Summary
A prompt library is a versioned, tested collection of prompts your team relies on. Not a Notion doc — a repository, with tests, changelog, and retirement discipline. The one habit that separates production teams from tinkerers.
Objectives
- 01Design the folder structure of a prompt library.
- 02Version prompts and track changes.
- 03Set the retirement rule for a failing prompt.
The Lesson
The structure
One prompt per file, with metadata: intent, input schema, expected output, evaluation set, changelog, owner. Store in Git. Automated tests run on each prompt against a fixed test set. Failing tests block merge.
The discipline
Every change is a diff, reviewed. Every prompt has an owner. Every prompt has a retirement rule ('if pass rate drops below 90% for two weeks, retire'). Without discipline, prompt libraries decay into folklore.
Key Ideas
- A prompt library is a Git repository with tests.
- Retirement discipline prevents rot.