/arn-code-execute-plan

name: arn-code-execute-plan
description: >-
  This skill should be used when the user says "execute plan", "run the plan",
  "execute project", "execute all tasks", "run all tasks",
  "run plan in parallel", "execute with review gates", or wants to execute
  a full structured project plan after tasks have been created via arn-code-taskify.
  This skill runs ALL tasks from the task list — for executing a single specific
  task, use arn-code-execute-task instead. For Agent Teams mode, use
  arn-code-execute-plan-teams. Do NOT use this skill when executing a single task —
  use `/arn-code-execute-task` instead.
version: 0.4.0

Arness Execute Plan

Execute a structured project plan by dispatching parallel batches of `arn-code-task-executor` agents and validating each completed task through a `arn-code-task-reviewer` agent before marking it done. Independent tasks run concurrently; dependent tasks wait for their blockers to clear. Each task goes through an execute-review-gate cycle: the executor implements and tests, the reviewer validates against patterns and acceptance criteria, and the orchestrator (this skill) decides whether to pass, retry, or escalate.

**Key architectural constraint:** Subagents cannot spawn other subagents. The dispatch loop MUST stay in the main session (this skill).

Pipeline position:

arn-code-init -> arn-code-feature-spec / arn-code-bug-spec -> arn-code-plan -> arn-code-save-plan -> arn-code-review-plan -> arn-code-taskify -> **arn-code-execute-plan** (dispatch -> execute -> review -> gate) -> arn-code-review-implementation -> arn-code-document-project -> arn-code-ship

Prerequisites

If no `## Arness` section exists in the project's CLAUDE.md, inform the user: "Arness is not configured for this project yet. Run `/arn-implementing` to get started — it will set everything up automatically." Do not proceed without it.

Workflow

Step 1: Load Configuration

1. Read the project's CLAUDE.md and extract the `## Arness` section to find:

• **Plans directory** -- base path where project plans are saved
• **Code patterns** -- path to the directory containing stored pattern documentation
• **Template path** -- path to the report template set (JSON templates)
• **Template version** -- plugin version the templates were copied from (if present)
• **Template updates** -- user preference: `ask`, `auto`, or `manual` (if present)
• **Specs directory** -- path to the directory containing specification files (if present)

**Template version check:** If `Template version` and `Template updates` fields are present, run the template version check procedure documented in arn-code-save-plan Step 1 (Template Version Check) before proceeding. If `## Arness` does not contain these fields, treat as legacy and skip.

2. Ask the user for `PROJECT_NAME` if not provided in the trigger message

3. Verify the project directory exists and contains the required structure:

   <plans-dir>/<PROJECT_NAME>/
   ├── INTRODUCTION.md
   ├── TASKS.md
   ├── PROGRESS_TRACKER.json
   ├── plans/PHASE_*.md
   └── reports/

4. If the project directory is missing, suggest running `/arn-code-save-plan` first 5. If INTRODUCTION.md or phase plans are missing, suggest running `/arn-code-save-plan` first 6. If `PROGRESS_TRACKER.json` is missing, warn that progress tracking will not be available. Execution can still proceed. 7. If `### Visual Testing` is configured in CLAUDE.md, note the presence of visual testing. Per-task execution uses Layer 1 config only (top-level fields). Multi-layer visual validation is handled by `/arn-code-review-implementation` after plan execution completes. 8. **Detect sketch artifacts** -- Read `<project-folder>/INTRODUCTION.md` and check for a `### Sketch Artifacts` section. If found, extract the sketch manifest path listed there (typically a relative path to `sketch-manifest.json`). Resolve it to an absolute path relative to the project directory. Also resolve the sketch directory path (the parent directory of the manifest). If no Sketch Artifacts section is found, check for manifests by scanning `arness-sketches/` in the project's source directory for any `sketch-manifest.json` matching `PROJECT_NAME`. Store the resolved manifest path and sketch directory path for use in the dispatch loop (Step 4). If no manifest is found from either source, proceed normally -- the dispatch loop will not pass sketch context to executors.

---

Step 2: Verify Task List and Build Dependency Graph

**Deferred Task List Setup:**

Check for **Task list ID** in `## Arness` config. If absent:

Ask (using `AskUserQuestion`):

**"Persistent task lists are not configured. Would you like to enable them? (Recommended — tasks survive across sessions)"**

1. **Yes** (Recommended) — Auto-generate ID from project directory name 2. **Yes, with custom ID** — Specify the task list ID 3. **No** — Keep tasks session-scoped

If Yes: derive ID (slugify project directory name or use custom ID), write to `.claude/settings.json` (create if needed, preserve existing env vars), add `Task list ID` to `## Arness` config. Inform: "Persistent task list configured."

If No: proceed without persistence. Inform (once): "Tasks will be session-scoped. Enable persistence anytime with `/arn-code-taskify`."

1. Call `TaskList` to check for existing tasks 2. If **no tasks exist**:

• If `Task list ID` is configured in `## Arness`: tasks should have persisted — suggest: "No tasks found despite persistent task lists being configured. The task list may have been cleared. Run `/arn-code-taskify` to recreate tasks."
• If `Task list ID` is NOT configured: "No tasks found. Tasks may have been lost when the previous session ended (session-scoped storage). Run `/arn-code-taskify` to recreate them. To enable persistent task lists for future sessions, run `/arn-code-taskify` which will offer to configure persistence."

3. If **tasks already exist with progress** (some in_progress or comp