signal-ha

Async Rust toolkit for writing Home Assistant automations as standalone processes managed by systemd.

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What it does

signal-ha gives you a WebSocket client, sun-aware scheduler, lighting engine, embedded LLM agent, and Python bindings — everything needed to build Home Assistant automations that run as plain systemd services.

Each automation is its own OS process. systemd handles restarts, dependency ordering, and resource limits. No plugin loader, no shared runtime, no framework. The OS is the framework.

Crates

Crate	Description
signal-ha	Core library — HaClient (WebSocket + REST) and Scheduler (sun-aware timers)
signal-ha-lighting	Lighting primitives — actuator, overlay, reconciler, lux-adaptive targets
signal-ha-agent	Embedded LLM observation agent (HA Conversation API)
signal-ha-shell	Portable Monty Python runtime for agent code execution
signal-ha-py	PyO3 bindings — use signal-ha from Python
message-board	SQLite-backed findings board REST API for agents

Quick start

# Build all crates
cargo build --release

# Build the Python module
pip install maturin
cd crates/signal-ha-py && maturin develop --release

Automations are separate binaries that depend on these library crates — add signal-ha (and optionally signal-ha-lighting / signal-ha-agent) as dependencies in your own Cargo workspace.

Philosophy

• One process per automation — crash isolation, independent restarts
• systemd is the supervisor — no custom daemon, no watchdog
• Read-only agents — LLM observers that watch but don't act (unless you let them)
• Sun-aware scheduling — first-class sunrise/sunset primitives, not cron hacks
• Rust all the way down — Python only at the edges (PyO3 bindings, agent scripts)