price-watch

Price Watch

A fork of source-watch where the "item" is a product and "interesting" means cheaper than it has ever been. It shows the shape worth copying: memory holds a running extreme, not just a list of things already seen.

Configure

• Products — a list of product URLs the user cares about.
• Memory key — price:<product-slug>, one per product.
• Floor (optional) — alert only below this price regardless of history.

Procedure

For each product URL:

1. Recall the history. recall(query="price:<product-slug>", limit=20) and take the lowest price previously recorded.
2. Fetch the page. fetch_page(url).
3. Extract the current price. Pull the number and its currency. Watch for the traps: a struck-through list price next to the real one, a subscription price next to the one-time price, and a per-unit price on a multipack. If you cannot find a price with confidence, say so — do not guess, and do not record a guessed number, because a wrong low poisons every future comparison.
4. Compare. Alert when the current price is below the recorded low (or below the configured floor). Otherwise report the current price and the delta in one line.
5. Record the observation. remember(fact="price:<product-slug>: <amount> <currency> on <YYYY-MM-DD> — <url>", category="fact"). Record every observation, not only the lows, so the history is a real series.

Report format

— now , previously (). Down .

Honest limits

• Runs on demand, not on a schedule — the scheduler cannot run skills yet (see source-watch for the detail).
• Many retailers vary price by region, login state, or bot detection. The price a fetched page shows may not be the price the user is offered. Say which page you read.
• Needs memory enabled for the history to survive between runs.

Fork this

Swap "lowest price" for any running extreme — highest rating, largest discount, shortest lead time — and the same three steps (recall the extreme, extract the current value, alert on a new record) carry over unchanged.