Implement
Follow the shared execution scope for standalone and composed invocation.
Implement exactly the selected spec, ticket, directly described work, or
caller-assigned repair batch. Read the main spec and detailed task contract when
provided; a spec is not required for a direct implementation or review fix.
Use se:deliver for explicitly requested reviewed delivery of saved
specs. Discussion of implementation does not itself select work.
Assignment and execution
Standalone work uses the current repository and branch. A composed assignment supplies the bounded contribution or selected findings, accepted requirements, exact repository/worktree/branch/base and starting HEAD, relevant instructions, and validation requirements. Verify the actual target before mutation; report an unresolved mismatch to the owner. Preserve unrelated work and never add unselected prerequisites or change requirements to make checks pass.
The executing task or developer subagent retains the caller-selected profile. Implement creates no tasks and never operates claims. Its only delegation is the optional UI designer below, with the same policy standalone or composed. Preserve any separately established caller-owned budget.
Use test-driven development where practical, especially at pre-agreed seams. Run checks covering the changed behavior and repository-required gates. Broaden validation only for unresolved risks or failures.
Optional UI design
For new screens, substantial redesigns, or unresolved visual and interaction choices, consider one read-only designer subagent under shared designer role. Skip routine component work, small fixes, and work with an already precise design. Implementation invocation authorizes this bounded helper when useful, subject to explicit caller constraints and available capabilities. The executing worker owns its selection and result; do not add a delivery-coordinator gate.
Use one native helper and retain the implementation worker's own profile. Provide a self-contained brief, evaluate its proposal against the selected scope, and resolve routine choices locally. Reuse that helper for bounded clarification; do not fan out or invoke Implement recursively. Finish or stop it before candidate handoff. If delegation is unavailable or fails, continue with local design judgment and report the limitation. Reconcile an uncertain launch before replacing it; optional design help does not block otherwise feasible work.
Implement owns the code and verifies the rendered UI in the browser or relevant native interface, including responsive behavior and accessibility appropriate to the change. A design proposal does not establish implementation quality; report any unavailable visual verification.
Review and handoff
Return the validated candidate to the caller. Independent review is a separate workflow owned by the user or orchestrator; it is never launched by Implement. Local checks and self-inspection do not satisfy a caller-required independent review gate. This boundary is the same for standalone and composed work.
Commit only files required for the selected work to the verified target branch. When the assignment includes later publication, apply hosted-content safety to the commit message before creating it. Return the committed HEAD and base, changed scope, validation evidence, worktree state, any reserved batch identity/count, and blockers. Become quiescent before handoff so the owner can review a stable candidate. Preserve unrelated dirty work and disclose it; a composed caller may require a clean isolated lane.
This skill ends at local implementation. A separately authorized push, publication, hosted review, merge, deployment, or issue action belongs to its owning workflow after this handoff; authorization for that later phase does not bypass the caller's review gate.