/extend

Extend an existing mission with new goals, or change mission scope mid-flight. Adds new phases/tasks to the taskplan while preserving all completed work.

As of v0.4, /extend is the only scope-change command. The old /pivot skill was removed because it duplicated extend's functionality without adding value. /extend now handles both:

• Adding new goals to a completed mission ("v0.2 features after v0.1 ships")
• Modifying/extending scope mid-mission (the old /pivot use case)

Phase 0: Validate Mission State

Read .chariot/state.json.

• status: "completed" → Ideal. Reactivate and extend.
• status: "paused" → Good. Extend and resume.
• status: "running" → A runner is active. Tell the user to run /chariot:halt first, then /chariot:extend. (We can't safely modify taskplan.md while the runner is iterating over it.) STOP.
• status: "escalated" → OK. Extend with awareness of the escalated task.
• No state / "idle" → "No mission found. Run /chariot:set-mission first." STOP.

If runner_pid exists, check if alive:

kill -0 {runner_pid} 2>/dev/null && echo "ALIVE" || echo "DEAD"

If ALIVE → "Runner is active. Run /chariot:halt first." STOP.

Phase A: Context Review

Before asking about new goals, summarize what exists:

1. Read CLAUDE.md CHARIOT block → current mission, scope, tech stack
2. Read .chariot/taskplan.md → show completed vs remaining tasks
3. Read .chariot/review-log.md (last 5 entries) → recent work quality

Present to the user:

=== Current Mission ===
{mission overview}

Completed: {N}/{total} tasks
  Phase 1: {title} — {status}
  Phase 2: {title} — {status}
  ...

Tech Stack: {list}
Scope: {current scope items}
Out of Scope: {current exclusions}

What would you like to add?

Phase B: Extension Q&A

Similar to set-mission Q&A but focused on additions only. Do NOT re-ask about existing scope.

Questions to ask:

1. "What new features or goals do you want to add?"
2. "Do these new goals require any new tech stack additions?" (e.g., new API, new library)
3. "Any new out-of-scope boundaries for the extension?"
4. "Should any existing completed work be modified?" (careful — this means rework)
5. "Time limit for the extension? (default: inherit from original mission)"

Q&A Rules

• NEVER end Q&A until user explicitly approves ("start", "go", "enough", etc.)
• Keep it shorter than set-mission — the foundation already exists
• Record exchanges to .chariot/qna_history.md (append, don't overwrite)

Phase C: Generate Extension

1. Update CLAUDE.md CHARIOT block

Add new scope items to the Scope section:

## Scope
{existing items}
- [EXT] {new item 1}
- [EXT] {new item 2}

Add any new out-of-scope items. Do NOT remove existing scope or out-of-scope items.

Update Success Criteria if new goals add new criteria.

2. Append to taskplan.md

Find the last phase number and continue from there:

## Phase {N+1}: {Extension title}

### Task {N+1}.1: {title}
- **Work**: {specific items}
- **Verify**: {automatable criteria}
- **Status**: [ ]

### Task {N+1}.2: {title}
- **Work**: {specific items}
- **Verify**: {criteria}
- **Depends**: {N+1}.1
- **Status**: [ ]

Rules:

• Same task sizing as set-mission (20-60 min per task)
• New tasks can depend on previously completed tasks
• Do NOT modify completed tasks' status
• Do NOT renumber existing tasks

3. Update state.json

node -e "
const fs = require('fs');
const state = JSON.parse(fs.readFileSync('.chariot/state.json', 'utf-8'));

// Reactivate if completed
state.status = 'running';
state.fail_count = 0;
state.consecutive_fails = 0;

// Update task count
state.total_tasks = {new total};

// Set current task to first new task (or first incomplete task)
state.current_task = '{first new task id}';
state.current_phase = '{new phase id}';
state.current_task_started_at = new Date().toISOString();
state.updated_at = new Date().toISOString();

// Reset circuit breaker
state.circuit_breaker = { state: 'CLOSED', consecutive_no_change: 0, total_trips: 0 };

fs.writeFileSync('.chariot/state.json', JSON.stringify(state, null, 2) + '\n');
console.log('State updated for extension');
"

4. Commit extension

git add CLAUDE.md .chariot/taskplan.md .chariot/state.json .chariot/qna_history.md
git commit -m "chore(chariot): extend mission — {extension summary}"

Phase D: Launch Runner

Use the dedicated launcher (bin/chariot-spawn.js). It handles the state transition (status → running, plugin_root refresh, env cleanup) and the detached spawn in one call. Do NOT inline node -e blobs — zsh history expansion mangles ! characters and the spawn fails.

PLUGIN_ROOT=$(node -p "JSON.parse(require('fs').readFileSync('.chariot/state.json','utf-8')).plugin_root")
node "$PLUGIN_ROOT/bin/chariot-spawn.js"

Display:

══════════════════════════════════════════════════════════
 CHARIOT EXTENSION STARTED
══════════════════════════════════════════════════════════

 Extended with: {N} new tasks across {M} new phases
 Total progress: {completed}/{new total}
 Starting from: Task {first new task}
 Runner PID: {pid}
 Log: .chariot/runner.log

 Commands:
   /chariot:status     — Check progress
   /chariot:halt       — Pause execution
   tail -f .chariot/runner.log  — Live log

 You can close this session safely.
══════════════════════════════════════════════════════════

Step 5: Done

STOP. Do not start any implementation work. The runner handles everything.