implementation-sketch

Implementation Sketch

Purpose

Transform requirements or feature descriptions into actionable implementation plans with technical decisions, component breakdowns, task lists, and risk identification. The output should be sufficient for a development team to start building.

When to Use

• User has requirements and wants a technical plan
• User asks "how would we build this?"
• User wants to break a feature into development tasks
• User asks for a system design or architecture sketch
• User wants to evaluate technical approaches for a problem

When NOT to Use

• User needs requirements first (use requirement-study)
• User wants actual code written (that's coding, not sketching)
• User wants a presentation of the plan (use deck-creator after this)

Inputs

Required:

• Requirements or feature description — what needs to be built

Optional:

• Tech stack constraints — languages, frameworks, infrastructure
• Team context — team size, skill sets, timeline
• Existing architecture — current system to extend
• Non-functional requirements — performance, scale, security targets

Process

Step 1: Preflight Tooling Check

Run a non-blocking Mermaid check before generating architecture diagrams:

if command -v mmdc >/dev/null 2>&1; then
  mmdc --version
else
  echo "mmdc not installed; continue with text diagram descriptions and add TODO entry"
fi

If mmdc is missing, update agent.todo.md with a tooling task.

Interaction Protocol (Mandatory)

For all substantive responses while running this skill:

• Include Stage: Gx <name> and Next: <immediate next step>
• At each gate transition, ask 2-4 decision-oriented questions before advancing
• Challenge weak assumptions and provide better alternatives where tradeoffs are clear

Step 2: Understand What's Being Built

Read the requirements/description thoroughly. Identify:

• Core functionality (what MUST work)
• Integration points (what connects to what)
• Data flows (what data moves where)
• User interactions (who does what)