configurable autosave

backend/main.py

@@ -230,6 +230,16 @@ UPLOAD_MAX_AUDIO_MB = int(os.getenv('UPLOAD_MAX_AUDIO_MB', '50'))
 UPLOAD_MAX_VIDEO_MB = int(os.getenv('UPLOAD_MAX_VIDEO_MB', '100'))
 UPLOAD_MAX_PDF_MB = int(os.getenv('UPLOAD_MAX_PDF_MB', '20'))
 
+# Autosave debounce in milliseconds (applies to note typing AND drawing PNG autosave).
+try:
+    _autosave_raw = int(os.getenv(
+        'AUTOSAVE_DELAY_MS',
+        str(config.get('ui', {}).get('autosave_delay_ms', 1000))
+    ))
+except (TypeError, ValueError):
+    _autosave_raw = 1000
+AUTOSAVE_DELAY_MS = max(250, min(60000, _autosave_raw))
+
 if DEMO_MODE:
     # Enable rate limiting for demo deployments
     limiter = Limiter(key_func=get_remote_address, default_limits=["200/hour"])
@@ -488,6 +498,7 @@ async def get_config():
         "searchEnabled": config['search']['enabled'],
         "demoMode": DEMO_MODE,  # Expose demo mode flag to frontend
         "alreadyDonated": ALREADY_DONATED,  # Hide support buttons if true
+        "autosaveDelayMs": AUTOSAVE_DELAY_MS,  # Debounce for note/drawing autosave
         "authentication": {
             "enabled": config.get('authentication', {}).get('enabled', False)
         }

config.yaml

@@ -22,7 +22,14 @@ storage:
   
 search:
   enabled: true
-  
+
+# User interface behavior
+ui:
+  # Autosave debounce in milliseconds (applies to note typing and drawing autosave).
+  # Lower = saves more often (more disk writes); higher = saves less often.
+  # Override via the AUTOSAVE_DELAY_MS env var. Server clamps to 250-60000ms.
+  autosave_delay_ms: 1000
+
 authentication:
   # Authentication settings
   # Set enabled to true to require login

documentation/ENVIRONMENT_VARIABLES.md

@@ -67,6 +67,30 @@ environment:
   - UPLOAD_MAX_VIDEO_MB=500
 ```
 
+### User Interface
+
+| Variable | Type | Default | Description |
+|----------|------|---------|-------------|
+| `AUTOSAVE_DELAY_MS` | integer | `1000` | Autosave debounce in milliseconds (applies to note typing and drawing autosave). Server-clamped to 250–60000ms. |
+
+#### Example: Slower autosave for very large notes
+
+```bash
+# Docker
+docker run -e AUTOSAVE_DELAY_MS=5000 ...
+
+# Docker Compose
+environment:
+  - AUTOSAVE_DELAY_MS=5000
+```
+
+Equivalent in `config.yaml`:
+
+```yaml
+ui:
+  autosave_delay_ms: 5000
+```
+
 ## 🎯 Configuration Priority
 
 Configuration is loaded in this order (later overrides earlier):

frontend/app.js

@@ -2,7 +2,7 @@
 
 // Configuration constants
 const CONFIG = {
-    AUTOSAVE_DELAY: 1000,              // ms - Debounce before note save (autoSave) and drawing PNG autosave (_drawingScheduleAutosave)
+    AUTOSAVE_DELAY: 1000,              // ms - Fallback only; runtime value lives on this.autosaveDelayMs (hydrated from /api/config). Used by autoSave() and _drawingScheduleAutosave().
     /** Must match drawingRedraw() fill and eraser stroke color (opaque “whiteboard”). */
     DRAWING_BACKGROUND: '#ffffff',
     /**
@@ -260,6 +260,7 @@ function noteApp() {
         authEnabled: false,
         demoMode: false,
         alreadyDonated: false,
+        autosaveDelayMs: CONFIG.AUTOSAVE_DELAY,  // hydrated from /api/config in loadConfig()
         notes: [],
         currentNote: '',
         currentNoteName: '',
@@ -959,6 +960,10 @@ function noteApp() {
                 this.authEnabled = config.authentication?.enabled || false;
                 this.demoMode = config.demoMode || false;
                 this.alreadyDonated = config.alreadyDonated || false;
+                // Server already clamps autosaveDelayMs to a sane range; we just sanity-check the type.
+                if (Number.isFinite(config.autosaveDelayMs) && config.autosaveDelayMs > 0) {
+                    this.autosaveDelayMs = config.autosaveDelayMs;
+                }
             } catch (error) {
                 console.error('Failed to load config:', error);
             }
@@ -3253,7 +3258,7 @@ function noteApp() {
                 this._drawingAutosaveTimeout = null;
                 this.drawingSave();
             };
-            this._drawingAutosaveTimeout = setTimeout(attemptSave, CONFIG.AUTOSAVE_DELAY);
+            this._drawingAutosaveTimeout = setTimeout(attemptSave, this.autosaveDelayMs);
         },
         
         /**
@@ -5064,7 +5069,7 @@ function noteApp() {
                     this.commitToHistory();
                 }
                 this.saveNote();
-            }, CONFIG.AUTOSAVE_DELAY);
+            }, this.autosaveDelayMs);
         },
         
         // Mark that we have pending changes (called on each keystroke)