Streamline Bridge

Streamline Bridge connects your Decent Espresso machine to beautiful, modern user interfaces (called "skins").
Think of it as the bridge between your DE1 (or Bengle) and sleek touchscreen experiences like Streamline.js.

What it does:

• Connects to your Decent Espresso machine via Bluetooth or USB
• Lets you control your machine through modern web-based interfaces
• Provides real-time shot data, temperatures, and pressure readings
• Works with scales to automatically stop shots at your target weight
• Runs on Android tablets, desktop computers, and more

For developers: Streamline Bridge provides a complete REST and WebSocket API, making it easy to build custom interfaces without dealing with the complexity of machine communication and device connectivity.

Table of Contents

• Features
• API Documentation
• Supported Platforms
• WebUI / Skins
• Supported Operations
• Plugins
• Documentation
• Building
• System Requirements
• Troubleshooting
• Credits

Features

• REST API for machine control, settings, and shot management
• WebSocket streams for real-time updates (shot progress, weight, temperature)
• Profile management with content-based hashing and automatic deduplication
• Auto-connect to preferred devices on startup
• Gateway modes for flexible control delegation
• Display control — screen brightness and wake-lock management via API
• Presence-based auto-sleep with configurable timeouts and scheduled wake times
• Plugin system for extensibility
• WebUI support with multiple skins
• Cross-platform support (Android, macOS, Linux, Windows, iOS)

API Documentation

To browse the complete API documentation:

1. Start Streamline Bridge
2. Navigate to http://localhost:4001

Or:

1. Change directory to assets/api/ on your computer
2. Run npx httpserver -p 4001 to start a http server in that folder
3. Navigate to http://localhost:4001

The API provides:

• REST endpoints on port 8080
• WebSocket streams for real-time data
• Plugin HTTP endpoints for custom integrations

Supported Platforms

Platform	Status	Notes
Android	✅ Primary	Runs on Decent Espresso tablets
macOS	✅ Full support	Desktop development and testing
Linux	✅ Full support	ARM64 and x86_64
Windows	✅ Full support	Desktop operation
iOS	⚠️ Experimental	Limited testing

Background Operation

On Android, Streamline Bridge can run as a foreground service, maintaining stable connections to your machine and scale while tucked away in the background.

WebUI / Skins

Similar to the original DE1 app, Streamline Bridge supports loading and displaying different "skins" (web-based UIs).

Accessing Skins

• Network access: From any device on your local network at http://<device-ip>:3000
• In-app WebView: On supported platforms, use the embedded browser to access skins directly

Android WebView Compatibility

Note for Teclast tablets: Some older Android System WebView versions may cause display issues with the in-app skin view.

Solutions:

1. Update Android System WebView from APKMirror
2. Restart your device after updating
3. Use an external browser if issues persist (the app will automatically detect incompatible WebViews)

Supported Operations

Machine Operations

• ✅ Query and control machine state (power on/off, start/stop espresso)
• ✅ Configure machine settings (temperatures, flow rates, timeouts)
• ✅ Upload v2 JSON profiles (compatible with DE1 app profiles_v2 format)
• ✅ Real-time shot telemetry via WebSocket
• ✅ Advanced settings management

Scale Operations

• ✅ Tare scale
• ✅ Real-time weight updates via WebSocket
• ✅ Auto-stop shots at target weight
• ✅ Power management (auto-disconnect/display-off when machine sleeps)

Supported Scales

• Felicita Arc
• Decent Scale
• Bookoo Mini Scale

Workflow Management

• ✅ Create and save multi-step workflows
• ✅ Set target weight for automatic shot stopping
• ✅ Profile selection per workflow

Display & Presence

• ✅ Screen brightness control (dim/restore) via REST and WebSocket
• ✅ Wake-lock management (keep screen on) with auto-cleanup
• ✅ User presence heartbeats with configurable auto-sleep timeout
• ✅ Scheduled wake times (e.g., warm up the machine every weekday at 6:30 AM)

Additional Features

• ✅ Auto-connect: Set preferred devices for automatic connection on startup
• ✅ Gateway modes:
  • Disabled: Full local control
  • Tracking: Monitor and stop at target weight
  • Full: Complete remote control
• ✅ Shot history: Save and export shot data
• ✅ Device simulation: Test without physical hardware

Plugins

Streamline Bridge features a JavaScript plugin system for dynamic functionality expansion.

Capabilities:

• React to machine state changes
• Make HTTP requests
• Store persistent data
• Emit custom events
• Serve custom HTTP endpoints

Bundled Plugins:

• settings.reaplugin: Web-based settings dashboard
• time-to-ready.reaplugin: Machine warm-up notifications
• visualizer.reaplugin: Real-time shot visualization

📖 Read the Plugin Development Guide →

Documentation

In-depth guides and API references are available in the doc/ directory:

Document	Description
Skins.md	WebUI skin development guide — REST & WebSocket API reference, development workflow, deployment via GitHub Releases
Plugins.md	JavaScript plugin development — host API, event system, manifest structure, and examples
Profiles.md	Profiles API — content-based hash IDs, version tracking, import/export, and storage architecture
DeviceManagement.md	Device discovery and connection management — transport abstraction, auto-connect logic, adding new device types
RELEASE.md	Release process — Git tag workflow, GitHub Actions CI, versioning conventions

Building

Prerequisites

• Flutter SDK: Version 3.7.0 or later
• Platform-specific tools:
  • Android: Android Studio / SDK
  • macOS: Xcode
  • Linux: Standard build tools
  • Windows: Visual Studio

Development Build

The project includes a build script that injects version information from Git:

./flutter_with_commit.sh run

For standard Flutter builds:

flutter run

Linux ARM64 (Docker/Colima)

Build for ARM64 tablets using containers:

# Start Colima with ARM64 profile
make colima-arm

# Build
make build-arm

For x86_64:

make colima-amd
make build-amd

Build both architectures:

make dual-build

System Requirements

Minimum Requirements

• Android: 8.0 (API 26) or later
• macOS: 10.14 or later
• Linux: Modern distribution with GTK 3.0+
• Windows: Windows 10 or later
  • Important: Requires Microsoft Visual C++ Redistributable to be installed

Recommended

• RAM: 2GB+ available
• Storage: 500MB for app + skins
• Network: Local WiFi network for skin access
• Bluetooth: Bluetooth 4.0+ for device connectivity

Troubleshooting

WebView Issues (Android)

Problem: Blank screen or rendering artifacts in skin view

Solutions:

1. Update Android System WebView
2. Clear app data and restart
3. Use external browser option (Settings → Auto-detected)

Connection Issues

Problem: Cannot connect to machine or scale

Solutions:

1. Verify Bluetooth is enabled
2. Check device permissions (Location, Bluetooth)
3. Try "Scan Again" in device selection
4. Check if device is already connected to another app

Auto-Connect Not Working

Problem: Preferred device doesn't auto-connect

Solutions:

1. Verify device ID is correct (Settings → Auto-Connect Device)
2. Ensure device is powered on during scan
3. Clear and re-set preferred device
4. Check logs for connection errors

API Not Accessible

Problem: Cannot reach API at localhost:8080

Solutions:

1. Verify app is running
2. Check firewall settings
3. On network access: use device's local IP instead of localhost
4. Check port 8080 is not in use by another application

About the Name

Streamline Bridge (formerly known as REA/ReaPrime) represents a simplified approach to the project's terminology.

The Evolution

The original name REA stood for "Reasonable Espresso App" - a tongue-in-cheek reference to brewing something "reasonably decent" with a Decent Espresso machine. As the project evolved into ReaPrime, we realized the naming could be clearer for users.

Why Streamline Bridge?

The rename to Streamline Bridge better reflects the project's role in the ecosystem:

• Streamline.js: Our modern, sleek WebUI skin being developed separately - the user-facing interface
• Streamline Bridge: This application - the bridge that connects Streamline.js (and other skins) to your espresso machine

The name emphasizes the app's purpose: bridging the gap between beautiful user interfaces and the complexity of machine communication, device connectivity, and state management.

Credits

Acknowledgments

• @randomcoffeesnob: Original name inspiration and ongoing support
• @mimoja: First Flutter app version
• Decent Espresso community: Testing, feedback, and feature requests

License

This project is licensed under the GNU General Public License v3.0 (GPL-3.0).

See the LICENSE file for details.

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Need help? Check our documentation or open an issue.