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HUD — Heads-Up Display ​

Planned

The HUD is a visual filesystem interface mounted at /Bus/hud/. It provides a structured way for applications and system services to expose status information, controls, and notifications through the display system.

Concept ​

Instead of each application implementing its own status bar, notification system, or system tray, the HUD provides a unified endpoint:

/Bus/hud/
├── system/
│   ├── cpu          # CPU utilization
│   ├── memory       # Memory usage
│   ├── network      # Network status
│   └── battery      # Battery level (if applicable)
├── notifications/
│   └── <id>         # Active notifications
└── surfaces/
    └── <surface-id> # Active surface metadata

Applications write to HUD endpoints. The Surface Manager reads them and composites them into the display.

Integration ​

The HUD is tightly integrated with:

  • Surface Manager — renders HUD data as overlays
  • ProvChain — system health events are logged
  • Kinetic Economy — budget warnings appear in the HUD

Why a Filesystem Interface? ​

Following the Plan 9 philosophy: if it has state, it's a file. The HUD filesystem approach means:

  • Any programming language can write HUD data (just write to a file)
  • Remote monitoring works through standard file protocols
  • Access control uses the same capability system as everything else
  • No custom IPC protocols, no D-Bus, no notification daemons