| name | spec-kit-specify |
| description | Use when a Spec Kit feature needs `spec.md` authored or rewritten from natural-language requirements, especially when the feature has no usable specification or requirements are too vague for planning. |
Spec Kit Specify
Create or refresh the feature specification for the active Spec Kit feature.
Invocation Notice
- Inform the user when this skill is being invoked by name:
spec-kit-specify.
When to Use
- Start a new feature and create the first
spec.md.
- Convert free-form requirements into a structured, testable, implementation-agnostic specification.
- Rework an existing spec draft so it is ready for
spec-kit-clarify or spec-kit-plan.
When Not to Use
- Clarify ambiguity in an already-written spec without redrafting it (
spec-kit-clarify).
- Generate design artifacts or tasks from an approved spec (
spec-kit-plan, spec-kit-tasks).
- Reconcile cross-artifact drift in an existing feature (
spec-kit-reconcile).
Router Fit
- Primary route from
spec-kit when spec.md does not exist yet.
- Downstream: hand off to
spec-kit-clarify (if high-impact ambiguity remains) or spec-kit-plan (if spec is ready).
Preconditions
- User provided a non-empty feature description.
- Run from repository root (or a subdirectory inside the repository).
Workflow
-
Normalize input:
- Treat the full user request as the feature description.
- If empty, stop:
ERROR: No feature description provided.
-
Generate a short branch suffix (2-4 words, kebab-case):
- Preserve meaningful technical terms/acronyms.
- Prefer action-noun phrasing (for example
user-auth, bulk-export-audit-log).
-
Bootstrap feature branch and spec exactly once:
- Run
scripts/create-new-feature.sh --json --short-name "<short-name>" "<feature description>".
- Do not manually pre-compute branch numbers; let the script assign the next number.
- Parse JSON output and capture:
BRANCH_NAME
SPEC_FILE
FEATURE_NUM
- Derive
FEATURE_DIR as dirname(SPEC_FILE).
-
Load template context:
- Preferred template:
{REPO_ROOT}/templates/spec-template.md.
- Fallback template:
assets/spec-template.md.
- Preserve heading order from the selected template.
-
Draft spec.md content (focus on WHAT/WHY, not HOW):
- Fill prioritized user stories with independent tests and acceptance scenarios.
- Write testable functional requirements.
- Add edge cases and scope boundaries.
- Add measurable, technology-agnostic success criteria.
- Include key entities when data is central.
- Use reasonable defaults and document assumptions when needed.
-
Clarification policy while drafting:
- First, make informed defaults using domain norms.
- Add
[NEEDS CLARIFICATION: ...] only for high-impact uncertainty.
- Hard limit: at most 3 clarification markers.
- Prioritize by impact: scope > security/privacy > UX > technical detail.
-
Write the spec to SPEC_FILE.
-
Create and run requirements quality validation:
- Create
FEATURE_DIR/checklists/requirements.md.
- Validate spec against this checklist:
- No implementation details (frameworks, languages, APIs, internal architecture).
- Mandatory sections are complete.
- Requirements are unambiguous and testable.
- Success criteria are measurable and technology-agnostic.
- User scenarios and edge cases are covered.
- Scope boundaries, dependencies, and assumptions are explicit.
- No unresolved
[NEEDS CLARIFICATION] markers for plan-ready specs.
- If non-clarification issues fail, revise spec and re-validate (max 3 passes).
-
If clarification markers remain after validation:
- Ask up to 3 numbered clarification questions total.
- For each question, present 2-3 concrete options plus a short custom answer path.
- Wait for user responses, update
spec.md, then re-run validation.
-
Report completion:
- Branch name.
spec.md path.
requirements.md path and pass/fail summary.
- Recommended next step:
spec-kit-clarify if high-impact ambiguity remains.
spec-kit-plan if ready.
Output
- Active feature branch from
scripts/create-new-feature.sh
specs/<feature>/spec.md
specs/<feature>/checklists/requirements.md
- readiness handoff for
spec-kit-clarify or spec-kit-plan
Common Mistakes
- Writing implementation design into the spec instead of user-visible behavior and outcomes.
- Leaving vague requirements that cannot be acceptance-tested.
- Asking too many clarification questions instead of making reasonable defaults.
- Running feature bootstrap script multiple times for one request.
References
references/spec-kit-workflow.dot
scripts/create-new-feature.sh
assets/spec-template.md
https://github.com/github/spec-kit/blob/9111699cd27879e3e6301651a03e502ecb6dd65d/templates/commands/specify.md