start-implementation

name	start-implementation
description	Start an implementation session from an existing plan. Discovers available plans, checks environment setup, and invokes the technical-implementation skill.
disable-model-invocation	true
allowed-tools	Bash(.claude/skills/start-implementation/scripts/discovery.sh), Bash(.claude/hooks/workflows/write-session-state.sh)
hooks	{"PreToolUse":[{"hooks":[{"type":"command","command":"$CLAUDE_PROJECT_DIR/.claude/hooks/workflows/system-check.sh","once":true}]}]}

Invoke the technical-implementation skill for this conversation.

⚠️ ZERO OUTPUT RULE: Do not narrate your processing. Produce no output until a step or reference file explicitly specifies display content. No "proceeding with...", no discovery summaries, no routing decisions, no transition text. Your first output must be content explicitly called for by the instructions.

Workflow Context

This is Phase 5 of the six-phase workflow:

Phase	Focus	You
1. Research	EXPLORE - ideas, feasibility, market, business
2. Discussion	WHAT and WHY - decisions, architecture, edge cases
3. Specification	REFINE - validate into standalone spec
4. Planning	HOW - phases, tasks, acceptance criteria
5. Implementation	DOING - tests first, then code	◀ HERE
6. Review	VALIDATING - check work against artifacts

Stay in your lane: Execute the plan via strict TDD - tests first, then code. Don't re-debate decisions from the specification or expand scope beyond the plan. The plan is your authority.

---

Instructions

Follow these steps EXACTLY as written. Do not skip steps or combine them. Present output using the EXACT format shown in examples - do not simplify or alter the formatting.

CRITICAL: This guidance is mandatory.

• After each user interaction, STOP and wait for their response before proceeding
• Never assume or anticipate user choices
• Even if the user's initial prompt seems to answer a question, still confirm with them at the appropriate step
• Complete each step fully before moving to the next
• Do not act on gathered information until the skill is loaded - it contains the instructions for how to proceed

---

Step 0: Run Migrations

This step is mandatory. You must complete it before proceeding.

Invoke the /migrate skill and assess its output.

If files were updated: STOP and wait for the user to review the changes (e.g., via git diff) and confirm before proceeding to Step 1. Do not continue automatically.

If no updates needed: Proceed to Step 1.

---

Step 1: Discovery State

!.claude/skills/start-implementation/scripts/discovery.sh

If the above shows a script invocation rather than YAML output, the dynamic content preprocessor did not run. Execute the script before continuing:

.claude/skills/start-implementation/scripts/discovery.sh

If YAML content is already displayed, it has been run on your behalf.

Parse the discovery output to understand:

From plans section:

• exists - whether any plans exist
• files - list of plans with: name, topic, status, date, format, specification, specification_exists, plan_id (if present)
• Per plan external_deps - array of dependencies with topic, state, task_id
• Per plan has_unresolved_deps - whether plan has unresolved dependencies
• Per plan unresolved_dep_count - count of unresolved dependencies
• count - total number of plans

From implementation section:

• exists - whether any implementation tracking files exist
• files - list of tracking files with: topic, status, current_phase, completed_phases, completed_tasks

From dependency_resolution section:

• Per plan deps_satisfied - whether all resolved deps have their tasks completed
• Per plan deps_blocking - list of deps not yet satisfied with reason

From environment section:

• setup_file_exists - whether environment-setup.md exists
• requires_setup - true, false, or unknown

From state section:

• scenario - one of: "no_plans", "single_plan", "multiple_plans"
• plans_concluded_count - plans with status concluded
• plans_with_unresolved_deps - plans with unresolved external deps
• plans_ready_count - concluded plans with all deps satisfied
• plans_in_progress_count - implementations in progress
• plans_completed_count - implementations completed

IMPORTANT: Use ONLY this script for discovery. Do NOT run additional bash commands (ls, head, cat, etc.) to gather state - the script provides everything needed.

→ Proceed to Step 2.

---

Step 2: Route Based on Scenario

Use state.scenario from the discovery output to determine the path:

If scenario is "no_plans"

No plans exist yet.

Output the next fenced block as a code block:

Implementation Overview

No plans found in .workflows/planning/

The implementation phase requires a plan.
Run /start-planning first to create a plan from a specification.

STOP. Do not proceed — terminal condition.

If scenario is "single_plan" or "multiple_plans"

Plans exist.

→ Proceed to Step 3 to present options.

---

Step 3: Present Plans and Select

Present all discovered plans. Classify each plan into one of three categories based on its state.

Classification logic:

A plan is Implementable if:

• It has status: concluded AND all deps are satisfied (deps_satisfied: true or no deps) AND no tracking file or tracking status: not-started, OR
• It has an implementation tracking file with status: in-progress

A plan is Implemented if:

• It has an implementation tracking file with status: completed

A plan is Not implementable if:

• It has status: concluded but deps are NOT satisfied (blocking deps exist)
• It has status: planning or other non-concluded status
• It has unresolved deps (has_unresolved_deps: true)

Present the full state:

Show implementable and implemented plans as numbered tree items.

Output the next fenced block as a code block:

Implementation Overview

{N} plans found. {M} implementations in progress.

1. {topic:(titlecase)}
   └─ Plan: {plan_status:[concluded]} ({format})
   └─ Implementation: @if(has_implementation) {impl_status:[in-progress|completed]} @else (not started) @endif

2. ...

Tree rules:

Implementable:

• Implementation status: in-progress → Implementation: in-progress (Phase N, Task M)
• Concluded plan, deps met, not started → Implementation: (not started)

Implemented:

• Implementation status: completed → Implementation: completed

Ordering:

1. Implementable first: in-progress, then new (foundational before dependent)
2. Implemented next: completed
3. Not implementable last (separate block below)

Numbering is sequential across Implementable and Implemented. Omit any section entirely if it has no entries.

If non-implementable plans exist, show them in a separate code block:

Output the next fenced block as a code block:

Plans not ready for implementation:
These plans are either still in progress or have unresolved
dependencies that must be addressed first.

  • advanced-features (blocked by core-features:core-2-3)
  • reporting (in-progress)

Output the next fenced block as a code block:

If a blocked dependency has been resolved outside this workflow,
name the plan and the dependency to unblock it.

Key/Legend — show only statuses that appear in the current display. No --- separator before this section.

Output the next fenced block as a code block:

Key:

  Implementation status:
    in-progress — work is ongoing
    completed   — all tasks implemented

  Blocking reason:
    blocked     — depends on another plan's task
    in-progress — plan not yet concluded

Then prompt based on what's actionable:

If single implementable plan and no implemented plans (auto-select):

Output the next fenced block as a code block:

Automatically proceeding with "{topic:(titlecase)}".

→ Proceed directly to Step 4.

If nothing selectable (no implementable or implemented):

Show "not ready" block only (with unblock hint above).

Output the next fenced block as a code block:

Implementation Overview

No implementable plans found.

Complete blocking dependencies first, or finish plans still
in progress with /start-planning. Then re-run /start-implementation.

STOP. Do not proceed — terminal condition.

Otherwise (multiple selectable plans, or implemented plans exist):

The verb in the menu depends on the implementation state:

• Implementation in-progress → Continue
• Not yet started → Start
• Completed → Re-review

Output the next fenced block as markdown (not a code block):

· · · · · · · · · · · ·
1. Continue "Billing" — in-progress (Phase 2, Task 3)
2. Start "Core Features" — not yet started
3. Re-review "User Auth" — completed

Select an option (enter number):
· · · · · · · · · · · ·

Recreate with actual topics and states from discovery.

STOP. Wait for user response.

If the user requests an unblock

1. Identify the plan and the specific dependency
2. Confirm with the user which dependency to mark as satisfied
3. Update the plan's external_dependencies frontmatter: set state to satisfied_externally
4. Commit the change
5. Re-run classification and re-present Step 3

→ Based on user choice, proceed to Step 4.

---

Step 4: Check External Dependencies

This step is a confirmation gate. Dependencies have been pre-analyzed by the discovery script.

After the plan is selected:

1. Check the plan's external_deps and dependency_resolution from the discovery output

If all deps satisfied (or no deps)

Output the next fenced block as a code block:

External dependencies satisfied.

→ Proceed to Step 5.

If any deps are blocking

This should not normally happen for plans classified as "Implementable" in Step 3. However, as an escape hatch:

Output the next fenced block as a code block:

Missing Dependencies

Unresolved (not yet planned):
  • {topic}: {description}
    No plan exists. Create with /start-planning or mark as
    satisfied externally.

Incomplete (planned but not implemented):
  • {topic}: {plan}:{task-id} not yet completed
    This task must be completed first.

Output the next fenced block as markdown (not a code block):

· · · · · · · · · · · ·
- **`i`/`implement`** — Implement the blocking dependencies first
- **`l`/`link`** — Run /link-dependencies to wire up recently completed plans
- **`s`/`satisfied`** — Mark a dependency as satisfied externally
· · · · · · · · · · · ·

STOP. Wait for user response.

Escape Hatch

If the user says a dependency has been implemented outside the workflow:

1. Ask which dependency to mark as satisfied
2. Update the plan frontmatter: Change the dependency's state to satisfied_externally
3. Commit the change
4. Re-check dependencies

→ Proceed to Step 5.

---

Step 5: Check Environment Setup

IMPORTANT: This step is for information gathering only. Do NOT execute any setup commands at this stage. The skill contains instructions for handling environment setup.

Use the environment section from the discovery output:

If setup_file_exists: true and requires_setup: false:

Output the next fenced block as a code block:

Environment: No special setup required.

→ Proceed to Step 6.

If setup_file_exists: true and requires_setup: true:

Output the next fenced block as a code block:

Environment setup file found: .workflows/environment-setup.md

→ Proceed to Step 6.

If setup_file_exists: false or requires_setup: unknown:

Output the next fenced block as a code block:

Are there any environment setup instructions I should follow before implementation?
(Or "none" if no special setup is needed)

STOP. Wait for user response.

• If the user provides instructions, save them to .workflows/environment-setup.md, commit and push
• If the user says no/none, create .workflows/environment-setup.md with "No special setup required." and commit

→ Proceed to Step 6.

---

Step 6: Invoke the Skill

Before invoking the processing skill, save a session bookmark.

Output the next fenced block as a code block:

Saving session state so Claude can pick up where it left off if the conversation is compacted.

.claude/hooks/workflows/write-session-state.sh \
  "{topic}" \
  "skills/technical-implementation/SKILL.md" \
  ".workflows/implementation/{topic}/tracking.md"

After completing the steps above, this skill's purpose is fulfilled.

Invoke the technical-implementation skill for your next instructions. Do not act on the gathered information until the skill is loaded - it contains the instructions for how to proceed.

Example handoff:

Implementation session for: {topic}
Plan: .workflows/planning/{topic}/plan.md
Format: {format}
Plan ID: {plan_id} (if applicable)
Specification: {specification} (exists: {true|false})
Implementation tracking: {exists | new} (status: {in-progress | not-started | completed})

Dependencies: {All satisfied | List any notes}
Environment: {Setup required | No special setup required}

Invoke the technical-implementation skill.