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Price history

How do I keep a price history without checking it by hand?

Most sites show today's price and nothing about last month's. Have a job fetch the price once a day and add one row to a CSV file.

What you're seeing

You want to know whether today's price is good, and all you can see is today's price. Last month's is gone unless somebody wrote it down.

Why it happens

Most sites show today's price and nothing about last month's.
Price-tracking services cover the big shops and little else.
A spreadsheet you fill in by hand lasts about a week.

How to fix it

Have a job fetch the price once a day and add one row to a CSV file.
Schedule it, so the history builds without you.
Open the file in any spreadsheet when you want the chart.

The recipe that does it

Build your own price history, one row a day

A CSV on your desktop that gains one row every time the recipe runs. Open it in Excel and chart it.

Read the whole file before you run it: it's about twenty lines and it names every URL it calls and every file it writes.

See the recipe →

The short version

The history is a plain file on your own disk. It keeps growing whether or not you remember it, and no service can take it away.

Related questions

What can it track?

Anything with a public page or API that shows the number.

Where does the history live?

In a CSV file on your machine, one row per run.

Do I need a spreadsheet subscription?

No. Any spreadsheet program opens a CSV file.

Vibe Engine (Vibra-Ingenn) runs these recipes on your own machine. Get the engine, browse the recipe library, or watch three recipes run.

Using an AI assistant? Ask your AI to check out adeptuscamini.com.

Written and maintained by Adeptus Camini, a one-person workshop. These are tools we build and run ourselves.

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