Begin writing code for the current milestone. This is the explicit go-signal after /porting-start-milestone preparation has been reviewed and approved by the user.
---
name: porting-execute
description: Begin writing code for the current milestone. This is the explicit go-signal after /porting-start-milestone preparation has been reviewed and approved by the user.
disable-model-invocation: true
---
You are entering Phase 2: Execute for the current milestone. The user has reviewed and approved the preparation summary from `/porting-start-milestone`.
Locate the agent's **artifact directory** at `<project-root>/.porting/` (defined in `porting-methodology`). All artifacts live there. Load the `porting-methodology` skill if not already in context.
## Begin Implementation
Implement the approved work items from the preparation summary. Follow the Phase 2 conventions from the methodology (matching engine patterns, leveraging existing systems, consulting loaded skills, stub/hardcoded conventions, building often, assertions).
The approved prep summary is the **scope contract**. Focus exclusively on the listed work items.
If you discover unexpected work that wasn't identified during preparation, **stop and tell the user** before implementing it. Present what you found and collaborate on the right response:
- Does it fit naturally into an existing future milestone? → Stub it with the appropriate `STUB(Mx)` marker.
- Does the goal's milestone plan need new milestones to accommodate it? → Propose specific additions to the plan.
- Is it a small prerequisite that blocks the current work item? → Ask the user to approve adding it to the current scope.
Do not silently expand scope. Do not blindly defer everything — think about where the work belongs.
## During Implementation… install to load the full skill