QUESTZ

stopping a scraper before it writes a CSV from a page that changed shape.

A scraper that writes a CSV from a page that quietly changed shape has not failed, it has lied. This one checks the shape first and fails closed when it cannot.

Tests

307

Python

3.11 to 3.14

Release

v0.1.0

The demo, as it really ran

$ questz canary check --contract examples/contracts/items.json --html questz/testsite/v2/items.html; echo "exit $?"

questz canary: DRIFT
contract: items v1
target:   questz/testsite/v2/items.html

findings (4):
  CRITICAL  missing_selector   tr[data-testid="item-row"] td[data-testid="price"]
                               expected 5 to 50, found 0
  CRITICAL  missing_selector   tr[data-testid="item-row"] td[data-testid="stock"]
                               expected 5 to 50, found 0
  MAJOR     structure_removed
                               expected every baseline node still present, found 4 gone
                               th[data-testid=col-price], th[data-testid=col-stock], td[data-testid=price], td[data-testid=stock]
  WARNING   structure_added
                               expected no nodes outside the baseline, found 7 new
                               th[data-testid=col-sku], th[data-testid=col-cost], td[data-testid=sku], td[data-testid=cost], and 3 more

signature: baseline 6c9c2add1e0b observed defb7f9573c6
counts:    tr[data-testid=item-row]=12, li[data-testid=stock]=12

structure diff:
  --- baseline
  +++ observed
  @@ -7,4 +7,4 @@
   4|th|data-testid=col-name
  -4|th|data-testid=col-price
  -4|th|data-testid=col-stock
  +4|th|data-testid=col-sku
  +4|th|data-testid=col-cost
   2|tbody|
  @@ -12,3 +12,6 @@
   4|td|data-testid=name
  -4|td|data-testid=price
  -4|td|data-testid=stock
  +4|td|data-testid=sku
  +4|td|data-testid=cost
  +1|div|data-testid=stock-panel
  +2|ul|
  +3|li|data-testid=stock|x*
exit 1

Output captured on 2026-08-30. It is committed to the repository and a test fails when it stops matching a live run, so this page cannot quietly drift from the code it describes.

Read it

• Source on GitHub the README carries the argument in full
• The whole toolset what these sixteen repositories argue together, and why there are sixteen
• Release v0.1.0 changelog and tag

The rest of the toolset

• QUACKZ deflating a backtest that only looks good because it was picked out of two hundred
• QUOTEZ market data an agent can read and cannot act on
• QUELLZ measuring what prompt-injection containment costs in utility as well as in attack rate
• QUIDZ refusing the outbound payment that would have gone out twice
• QUIZZ answering what a statistic said at the time, and refusing when it cannot
• QUARANTINEZ treating an outcome the venue never confirmed as terminal rather than as a retry
• QUENCHZ deciding in the open what a tool server gets free while it is still somebody's subprocess
• QUILTZ proving infrastructure code wrong without a cloud account, and saying what that cannot show
• QUAYZ telling a crash loop from an OOMKill, and naming the failure that no single field finds
• QUARRYZ keeping every version a statistical office published, and failing the build when it quietly issues another
• QUASHZ refusing a row whose outcome had not been decided yet when the decision would have been made
• QUALMZ a fixed number of looks at the holdout, where re-running the same configuration does not buy another
• QUEUEZ ordering a feed by its sequence, because on a real recorded session the clock goes backwards
• QUANDARYZ counting the distinct screens a component can settle into when its responses arrive out of order
• QUIETZ watching whether the data arrived rather than whether the server answered