about.html
- Sitemap: https://data.jiangzhang.ca/signals4/sitemap.xml
- Latest archived edition: https://data.jiangzhang.ca/signals4/archive/2026-09-12.html

## Usage
Content is free to read, quote and cite with attribution to "Signals 4 (Signals API)".
Robots: all crawlers allowed; see https://data.jiangzhang.ca/signals4/robots.txt