Pricing History Lab guide

Start with the sample

Open the sample: three invented products with several years of archived looking pricing. It works offline and fills every view.

Track a page and fetch its history

Add the public address of a pricing page, and a name if you like. Choose how many years back and how many snapshots a year. The Lab shows the request count and time before it runs. If the archive asks us to slow down, the fetch slows, and it never retries through a block.

The four views

• Timeline: one step line per plan, because a price holds until it changes. A dot marks each real snapshot, hatched stretches mark gaps, and numbered flags mark changes. The strip above shows lowest ever, highest ever, latest and raises counted.
• Then vs now: pick two snapshots and read two columns of plan cards, with price changes, features added and removed, plans added and removed, and one summary sentence.
• Competitors: every tracked page on one time axis, with a shared price scale per currency, change flags and a one line verdict.
• Changes: a dated log, newest first, with a chip for raised, cut, renamed, plan added, plan removed, feature added or feature removed, and a plain sentence for each. Since your last check counts the new ones. The first check is a baseline.

Honest limits

• Prices are read from archived copies of the page. A gap is not a price change.
• Many modern pricing pages draw prices with a script. The archived copy then has no prices, and the snapshot says could not read. It never means free.
• The reader works from the visible text of the archived page only. Your own AI can read an unclear snapshot through the MCP tools and hand back amounts, and each amount is accepted only if its digits appear in the stored text.
• One currency per chart. A page showing two currencies is refused as ambiguous.
• Prices are shown as the page lists them. The per month view divides a yearly price by 12 only when the page states per year, and says so.
• Archived copies are only the days the archive happened to visit, so a quick change between two copies can be missed.

Pin, watch and ask

Pin a change, or the page's price history, to the evidence board. Turn on the weekly re-check for a page (only while Desktop is open). Every action is an MCP tool: see the Pricing History Lab group in the tools reference.