Feature

Invocation

/feature
/feature 3
/feature "team invitations"

Use $feature for the same skill in Codex.

What happens

1. Select the next unchecked build-plan item or the requested item.
2. If a genuinely new capability does not match the plan, check for near-duplicates and propose a feature-sized plan addition.
3. After you approve the plan change, update the build plan, update the project plan only when necessary, and refresh the project overview.
4. Size the feature and split it if it contains independent outcomes.
5. Load the smallest relevant overview passages, repository paths, standards, and verification evidence.
6. Draft scope, exclusions, contracts, build steps, testing, and observable done-when criteria in context.
7. Check data formats, security boundaries, safe rendering, accessible errors, runtime reachability, scope creep, and vague proof.
8. Freeze the feature’s build attempt and full configured branch, write current-feature.md once, and stop for review before application code changes.

Feature does not guess when a missing choice would define public behavior, security, persisted data, or interoperability. It asks for that decision and leaves the active spec untouched. Reversible internal details with no current compatibility surface can use the simplest repository-native option when the spec records the choice and its test seam.

Proportional engineering

Feature adds an abstraction, dependency, service, configuration surface, compatibility layer, or security mechanism to a spec only when an established requirement needs it now. It prefers existing code, the standard library, native platform features, and installed dependencies. Unknown scale or future extensibility defaults to the smaller reversible design. A trust or data-integrity boundary counts as established when the repository exposes network or untrusted input, auth, session, or ownership, shared persisted data, destructive operations, secrets, or sensitive data, even when the plans do not name it. Untuned stack-specific defaults in coding-standards.md are not established requirements.

Reads and writes

For an unplanned bug or small change, use /fix. New-feature intake is for a product capability that belongs on the living roadmap.

Rebuild after rollback

A rebuilt feature keeps its stable plan ID. Feature proves the earlier builds and their completed rollbacks, then records the next build attempt before review. Attempt 2 uses a branch such as feature/export-reports--build-2 and gets a separate archive at completion. Missing or ambiguous history stops planning; Feature never overwrites an earlier build or guesses from filenames.

Visual features

If prototypes/ exists, the spec links the relevant mockups and makes porting the shared theme tokens the first implementation step. A visual target should not be reconstructed from prose when a real reference exists.