implement

Pre-computed context

Current branch: !git branch --show-current 2>/dev/null || echo "unknown" Working tree status (empty = clean): !{ git status --porcelain 2>/dev/null || echo "(git status unavailable)"; } | head -20 Recent commits: !git log --oneline -5 2>/dev/null || echo "no commits" Uncommitted changes: !git diff --stat HEAD 2>/dev/null | tail -1 || echo "none"

Purpose

Implementation is where plans become code. This skill structures the execution phase so changes are made incrementally, validated continuously, and abandoned early when the approach isn't working, rather than pushing through a broken implementation and discovering problems at PR time.

It sits between planning and verification: exploration and external research provide understanding, a planning pass produces an approved plan, this skill executes it with discipline, and the companion skills in the separate testing and verification plugins (/testing:plan, /testing:write, /testing:diagnose, /verification:confirm), no longer siblings of this skill after the plugin split, validate the result when those plugins are installed.

Philosophy: cost of a mid-implementation replan is minutes; cost of discovering a flawed approach at PR review is hours. Validate incrementally, commit at checkpoints, and route back to planning the moment something feels wrong.

Progress tracking

Track skill Steps 0–5 in-session via the task list. Durable progress lives in the plan artifact itself (phase tags, - [ ] step boxes) plus the handoff notes written at phase boundaries (Step 4). Do not mirror progress into a second checklist file. Placement resolves per the topic-docs binding (${CLAUDE_PLUGIN_ROOT}/reference/topic-docs.md): the plan artifact is contract-tier, at <contract_dir>/<slug>/PLAN.md (default docs/topics/), committed on the task branch (or the memory tier under contract_tier: local); handoff notes are memory-tier under <memory_dir>/handoffs/ (default .work/handoffs/).