# Procedural Custom Steps — Implementation Plan

> **For Claude:** REQUIRED SUB-SKILL: Use superpowers:executing-plans to implement this plan task-by-task.

**Goal:** Add "Add Custom Step" support to `ProceduralNavigationPage` so engineers can insert ad-hoc steps between existing checklist items during a session.

**Architecture:** Introduce a `RuntimeStep = ProceduralStep | CustomProceduralStep` discriminated union type. `ProceduralNavigationPage` grows new state + handlers for the custom-step modal flow (reusing `CustomStepModal` and `PostStepActionModal` as-is). `StepChecklist` and `StepDetail` accept `RuntimeStep` instead of `ProceduralStep`. No backend changes needed.

**Tech Stack:** React 19, TypeScript, Tailwind CSS, existing `sessionsApi.update`, `CustomStepModal`, `PostStepActionModal`

---

### Task 1: Add `RuntimeStep` union type

**Files:**
- Modify: `frontend/src/types/tree.ts`
- Modify: `frontend/src/types/index.ts` (re-export if needed)

**Context:** `ProceduralStep` is already in `tree.ts` along with `CommandBlock`. The new `CustomProceduralStep` interface lives in the same file. No hook needed — this is purely a type.

**Step 1: Add the types at the bottom of `frontend/src/types/tree.ts`**

After the existing `ProceduralStep` interface (line ~124), add:

```ts
export interface CustomProceduralStep {
  id: string
  type: 'procedure_step'
  title: string
  description?: string
  content_type: 'action'
  commands?: CommandBlock[]
  isCustom: true
}

export type RuntimeStep = ProceduralStep | CustomProceduralStep
```

**Step 2: Export from `frontend/src/types/index.ts`**

Check what is currently re-exported from `tree.ts` in `index.ts` and add `CustomProceduralStep` and `RuntimeStep` to the export list.

Run: `cd frontend && npm run build 2>&1 | tail -20`
Expected: no new type errors

**Step 3: Commit**

```bash
git add frontend/src/types/tree.ts frontend/src/types/index.ts
git commit -m "feat: add RuntimeStep union type for procedural custom steps

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>"
```

---

### Task 2: Update `StepChecklist` to accept `RuntimeStep[]`

**Files:**
- Modify: `frontend/src/components/procedural/StepChecklist.tsx`

**Context:** Currently `StepChecklistProps.steps` is `ProceduralStep[]`. It filters internally for `type === 'procedure_step'`. Custom steps already have `type: 'procedure_step'` so the filter still works. We need to:
1. Change prop type to `RuntimeStep[]`
2. Render an amber "Custom" badge next to custom step titles

**Step 1: Update the import and prop type**

Change:
```tsx
import type { ProceduralStep } from '@/types'
```
To:
```tsx
import type { RuntimeStep } from '@/types'
```

Change `StepChecklistProps`:
```tsx
interface StepChecklistProps {
  steps: RuntimeStep[]
  currentStepIndex: number
  completedStepIds: Set<string>
  onStepClick: (index: number) => void
}
```

**Step 2: Add the "Custom" badge in the step row**

In the button's `<span className="min-w-0 flex-1 truncate">` row, add a badge after the title when `'isCustom' in step && step.isCustom`:

```tsx
<span className="min-w-0 flex-1 flex items-center gap-1.5 truncate">
  <span className="truncate">{step.title || 'Untitled step'}</span>
  {'isCustom' in step && step.isCustom && (
    <span className="shrink-0 rounded-full bg-amber-400/15 px-1.5 py-0.5 text-[9px] font-semibold uppercase tracking-wide text-amber-400">
      Custom
    </span>
  )}
</span>
```

**Step 3: Build check**

Run: `cd frontend && npm run build 2>&1 | tail -20`
Expected: no new errors

**Step 4: Commit**

```bash
git add frontend/src/components/procedural/StepChecklist.tsx
git commit -m "feat: StepChecklist accepts RuntimeStep[], renders amber Custom badge

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>"
```

---

### Task 3: Update `StepDetail` to accept `RuntimeStep`

**Files:**
- Modify: `frontend/src/components/procedural/StepDetail.tsx`

**Context:** `StepDetail` currently only accepts `ProceduralStep`. For `CustomProceduralStep`, we skip the `content_type` badge (show "Custom Step" label instead), hide `warning_text`/`expected_outcome`/`verification`/`reference_url` sections (they don't exist on custom steps), and show description + commands normally. The `canComplete()` check and Mark Complete button stay the same.

**Step 1: Update import and prop type**

```tsx
import type { RuntimeStep, CommandBlock } from '@/types'
```

Change `StepDetailProps`:
```tsx
interface StepDetailProps {
  step: RuntimeStep
  // ... rest unchanged
}
```

**Step 2: Handle custom step header (replace content_type badge block)**

The existing header block uses `step.content_type` to pick a config. Add a guard:

```tsx
// At top of component body, after existing state:
const isCustom = 'isCustom' in step && step.isCustom

// In the header JSX, replace the content_type badge span:
{isCustom ? (
  <span className="inline-flex items-center gap-1 rounded-full bg-amber-400/15 px-2 py-0.5 text-xs text-amber-400">
    ✦ Custom Step
  </span>
) : (
  <span className={cn('inline-flex items-center gap-1 rounded-full px-2 py-0.5 text-xs', config.bg, config.color)}>
    <Icon className="h-3 w-3" />
    {config.label}
  </span>
)}
```

Note: `contentType` and `config` are still computed but only used in the non-custom branch. TypeScript will be happy because `ProceduralStep` has `content_type` and custom step skips that branch.

**Step 3: Guard sections that don't exist on custom steps**

Sections that need guarding (wrap with `!isCustom &&`):
- `{step.warning_text && ...}` — already implicitly guarded since `CustomProceduralStep` has no `warning_text`, but TypeScript may complain → add `!isCustom &&` before the expression
- `{step.expected_outcome && ...}` — same
- `{verificationPrompt && ...}` — same (derive `verificationPrompt` with `!isCustom &&` check)
- `{step.reference_url && ...}` — same

The description block, commandBlocks block, and notes block all work fine as-is (custom steps have `description?` and `commands?` matching the normalized shapes).

Specifically, for `verificationPrompt` / `verificationType`:
```tsx
const verificationPrompt = isCustom ? undefined : (step.verification_prompt || step.verification?.prompt)
const verificationType = isCustom ? undefined : (step.verification_type || step.verification?.type)
```

For `commandBlocks` normalization — `CustomProceduralStep.commands` is `CommandBlock[]` already, so the existing ternary handles it fine.

**Step 4: Build check**

Run: `cd frontend && npm run build 2>&1 | tail -20`
Expected: no errors

**Step 5: Commit**

```bash
git add frontend/src/components/procedural/StepDetail.tsx
git commit -m "feat: StepDetail accepts RuntimeStep, renders Custom Step badge for custom steps

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>"
```

---

### Task 4: Wire custom step flow into `ProceduralNavigationPage`

**Files:**
- Modify: `frontend/src/pages/ProceduralNavigationPage.tsx`

**Context:** This is the main task. Current page has no custom step support. We add:
- `runtimeSteps: RuntimeStep[]` state (replaces `procedureSteps` derived value)
- `sessionCustomSteps: CustomStep[]` state
- `showCustomStepModal`, `showPostStepModal`, `pendingCustomStep`, `pendingIsFromLibrary`, `isSavingStep` state
- `handleStepCreated` — closes CustomStepModal, opens PostStepActionModal
- `handleInsertCustomStep` — builds CustomProceduralStep, inserts into runtimeSteps, persists
- `handleSaveForLater` / `handleUseNow` / `handleBoth` — wire PostStepActionModal buttons
- "Add Step" button below StepDetail, above StepFeedback
- Resume: inject custom steps at correct positions

**Step 1: Add new imports**

```tsx
import { CustomStepModal } from '@/components/step-library/CustomStepModal'
import { PostStepActionModal } from '@/components/session/PostStepActionModal'
import type { RuntimeStep, CustomProceduralStep } from '@/types'
import type { CustomStep } from '@/types/session'
import type { Step } from '@/types/step'
import type { CustomStepDraft } from '@/components/step-library/CustomStepModal'
import { Plus } from 'lucide-react'
import { v4 as uuidv4 } from 'uuid'
```

Check if `uuid` package is already available: `grep -r "from 'uuid'" frontend/src/`. If not, use `crypto.randomUUID()` instead (available in all modern browsers and Node 16+).

**Step 2: Add new state (after existing state declarations)**

```tsx
const [runtimeSteps, setRuntimeSteps] = useState<RuntimeStep[]>([])
const [sessionCustomSteps, setSessionCustomSteps] = useState<CustomStep[]>([])
const [showCustomStepModal, setShowCustomStepModal] = useState(false)
const [showPostStepModal, setShowPostStepModal] = useState(false)
const [pendingCustomStep, setPendingCustomStep] = useState<Step | CustomStepDraft | null>(null)
const [pendingIsFromLibrary, setPendingIsFromLibrary] = useState(false)
const [isSavingStep, setIsSavingStep] = useState(false)
```

**Step 3: Replace `procedureSteps` derivation**

Currently:
```tsx
const procedureSteps = steps.filter((s) => s.type === 'procedure_step')
```

Replace with:
```tsx
// runtimeSteps is the authoritative list; filter for rendering (excludes section_headers)
const procedureSteps = runtimeSteps.filter((s) => s.type === 'procedure_step')
```

Also update `estimatedTotalMinutes` — it only sums `estimated_minutes` which only exists on `ProceduralStep`. Cast safely:
```tsx
const estimatedTotalMinutes = procedureSteps.reduce(
  (sum, step) => sum + (('estimated_minutes' in step ? step.estimated_minutes : undefined) || 0),
  0
)
```

**Step 4: Initialize `runtimeSteps` in `startSession`**

After `setSession(newSession)`, add:
```tsx
// Initialize runtimeSteps from tree steps
const allSteps = getStepsFromTree(tree!)
setRuntimeSteps(allSteps)
setSessionCustomSteps([])
```

The existing step state initialization loop stays the same — custom steps will add to it when inserted.

**Step 5: Initialize `runtimeSteps` in `resumeSession`**

After loading `sessionData`, before computing `pSteps`:
```tsx
// Build runtimeSteps: start with tree steps, then inject custom steps
const allSteps = getStepsFromTree(treeData)
const customSteps = sessionData.custom_steps || []
setSessionCustomSteps(customSteps)

// Inject custom steps at correct positions
const hydrated = buildRuntimeSteps(allSteps, customSteps)
setRuntimeSteps(hydrated)
```

And update the `pSteps` / `firstIncomplete` calculation to use `hydrated` (not `allSteps`):
```tsx
const pSteps = hydrated.filter((s) => s.type === 'procedure_step')
const firstIncomplete = pSteps.findIndex((s) => !initialStates.get(s.id)?.completedAt)
setCurrentStepIndex(firstIncomplete >= 0 ? firstIncomplete : pSteps.length - 1)
```

**Step 6: Add `buildRuntimeSteps` helper**

Add this function before the component (or as a module-level utility):

```ts
function buildRuntimeSteps(baseSteps: ProceduralStep[], customSteps: CustomStep[]): RuntimeStep[] {
  const result: RuntimeStep[] = [...baseSteps]
  // Sort custom steps by timestamp so earlier insertions come first if multiple
  const sorted = [...customSteps].sort((a, b) => a.timestamp.localeCompare(b.timestamp))
  for (const cs of sorted) {
    // Find the index of the step this was inserted after
    const afterIdx = result.findIndex((s) => s.id === cs.inserted_after_node_id)
    const insertAt = afterIdx >= 0 ? afterIdx + 1 : result.length
    const runtimeCustom: CustomProceduralStep = {
      id: cs.id,
      type: 'procedure_step',
      title: cs.step_data.title,
      description: cs.step_data.content?.instructions,
      content_type: 'action',
      commands: cs.step_data.content?.commands?.map((c) => ({
        code: c.command,
        label: c.label,
      })),
      isCustom: true,
    }
    result.splice(insertAt, 0, runtimeCustom)
  }
  return result
}
```

Note: `ProceduralStep` needs to be imported in scope here. Since it's used in `getStepsFromTree` already, it's available.

**Step 7: Add `handleStepCreated`**

```tsx
const handleStepCreated = (step: Step | CustomStepDraft, isFromLibrary: boolean) => {
  setPendingCustomStep(step)
  setPendingIsFromLibrary(isFromLibrary)
  setShowCustomStepModal(false)
  setShowPostStepModal(true)
}
```

**Step 8: Add `handleInsertCustomStep`**

```tsx
const handleInsertCustomStep = async (step: Step | CustomStepDraft) => {
  if (!session) return

  const id = crypto.randomUUID()
  const currentStep = procedureSteps[currentStepIndex]
  const insertedAfterId = currentStep?.id ?? ''

  // Build the runtime representation
  const runtimeCustom: CustomProceduralStep = {
    id,
    type: 'procedure_step',
    title: step.title,
    description: step.content?.instructions,
    content_type: 'action',
    commands: step.content?.commands?.map((c) => ({
      code: c.command,
      label: c.label,
    })),
    isCustom: true,
  }

  // Insert after currentStepIndex in runtimeSteps
  setRuntimeSteps((prev) => {
    const next = [...prev]
    // Find the global index of the current procedureStep in runtimeSteps
    const globalIdx = next.findIndex((s) => s.id === insertedAfterId)
    const insertAt = globalIdx >= 0 ? globalIdx + 1 : next.length
    next.splice(insertAt, 0, runtimeCustom)
    return next
  })

  // Initialize step state for the new step
  setStepStates((prev) => {
    const next = new Map(prev)
    next.set(id, { notes: '', verificationValue: '', completedAt: null })
    return next
  })

  // Persist to session
  const newCustomStep: CustomStep = {
    id,
    inserted_after_node_id: insertedAfterId,
    step_data: step,
    timestamp: new Date().toISOString(),
  }
  const newCustomSteps = [...sessionCustomSteps, newCustomStep]
  setSessionCustomSteps(newCustomSteps)

  try {
    await sessionsApi.update(session.id, { custom_steps: newCustomSteps })
  } catch {
    toast.error('Failed to save custom step')
  }

  // Advance to the new step (it's now at currentStepIndex + 1)
  setCurrentStepIndex(currentStepIndex + 1)
}
```

**Step 9: Add `handleSaveForLater`, `handleUseNow`, `handleBoth`**

```tsx
const handleSaveForLater = async () => {
  if (!pendingCustomStep || pendingIsFromLibrary) return
  setIsSavingStep(true)
  try {
    await stepsApi.create({
      title: pendingCustomStep.title,
      step_type: pendingCustomStep.step_type,
      content: pendingCustomStep.content,
      visibility: 'private',
    })
    toast.success('Step saved to library')
  } catch {
    toast.error('Failed to save step')
  } finally {
    setIsSavingStep(false)
    setShowPostStepModal(false)
    setPendingCustomStep(null)
  }
}

const handleUseNow = async () => {
  if (!pendingCustomStep) return
  setShowPostStepModal(false)
  await handleInsertCustomStep(pendingCustomStep)
  setPendingCustomStep(null)
}

const handleBoth = async () => {
  if (!pendingCustomStep || pendingIsFromLibrary) return
  setIsSavingStep(true)
  try {
    await stepsApi.create({
      title: pendingCustomStep.title,
      step_type: pendingCustomStep.step_type,
      content: pendingCustomStep.content,
      visibility: 'private',
    })
  } catch {
    toast.error('Failed to save step to library')
  } finally {
    setIsSavingStep(false)
  }
  setShowPostStepModal(false)
  await handleInsertCustomStep(pendingCustomStep)
  setPendingCustomStep(null)
}
```

Add `stepsApi` import at the top: `import { stepsApi } from '@/api/steps'`

**Step 10: Update `handleMarkComplete` to use `runtimeSteps`-based `procedureSteps`**

The existing `handleMarkComplete` reads `procedureSteps[currentStepIndex]` — since `procedureSteps` is now derived from `runtimeSteps`, this Just Works. But the completion check `currentStepIndex >= procedureSteps.length - 1` also works correctly.

No changes needed to `handleMarkComplete` itself.

**Step 11: Update `StepChecklist` call in JSX**

Change `steps={steps}` to `steps={runtimeSteps}`:
```tsx
<StepChecklist
  steps={runtimeSteps}
  currentStepIndex={currentStepIndex}
  completedStepIds={completedStepIds}
  onStepClick={setCurrentStepIndex}
/>
```

**Step 12: Update `StepDetail` call + add "Add Step" button**

Change `step={currentStep}` prop type is now `RuntimeStep` (TypeScript satisfied since `procedureSteps` is `RuntimeStep[]`).

Change `totalSteps={procedureSteps.length}` — still correct.

After the `StepDetail` closing tag and before `StepFeedback`, add the "Add Step" button:

```tsx
{/* Add Custom Step button — only on current active (incomplete) step, not on custom steps */}
{currentStep && !completedStepIds.has(currentStep.id) && !('isCustom' in currentStep && currentStep.isCustom) && (
  <div className="mt-4">
    <button
      onClick={() => setShowCustomStepModal(true)}
      className="flex w-full items-center justify-center gap-2 rounded-lg border border-dashed border-border px-4 py-2.5 text-sm text-muted-foreground transition-colors hover:border-primary/50 hover:text-foreground"
    >
      <Plus className="h-4 w-4" />
      Add Step
    </button>
  </div>
)}
```

**Step 13: Add modals at the bottom of the JSX (before closing `</div>`)**

After the `ConfirmDialog` and parameters popover, add:

```tsx
{/* Custom Step Modal */}
<CustomStepModal
  isOpen={showCustomStepModal}
  onClose={() => setShowCustomStepModal(false)}
  onInsertStep={handleStepCreated}
/>

{/* Post Step Action Modal */}
{pendingCustomStep && (
  <PostStepActionModal
    isOpen={showPostStepModal}
    onClose={() => { setShowPostStepModal(false); setPendingCustomStep(null) }}
    step={pendingCustomStep}
    onSaveForLater={handleSaveForLater}
    onUseNow={handleUseNow}
    onBoth={handleBoth}
    isFromLibrary={pendingIsFromLibrary}
    isSaving={isSavingStep}
  />
)}
```

**Step 14: ProgressBar total count update**

The `ProgressBar` already uses `procedureSteps.length` as `totalSteps` which is derived from `runtimeSteps` — so the progress bar total automatically updates when custom steps are inserted.

**Step 15: Build check**

Run: `cd frontend && npm run build 2>&1 | tail -30`
Expected: no errors. Watch especially for:
- `CustomStep` import (it's in `@/types/session`, not `@/types` — import directly if needed)
- `buildRuntimeSteps` needing `ProceduralStep` type explicitly imported

**Step 16: Commit**

```bash
git add frontend/src/pages/ProceduralNavigationPage.tsx
git commit -m "feat: custom step insertion in procedural flow sessions

Engineers can add custom steps inline during execution. Steps are
persisted to session.custom_steps and restored on resume.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>"
```

---

### Task 5: Manual verification checklist

**No code changes — verification only.**

Start a procedural session (or maintenance session). Verify:

1. **Add Step button appears** below the current step detail on an active, incomplete, non-custom step
2. **Add Step button is hidden** on completed steps
3. **Clicking Add Step** opens `CustomStepModal` with Create + Browse Library tabs
4. **Creating a step** → `PostStepActionModal` appears
5. **"Use Now"** → closes modal, custom step appears as next step in checklist with amber "Custom" badge, current view advances to it
6. **"Save for Later"** → closes modal, nothing inserted, no crash
7. **"Do Both"** → saves to library AND inserts
8. **Mark Complete on custom step** → advances to next step normally
9. **Custom step in StepDetail** → shows "Custom Step" amber badge instead of content_type badge
10. **Progress bar total** increments when custom step is inserted
11. **Resume session** (navigate away and back with `{ state: { sessionId } }`) → custom step reappears at correct position in checklist

---

### Task 6: Final build validation

Run: `cd frontend && npm run build`
Expected: build succeeds with zero errors (pre-existing chunk-size warnings are fine).

Commit build validation result if no issues:

```bash
git add -p  # stage any incidental fixes
git commit -m "chore: final build validation for procedural custom steps

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>"
```

Only commit if there were actual changes to stage.