| name | fantasia-yagni |
| description | YAGNI and minimal diffs inside Fantasia mandatory structure: reuse ladder, no unrequested features or deps, shortest change that passes gates. Apply when scoping work, reviewing bloat, or choosing reuse vs greenfield. |
YAGNI — implementation discipline
When to follow
- New feature, refactor, or dependency choice
- User request sounds heavy — check reuse first
- Diff review: duplicate util, speculative abstraction, parallel pattern
Always-on rule: yagni.mdc. Precedence: other .cursor/rules/* and fantasia-* skills win on structure, tests, i18n, gates.
Ladder (summary)
- Need build at all?
- Already in codebase?
- Stdlib / platform?
- Installed
package.json dep?
- Minimum inside conventions — shortest diff passing dev scoped gate (dev-scoped-verify.mdc); full
yarn testbatch:verify at commit/final cleanup
Trace real flow before picking rung. Mandatory two-level, types/, Vitest/Playwright/Storybook, neverthrow, line caps — not skippable for brevity.
Orthogonal to caveman
Both can stay on. YAGNI does not replace caveman or cavemem hooks.
Links
