Every failing endpoint returned "An error occurred; see logs for
details" and nothing else. That is survivable until the logs are the
thing you cannot reach: a device whose SD card was failing answered the
restart action, /system/status and /logs with that same sentence -- the
log viewer included, because journalctl could not be executed -- while
the exception underneath said
[Errno 5] Input/output error: 'systemctl'
which names the fault outright. The only endpoint that helped was
/health, and only because it happens to pass a subprocess's stderr
through. Diagnosis came down to guessing which endpoint leaked something.
Add describe_exception(), returning "TypeName: message" on one line, and
populate the `details` field that the response schema has always had and
nothing ever filled. The type alone carries information -- a bare
PermissionError says more than any generic sentence.
Exception text is not automatically safe to echo: a requests error
quotes the URL it failed on, and plugins that authenticate by query
string put their key there. Credential values are redacted while the
parameter name is kept, since knowing which credential was involved is
part of the diagnosis. Length is capped and newlines collapsed so a
parser's context cannot flood a JSON field.
Nine handlers in api_v3 bound the exception and never used it, so the
promised log entry was never written either -- "see logs for details"
was false, not merely unhelpful. Those now log with a traceback and
carry the detail. The other 60 already logged and are unchanged; they
can adopt the helper as they are touched.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Udr6MfaFLUPhX5Fgo67Jf5
LED Matrix Web Interface V3
Modern, production web interface for controlling the LED Matrix display.
Overview
This directory contains the active V3 web interface with the following features:
- Real-time display preview via Server-Sent Events (SSE)
- Plugin management and configuration
- System monitoring and logs
- Modern, responsive UI
- RESTful API
Directory Structure
web_interface/
├── app.py # Main Flask application
├── start.py # Startup script
├── run.sh # Shell runner script
├── requirements.txt # Python dependencies
├── blueprints/ # Flask blueprints
│ ├── api_v3.py # API endpoints
│ └── pages_v3.py # Page routes
├── templates/ # HTML templates
│ └── v3/
│ ├── base.html
│ ├── index.html
│ └── partials/
└── static/ # CSS/JS assets
└── v3/
├── app.css
├── app.js
├── manifest.json # PWA manifest
├── plugins_manager.js
├── icons/ # PWA / touch icons
├── js/ # Alpine, htmx, app shell, widgets, utils
└── vendor/ # codemirror, fontawesome
Running the Web Interface
Standalone (Development)
From the project root:
python3 web_interface/start.py
Or using the shell script:
./web_interface/run.sh
As a Service (Production)
The web interface can run as a systemd service that starts automatically based on the web_display_autostart configuration setting:
sudo systemctl start ledmatrix-web
sudo systemctl enable ledmatrix-web # Start on boot
Accessing the Interface
Once running, access the web interface at:
- Local: http://localhost:5000
- Network: http://:5000
Configuration
The web interface reads configuration from:
config/config.json- Main configurationconfig/config_secrets.json- API keys and secrets
API Documentation
The V3 API is mounted at /api/v3/ (app.py:144). For the complete
list and request/response formats, see
docs/REST_API_REFERENCE.md. Quick
reference for the most common endpoints:
Configuration
GET /api/v3/config/main- Get main configurationPOST /api/v3/config/main- Save main configurationGET /api/v3/config/secrets- Get secrets configurationPOST /api/v3/config/raw/main- Save raw main config (Config Editor)POST /api/v3/config/raw/secrets- Save raw secrets
Display & System Control
GET /api/v3/system/status- System statusPOST /api/v3/system/action- Control display (action body:start_display,stop_display,restart_display_service,restart_web_service,git_pull,reboot_system,shutdown_system,enable_autostart,disable_autostart)GET /api/v3/display/current- Current display frameGET /api/v3/display/on-demand/status- On-demand statusPOST /api/v3/display/on-demand/start- Trigger on-demand displayPOST /api/v3/display/on-demand/stop- Clear on-demand
Plugins
GET /api/v3/plugins/installed- List installed pluginsGET /api/v3/plugins/config?plugin_id=<id>- Get plugin configPOST /api/v3/plugins/config- Update plugin configurationGET /api/v3/plugins/schema?plugin_id=<id>- Get plugin schemaPOST /api/v3/plugins/toggle- Enable/disable pluginPOST /api/v3/plugins/install- Install from registryPOST /api/v3/plugins/install-from-url- Install from GitHub URLPOST /api/v3/plugins/uninstall- Uninstall pluginPOST /api/v3/plugins/update- Update plugin
Plugin Store
GET /api/v3/plugins/store/list- List available registry pluginsGET /api/v3/plugins/store/github-status- GitHub authentication statusPOST /api/v3/plugins/store/refresh- Refresh registry from GitHub
Real-time Streams (SSE)
SSE stream endpoints are defined directly on the Flask app
(app.py:607-619 — includes the CSRF exemption and rate-limit hookup
alongside the three route definitions), not on the api_v3 blueprint:
GET /api/v3/stream/stats- System statistics streamGET /api/v3/stream/display- Display preview streamGET /api/v3/stream/logs- Service logs stream
Development
When making changes to the web interface:
- Edit files in this directory
- Test changes by running
python3 web_interface/start.py - Restart the service if running:
sudo systemctl restart ledmatrix-web
Notes
- Templates and static files use the
v3/prefix to allow for future versions - The interface uses Flask blueprints for modular organization
- SSE streams provide real-time updates without polling