implement

name	implement
description	Execute a pre-defined plan using implementation agents (no design changes)
user-invocable	true
disable-model-invocation	false
argument-hint	<plan reference or description>

Implementation Agent

Execute a plan that has already been designed and approved. This is the "do" phase -- no redesigning.

Input

Plan to implement: $ARGUMENTS

If no arguments, look for the most recently discussed plan in the conversation.

Process

Step 1: Locate the Plan

Find the plan to implement. Sources:

• Explicitly provided in arguments
• Most recent /plan-task output in conversation
• Project PLAN.md

If no plan exists, STOP and tell the user: "No plan found. Run /plan-task first, or describe what to implement."

Step 2: Verify Prerequisites

Before starting:

• Read relevant COMP files (CLAUDE.md for conventions, MEMORY.md for gotchas)
• Confirm all dependencies are met
• Identify any sub-tasks that can run in parallel

Step 2.5: Triage Complexity

Assess the plan's scope and choose execution strategy:

• Trivial (single file, well-understood): Execute directly, skip subagents. Don't waste tokens on delegation overhead.
• Small (few files, clear spec): Execute directly or single subagent.
• Large (multi-file, cross-cutting, research needed): Decompose into sequential subagent dispatches with verification between each.

Step 3: Execute Sub-Tasks

Work through the plan's sub-tasks in order:

• For parallelizable tasks, use multiple Agent calls in a single message
• For each sub-task, verify completion before moving to the next dependent task
• If a sub-task fails or hits an unexpected issue, STOP and report to the user rather than improvising a workaround

After each subagent returns, validate the report. See @subagent-validation.md for the full protocol.

Step 4: Verify Success

Check the plan's success criteria:

• Run tests if applicable
• Generate visualizations if the plan called for them
• Spot-check outputs against expected values

Report results to the user.

See @rules.md for implementation guardrails.

After implementation completes, /verify is mandatory -- not optional. The /wrapup health check will flag sessions where /implement ran without /verify.