| name | spec-driven-development |
| description | Use when implementing or changing a non-trivial fastxlsx feature. Require a written spec before code changes for API, CLI, metadata, XML, structural edit, or lossless-roundtrip-sensitive work. |
Spec-Driven Development
Use this skill for non-trivial feature work in this repository.
Before changing code, confirm there is an SDD document for the feature.
- Preferred feature spec location:
docs/spec/<feature-name>.md
- Repository contract:
docs/spec-driven-development.md
- Spec index:
docs/spec/README.md
Required Gate
Do not start implementation until the spec covers:
- background and current gap
- goals and non-goals
- public API or CLI surface, if affected
- structural edit semantics when rows, columns, ranges, or cells are involved
- test plan and acceptance criteria
When This Is Required
Use the spec gate for changes that touch:
- public API or TypeScript types
- CLI behavior or JSON output
- workbook or worksheet metadata
- XML read or write helpers
- row or column structural transforms
- comments, formulas, validations, filters, merges, protection, styles, tables, or defined names
- any work where lossless roundtrip could regress
Exceptions
You do not need a dedicated feature spec for:
- typo-only edits
- comment-only edits
- isolated refactors with no behavior change
- narrowly scoped test cleanup without feature changes
Implementation Order
Default order:
- Write or update the spec.
- Get alignment on the spec.
- Implement code.
- Add or update tests.
- Update public docs if the user-facing surface changed.
