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+# Parameterize & Save — Script Library Integration
+
+> **Date:** 2026-03-29
+> **Status:** Approved
+> **Scope:** Fix AI-generated scripts saving to library without parameters; add parameter detection/review to save flow; add "New from Script" paste entry point
+
+---
+
+## Problem
+
+When the AI Script Builder generates a script and the user saves it to the Script Library:
+
+1. **`parameters_schema` is hardcoded to `{"parameters": []}`** in `save_to_library()` — no parameter detection runs
+2. **The script body uses raw PowerShell `param()` syntax**, not the `{{ key }}` template placeholders that `ScriptTemplateEngine.render()` expects
+
+The result: saved templates have no parameters and can't be rendered with user-provided values. The template engine has nothing to substitute.
+
+The frontend already has working parameter detection (`scriptParameterDetector.ts`) and a review UI (`ParameterDetectorStepper`), but they're only wired into `ScriptTemplateEditor` — not the save-to-library flow.
+
+## Solution
+
+A shared `ParameterizeAndSavePanel` component that:
+
+1. Shows the script with live preview of `{{ }}` replacements
+2. Auto-runs parameter detection and lets the user review/accept/skip each candidate
+3. Collects minimal metadata (name, description, category, share toggle)
+4. Sends the rewritten script body + built parameters schema to the backend
+
+Used in two entry points:
+- **AI Script Builder** — replaces the current `SaveToLibraryDialog`
+- **Script Library page** — "New from Script" button for pasting raw scripts
+
+> **Note:** Parameter detection currently supports PowerShell only. Bash and Python scripts will show "No parameters detected" and save as-is. Detection for those languages is planned for a future iteration.
+
+---
+
+## Design
+
+### `ParameterizeAndSavePanel` Component
+
+A slide-in panel from the right, ~480px wide, semi-transparent scrim behind it. Close via X button or scrim click.
+
+**Layout (top to bottom):**
+
+1. **Script Preview** — read-only code block showing the script body. As parameters are accepted via the stepper, the preview updates live to show `{{ key }}` replacements highlighted in amber.
+
+2. **Parameter Detection Zone** — auto-runs `detectParameterCandidates()` when the panel opens.
+   - If candidates found: renders the existing `ParameterDetectorStepper` inline
+   - If no candidates found: shows "No parameters detected — script will be saved as-is"
+
+3. **Metadata Fields** — name (required), description, category dropdown, share-with-team toggle. Same fields as the current `SaveToLibraryDialog`.
+
+4. **Save Button** — sends rewritten script body + parameters schema + metadata to the backend.
+
+**Two modes controlled by props:**
+
+- **`script` mode** (from AI builder): script body + language provided, skips straight to preview + detection
+- **`paste` mode** (from library page): shows a textarea + language picker at the top of the panel, above the preview area. Once pasted and confirmed, textarea collapses into the read-only preview and detection runs.
+
+**State:** Local React state (not Zustand). Tracks:
+- `workingScript`: the in-progress script body, mutated as candidates are accepted
+- `parametersSchema`: accumulated `ScriptParameter[]` array
+- `metadata`: name, description, categoryId, shareWithTeam
+- `mode`: paste vs script (derived from props)
+
+### Entry Point 1: AI Script Builder
+
+`ScriptBuilderPage` currently opens `SaveToLibraryDialog`. Replace with `ParameterizeAndSavePanel` in `script` mode.
+
+**Props:**
+- `scriptBody`: `session.latest_script`
+- `language`: `session.language`
+- `defaultName`: suggested filename minus extension
+- `onSave`: calls `scriptBuilderApi.saveToLibrary()` with enriched payload
+- `onClose`: closes the panel
+
+### Entry Point 2: Script Library Page
+
+Add a "New from Script" button on `ScriptLibraryPage` (near the "Manage Templates" link). Opens `ParameterizeAndSavePanel` in `paste` mode.
+
+**Props:**
+- `scriptBody`: `undefined` (triggers paste mode)
+- `language`: `undefined` (user picks in the panel)
+- `onSave`: calls `scriptsApi.createTemplate()` directly
+- `onClose`: closes the panel
+
+### Backend Changes
+
+**`SaveToLibraryRequest` schema** (`backend/app/schemas/script_builder.py`):
+
+Add two optional fields:
+```python
+script_body: str | None = None        # Rewritten script with {{ }} placeholders
+parameters_schema: dict | None = None  # Built parameter schema from frontend
+```
+
+**`save_to_library()` service** (`backend/app/services/script_builder_service.py`):
+
+Add `script_body: str | None = None` and `parameters_schema: dict | None = None` to the function signature. Use provided values instead of hardcoding:
+```python
+template = ScriptTemplate(
+    ...
+    script_body=script_body or session.latest_script,
+    parameters_schema=parameters_schema or {"parameters": []},
+    ...
+)
+```
+
+**`save_to_library` endpoint** (`backend/app/api/endpoints/script_builder.py`):
+
+Pass `data.script_body` and `data.parameters_schema` from the request through to the service function.
+
+**No new endpoints needed.** The library paste flow uses the existing `POST /scripts/templates` which already accepts `script_body` + `parameters_schema`.
+
+### Script Rewriting Logic
+
+The `ParameterizeAndSavePanel` reuses the same approach as `ScriptTemplateEditor.handleAcceptCandidate()`:
+
+When a candidate is accepted:
+1. Find the matched line in the working script
+2. Replace the default value portion with `'{{ key }}'`
+3. Add the parameter to the accumulated schema
+
+This happens in the panel's local state. The stepper emits accept/skip events; the panel handles the rewriting.
+
+---
+
+## File Changes
+
+### New Files
+- `frontend/src/components/scripts/ParameterizeAndSavePanel.tsx` — shared panel component
+
+### Modified Files
+- `frontend/src/pages/ScriptBuilderPage.tsx` — replace `SaveToLibraryDialog` with `ParameterizeAndSavePanel` (script mode)
+- `frontend/src/pages/ScriptLibraryPage.tsx` — add "New from Script" button, render `ParameterizeAndSavePanel` (paste mode)
+- `backend/app/schemas/script_builder.py` — add `script_body` and `parameters_schema` to `SaveToLibraryRequest`
+- `backend/app/services/script_builder_service.py` — use provided values in `save_to_library()`
+- `backend/app/api/endpoints/script_builder.py` — pass new fields through
+
+### Deleted Files
+- `frontend/src/components/script-builder/SaveToLibraryDialog.tsx` — replaced entirely
+
+### Unchanged (reused as-is)
+- `frontend/src/components/script-editor/ParameterDetectorStepper.tsx`
+- `frontend/src/lib/scriptParameterDetector.ts`
+- `frontend/src/components/script-editor/ScriptTemplateEditor.tsx`
+- `POST /scripts/templates` endpoint
+
+---
+
+## Scope Boundaries
+
+**In scope:**
+- `ParameterizeAndSavePanel` component with script/paste modes
+- Parameter detection + stepper review in the save flow
+- Script body rewriting with `{{ }}` placeholders
+- Backend accepting enriched save payload
+- "New from Script" button on library page
+- PowerShell parameter detection only
+
+**Out of scope:**
+- Bash/Python parameter detection (future iteration)
+- Changes to `ScriptTemplateEditor` or `ParameterSchemaBuilder`
+- Changes to `ScriptTemplateEngine` rendering logic
+- New API endpoints