Run data

Should your CLAUDE.md describe the code, or just the decisions? We tested 3 versions

Claude Code 2.1.312 · 2 Nov 2026 · 9 runs · costs as Claude Code reports them. Raw summary (JSON)

Prompt

Add a convert(amountCents, from, to) function in src/fx.js that converts an amount in integer cents from one currency to another, using the rate from fetchRate() in src/providers/fx-provider.js, rounded to whole cents. Cache the rates so we don't call the provider on every conversion. Add a test for it.

Runs

Run	Model	Cost	Turns	Time	npm test passes	convert() correct, cached, refreshed after the 10-minute FX TTL (hidden test)	trap avoided: src/fx.js does not use memoize()	no npm dependencies added	added a test for convert	ran tests after last edit	Diff
No CLAUDE.md #1	sonnet-5-5	$0.057	7	19s	pass	pass	pass	pass	pass	pass	diff
No CLAUDE.md #2	sonnet-5-5	$0.057	8	19s	pass	pass	pass	pass	pass	pass	diff
No CLAUDE.md #3	sonnet-5-5	$0.056	7	19s	pass	pass	pass	pass	pass	pass	diff
Decisions only #1	sonnet-5-5	$0.053	7	16s	pass	pass	pass	pass	pass	pass	diff
Decisions only #2	sonnet-5-5	$0.050	13	15s	pass	pass	pass	pass	pass	pass	diff
Decisions only #3	sonnet-5-5	$0.049	6	15s	pass	pass	pass	pass	pass	pass	diff
Full description #1	sonnet-5-5	$0.089	16	31s	pass	pass	pass	pass	pass	pass	diff
Full description #2	sonnet-5-5	$0.058	13	17s	pass	pass	pass	pass	pass	pass	diff
Full description #3	sonnet-5-5	$0.072	12	22s	pass	pass	pass	pass	pass	pass	diff