Implement feature task

Implement Feature Task

Outcome

Complete one implementation task as a functional, incremental deliverable, including:

• Code changes aligned to PRD and tech spec
• Tests for task acceptance criteria
• Updated task status in tasks.md and task file
• Task review handoff to task-reviewer agent

When to Use

• User asks to implement a task
• User asks to execute a task number (for example, TASK-004)
• User asks to start work on a specific task file

Do Not Use

• Creating or rewriting task plans
• Running full QA cycles
• Performing code review-only work
• General bug-fix requests outside the selected task scope

Required Inputs

• Task identifier or task file path
• Relevant planning bundle path (folder containing tasks.md)
• Related PRD and tech spec references (from task traceability)

Required Context and Skills to Load

Load these references before implementing:

• Create Implementation Tasks Skill
• Create PRD Skill
• Create Tech Spec Skill

Use them to validate scope boundaries, traceability, and expected test coverage.

Workflow

1) Resolve Task Context

Identify and open:

• Target task file (task-###-<slug>.md)
• Associated tasks.md
• Linked PRD and tech spec sections from task traceability

Decision points:

• If the task cannot be found, stop and request the exact task ID/path.
• If traceability references are missing, request missing links before implementation.

2) Validate Dependencies and Readiness

Check task preconditions before coding.

Validate:

• Depends On tasks are complete
• Required interfaces/contracts are available
• No unresolved blocking open questions

Decision points:

• If dependencies are incomplete, mark task as blocked and stop.
• If prerequisite decisions are unclear, request clarification before proceeding.

3) Plan Task-Scoped Implementation

Create a short implementation plan bounded to the selected task.

Plan must include:

• Files/components expected to change
• How acceptance criteria will be satisfied
• Task-specific test strategy (unit, integration, workflow, and non-functional if required)

Guardrails:

• Stay within task scope and explicit traceability.
• Do not expand into unrelated enhancements or backlog items.

4) Execute Implementation and Tests

Implement code changes for the selected task increment.

Execution rules:

• Implement only what is required for this task's objective and ACs.
• Add/update tests so the task has its own validation suite.
• Run relevant tests and fix failures tied to this task.

Decision points:

• If test failures reveal out-of-scope defects, note them and continue only if they block this task.
• If implementation requires scope changes, pause and request approval.

5) Update Task Tracking Artifacts

After successful implementation and tests:

• Update task file status to completed using Task completion update template
• Update tasks.md to reflect completion state
• Record test evidence and any follow-up notes

6) Trigger Task Review Handoff

Trigger task-reviewer agent with:

• Task ID and title
• Changed files summary
• Test results summary
• Outstanding risks or caveats

Decision points:

• If task-reviewer agent is unavailable, provide the same review packet in the response and flag manual review required.

7) Return Result

Provide:

• Completed task ID/path
• Summary of implemented behavior
• Files changed
• Tests run and outcomes
• Confirmation of tasks.md and task file updates
• Task-reviewer handoff status

Quality Check Before Finalizing

Completion checks:

• Implementation satisfies task objective and acceptance criteria.
• Tests exist and pass for the task's functional increment.
• Task status is updated in both task file and tasks.md.
• Scope remained aligned with PRD and tech spec traceability.
• Review handoff was completed or explicitly flagged as manual fallback.

Output Contract

The output must include implemented task changes, passing task-scoped tests, updated task tracking artifacts, and a review handoff packet for task-reviewer.