Impl

impl — Autonomous Implementation Engine (the "harnish" engine)

Do not judge. Follow the rules. When lost, return to harnish-current-work.json. When stuck, escalate. No invention.

Skill Chain

drafti-architect (or drafti-feature) → impl → galmuri:ralphi (sibling plugin)

When harnish starts without a PRD: "No PRD found. Please create one first with /drafti-architect or /drafti-feature."

Bash Convention

bash 3.2+, python3 (3.14+). macOS/Linux. No jq required as of v0.1.0.

Each Bash tool invocation is a fresh subshell — variables do not survive across calls. Every bash block in this skill must re-declare HARNISH_ROOT="${CLAUDE_PLUGIN_ROOT}" inline before using any script path. There are no persistent script-name aliases; full paths ($HARNISH_ROOT/scripts/{name}.sh) are used directly.

State counters (TASK_COMPLETE_COUNT, etc.) are tracked by the LLM in conversation memory, not in shell variables. COMPRESS_EVERY_N = 5.

Entry Check

If invoked with no context (no PRD path, no task description, no experience command, no harnish-current-work.json in CWD): → Ask: "무엇을 구현할까요? PRD 파일 경로나 작업 내용을 알려주세요." → Wait for user response before proceeding to Step 1.

Step 1: Mode Detection

Load at most 2 references at a time. (See Context Budget below.)

Note: references/retention-policy.md is not auto-loaded by any utterance — it documents an out-of-band ops flow (scripts/purge-assets.sh, asset deletion). It is referenced only on explicit 자산 보존 정책 / asset retention policy utterance per Step 5.

Step 2: Seeding (PRD → harnish-current-work.json)

1. Verify PRD file: docs/prd-{name}.md. Confirm existence of §4 (Implementation Spec), §6 (Tests), §7 (Guardrails)
2. Query existing assets:

   HARNISH_ROOT="${CLAUDE_PLUGIN_ROOT}"
   bash "$HARNISH_ROOT/scripts/query-assets.sh" \
     --tags "{key}" --types guardrail --format text \
     --base-dir "$(pwd)/.harnish"
   

3. Phase splitting: Data → Business Logic → UI → Integration Tests
4. Task decomposition: 1 task = 1 file | 1 function | 1 test | 1 config
5. Read references/progress-template.md and generate harnish-current-work.json → validate:

   HARNISH_ROOT="${CLAUDE_PLUGIN_ROOT}"
   bash "$HARNISH_ROOT/scripts/validate-progress.sh" .harnish/harnish-current-work.json
   

6. Report to user: "Seeding complete — {N} Phases, {M} Tasks — review and say 'run loop'"
7. → Proceed to Step 3

Step 3: Implementation Loop (ralph)

Entry

HARNISH_ROOT="${CLAUDE_PLUGIN_ROOT}"
bash "$HARNISH_ROOT/scripts/validate-progress.sh" .harnish/harnish-current-work.json
bash "$HARNISH_ROOT/scripts/loop-step.sh" .harnish/harnish-current-work.json

• STATUS=ALL_DONE → report completion → STOP
• STATUS=NO_DOING → move first Todo to Doing (see "Todo→Doing" below)
• STATUS=ACTIVE → check next action of current task → start loop

One Loop Cycle = READ → ACT → LOG → PROGRESS

[READ]

• Read the doing task's objective, strategy, files, and prohibitions from harnish-current-work.json
• Query assets:

  HARNISH_ROOT="${CLAUDE_PLUGIN_ROOT}"
  bash "$HARNISH_ROOT/scripts/query-assets.sh" --tags "{task-id},{phase}" --format inject --base-dir "$(pwd)/.harnish"
  

[ACT]

• Create/modify files according to the guide
• Hard guardrail violation → immediately STOP + escalation
• Soft guardrail violation → warning + auto-correction

[LOG] (every 3 actions)

• Update harnish-current-work.json doing: current / last action / next action

• HARNISH_ROOT="${CLAUDE_PLUGIN_ROOT}"
  bash "$HARNISH_ROOT/scripts/validate-progress.sh" .harnish/harnish-current-work.json
  

[PROGRESS] Run acceptance_criteria:

• Pass → move Doing→Done → record asset (if applicable) → TASK_COMPLETE_COUNT += 1 → move next Todo→Doing → repeat loop
• 1-2 failures → analyze cause → fix → go to [ACT]
• 3 failures → record failure asset → escalation. Do not attempt to resolve alone.

How to Run acceptance_criteria

Behavior When acceptance_criteria Is Empty

The empty-criteria check is an entry gate at every transition into Doing, not a post-execution check:

1. Seeding (Step 2): Extract criteria from PRD §6. If mapping is not possible → immediately ask the user: "Please specify acceptance_criteria for Task {id}." Do not seed the task without criteria.
2. Todo→Doing transition: If acceptance_criteria is empty or missing → escalate before transitioning to Doing. The task does not enter Doing.
3. Mid-session edits: If a task already in Doing has its criteria emptied (rare; usually a user manual edit) → escalate immediately on next loop entry, before [ACT]. This is separate from the 3-failure rule.

Todo→Doing Transition

1. Check .todo.phases[0].tasks[0] (first incomplete task)
2. Verify depends_on is satisfied (all prerequisite Tasks exist in .done.phases)
3. Update harnish-current-work.json: .doing.task = {id, title, started_at, current, next_action, blocker:null, retry_count:0, context}, remove the task from .todo
4. Update .metadata.status

5. HARNISH_ROOT="${CLAUDE_PLUGIN_ROOT}"
   bash "$HARNISH_ROOT/scripts/validate-progress.sh" .harnish/harnish-current-work.json
   

Doing→Done Transition

1. Find the same phase in .done.phases (add a new Phase if not found)
2. Add completed task: {id, title, result: "one-line summary", files_changed, verification, duration}
3. .doing.task = null, .stats.completed_tasks += 1

4. HARNISH_ROOT="${CLAUDE_PLUGIN_ROOT}"
   bash "$HARNISH_ROOT/scripts/validate-progress.sh" .harnish/harnish-current-work.json
   

On Phase Completion (Milestone)

✅ Milestone: Phase {N} — {title}
Completed: {M} tasks / Changed: {K} files
Next: Phase {N+1} — Shall we continue?

Run RAG compression:

HARNISH_ROOT="${CLAUDE_PLUGIN_ROOT}"
bash "$HARNISH_ROOT/scripts/compress-progress.sh" .harnish/harnish-current-work.json --trigger milestone --phase {N}

Counter-based compression (LLM tracks TASK_COMPLETE_COUNT in conversation; every 5):

HARNISH_ROOT="${CLAUDE_PLUGIN_ROOT}"
bash "$HARNISH_ROOT/scripts/compress-progress.sh" .harnish/harnish-current-work.json --trigger count

Run the above only when TASK_COMPLETE_COUNT % 5 == 0. The decision to run is the LLM's; the bash invocation itself does not check the counter.

Wait for user response → "continue" → next Phase → repeat loop. All Phases Done → completion report.

Escalation Report

🆘 Escalation: Task {ID} — {title}
Blocked at: {file/function/command}
Attempts: 1. {attempt}: {result} / 2. ... / 3. ...
Options: A. {A} / B. {B}

Prohibited Mid-Loop

The only permitted stop points inside Step 3 are:

1. Milestone HITL — at phase boundary (see "On Phase Completion")
2. Escalation — 3 consecutive acceptance_criteria failures
3. Hard guardrail violation — see Guardrails

Any other interruption is prohibited — including but not limited to:

• Asking the user for permission to continue without a blocker
• Proposing a mid-phase summary/checkpoint due to context size or task count
• Stopping because "many tasks completed" without a defined phase boundary

Context fatigue is not a stop condition. If context is tight, rely on compress-progress.sh and continue.

Step 4: Session Restore (Anchoring)

When harnish-current-work.json exists + new session starts:

HARNISH_ROOT="${CLAUDE_PLUGIN_ROOT}"
bash "$HARNISH_ROOT/scripts/validate-progress.sh" .harnish/harnish-current-work.json   # verify structure integrity
bash "$HARNISH_ROOT/scripts/loop-step.sh" .harnish/harnish-current-work.json            # extract coordinates

If Doing exists, resume from "next action" / otherwise first Todo Task. Report then → enter Step 3 loop:

🔄 Session restored
Current: Phase {N} / Task {ID} — {title}
Next: {next_action}

Step 5: Experience Accumulation

Asset Recording Criteria

Recording:

HARNISH_ROOT="${CLAUDE_PLUGIN_ROOT}"
bash "$HARNISH_ROOT/scripts/record-asset.sh" \
  --type {type} --tags "{task-id},{phase}" \
  --title "{one line}" --content "{content}" \
  --base-dir "$(pwd)/.harnish"

Manual Triggers

Step 6: Post-Completion Ceremony

Trigger: Todo empty AND no Doing AND .metadata.ceremony_done is false/missing.

Purpose: turn "all tasks done" into a deliberate closing beat — inspect, compress, summarize, suggest next — rather than a sudden STOP.

6.1 Automatic Inspection (read-only)

Invoke galmuri:ralphi (sibling plugin) on files changed since session start. Report findings inline. DO NOT auto-fix — fixing is a separate user trigger. If galmuri is not installed, skip this step and surface a one-line note ("galmuri not installed — skipping post-Done inspection").

📋 Post-Done inspection (galmuri:ralphi, read-only)
Files changed this session: {N}
Findings: {count by severity}

6.2 Asset Compression Check

Run compress-assets.sh with --dry-run. If any tag accumulated ≥ COMPRESS_EVERY_N (5) entries, suggest compression (do not auto-apply):

HARNISH_ROOT="${CLAUDE_PLUGIN_ROOT}"
bash "$HARNISH_ROOT/scripts/compress-assets.sh" --dry-run --all --base-dir "$(pwd)/.harnish"

6.3 Summary Generation

3-line summary:

✅ Session summary
Files changed: {count} ({short list})
Key decisions: {1-2 one-liners from .harnish/harnish-assets.jsonl recorded this session}
Suggested next: {e.g., galmuri:ralphi fix | deploy | handoff | sibling plugin invocation}

6.4 HITL Before Persist

"Ceremony complete. Save session summary to docs/session-{YYYY-MM-DD}.md? (y / n / edit-slug)"

• y → save + set .metadata.ceremony_done: true → STOP
• n → set .metadata.ceremony_done: true → STOP without save
• edit-slug → ask for slug, then y path

Prohibited in Step 6

• Auto-fixing galmuri:ralphi findings (report only)
• Auto-applying asset compression (suggest only)
• Modifying harnish-current-work.json beyond .metadata.ceremony_done (done object is frozen)
• Re-entering the ceremony on a session that already ran it (single-fire per session)

Context Budget

Load at most 2 references at a time. Other references must wait for a phase switch.

Guardrails

Soft (warning + correction):

• 100+ line file change → review task splitting
• Cannot declare Done without tests
• Cannot mark Done a task without acceptance_criteria
• Warning when modifying files outside current task scope

Hard (immediate STOP + escalation):

• DROP TABLE / DROP DATABASE prohibited
• Installing new packages not specified in PRD prohibited
• Inserting hardcoded secrets prohibited
• Unrelated refactoring of files outside scope prohibited
• Deleting harnish-current-work.json or directly modifying the done object prohibited
• Mid-loop interruption outside milestone HITL / 3-failure escalation / hard-guardrail violation prohibited

Termination Conditions

• Todo is empty and no Doing → Step 6 Post-Completion Ceremony → after 6.4 HITL → STOP
• User says "stop" → record current state in harnish-current-work.json → STOP
• On session end →

  HARNISH_ROOT="${CLAUDE_PLUGIN_ROOT}"
  bash "$HARNISH_ROOT/scripts/check-violations.sh" .harnish/harnish-current-work.json