SKILL GUIDE
Implementing Features
Implement requested behavior with the smallest maintainable change. Reuse existing architecture, keep contracts synchronized, and verify the result.
implementing-featuresOn this page
When to use it
- You are implementing a feature, ticket, or behavior change in an existing repository.
- You need to extend an API, interface, or workflow while preserving compatibility.
- A change crosses several layers and their contracts must stay aligned.
Workflow
Define observable behavior
Identify inputs, outputs, success and failure cases, acceptance criteria, and behavior that must remain unchanged.
Find existing patterns
Trace the affected path and search for analogous implementations, tests, and shared interfaces before creating abstractions.
Plan the smallest coherent change
Identify the affected files, contract changes, compatibility needs, and appropriate verification.
Implement and synchronize contracts
Follow repository conventions and update the participating producers and consumers of changed types, APIs, events, or configuration.
Verify and review
Exercise the requested behavior, then relevant lint, type, and build checks. Review the diff and report actual results and gaps.
Practical use cases and prompts
Implementing a feature
A catalog needs search and category filtering without changing its existing layout or data contracts.
Use implementing-features. Add search by name and description plus category filtering to this catalog. Reuse existing components and data types, handle empty results, preserve unrelated behavior, and verify the requested interactions. Report the checks actually run.Expected output: Working filtering behavior, appropriate coverage, and a focused implementation report.
Extend an API contract
A new response field must be consumed by an existing client.
Use implementing-features. Add the requested optional response field to this endpoint and update its client and shared types. Search all usages, preserve existing callers, cover the new behavior, and report compatibility decisions and verification.Expected output: A compatible API extension with synchronized types, consumers, and relevant tests.
Add a validation rule
A form needs a new business rule with consistent behavior across UI and backend.
Use implementing-features. Implement the validation rule described in this task at the existing authoritative boundary and update the form’s feedback. Preserve current error conventions, test valid and invalid inputs, and review the final diff.Expected output: Consistent validation and user feedback with targeted success and failure checks.
Expected outputs
- The requested behavior implemented within the existing architecture.
- Synchronized interfaces and focused tests where practical.
- A reviewed diff and a report of checks actually run, assumptions, and unverified areas.
Requirements and optional helpers
- A coding agent with Agent Skills support and permission to read the target repository.
- Permission to edit the requested change surface. Repository search and shell access are recommended.
- The target project’s own tooling is needed to run its checks. Follow existing test infrastructure.
Verification command detector
Optional verify-project.mjs needs Node.js 18+. It accepts --root and reports detected checks by default. --run deliberately executes project-defined commands; inspect those commands first and select workspace packages explicitly.
Installation
Open a terminal in your target project and install this package. Project scope is the default; choose your agent when prompted.
npx skills add https://github.com/GiovanniL30/ai-skills/tree/main/skills --skill implementing-featuresRefresh your agent session, confirm the skill is available, and give it a concrete task. Keep the whole package, including references and helpers.
Choose an agent and installation scope →Source and focused references
This guide summarizes the original package. Read its complete workflow and supporting references on GitHub.
Read the original SKILL.md ↗