WHAT-IF — anchored premortem for your code

WHAT-IF does what an experienced engineer does silently and a new developer can't yet: run the plan forward and notice what breaks.

Point it at a plan (before any code) or at code that already runs. It collects real anchors — a file and line it re-read, a plan item, a dependency version, a search that came back empty — and walks a fixed set of deviation operators (NONE, MORE, LESS, AS WELL AS, PART OF, REVERSE, OTHER THAN, EARLY/LATE) across them through up to 10 distinct lenses: error paths, omissions, volume, human behavior, external deps, money, time, concurrency, access, drift.

Each surviving branch is written as something that already happened:

### The same order was charged twice
Anchor            checkout.ts:88 — <button onClick={submit}> with no disabled state
Lens / Deviation  Human behavior / AS WELL AS
How               Two requests left before the first response returned…
Cost              Customer's money, a manual refund, a support conversation.
Early signal      Pairs of near-identical orders — but nothing watches that table.
Window            Cheap while the button is one component.
Action            Disable the button until the response lands; send an idempotency key.

What makes it different:

• No anchor, no branch. Unanchored "the database might not scale" futures are deleted, not reworded.
• Honest count. Ask for 5, get "Requested 5, found 2" rather than padding.
• No fake probabilities. Branches are ordered by irreversibility: lost data → money → time → annoyance.
• Read-only. It never edits your code; the only file it writes is its own .what-if.md log, so dismissed risks don't come back next run — unless the condition you dismissed them under has changed.
• Built on measured results, not intuition: structured hazard questioning vs. brainstorming (Kobo-Greenhut 2019), method overlap of only 32–37% (Potts 2014), 92% of catastrophic failures from mishandled errors (Yuan, OSDI '14), omissions outnumbering commissions 2:1 (Bass, SEI 2006). Full references with DOIs in the GitHub README.

Not prediction: it widens coverage of concrete failure causes and nudges you toward reversible designs.

Usage: /what-if (3 branches) or /what-if 5. Source and plugin install: https://github.com/K0m04ek/what-if (MIT).