Prompts as files

prompts/
  triage/
    v1.json
    v2.json
    v3.json

PromptStore.save() always writes a new numbered file and records a note and a fingerprint, a short hash of the prompt content.

store = PromptStore("prompts")
v = store.save("triage", spec, note="add 'other', add word limit")   # -> 2
spec = store.load("triage")          # latest; or store.load("triage", 1)

Why this shape:

• Git does the history. Each version is a small text file, and git diff and git blame just work.
• Old versions stay, so a rollback is "load version 2".
• The fingerprint catches accidental hand edits. If someone edits the prompt text in v1.json directly, load raises a clear error instead of silently running a different prompt than the one that was tested. Someone who edits both the text and the fingerprint is stopped only by code review, which is what Git is for.
• diff for reviewers prints changes field by field:

~ context: 'Labels: billing, bug, account, other' -> 'Labels: billing, bug, other'

• Names are checked. A prompt called ../escape used to write outside the prompts folder. Names now allow only letters, digits, - and _.

Also store with each result which model and which settings (temperature, for example) were used. The fingerprint covers the prompt text, but the same text on another model is a different system.