Fix potential timeline hangs from cycles and refresh cascades

Add cycle detection and O(n) path building to getAllBranches, and a
concurrency guard on timeline refresh to drop overlapping calls.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.gitignore

@@ -1,2 +1,3 @@
 __pycache__/
 *.pyc
+data/

README.md

@@ -5,13 +5,13 @@
 <p align="center">
   <a href="https://registry.comfy.org/publishers/ethanfel/nodes/comfyui-snapshot-manager"><img src="https://img.shields.io/badge/ComfyUI-Registry-blue?logo=data:image/svg%2bxml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHZpZXdCb3g9IjAgMCAyNCAyNCI+PHBhdGggZD0iTTEyIDJMMyA3djEwbDkgNSA5LTVWN2wtOS01eiIgZmlsbD0id2hpdGUiLz48L3N2Zz4=" alt="ComfyUI Registry"/></a>
   <a href="LICENSE"><img src="https://img.shields.io/badge/license-MIT-green" alt="MIT License"/></a>
-  <img src="https://img.shields.io/badge/version-1.0.0-blue" alt="Version"/>
+  <img src="https://img.shields.io/badge/version-3.0.0-blue" alt="Version"/>
   <img src="https://img.shields.io/badge/ComfyUI-Extension-purple" alt="ComfyUI Extension"/>
 </p>
 
 ---
 
-**Workflow Snapshot Manager** automatically captures your ComfyUI workflow as you edit. Browse, name, search, and restore any previous version from a sidebar panel — all stored locally in your browser's IndexedDB.
+**Workflow Snapshot Manager** automatically captures your ComfyUI workflow as you edit. Browse, name, search, and restore any previous version from a sidebar panel — stored as JSON files on the server, accessible from any browser.
 
 <p align="center">
   <img src="assets/sidebar-preview.png" alt="Sidebar Preview" width="300"/>
@@ -23,11 +23,25 @@
 - **Custom naming** — Name your snapshots when taking them manually ("Before merge", "Working v2", etc.)
 - **Search & filter** — Quickly find snapshots by name with the filter bar
 - **Restore or Swap** — Open a snapshot as a new workflow, or replace the current one in-place
+- **Workflow browser** — Browse and recover snapshots from any workflow, including renamed or deleted ones
 - **Per-workflow storage** — Each workflow has its own independent snapshot history
 - **Theme-aware UI** — Adapts to light and dark ComfyUI themes
 - **Toast notifications** — Visual feedback for save, restore, and error operations
+- **SaveSnapshot node** — Trigger snapshot captures from your workflow with a custom node; node snapshots are visually distinct (purple border + "Node" badge) and have their own rolling limit
+- **Change-type icons** — Timeline markers show what kind of change each snapshot represents (node add, remove, connection, parameter, move, mixed) with distinct colored icons — like Fusion 360's operation timeline
+- **Timeline bar** — Optional centered floating bar on the canvas showing all snapshots as iconic markers, with a Snapshot button for quick captures; tucks behind the sidebar when open
+- **Active & current markers** — When you swap to a snapshot, the timeline highlights where you came from (green dot) and where you are (white ring)
+- **Auto-save before swap** — Swapping to an older snapshot automatically saves your current state first, so you can always get back; browsing between saved snapshots skips redundant saves
+- **Ctrl+S shortcut** — Press Ctrl+S (or Cmd+S on Mac) to take a manual snapshot alongside ComfyUI's own save
+- **SVG graph previews** — Hover any snapshot for a tooltip preview of the workflow graph; click the eye button for a full-size modal; diff view now shows side-by-side SVG comparison with color-coded highlights (green = added, red = removed, amber = modified)
+- **Diff view** — Compare any snapshot against the current workflow (one click) or two snapshots against each other (Shift+click to set base); see added/removed/modified nodes, widget value changes, and rewired connections in a single modal
+- **Snapshot branching** — Swap to an old snapshot and edit to fork into a new branch; navigate between branches with `< 1/3 >` arrows at fork points in the sidebar and timeline, like ChatGPT conversation branching
+- **Profile manager** — Save and load named sets of workflows as session profiles (like browser tab groups); profiles track which workflows you visited and restore the latest snapshot for each
+- **Hide auto-saves** — Toggle button next to the search bar hides auto-save snapshots to reduce clutter while keeping manual, locked, and node-triggered snapshots visible
+- **Lock/pin snapshots** — Protect important snapshots from auto-pruning and "Clear All" with a single click
 - **Concurrency-safe** — Lock guard prevents double-click issues during restore
-- **Zero backend** — Pure frontend extension, no server dependencies
+- **Server-side storage** — Snapshots persist on the ComfyUI server's filesystem, accessible from any browser
+- **Automatic migration** — Existing IndexedDB snapshots are imported to the server on first load
 
 ## Installation
 
@@ -64,28 +78,166 @@ Use the filter bar at the top of the panel to search snapshots by name. The clea
 
 ### 5. Restore or Swap
 
-Each snapshot has two action buttons:
+Each snapshot has action buttons:
 
 | Button | Action |
 |--------|--------|
+| **Preview** (eye icon) | Opens a full-size SVG preview of the workflow graph |
+| **Lock** | Toggles lock protection (padlock icon) |
 | **Swap** | Replaces the current workflow in-place (same tab) |
 | **Restore** | Opens the snapshot as a new workflow |
 
-### 6. Delete & Clear
+### 6. Lock / Pin Snapshots
 
-- Click **&times;** on any snapshot to delete it individually
-- Click **Clear All Snapshots** in the footer to remove all snapshots for the current workflow (with confirmation dialog)
+Click the **padlock icon** on any snapshot to lock it. Locked snapshots are protected from:
+
+- **Auto-pruning** — When the snapshot count exceeds the max, only unlocked snapshots are pruned
+- **Clear All** — Locked snapshots survive bulk deletion (the toast reports how many were kept)
+
+To unlock, click the padlock again. Deleting a locked snapshot individually is still possible but requires confirmation.
+
+### 7. Browse Other Workflows
+
+Click the **workflow name** below the header to expand the workflow picker. It lists every workflow that has snapshots in the database, with counts. Click any workflow to view its snapshots — an amber banner confirms you're viewing a different workflow, and "Take Snapshot" is disabled to avoid confusion. Click **Back to current** to return.
+
+This is especially useful for recovering snapshots from workflows that were renamed or deleted.
+
+### 8. Timeline Bar
+
+Enable the timeline in **Settings > Snapshot Manager > Timeline > Show snapshot timeline on canvas**. A centered floating bar appears at the bottom of the canvas with an iconic marker for each snapshot — each icon shows what kind of change the snapshot represents:
+
+<p align="center">
+  <img src="assets/timeline-icons.svg" alt="Timeline change-type icons" width="720"/>
+</p>
+
+| Icon | Color | Change Type |
+|------|-------|-------------|
+| Filled circle | Blue | **Initial** — first snapshot after load |
+| Plus **+** | Green | **Node Add** — nodes were added |
+| Minus **−** | Red | **Node Remove** — nodes were removed |
+| Zigzag | Amber | **Connection** — links/wires changed |
+| Wave | Purple | **Param** — widget values changed |
+| Arrows ↕ | Gray | **Move** — nodes repositioned |
+| Star ✱ | Orange | **Mixed** — multiple change types |
+| Faded dot | Gray | **Unknown** — legacy snapshot or no detected change |
+
+Additional marker styles are layered on top of the change-type icon:
+
+| Overlay | Meaning |
+|---------|---------|
+| **Purple background** | Node-triggered snapshot (overrides change-type color) |
+| **Yellow border** | Locked snapshot |
+| **White ring (larger)** | Active — the snapshot you swapped TO |
+| **Green background** | Current — your auto-saved state before the swap |
+
+Click any marker to swap to that snapshot. Hover to see a tooltip with the snapshot name, time, and change description. The **Snapshot** button on the right takes a quick manual snapshot. The bar is centered at 80% width to clear both the sidebar icon strip and bottom-right controls, and tucks behind the sidebar panel when it's open.
+
+The sidebar list also shows the change type in the meta line below each snapshot (e.g., "5 nodes · Parameters changed").
+
+### 9. Auto-save Before Swap
+
+When you swap to an older snapshot (via the sidebar or timeline), the extension automatically captures a "Current" snapshot of your work-in-progress first. This green-marked snapshot appears on the timeline so you can click it to get back. The marker disappears once you edit the graph (since auto-capture creates a proper snapshot at that point). Browsing between existing snapshots does not create additional "Current" entries — the auto-save only triggers on the first swap away from unsaved work.
+
+### 10. Keyboard Shortcut
+
+Press **Ctrl+S** (or **Cmd+S** on Mac) to take a manual snapshot. This works alongside ComfyUI's own workflow save — both fire simultaneously.
+
+### 11. Delete & Clear
+
+- Click **&times;** on any snapshot to delete it individually (locked snapshots prompt for confirmation)
+- Click **Clear All Snapshots** in the footer to remove all unlocked snapshots for the current workflow (locked snapshots are preserved)
+
+### 12. Diff View
+
+Compare two snapshots — or a snapshot against the current workflow — to see exactly what changed without touching the graph.
+
+**One-click (vs current workflow):** Click **Diff** on any snapshot to see what changed between that snapshot and your current live workflow.
+
+**Two-snapshot compare:** **Shift+click** **Diff** on snapshot A to set it as the base (purple outline + toast confirmation), then click **Diff** on snapshot B to compare A → B. The base clears after comparison.
+
+The diff modal shows:
+
+| Section | Details |
+|---------|---------|
+| **SVG comparison** | Side-by-side graph previews at the top — base on the left, target on the right, with highlighted nodes (green = added, red = removed, amber = modified) |
+| **Summary pills** | Colored counts — green (added), red (removed), amber (modified), blue (links) |
+| **Added Nodes** | Nodes present in the target but not the base |
+| **Removed Nodes** | Nodes present in the base but not the target |
+| **Modified Nodes** | Nodes with changed position, size, title, mode, widget values, or properties — each change shown as old (red strikethrough) → new (green) |
+| **Link Changes** | Added/removed connections with node names and slot indices |
+
+Sections are collapsible (click the header to toggle). If the two snapshots are identical, a "No differences found." message is shown. Dismiss the modal with **Escape**, the **X** button, or by clicking outside.
+
+### 13. SVG Graph Previews
+
+Visually inspect any snapshot without restoring or swapping it.
+
+**Hover tooltip:** Hover over any snapshot in the sidebar list. After 200ms, a small SVG preview appears next to the item showing the graph layout with nodes, links, and groups. Move the mouse away to dismiss.
+
+**Preview modal:** Click the **eye button** on any snapshot to open a full-size preview modal showing the complete graph with node titles, colored link beziers, input/output slot dots, and group overlays. Dismiss with **Escape**, the **X** button, or by clicking outside.
+
+The SVG renderer draws nodes with their stored position, size, and colors. Links are rendered as bezier curves colored by type (blue for IMAGE, orange for CLIP, purple for MODEL, etc.). Collapsed nodes appear as thin title-only strips. Thumbnails (hover tooltips) auto-simplify by hiding labels and slot dots for clarity at small sizes.
+
+### 14. Snapshot Branching
+
+Branching lets you explore multiple variations of a workflow without losing any history — similar to conversation branching in ChatGPT.
+
+**How it works:**
+
+1. Work normally — snapshots chain linearly as you edit
+2. **Swap** to an older snapshot and start editing — the next auto-capture forks into a new branch from that point
+3. A **`< 1/2 >`** branch navigator appears at every fork point in the sidebar and the timeline
+4. Click the arrows to switch between branches — the sidebar and timeline update together
+
+**Details:**
+
+- Each snapshot stores a `parentId` linking it to its predecessor, forming a tree
+- Legacy snapshots (from before branching) are automatically chained by timestamp for backwards compatibility
+- **Pruning is branch-safe** — ancestors of the current branch tip and fork-point snapshots are never auto-pruned
+- **Deleting a fork point** re-parents its children to the deleted snapshot's parent (with a confirmation dialog)
+- Switching workflows clears branch navigation state
+
+### 15. Hide Auto-saves
+
+Click the **Hide Auto** button next to the search bar to hide all auto-save snapshots ("Auto" and "Initial"). The button turns blue and switches to **Show Auto** when active.
+
+The filter works together with text search — both are applied simultaneously. Branch navigators remain visible regardless of the filter. Manual, locked, node-triggered, and "Current" snapshots are always shown.
+
+### 16. Session Profiles
+
+Save and load named sets of workflows — like browser tab groups for ComfyUI.
+
+**Save a profile:**
+
+1. Click the **`>`** Profiles toggle between the workflow picker and search bar to expand
+2. Click **Save** — enter a profile name
+3. The profile captures all workflows you've visited in this session
+
+**Load a profile:**
+
+1. Expand the Profiles section
+2. Click **Load** on any profile — the extension fetches the latest snapshot for each workflow and loads them via `loadGraphData`
+3. The profile's active workflow is loaded last so it ends up visible
+4. A toast reports how many workflows were loaded and how many were skipped (missing snapshots)
+
+**Delete a profile:** Click **X** on any profile (with confirmation).
+
+Profiles are stored as JSON files on the server at `<extension_dir>/data/profiles/`.
+
+> **Note:** ComfyUI's `loadGraphData` replaces the current workflow — there is no API to open new tabs. Each loaded workflow overwrites the previous one. The user ends up seeing the last loaded workflow (the active one). Previously loaded workflows may appear in ComfyUI's workflow history/tabs depending on the frontend version.
 
 ## Settings
 
-All settings are available in **ComfyUI Settings > Snapshot Manager > Capture Settings**:
+All settings are available in **ComfyUI Settings > Snapshot Manager**:
 
 | Setting | Type | Default | Description |
 |---------|------|---------|-------------|
 | **Auto-capture on edit** | Toggle | `On` | Automatically save snapshots when the workflow changes |
 | **Capture delay** | Slider | `3s` | Seconds to wait after the last edit before auto-capturing (1–30s) |
-| **Max snapshots per workflow** | Slider | `50` | Maximum number of snapshots kept per workflow (5–200). Oldest are pruned automatically |
+| **Max snapshots per workflow** | Slider | `50` | Maximum number of unlocked snapshots kept per workflow (5–200). Oldest unlocked are pruned automatically; locked snapshots are never pruned |
 | **Capture on workflow load** | Toggle | `On` | Save an "Initial" snapshot when a workflow is first loaded |
+| **Max node-triggered snapshots** | Slider | `5` | Rolling limit for SaveSnapshot node captures per workflow (1–50). Node snapshots are pruned independently from auto/manual snapshots |
+| **Show snapshot timeline** | Toggle | `Off` | Display a timeline bar at the bottom of the canvas with snapshot markers, active/current indicators, and a quick Snapshot button |
 
 ## Architecture
 
@@ -93,27 +245,72 @@ All settings are available in **ComfyUI Settings > Snapshot Manager > Capture Se
   <img src="assets/architecture.png" alt="Architecture Diagram" width="100%"/>
 </p>
 
-**Data flow:**
+**Auto/manual capture flow:**
 
 1. **Graph edits** trigger a `graphChanged` event
 2. A **debounce timer** prevents excessive writes
 3. The workflow is serialized and **hash-checked** against the last capture (per-workflow) to avoid duplicates
-4. New snapshots are written to **IndexedDB** (browser-local, persistent)
-5. The **sidebar panel** reads from IndexedDB and renders the snapshot list
-6. **Restore/Swap** loads graph data back into ComfyUI with a lock guard to prevent concurrent operations
+4. The previous graph state is diffed against the current to **detect the change type** (node add/remove, connection, parameter, move, or mixed) — stored as a `changeType` field on the record
+5. New snapshots are sent to the **server** and stored as individual JSON files under `data/snapshots/`
+6. The **sidebar panel** and **timeline bar** fetch snapshots from the server and render them with change-type icons
+7. **Restore/Swap** loads graph data back into ComfyUI with a lock guard to prevent concurrent operations, and updates the graph cache so the next diff is accurate
 
-**Storage:** All data stays in your browser's IndexedDB — nothing is sent to any server. Snapshots persist across browser sessions and ComfyUI restarts.
+**Node-triggered capture flow:**
+
+1. **SaveSnapshot node** executes during a queue prompt run
+2. A **WebSocket event** is sent to the frontend, **skipping hash dedup** (the workflow doesn't change between runs)
+3. The snapshot is saved with `source: "node"` and pruned against its own rolling limit (`maxNodeSnapshots`)
+4. Node snapshots appear in the sidebar with a **purple left border** and **"Node" badge**
+
+**Swap with auto-save:**
+
+1. User clicks **Swap** (sidebar or timeline marker)
+2. If the current graph is unsaved work (not already a swapped snapshot), `captureSnapshot("Current")` saves it **before** the swap — browsing between existing snapshots skips this step
+3. The target snapshot is loaded into the graph
+4. The **timeline** updates: the swapped-to snapshot gets a white ring (active), the auto-saved snapshot gets a green dot (current)
+5. Clicking the green dot swaps back; editing the graph clears both markers (the next auto-capture supersedes them)
+
+**Branching:**
+
+1. Each snapshot stores a `parentId` pointing to its predecessor
+2. `buildSnapshotTree()` constructs parent/child maps from all records — legacy snapshots (no `parentId`) are chained by timestamp automatically
+3. `getDisplayPath()` walks the tree from root to tip, following `activeBranchSelections` at each fork point, producing the linear branch view
+4. The sidebar and timeline render only the current branch; `< 1/3 >` navigators at fork points switch between branches
+5. **Pruning protection**: before pruning, `getAncestorIds()` collects all ancestors of the branch tip; these IDs plus fork-point IDs are sent as `protectedIds` to the server
+
+**Profiles:**
+
+1. Session tracking records each visited workflow key with timestamps
+2. **Save** creates a JSON file at `<extension_dir>/data/profiles/<id>.json` with the workflow list and active workflow
+3. **Load** fetches the latest snapshot for each workflow in the profile and calls `loadGraphData`
+
+**Storage:** Snapshots are stored as JSON files on the server at `<extension_dir>/data/snapshots/<workflow_key>/<id>.json`. Profiles are stored at `<extension_dir>/data/profiles/<id>.json`. Both persist across browser sessions, ComfyUI restarts, and are accessible from any browser connecting to the same server.
 
 ## FAQ
 
 **Where are snapshots stored?**
-In your browser's IndexedDB under the database `ComfySnapshotManager`. They persist across sessions but are browser-local (not synced between devices).
+On the server's filesystem under `<extension_dir>/data/snapshots/`. Each workflow gets its own directory, and each snapshot is an individual JSON file. They persist across browser sessions and are accessible from any browser connecting to the same ComfyUI server.
+
+**I'm upgrading from v1.x — what happens to my existing snapshots?**
+On first load after upgrading, the extension automatically migrates all snapshots from your browser's IndexedDB to the server. Once migration succeeds, the old IndexedDB database is deleted. If migration fails (e.g., server unreachable), your old data is preserved and migration will retry on the next load.
 
 **Will this slow down ComfyUI?**
 No. Snapshots are captured asynchronously after a debounce delay. The hash check prevents redundant writes.
 
 **What happens if I switch workflows?**
-Each workflow has its own snapshot history. Switching workflows cancels any pending captures and shows the correct snapshot list.
+Each workflow has its own snapshot history. Switching workflows cancels any pending captures and shows the correct snapshot list. You can also browse snapshots from other workflows using the workflow picker.
+
+**I renamed/deleted a workflow — are my snapshots gone?**
+No. Snapshots are keyed by the workflow name at capture time. Use the workflow picker to find and restore them under the old name.
+
+**How does branching work?**
+When you swap to an old snapshot and then edit, the next capture forks into a new branch. A `< 1/2 >` navigator appears at the fork point — click the arrows to switch branches. The tree structure is computed from `parentId` links on each snapshot. Old snapshots without `parentId` (from before v3.0) are automatically chained by timestamp.
+
+**Can I delete a fork-point snapshot?**
+Yes. The extension re-parents its children to the deleted snapshot's parent, preserving the branch structure. A confirmation dialog warns you first.
+
+**What are profiles?**
+Profiles save a list of workflows you've visited in a session. Loading a profile restores the latest snapshot for each workflow. They're useful for switching between project contexts — like browser tab groups.
 
 **Can I use this with ComfyUI Manager?**
 Yes — install via ComfyUI Manager or clone the repo into `custom_nodes/`.

__init__.py

@@ -2,9 +2,12 @@
 ComfyUI Snapshot Manager
 
 Automatically snapshots workflow state as you edit, with a sidebar panel
-to browse and restore any previous version. Stored in IndexedDB.
+to browse and restore any previous version. Stored in server-side JSON files.
 """
 
+from . import snapshot_routes
+from .snapshot_node import SaveSnapshot
+
 WEB_DIRECTORY = "./js"
-NODE_CLASS_MAPPINGS = {}
-NODE_DISPLAY_NAME_MAPPINGS = {}
+NODE_CLASS_MAPPINGS = {"SaveSnapshot": SaveSnapshot}
+NODE_DISPLAY_NAME_MAPPINGS = {"SaveSnapshot": "Save Snapshot"}

assets/architecture.svg

@@ -1,93 +1,100 @@
-<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 800 420">
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 800 450">
   <defs>
     <linearGradient id="abg" x1="0%" y1="0%" x2="100%" y2="100%">
       <stop offset="0%" style="stop-color:#0f172a"/>
       <stop offset="100%" style="stop-color:#1e293b"/>
     </linearGradient>
-  </defs>
-  <rect width="800" height="420" rx="12" fill="url(#abg)"/>
-
-  <!-- Title -->
-  <text x="400" y="35" text-anchor="middle" font-family="system-ui, sans-serif" font-size="16" font-weight="600" fill="#94a3b8">How It Works</text>
-
-  <!-- Graph Edit box -->
-  <rect x="40" y="60" width="160" height="70" rx="8" fill="#1e293b" stroke="#3b82f6" stroke-width="2"/>
-  <text x="120" y="92" text-anchor="middle" font-family="system-ui, sans-serif" font-size="13" font-weight="600" fill="#e2e8f0">Graph Edit</text>
-  <text x="120" y="112" text-anchor="middle" font-family="system-ui, sans-serif" font-size="11" fill="#64748b">graphChanged event</text>
-
-  <!-- Arrow 1 -->
-  <line x1="200" y1="95" x2="250" y2="95" stroke="#475569" stroke-width="2" marker-end="url(#arrowhead)"/>
-
-  <!-- Debounce box -->
-  <rect x="250" y="60" width="160" height="70" rx="8" fill="#1e293b" stroke="#f59e0b" stroke-width="2"/>
-  <text x="330" y="92" text-anchor="middle" font-family="system-ui, sans-serif" font-size="13" font-weight="600" fill="#e2e8f0">Debounce Timer</text>
-  <text x="330" y="112" text-anchor="middle" font-family="system-ui, sans-serif" font-size="11" fill="#64748b">configurable delay</text>
-
-  <!-- Arrow 2 -->
-  <line x1="410" y1="95" x2="460" y2="95" stroke="#475569" stroke-width="2" marker-end="url(#arrowhead)"/>
-
-  <!-- Hash Check box -->
-  <rect x="460" y="60" width="160" height="70" rx="8" fill="#1e293b" stroke="#8b5cf6" stroke-width="2"/>
-  <text x="540" y="92" text-anchor="middle" font-family="system-ui, sans-serif" font-size="13" font-weight="600" fill="#e2e8f0">Hash Check</text>
-  <text x="540" y="112" text-anchor="middle" font-family="system-ui, sans-serif" font-size="11" fill="#64748b">per-workflow map</text>
-
-  <!-- Arrow 3 -->
-  <line x1="620" y1="95" x2="640" y2="95" stroke="#475569" stroke-width="2"/>
-  <line x1="640" y1="95" x2="640" y2="180" stroke="#475569" stroke-width="2"/>
-  <line x1="640" y1="180" x2="620" y2="180" stroke="#475569" stroke-width="2" marker-end="url(#arrowhead-left)"/>
-
-  <!-- IndexedDB box -->
-  <rect x="460" y="150" width="160" height="70" rx="8" fill="#1e293b" stroke="#22c55e" stroke-width="2"/>
-  <text x="540" y="182" text-anchor="middle" font-family="system-ui, sans-serif" font-size="13" font-weight="600" fill="#e2e8f0">IndexedDB</text>
-  <text x="540" y="202" text-anchor="middle" font-family="system-ui, sans-serif" font-size="11" fill="#64748b">persistent storage</text>
-
-  <!-- Arrow 4 down to sidebar -->
-  <line x1="540" y1="220" x2="540" y2="265" stroke="#475569" stroke-width="2" marker-end="url(#arrowhead)"/>
-
-  <!-- Sidebar Panel box (wide) -->
-  <rect x="250" y="265" width="370" height="130" rx="8" fill="#1e293b" stroke="#3b82f6" stroke-width="2"/>
-  <text x="435" y="295" text-anchor="middle" font-family="system-ui, sans-serif" font-size="14" font-weight="600" fill="#e2e8f0">Sidebar Panel</text>
-
-  <!-- Sidebar sub-items -->
-  <rect x="270" y="310" width="100" height="32" rx="5" fill="#3b82f6" opacity="0.15" stroke="#3b82f6" stroke-width="1"/>
-  <text x="320" y="330" text-anchor="middle" font-family="system-ui, sans-serif" font-size="11" fill="#93c5fd">Take Snapshot</text>
-
-  <rect x="380" y="310" width="70" height="32" rx="5" fill="#22c55e" opacity="0.15" stroke="#22c55e" stroke-width="1"/>
-  <text x="415" y="330" text-anchor="middle" font-family="system-ui, sans-serif" font-size="11" fill="#86efac">Restore</text>
-
-  <rect x="460" y="310" width="55" height="32" rx="5" fill="#f59e0b" opacity="0.15" stroke="#f59e0b" stroke-width="1"/>
-  <text x="488" y="330" text-anchor="middle" font-family="system-ui, sans-serif" font-size="11" fill="#fcd34d">Swap</text>
-
-  <rect x="525" y="310" width="70" height="32" rx="5" fill="#8b5cf6" opacity="0.15" stroke="#8b5cf6" stroke-width="1"/>
-  <text x="560" y="330" text-anchor="middle" font-family="system-ui, sans-serif" font-size="11" fill="#c4b5fd">Search</text>
-
-  <text x="435" y="375" text-anchor="middle" font-family="system-ui, sans-serif" font-size="11" fill="#64748b">toast notifications &#183; confirm dialogs &#183; loading states</text>
-
-  <!-- Restore arrow back up -->
-  <rect x="40" y="180" width="160" height="70" rx="8" fill="#1e293b" stroke="#22c55e" stroke-width="2"/>
-  <text x="120" y="207" text-anchor="middle" font-family="system-ui, sans-serif" font-size="13" font-weight="600" fill="#e2e8f0">Restore / Swap</text>
-  <text x="120" y="227" text-anchor="middle" font-family="system-ui, sans-serif" font-size="11" fill="#64748b">with lock guard</text>
-
-  <line x1="250" y1="330" x2="200" y2="265" stroke="#22c55e" stroke-width="1.5" stroke-dasharray="6,3" marker-end="url(#arrowhead-green)"/>
-  <line x1="120" y1="180" x2="120" y2="130" stroke="#22c55e" stroke-width="1.5" stroke-dasharray="6,3" marker-end="url(#arrowhead-green)"/>
-  <text x="120" y="155" text-anchor="middle" font-family="system-ui, sans-serif" font-size="10" fill="#22c55e">loadGraphData</text>
-
-  <!-- Manual capture arrow -->
-  <line x1="320" y1="310" x2="460" y2="185" stroke="#3b82f6" stroke-width="1.5" stroke-dasharray="6,3" marker-end="url(#arrowhead-blue)"/>
-
-  <!-- Arrowhead markers -->
-  <defs>
     <marker id="arrowhead" markerWidth="10" markerHeight="7" refX="10" refY="3.5" orient="auto">
       <polygon points="0 0, 10 3.5, 0 7" fill="#475569"/>
     </marker>
-    <marker id="arrowhead-left" markerWidth="10" markerHeight="7" refX="0" refY="3.5" orient="auto-start-reverse">
-      <polygon points="10 0, 0 3.5, 10 7" fill="#475569"/>
-    </marker>
     <marker id="arrowhead-green" markerWidth="10" markerHeight="7" refX="10" refY="3.5" orient="auto">
       <polygon points="0 0, 10 3.5, 0 7" fill="#22c55e"/>
     </marker>
     <marker id="arrowhead-blue" markerWidth="10" markerHeight="7" refX="10" refY="3.5" orient="auto">
       <polygon points="0 0, 10 3.5, 0 7" fill="#3b82f6"/>
     </marker>
+    <marker id="arrowhead-purple" markerWidth="10" markerHeight="7" refX="10" refY="3.5" orient="auto">
+      <polygon points="0 0, 10 3.5, 0 7" fill="#6d28d9"/>
+    </marker>
   </defs>
+  <rect width="800" height="450" rx="12" fill="url(#abg)"/>
+
+  <!-- Title -->
+  <text x="400" y="35" text-anchor="middle" font-family="system-ui, sans-serif" font-size="16" font-weight="600" fill="#94a3b8">How It Works</text>
+
+  <!-- ═══ Row 1: Auto-capture path ═══ -->
+
+  <rect x="40" y="55" width="160" height="70" rx="8" fill="#1e293b" stroke="#3b82f6" stroke-width="2"/>
+  <text x="120" y="87" text-anchor="middle" font-family="system-ui, sans-serif" font-size="13" font-weight="600" fill="#e2e8f0">Graph Edit</text>
+  <text x="120" y="107" text-anchor="middle" font-family="system-ui, sans-serif" font-size="11" fill="#64748b">graphChanged event</text>
+
+  <line x1="200" y1="90" x2="250" y2="90" stroke="#475569" stroke-width="2" marker-end="url(#arrowhead)"/>
+
+  <rect x="250" y="55" width="160" height="70" rx="8" fill="#1e293b" stroke="#f59e0b" stroke-width="2"/>
+  <text x="330" y="87" text-anchor="middle" font-family="system-ui, sans-serif" font-size="13" font-weight="600" fill="#e2e8f0">Debounce Timer</text>
+  <text x="330" y="107" text-anchor="middle" font-family="system-ui, sans-serif" font-size="11" fill="#64748b">configurable delay</text>
+
+  <line x1="410" y1="90" x2="460" y2="90" stroke="#475569" stroke-width="2" marker-end="url(#arrowhead)"/>
+
+  <rect x="460" y="55" width="160" height="70" rx="8" fill="#1e293b" stroke="#8b5cf6" stroke-width="2"/>
+  <text x="540" y="87" text-anchor="middle" font-family="system-ui, sans-serif" font-size="13" font-weight="600" fill="#e2e8f0">Hash Check</text>
+  <text x="540" y="107" text-anchor="middle" font-family="system-ui, sans-serif" font-size="11" fill="#64748b">per-workflow dedup</text>
+
+  <!-- Arrow: Hash Check → Server Storage (bend down) -->
+  <line x1="620" y1="90" x2="655" y2="90" stroke="#475569" stroke-width="2"/>
+  <line x1="655" y1="90" x2="655" y2="160" stroke="#475569" stroke-width="2" marker-end="url(#arrowhead)"/>
+
+  <!-- ═══ Row 2: Node path + Server Storage ═══ -->
+
+  <rect x="40" y="165" width="170" height="70" rx="8" fill="#1e293b" stroke="#6d28d9" stroke-width="2"/>
+  <text x="125" y="197" text-anchor="middle" font-family="system-ui, sans-serif" font-size="13" font-weight="600" fill="#e2e8f0">SaveSnapshot Node</text>
+  <text x="125" y="217" text-anchor="middle" font-family="system-ui, sans-serif" font-size="11" fill="#64748b">queue prompt trigger</text>
+
+  <!-- Arrow: SaveSnapshot → Server Storage with label -->
+  <line x1="210" y1="200" x2="545" y2="200" stroke="#6d28d9" stroke-width="2" marker-end="url(#arrowhead-purple)"/>
+  <text x="378" y="192" text-anchor="middle" font-family="system-ui, sans-serif" font-size="10" fill="#a78bfa">WS event &#183; skips hash dedup</text>
+
+  <rect x="545" y="160" width="220" height="80" rx="8" fill="#1e293b" stroke="#22c55e" stroke-width="2"/>
+  <text x="655" y="195" text-anchor="middle" font-family="system-ui, sans-serif" font-size="13" font-weight="600" fill="#e2e8f0">Server Storage</text>
+  <text x="655" y="215" text-anchor="middle" font-family="system-ui, sans-serif" font-size="11" fill="#64748b">JSON files &#183; per-workflow dirs</text>
+
+  <!-- Arrow: Server Storage → Sidebar -->
+  <line x1="655" y1="240" x2="655" y2="285" stroke="#475569" stroke-width="2" marker-end="url(#arrowhead)"/>
+
+  <!-- ═══ Row 3: Sidebar + Restore ═══ -->
+
+  <rect x="250" y="285" width="515" height="130" rx="8" fill="#1e293b" stroke="#3b82f6" stroke-width="2"/>
+  <text x="507" y="313" text-anchor="middle" font-family="system-ui, sans-serif" font-size="14" font-weight="600" fill="#e2e8f0">Sidebar Panel</text>
+
+  <rect x="270" y="327" width="100" height="32" rx="5" fill="#3b82f6" opacity="0.15" stroke="#3b82f6" stroke-width="1"/>
+  <text x="320" y="347" text-anchor="middle" font-family="system-ui, sans-serif" font-size="11" fill="#93c5fd">Take Snapshot</text>
+
+  <rect x="380" y="327" width="70" height="32" rx="5" fill="#22c55e" opacity="0.15" stroke="#22c55e" stroke-width="1"/>
+  <text x="415" y="347" text-anchor="middle" font-family="system-ui, sans-serif" font-size="11" fill="#86efac">Restore</text>
+
+  <rect x="460" y="327" width="55" height="32" rx="5" fill="#f59e0b" opacity="0.15" stroke="#f59e0b" stroke-width="1"/>
+  <text x="488" y="347" text-anchor="middle" font-family="system-ui, sans-serif" font-size="11" fill="#fcd34d">Swap</text>
+
+  <rect x="525" y="327" width="70" height="32" rx="5" fill="#8b5cf6" opacity="0.15" stroke="#8b5cf6" stroke-width="1"/>
+  <text x="560" y="347" text-anchor="middle" font-family="system-ui, sans-serif" font-size="11" fill="#c4b5fd">Search</text>
+
+  <rect x="605" y="327" width="55" height="32" rx="5" fill="#6d28d9" opacity="0.15" stroke="#6d28d9" stroke-width="1"/>
+  <text x="633" y="347" text-anchor="middle" font-family="system-ui, sans-serif" font-size="11" fill="#a78bfa">Lock</text>
+
+  <text x="507" y="395" text-anchor="middle" font-family="system-ui, sans-serif" font-size="11" fill="#64748b">toast notifications &#183; confirm dialogs &#183; loading states</text>
+
+  <!-- Restore/Swap box -->
+  <rect x="40" y="305" width="160" height="70" rx="8" fill="#1e293b" stroke="#22c55e" stroke-width="2"/>
+  <text x="120" y="337" text-anchor="middle" font-family="system-ui, sans-serif" font-size="13" font-weight="600" fill="#e2e8f0">Restore / Swap</text>
+  <text x="120" y="357" text-anchor="middle" font-family="system-ui, sans-serif" font-size="11" fill="#64748b">with lock guard</text>
+
+  <!-- Dashed: Sidebar → Restore -->
+  <line x1="250" y1="350" x2="200" y2="340" stroke="#22c55e" stroke-width="1.5" stroke-dasharray="6,3" marker-end="url(#arrowhead-green)"/>
+
+  <!-- Dashed: Restore → Graph Edit (routed around left side) -->
+  <path d="M 40 335 H 20 V 90 H 40" fill="none" stroke="#22c55e" stroke-width="1.5" stroke-dasharray="6,3" marker-end="url(#arrowhead-green)"/>
+  <text x="11" y="250" text-anchor="middle" font-family="system-ui, sans-serif" font-size="10" fill="#22c55e" transform="rotate(-90, 11, 250)">loadGraphData</text>
+
+  <!-- Dashed: Take Snapshot → Server Storage -->
+  <line x1="320" y1="327" x2="558" y2="240" stroke="#3b82f6" stroke-width="1.5" stroke-dasharray="6,3" marker-end="url(#arrowhead-blue)"/>
 </svg>

assets/timeline-icons.svg

@@ -0,0 +1,106 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="720" height="80" viewBox="0 0 720 80">
+  <!-- Background -->
+  <rect width="720" height="80" rx="8" fill="#1e293b"/>
+
+  <!-- Icon definitions -->
+  <defs>
+    <!-- Initial (blue) -->
+    <symbol id="icon-initial" viewBox="0 0 12 12">
+      <circle cx="6" cy="6" r="5" fill="currentColor"/>
+    </symbol>
+
+    <!-- Node Add (green) -->
+    <symbol id="icon-node-add" viewBox="0 0 12 12">
+      <path d="M6 2v8M2 6h8" stroke="currentColor" stroke-width="2" stroke-linecap="round"/>
+    </symbol>
+
+    <!-- Node Remove (red) -->
+    <symbol id="icon-node-remove" viewBox="0 0 12 12">
+      <path d="M2 6h8" stroke="currentColor" stroke-width="2" stroke-linecap="round"/>
+    </symbol>
+
+    <!-- Connection (amber) -->
+    <symbol id="icon-connection" viewBox="0 0 12 12">
+      <path d="M1 9L4 3L8 9L11 3" stroke="currentColor" stroke-width="1.5" stroke-linecap="round" stroke-linejoin="round" fill="none"/>
+    </symbol>
+
+    <!-- Param (purple) -->
+    <symbol id="icon-param" viewBox="0 0 12 12">
+      <path d="M0 6Q3 2 6 6Q9 10 12 6" stroke="currentColor" stroke-width="1.5" fill="none"/>
+    </symbol>
+
+    <!-- Move (gray) -->
+    <symbol id="icon-move" viewBox="0 0 12 12">
+      <path d="M6 1L3 4h6L6 1ZM6 11L3 8h6L6 11Z" fill="currentColor"/>
+    </symbol>
+
+    <!-- Mixed (orange) -->
+    <symbol id="icon-mixed" viewBox="0 0 12 12">
+      <path d="M6 1L7.5 4.5H11L8.25 6.75L9.5 10.5L6 8L2.5 10.5L3.75 6.75L1 4.5H4.5Z" fill="currentColor"/>
+    </symbol>
+
+    <!-- Unknown (gray) -->
+    <symbol id="icon-unknown" viewBox="0 0 12 12">
+      <circle cx="6" cy="6" r="3" fill="currentColor" opacity="0.5"/>
+    </symbol>
+  </defs>
+
+  <!-- 8 icons evenly spaced: center positions at 45, 141.43, 237.86, 334.29, 430.71, 527.14, 623.57, 720-45=675 -->
+  <!-- Spacing: (720 - 2*45) / 7 = 90 -->
+
+  <!-- 1. Initial -->
+  <g transform="translate(45, 0)">
+    <circle cx="0" cy="28" r="16" fill="#3b82f6"/>
+    <use href="#icon-initial" x="-8" y="20" width="16" height="16" color="white"/>
+    <text x="0" y="60" text-anchor="middle" font-family="system-ui, -apple-system, sans-serif" font-size="11" fill="#94a3b8">Initial</text>
+  </g>
+
+  <!-- 2. Node Add -->
+  <g transform="translate(135, 0)">
+    <circle cx="0" cy="28" r="16" fill="#22c55e"/>
+    <use href="#icon-node-add" x="-8" y="20" width="16" height="16" color="white"/>
+    <text x="0" y="60" text-anchor="middle" font-family="system-ui, -apple-system, sans-serif" font-size="11" fill="#94a3b8">Node Add</text>
+  </g>
+
+  <!-- 3. Node Remove -->
+  <g transform="translate(225, 0)">
+    <circle cx="0" cy="28" r="16" fill="#ef4444"/>
+    <use href="#icon-node-remove" x="-8" y="20" width="16" height="16" color="white"/>
+    <text x="0" y="60" text-anchor="middle" font-family="system-ui, -apple-system, sans-serif" font-size="11" fill="#94a3b8">Node Remove</text>
+  </g>
+
+  <!-- 4. Connection -->
+  <g transform="translate(315, 0)">
+    <circle cx="0" cy="28" r="16" fill="#f59e0b"/>
+    <use href="#icon-connection" x="-8" y="20" width="16" height="16" color="white"/>
+    <text x="0" y="60" text-anchor="middle" font-family="system-ui, -apple-system, sans-serif" font-size="11" fill="#94a3b8">Connection</text>
+  </g>
+
+  <!-- 5. Param -->
+  <g transform="translate(405, 0)">
+    <circle cx="0" cy="28" r="16" fill="#a78bfa"/>
+    <use href="#icon-param" x="-8" y="20" width="16" height="16" color="white"/>
+    <text x="0" y="60" text-anchor="middle" font-family="system-ui, -apple-system, sans-serif" font-size="11" fill="#94a3b8">Param</text>
+  </g>
+
+  <!-- 6. Move -->
+  <g transform="translate(495, 0)">
+    <circle cx="0" cy="28" r="16" fill="#64748b"/>
+    <use href="#icon-move" x="-8" y="20" width="16" height="16" color="white"/>
+    <text x="0" y="60" text-anchor="middle" font-family="system-ui, -apple-system, sans-serif" font-size="11" fill="#94a3b8">Move</text>
+  </g>
+
+  <!-- 7. Mixed -->
+  <g transform="translate(585, 0)">
+    <circle cx="0" cy="28" r="16" fill="#f97316"/>
+    <use href="#icon-mixed" x="-8" y="20" width="16" height="16" color="white"/>
+    <text x="0" y="60" text-anchor="middle" font-family="system-ui, -apple-system, sans-serif" font-size="11" fill="#94a3b8">Mixed</text>
+  </g>
+
+  <!-- 8. Unknown -->
+  <g transform="translate(675, 0)">
+    <circle cx="0" cy="28" r="16" fill="#6b7280"/>
+    <use href="#icon-unknown" x="-8" y="20" width="16" height="16" color="white"/>
+    <text x="0" y="60" text-anchor="middle" font-family="system-ui, -apple-system, sans-serif" font-size="11" fill="#94a3b8">Unknown</text>
+  </g>
+</svg>

pyproject.toml

@@ -1,7 +1,7 @@
 [project]
 name = "comfyui-snapshot-manager"
 description = "Automatically snapshots workflow state with a sidebar to browse and restore previous versions."
-version = "1.0.0"
+version = "3.1.0"
 license = {text = "MIT"}
 
 [project.urls]

snapshot_node.py

@@ -0,0 +1,70 @@
+import base64
+import io
+
+from server import PromptServer
+
+
+class _AnyType(str):
+    def __ne__(self, other):
+        return False
+
+
+ANY_TYPE = _AnyType("*")
+
+
+def _make_thumbnail(value):
+    """Convert an image tensor to a base64 JPEG thumbnail, or return None."""
+    try:
+        import torch
+        if not isinstance(value, torch.Tensor):
+            return None
+        if value.ndim != 4 or value.shape[3] not in (3, 4):
+            return None
+
+        from PIL import Image
+
+        frame = value[0]  # first frame only
+        if frame.shape[2] == 4:
+            frame = frame[:, :, :3]  # drop alpha
+        arr = frame.clamp(0, 1).mul(255).byte().cpu().numpy()
+        img = Image.fromarray(arr, mode="RGB")
+        img.thumbnail((200, 150), Image.LANCZOS)
+        buf = io.BytesIO()
+        img.save(buf, format="JPEG", quality=75)
+        return base64.b64encode(buf.getvalue()).decode("ascii")
+    except Exception:
+        return None
+
+
+class SaveSnapshot:
+    CATEGORY = "Snapshot Manager"
+    FUNCTION = "execute"
+    RETURN_TYPES = (ANY_TYPE,)
+    OUTPUT_NODE = True
+
+    @classmethod
+    def INPUT_TYPES(cls):
+        return {
+            "required": {
+                "value": (ANY_TYPE, {}),
+                "label": ("STRING", {"default": "Node Trigger"}),
+            }
+        }
+
+    @classmethod
+    def VALIDATE_INPUTS(cls, input_types):
+        return True
+
+    @classmethod
+    def IS_CHANGED(cls, *args, **kwargs):
+        return float("NaN")
+
+    def execute(self, value, label):
+        payload = {"label": label}
+        thumbnail = _make_thumbnail(value)
+        if thumbnail is not None:
+            payload["thumbnail"] = thumbnail
+        PromptServer.instance.send_sync(
+            "snapshot-manager-capture", payload
+        )
+        return (value,)

snapshot_routes.py

@@ -0,0 +1,208 @@
+"""
+HTTP route handlers for snapshot storage.
+
+Registers endpoints with PromptServer.instance.routes at import time.
+"""
+
+from aiohttp import web
+from server import PromptServer
+
+from . import snapshot_storage as storage
+
+routes = PromptServer.instance.routes
+
+
+@routes.post("/snapshot-manager/save")
+async def save_snapshot(request):
+    try:
+        data = await request.json()
+        record = data.get("record")
+        if not record or "id" not in record or "workflowKey" not in record:
+            return web.json_response({"error": "Missing record with id and workflowKey"}, status=400)
+        storage.put(record)
+        return web.json_response({"ok": True})
+    except ValueError as e:
+        return web.json_response({"error": str(e)}, status=400)
+    except Exception as e:
+        return web.json_response({"error": str(e)}, status=500)
+
+
+@routes.post("/snapshot-manager/list")
+async def list_snapshots(request):
+    try:
+        data = await request.json()
+        workflow_key = data.get("workflowKey")
+        if not workflow_key:
+            return web.json_response({"error": "Missing workflowKey"}, status=400)
+        records = storage.get_all_for_workflow(workflow_key)
+        return web.json_response(records)
+    except Exception as e:
+        return web.json_response({"error": str(e)}, status=500)
+
+
+@routes.post("/snapshot-manager/get")
+async def get_snapshot(request):
+    try:
+        data = await request.json()
+        workflow_key = data.get("workflowKey")
+        snapshot_id = data.get("id")
+        if not workflow_key or not snapshot_id:
+            return web.json_response({"error": "Missing workflowKey or id"}, status=400)
+        record = storage.get_full_record(workflow_key, snapshot_id)
+        if record is None:
+            return web.json_response({"error": "Not found"}, status=404)
+        return web.json_response(record)
+    except ValueError as e:
+        return web.json_response({"error": str(e)}, status=400)
+    except Exception as e:
+        return web.json_response({"error": str(e)}, status=500)
+
+
+@routes.post("/snapshot-manager/update-meta")
+async def update_snapshot_meta(request):
+    try:
+        data = await request.json()
+        workflow_key = data.get("workflowKey")
+        snapshot_id = data.get("id")
+        fields = data.get("fields")
+        if not workflow_key or not snapshot_id or not isinstance(fields, dict):
+            return web.json_response({"error": "Missing workflowKey, id, or fields"}, status=400)
+        ok = storage.update_meta(workflow_key, snapshot_id, fields)
+        if not ok:
+            return web.json_response({"error": "Not found"}, status=404)
+        return web.json_response({"ok": True})
+    except ValueError as e:
+        return web.json_response({"error": str(e)}, status=400)
+    except Exception as e:
+        return web.json_response({"error": str(e)}, status=500)
+
+
+@routes.post("/snapshot-manager/delete")
+async def delete_snapshot(request):
+    try:
+        data = await request.json()
+        workflow_key = data.get("workflowKey")
+        snapshot_id = data.get("id")
+        if not workflow_key or not snapshot_id:
+            return web.json_response({"error": "Missing workflowKey or id"}, status=400)
+        storage.delete(workflow_key, snapshot_id)
+        return web.json_response({"ok": True})
+    except ValueError as e:
+        return web.json_response({"error": str(e)}, status=400)
+    except Exception as e:
+        return web.json_response({"error": str(e)}, status=500)
+
+
+@routes.post("/snapshot-manager/delete-all")
+async def delete_all_snapshots(request):
+    try:
+        data = await request.json()
+        workflow_key = data.get("workflowKey")
+        if not workflow_key:
+            return web.json_response({"error": "Missing workflowKey"}, status=400)
+        result = storage.delete_all_for_workflow(workflow_key)
+        return web.json_response(result)
+    except Exception as e:
+        return web.json_response({"error": str(e)}, status=500)
+
+
+@routes.get("/snapshot-manager/workflows")
+async def list_workflows(request):
+    try:
+        keys = storage.get_all_workflow_keys()
+        return web.json_response(keys)
+    except Exception as e:
+        return web.json_response({"error": str(e)}, status=500)
+
+
+@routes.post("/snapshot-manager/prune")
+async def prune_snapshots(request):
+    try:
+        data = await request.json()
+        workflow_key = data.get("workflowKey")
+        max_snapshots = data.get("maxSnapshots")
+        source = data.get("source")
+        protected_ids = data.get("protectedIds")
+        if not workflow_key or max_snapshots is None:
+            return web.json_response({"error": "Missing workflowKey or maxSnapshots"}, status=400)
+        deleted = storage.prune(workflow_key, int(max_snapshots), source=source, protected_ids=protected_ids)
+        return web.json_response({"deleted": deleted})
+    except Exception as e:
+        return web.json_response({"error": str(e)}, status=500)
+
+
+@routes.post("/snapshot-manager/migrate")
+async def migrate_snapshots(request):
+    try:
+        data = await request.json()
+        records = data.get("records")
+        if not isinstance(records, list):
+            return web.json_response({"error": "Missing records array"}, status=400)
+        imported = 0
+        for record in records:
+            if "id" in record and "workflowKey" in record:
+                storage.put(record)
+                imported += 1
+        return web.json_response({"imported": imported})
+    except ValueError as e:
+        return web.json_response({"error": str(e)}, status=400)
+    except Exception as e:
+        return web.json_response({"error": str(e)}, status=500)
+
+
+# ─── Profile Endpoints ───────────────────────────────────────────────
+
+@routes.post("/snapshot-manager/profile/save")
+async def save_profile(request):
+    try:
+        data = await request.json()
+        profile = data.get("profile")
+        if not profile or "id" not in profile:
+            return web.json_response({"error": "Missing profile with id"}, status=400)
+        storage.profile_put(profile)
+        return web.json_response({"ok": True})
+    except ValueError as e:
+        return web.json_response({"error": str(e)}, status=400)
+    except Exception as e:
+        return web.json_response({"error": str(e)}, status=500)
+
+
+@routes.get("/snapshot-manager/profile/list")
+async def list_profiles(request):
+    try:
+        profiles = storage.profile_get_all()
+        return web.json_response(profiles)
+    except Exception as e:
+        return web.json_response({"error": str(e)}, status=500)
+
+
+@routes.post("/snapshot-manager/profile/get")
+async def get_profile(request):
+    try:
+        data = await request.json()
+        profile_id = data.get("id")
+        if not profile_id:
+            return web.json_response({"error": "Missing id"}, status=400)
+        profile = storage.profile_get(profile_id)
+        if profile is None:
+            return web.json_response({"error": "Not found"}, status=404)
+        return web.json_response(profile)
+    except ValueError as e:
+        return web.json_response({"error": str(e)}, status=400)
+    except Exception as e:
+        return web.json_response({"error": str(e)}, status=500)
+
+
+@routes.post("/snapshot-manager/profile/delete")
+async def delete_profile(request):
+    try:
+        data = await request.json()
+        profile_id = data.get("id")
+        if not profile_id:
+            return web.json_response({"error": "Missing id"}, status=400)
+        storage.profile_delete(profile_id)
+        return web.json_response({"ok": True})
+    except ValueError as e:
+        return web.json_response({"error": str(e)}, status=400)
+    except Exception as e:
+        return web.json_response({"error": str(e)}, status=500)

snapshot_storage.py

@@ -0,0 +1,429 @@
+"""
+Filesystem storage layer for workflow snapshots.
+
+Stores each snapshot as an individual JSON file under:
+    <user_dir>/snapshot_manager/snapshots/<encoded_workflow_key>/<id>.json
+
+Workflow keys are percent-encoded for filesystem safety.
+
+An in-memory metadata cache avoids redundant disk reads for list/prune/delete
+operations.  Only get_full_record() reads a file from disk after warm-up.
+"""
+
+import json
+import os
+import shutil
+import urllib.parse
+
+# ─── Data directory resolution ───────────────────────────────────────
+# Prefer ComfyUI's persistent user directory; fall back to extension-local
+# paths when running outside ComfyUI (e.g. tests).
+
+_OLD_DATA_DIR = os.path.join(os.path.dirname(__file__), "data")
+
+try:
+    import folder_paths
+    _USER_SM_DIR = os.path.join(folder_paths.get_user_directory(), "snapshot_manager")
+except Exception:
+    _USER_SM_DIR = os.path.join(os.path.dirname(__file__), "data")
+
+_DATA_DIR = os.path.join(_USER_SM_DIR, "snapshots")
+
+# ─── In-memory metadata cache ────────────────────────────────────────
+# Maps workflow_key -> list of metadata dicts (sorted by timestamp asc).
+# Metadata is everything *except* graphData.
+_cache = {}
+_cache_warmed = set()  # workflow keys already loaded from disk
+
+
+def _extract_meta(record):
+    """Return a lightweight copy of *record* without graphData."""
+    return {k: v for k, v in record.items() if k != "graphData"}
+
+
+def _ensure_cached(workflow_key):
+    """Warm the cache for *workflow_key* if not already loaded. Return cached list."""
+    if workflow_key not in _cache_warmed:
+        d = _workflow_dir(workflow_key)
+        entries = []
+        if os.path.isdir(d):
+            for fname in os.listdir(d):
+                if not fname.endswith(".json"):
+                    continue
+                path = os.path.join(d, fname)
+                try:
+                    with open(path, "r", encoding="utf-8") as f:
+                        entries.append(_extract_meta(json.load(f)))
+                except (json.JSONDecodeError, OSError):
+                    continue
+        entries.sort(key=lambda r: r.get("timestamp", 0))
+        _cache[workflow_key] = entries
+        _cache_warmed.add(workflow_key)
+    return _cache.get(workflow_key, [])
+
+
+# ─── Helpers ─────────────────────────────────────────────────────────
+
+def _workflow_dir(workflow_key):
+    encoded = urllib.parse.quote(workflow_key, safe="")
+    return os.path.join(_DATA_DIR, encoded)
+
+
+def _validate_id(snapshot_id):
+    if not snapshot_id or "/" in snapshot_id or "\\" in snapshot_id or ".." in snapshot_id:
+        raise ValueError(f"Invalid snapshot id: {snapshot_id!r}")
+
+
+# ─── Public API ──────────────────────────────────────────────────────
+
+def put(record):
+    """Write one snapshot record to disk and update the cache."""
+    snapshot_id = record["id"]
+    workflow_key = record["workflowKey"]
+    _validate_id(snapshot_id)
+    d = _workflow_dir(workflow_key)
+    os.makedirs(d, exist_ok=True)
+    path = os.path.join(d, f"{snapshot_id}.json")
+    with open(path, "w", encoding="utf-8") as f:
+        json.dump(record, f, separators=(",", ":"))
+
+    # Update cache only if already warmed; otherwise _ensure_cached will
+    # pick up the new file from disk on next read.
+    if workflow_key in _cache_warmed:
+        meta = _extract_meta(record)
+        cached = _cache[workflow_key]
+        cached[:] = [e for e in cached if e.get("id") != snapshot_id]
+        cached.append(meta)
+        cached.sort(key=lambda r: r.get("timestamp", 0))
+
+
+def get_all_for_workflow(workflow_key):
+    """Return all snapshot metadata for a workflow (no graphData), sorted ascending by timestamp."""
+    return [dict(e) for e in _ensure_cached(workflow_key)]
+
+
+def get_full_record(workflow_key, snapshot_id):
+    """Read a single snapshot file from disk (with graphData). Returns dict or None."""
+    _validate_id(snapshot_id)
+    path = os.path.join(_workflow_dir(workflow_key), f"{snapshot_id}.json")
+    if not os.path.isfile(path):
+        return None
+    try:
+        with open(path, "r", encoding="utf-8") as f:
+            return json.load(f)
+    except (json.JSONDecodeError, OSError):
+        return None
+
+
+def update_meta(workflow_key, snapshot_id, fields):
+    """Merge *fields* into an existing snapshot on disk without touching graphData.
+
+    Returns True on success, False if the file does not exist.
+    """
+    _validate_id(snapshot_id)
+    path = os.path.join(_workflow_dir(workflow_key), f"{snapshot_id}.json")
+    if not os.path.isfile(path):
+        return False
+    with open(path, "r", encoding="utf-8") as f:
+        record = json.load(f)
+    # Merge fields; None values remove the key
+    for k, v in fields.items():
+        if v is None:
+            record.pop(k, None)
+        else:
+            record[k] = v
+    with open(path, "w", encoding="utf-8") as f:
+        json.dump(record, f, separators=(",", ":"))
+    # Update cache entry
+    for entry in _cache.get(workflow_key, []):
+        if entry.get("id") == snapshot_id:
+            for k, v in fields.items():
+                if k == "graphData":
+                    continue
+                if v is None:
+                    entry.pop(k, None)
+                else:
+                    entry[k] = v
+            break
+    return True
+
+
+def delete(workflow_key, snapshot_id):
+    """Remove one snapshot file and its cache entry. Cleans up empty workflow dir."""
+    _validate_id(snapshot_id)
+    d = _workflow_dir(workflow_key)
+    path = os.path.join(d, f"{snapshot_id}.json")
+    if os.path.isfile(path):
+        os.remove(path)
+
+    # Update cache
+    if workflow_key in _cache:
+        _cache[workflow_key] = [e for e in _cache[workflow_key] if e.get("id") != snapshot_id]
+        if not _cache[workflow_key]:
+            del _cache[workflow_key]
+            _cache_warmed.discard(workflow_key)
+
+    # Clean up empty directory
+    if os.path.isdir(d) and not os.listdir(d):
+        os.rmdir(d)
+
+
+def delete_all_for_workflow(workflow_key):
+    """Delete all unlocked snapshots for a workflow. Returns {lockedCount}."""
+    entries = _ensure_cached(workflow_key)
+    locked = []
+    locked_count = 0
+    d = _workflow_dir(workflow_key)
+    for rec in entries:
+        if rec.get("locked"):
+            locked_count += 1
+            locked.append(rec)
+        else:
+            _validate_id(rec["id"])
+            path = os.path.join(d, f"{rec['id']}.json")
+            if os.path.isfile(path):
+                os.remove(path)
+
+    # Update cache to locked-only
+    if locked:
+        _cache[workflow_key] = locked
+    else:
+        _cache.pop(workflow_key, None)
+        _cache_warmed.discard(workflow_key)
+
+    # Clean up empty directory
+    if os.path.isdir(d) and not os.listdir(d):
+        os.rmdir(d)
+    return {"lockedCount": locked_count}
+
+
+def get_all_workflow_keys():
+    """Scan subdirs and return [{workflowKey, count}]."""
+    if not os.path.isdir(_DATA_DIR):
+        return []
+    results = []
+    for encoded_name in os.listdir(_DATA_DIR):
+        subdir = os.path.join(_DATA_DIR, encoded_name)
+        if not os.path.isdir(subdir):
+            continue
+        workflow_key = urllib.parse.unquote(encoded_name)
+        entries = _ensure_cached(workflow_key)
+        if not entries:
+            continue
+        results.append({"workflowKey": workflow_key, "count": len(entries)})
+    results.sort(key=lambda r: r["workflowKey"])
+    return results
+
+
+def prune(workflow_key, max_snapshots, source=None, protected_ids=None):
+    """Delete oldest unlocked snapshots beyond limit. Returns count deleted.
+
+    source filtering:
+      - "node": only prune records where source == "node"
+      - "regular": only prune records where source is absent or not "node"
+      - None: prune all unlocked (existing behavior)
+
+    protected_ids: set/list of snapshot IDs that must not be pruned
+      (e.g. ancestors of active branch tip, fork-point snapshots).
+    """
+    _protected = set(protected_ids) if protected_ids else set()
+    entries = _ensure_cached(workflow_key)
+    if source == "node":
+        candidates = [r for r in entries if not r.get("locked") and r.get("source") == "node" and r.get("id") not in _protected]
+    elif source == "regular":
+        candidates = [r for r in entries if not r.get("locked") and r.get("source") != "node" and r.get("id") not in _protected]
+    else:
+        candidates = [r for r in entries if not r.get("locked") and r.get("id") not in _protected]
+    if len(candidates) <= max_snapshots:
+        return 0
+    to_delete = candidates[: len(candidates) - max_snapshots]
+    d = _workflow_dir(workflow_key)
+    deleted = 0
+    delete_ids = set()
+    for rec in to_delete:
+        _validate_id(rec["id"])
+        path = os.path.join(d, f"{rec['id']}.json")
+        if os.path.isfile(path):
+            os.remove(path)
+            deleted += 1
+            delete_ids.add(rec["id"])
+
+    # Update cache
+    if delete_ids and workflow_key in _cache:
+        _cache[workflow_key] = [e for e in _cache[workflow_key] if e.get("id") not in delete_ids]
+        if not _cache[workflow_key]:
+            del _cache[workflow_key]
+            _cache_warmed.discard(workflow_key)
+
+    # Clean up empty directory
+    if os.path.isdir(d) and not os.listdir(d):
+        os.rmdir(d)
+
+    return deleted
+
+
+# ─── Profile Storage ─────────────────────────────────────────────────
+# Profiles are stored as individual JSON files under snapshot_manager/profiles/<id>.json
+
+_PROFILES_DIR = os.path.join(_USER_SM_DIR, "profiles")
+_profile_cache = None  # list of profile dicts, or None if not loaded
+
+
+def _ensure_profiles_dir():
+    os.makedirs(_PROFILES_DIR, exist_ok=True)
+
+
+def _load_profile_cache():
+    global _profile_cache
+    if _profile_cache is not None:
+        return _profile_cache
+    _ensure_profiles_dir()
+    profiles = []
+    for fname in os.listdir(_PROFILES_DIR):
+        if not fname.endswith(".json"):
+            continue
+        path = os.path.join(_PROFILES_DIR, fname)
+        try:
+            with open(path, "r", encoding="utf-8") as f:
+                profiles.append(json.load(f))
+        except (json.JSONDecodeError, OSError):
+            continue
+    profiles.sort(key=lambda p: p.get("timestamp", 0))
+    _profile_cache = profiles
+    return _profile_cache
+
+
+def _invalidate_profile_cache():
+    global _profile_cache
+    _profile_cache = None
+
+
+def profile_put(profile):
+    """Create or update a profile. profile must have 'id'."""
+    pid = profile["id"]
+    _validate_id(pid)
+    _ensure_profiles_dir()
+    path = os.path.join(_PROFILES_DIR, f"{pid}.json")
+    with open(path, "w", encoding="utf-8") as f:
+        json.dump(profile, f, separators=(",", ":"))
+    _invalidate_profile_cache()
+
+
+def profile_get_all():
+    """Return all profiles sorted by timestamp."""
+    return [dict(p) for p in _load_profile_cache()]
+
+
+def profile_get(profile_id):
+    """Return a single profile by ID, or None."""
+    _validate_id(profile_id)
+    path = os.path.join(_PROFILES_DIR, f"{profile_id}.json")
+    if not os.path.isfile(path):
+        return None
+    try:
+        with open(path, "r", encoding="utf-8") as f:
+            return json.load(f)
+    except (json.JSONDecodeError, OSError):
+        return None
+
+
+def profile_delete(profile_id):
+    """Delete a profile by ID."""
+    _validate_id(profile_id)
+    path = os.path.join(_PROFILES_DIR, f"{profile_id}.json")
+    if os.path.isfile(path):
+        os.remove(path)
+    _invalidate_profile_cache()
+
+
+def profile_update(profile_id, fields):
+    """Merge fields into an existing profile. Returns True on success."""
+    _validate_id(profile_id)
+    path = os.path.join(_PROFILES_DIR, f"{profile_id}.json")
+    if not os.path.isfile(path):
+        return False
+    with open(path, "r", encoding="utf-8") as f:
+        profile = json.load(f)
+    for k, v in fields.items():
+        if v is None:
+            profile.pop(k, None)
+        else:
+            profile[k] = v
+    with open(path, "w", encoding="utf-8") as f:
+        json.dump(profile, f, separators=(",", ":"))
+    _invalidate_profile_cache()
+    return True
+
+
+# ─── Migration from old extension-local data ─────────────────────────
+
+def _migrate_old_data():
+    """Move data from the old <extension>/data/ location to the new user directory.
+
+    Only runs when the old directory exists, has content, and the new location
+    differs from the old one (i.e. we're actually inside ComfyUI).
+    """
+    old_snapshots = os.path.join(_OLD_DATA_DIR, "snapshots")
+    old_profiles = os.path.join(_OLD_DATA_DIR, "profiles")
+
+    # Nothing to migrate if old data dir doesn't exist or paths are the same
+    if os.path.normpath(_OLD_DATA_DIR) == os.path.normpath(_USER_SM_DIR):
+        return
+    if not os.path.isdir(_OLD_DATA_DIR):
+        return
+
+    migrated_anything = False
+
+    # Migrate snapshot workflow directories
+    if os.path.isdir(old_snapshots):
+        os.makedirs(_DATA_DIR, exist_ok=True)
+        for name in os.listdir(old_snapshots):
+            src = os.path.join(old_snapshots, name)
+            dst = os.path.join(_DATA_DIR, name)
+            if not os.path.isdir(src):
+                continue
+            if os.path.exists(dst):
+                # Merge: move individual files that don't already exist
+                for fname in os.listdir(src):
+                    s = os.path.join(src, fname)
+                    d = os.path.join(dst, fname)
+                    if not os.path.exists(d):
+                        shutil.move(s, d)
+                # Remove source dir if now empty
+                try:
+                    os.rmdir(src)
+                except OSError:
+                    pass
+            else:
+                shutil.move(src, dst)
+            migrated_anything = True
+
+    # Migrate profile files
+    if os.path.isdir(old_profiles):
+        os.makedirs(_PROFILES_DIR, exist_ok=True)
+        for fname in os.listdir(old_profiles):
+            if not fname.endswith(".json"):
+                continue
+            src = os.path.join(old_profiles, fname)
+            dst = os.path.join(_PROFILES_DIR, fname)
+            if not os.path.exists(dst):
+                shutil.move(src, dst)
+            else:
+                os.remove(src)
+            migrated_anything = True
+
+    if migrated_anything:
+        # Clean up old directories if empty
+        for d in (old_snapshots, old_profiles, _OLD_DATA_DIR):
+            try:
+                if os.path.isdir(d) and not os.listdir(d):
+                    os.rmdir(d)
+            except OSError:
+                pass
+        print("[Snapshot Manager] Migrated data to", _USER_SM_DIR)
+
+
+try:
+    _migrate_old_data()
+except Exception as e:
+    print(f"[Snapshot Manager] Migration failed, old data preserved: {e}")