impl-strategy

name	impl-strategy
description	Implementation orchestration strategy for the Principled framework. Consult when working with DDD plan execution, git worktrees for task isolation, task manifests, or the decompose-spawn-validate-merge lifecycle. Covers worktree management, sub-agent patterns, task state machines, and manifest schema.
user-invocable	false

Implementation Strategy — Background Knowledge

This skill provides Claude Code with comprehensive knowledge of the Principled implementation orchestration strategy. It is not directly invocable — it informs Claude's behavior when implementation-related context is encountered.

When to Consult This Skill

Activate this knowledge when:

• Working with .impl/ directory or manifest.json
• Executing tasks from a DDD implementation plan
• Managing git worktrees for isolated task execution
• Launching or monitoring implementation sub-agents
• Discussing the decompose → spawn → validate → merge lifecycle
• Encountering task status fields or state transitions

Reference Documentation

Read these files for detailed guidance on specific topics:

Task Lifecycle

• reference/task-lifecycle.md — Complete task state machine: pending → in_progress → validating → passed|failed → merged|abandoned. Defines all valid transitions, retry behavior, and terminal states.

Orchestration Guide

• reference/orchestration-guide.md — Full lifecycle walkthrough: decompose → spawn → validate → merge/re-decompose. Covers phase iteration, error recovery, merge conflict handling, and the decision framework for handling failures.

Manifest Schema

• reference/manifest-schema.md — JSON schema for .impl/manifest.json. Field descriptions, types, valid status values, and concurrency notes.

Key Principles

1. Isolation via worktrees. Every task gets its own git worktree via isolation: worktree. No task can interfere with another or with the main working tree.
2. Phases are sequential; tasks within a phase are parallel. Respect dependency ordering from the DDD plan.
3. Validate before merge. No worktree branch merges without passing the project's test/check suite.
4. Manifest is the single source of truth. All task state lives in .impl/manifest.json. Scripts read and update it atomically.
5. Sub-agents are stateless. Each impl-worker agent receives a self-contained prompt with all context needed to complete its task. It cannot access .impl/manifest.json directly.
6. The orchestrator decides. When failures occur, the orchestrator evaluates the failure type and decides whether to retry, skip, or pause for user input.