Clean up Nix configuration and remove old files

- Move Nix package and module to nix/ directory for better organization
- Remove old Nix files (systant.nix, systant-old.nix, etc.)
- Remove debug script and systemd service file
- Update config files for new Nix structure
- Add CLAUDE.md with project documentation

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

.claude/settings.json

@@ -1,40 +0,0 @@
-{
-  "$schema": "https://claude.ai/claude-code/settings.schema.json",
-  "permissions": {
-    "allow": [
-      "Bash(bun test*)",
-      "Bash(bun run*)",
-      "Bash(bun build*)",
-      "Bash(bun install*)",
-      "Bash(bunx tsc --noEmit*)",
-      "Bash(git status*)",
-      "Bash(git diff*)",
-      "Bash(git log*)",
-      "Bash(git add*)",
-      "Bash(git commit*)",
-      "Bash(ls*)",
-      "Bash(cat /proc/*)",
-      "Bash(cat /sys/*)"
-    ],
-    "deny": [
-      "Bash(rm -rf /)*",
-      "Bash(sudo *)",
-      "Bash(*--force*)"
-    ]
-  },
-  "hooks": {
-    "PostToolUse": [
-      {
-        "matcher": "Edit|Write",
-        "hooks": [
-          {
-            "type": "command",
-            "command": "bunx tsc --noEmit --pretty 2>&1 | head -20 || true",
-            "description": "Type check after file changes",
-            "timeout": 10000
-          }
-        ]
-      }
-    ]
-  }
-}

.claude/skills/build.md

@@ -1,28 +0,0 @@
-# /build
-
-Build the systant CLI binary.
-
-## Instructions
-
-1. Run type checking first: `bunx tsc --noEmit`
-2. If types pass, build the binary: `bun build index.ts --compile --outfile dist/systant`
-3. Report the binary size and location
-4. If there are errors, show them clearly and suggest fixes
-
-## Nix Build
-
-For NixOS deployment, the binary is built by Nix using:
-```bash
-nix build .#systant
-```
-
-If you update dependencies (bun.lock), update the hash in `nix/package.nix`:
-```bash
-nix build .#systant 2>&1 | grep 'got:'
-```
-
-## Success Criteria
-
-- No TypeScript errors
-- Binary created at `dist/systant`
-- Binary is executable

.claude/skills/plan.md

@@ -1,26 +0,0 @@
-# /plan
-
-Enter planning mode to design an implementation approach.
-
-## Instructions
-
-1. Enter plan mode using EnterPlanMode tool
-2. Explore the codebase to understand current state
-3. Identify affected files and components
-4. Design the implementation approach
-5. Present the plan for user approval before coding
-
-## When to Use
-
-- New features
-- Architectural changes
-- Complex bug fixes
-- Refactoring tasks
-
-## Output
-
-A clear plan including:
-- Files to create/modify
-- Key implementation steps
-- Potential risks or considerations
-- Testing approach

.claude/skills/release.md

@@ -1,28 +0,0 @@
-# /release
-
-Prepare a release of systant.
-
-## Instructions
-
-1. Ensure working directory is clean (`git status`)
-2. Run tests: `bun test`
-3. Type check: `bunx tsc --noEmit`
-4. Build binary: `bun build index.ts --compile --outfile dist/systant`
-5. Ask user for version bump type (patch/minor/major)
-6. Update version in package.json
-7. Create git commit with message: "release: v{version}"
-8. Create git tag: `v{version}`
-9. Report next steps (push, publish, etc.)
-
-## Prerequisites
-
-- All tests must pass
-- No TypeScript errors
-- Clean git working directory (or user confirms to proceed)
-
-## Success Criteria
-
-- Binary built successfully
-- Version bumped in package.json
-- Git commit and tag created
-- Clear instructions for next steps

.claude/skills/test.md

@@ -1,22 +0,0 @@
-# /test
-
-Run the test suite.
-
-## Instructions
-
-1. Run `bun test` to execute all tests
-2. If tests fail:
-   - Analyze the failure messages
-   - Identify the root cause
-   - Suggest specific fixes
-3. If tests pass, report the summary
-
-## Options
-
-- `/test <pattern>` - Run tests matching a pattern (e.g., `/test metrics`)
-- `/test --watch` - Run in watch mode
-
-## Success Criteria
-
-- All tests pass
-- Clear reporting of any failures with actionable suggestions

.claude/skills/typecheck.md

@@ -1,16 +0,0 @@
-# /typecheck
-
-Run TypeScript type checking.
-
-## Instructions
-
-1. Run `bunx tsc --noEmit --pretty`
-2. If errors found:
-   - List each error with file, line, and message
-   - Provide suggested fixes for each
-3. If no errors, confirm success
-
-## Success Criteria
-
-- Report all type errors clearly
-- Suggest actionable fixes

.formatter.exs

@@ -0,0 +1,4 @@
+# Used by "mix format"
+[
+  inputs: ["{mix,.formatter}.exs", "{config,lib,test}/**/*.{ex,exs}"]
+]

.gitignore

@@ -1,46 +1,30 @@
-# See https://help.github.com/articles/ignoring-files/ for more about ignoring files.
+# The directory Mix will write compiled artifacts to.
+/_build/
 
-# Dependencies
+# If you run "mix test --cover", coverage assets end up here.
-node_modules
+/cover/
-.pnp
-.pnp.js
 
-# Local env files
+# The directory Mix downloads your dependencies sources to.
-.env
+/deps/
-.env.local
-.env.development.local
-.env.test.local
-.env.production.local
 
-# Testing
+# Where third-party dependencies like ExDoc output generated docs.
-coverage
+/doc/
 
-# Turbo
+# If the VM crashes, it generates a dump, let's ignore it too.
-.turbo
+erl_crash.dump
 
-# Vercel
+# Also ignore archive artifacts (built via "mix archive.build").
-.vercel
+*.ez
 
-# Build Outputs
+# Ignore package tarball (built via "mix hex.build").
-.next/
+system_stats_daemon-*.tar
-out/
-build
-dist
 
+# Temporary files, for example, from tests.
+/tmp/
 
-# Debug
+# Nix direnv cache and generated files
-npm-debug.log*
+.direnv/
-yarn-debug.log*
-yarn-error.log*
 
-# Misc
+# Nix result symlinks
-.DS_Store
+result
-*.pem
+result-*
-auth_failures.log
-
-# Nix
-.direnv
-.direnv/*
-
-# Local config (use systant.toml.example as template)
-systant.toml

.vscode/settings.json

@@ -1,3 +0,0 @@
-{
-    "terminal.integrated.fontFamily": "Fira Code"
-}

AGENTS.md

@@ -1,102 +0,0 @@
-# Agents
-
-Specialized sub-agents for systant development tasks.
-
-## test-runner
-
-Use this agent after writing or modifying code to run the test suite and verify changes.
-
-**Responsibilities:**
-- Run `bun test` and report results
-- Identify failing tests and their root causes
-- Suggest fixes for test failures
-- Run specific test files when targeted testing is needed
-
-**Trigger:** After implementing features, fixing bugs, or modifying existing code.
-
-## code-reviewer
-
-Use this agent to review code changes before committing.
-
-**Responsibilities:**
-- Check for Bun best practices (no Node.js patterns)
-- Verify type safety and explicit return types
-- Look for potential bugs or edge cases
-- Ensure code follows project conventions
-- Flag any security concerns (especially in command execution)
-
-**Trigger:** Before creating commits or PRs.
-
-## entity-specialist
-
-Use this agent when working on entity configuration or the entity system.
-
-**Responsibilities:**
-- Understand entity types (sensor, binary_sensor, switch, light, button)
-- Design shell commands for state polling and actions
-- Ensure proper Home Assistant discovery payloads
-- Validate entity configuration options
-
-**Context:** Systant uses a unified "entity" system where all metrics and controls are defined as entities in TOML config. Each entity has a `state_command` and optionally `on_command`/`off_command`/`press_command` depending on type.
-
-## mqtt-specialist
-
-Use this agent when working on MQTT publishing or Home Assistant integration.
-
-**Responsibilities:**
-- Understand MQTT topic conventions
-- Know Home Assistant discovery protocol
-- Ensure proper QoS and retain flag usage
-- Handle connection lifecycle (connect, reconnect, disconnect)
-- Design topic hierarchies for commands and events
-
-**Context:** Systant publishes to MQTT with Home Assistant auto-discovery. Topics follow the pattern `systant/{hostname}/{entity_id}/state` for state updates, `systant/{hostname}/{entity_id}/set` for switch/light commands, and `homeassistant/{type}/{hostname}_{entity_id}/config` for discovery.
-
-## nix-specialist
-
-Use this agent when working on Nix packaging or the home-manager module.
-
-**Responsibilities:**
-- Maintain the Nix flake and package definition
-- Update the home-manager module options
-- Handle fixed-output derivations for npm dependencies
-- Ensure cross-system compatibility
-
-**Context:** Systant is packaged as a Nix flake with a home-manager module. The package uses a two-phase build: FOD for `bun install`, then `bun build --compile` for the binary. The home-manager module creates a systemd user service.
-
-## debug-investigator
-
-Use this agent when troubleshooting issues or unexpected behavior.
-
-**Responsibilities:**
-- Add strategic logging to trace execution
-- Isolate the problem to specific components
-- Form and test hypotheses
-- Propose minimal fixes
-
-**Trigger:** When something isn't working as expected.
-
-## architect
-
-Use this agent for design decisions and architectural questions.
-
-**Responsibilities:**
-- Evaluate trade-offs between approaches
-- Consider future extensibility
-- Maintain consistency with existing patterns
-- Document decisions in code comments or CLAUDE.md
-
-**Trigger:** When facing design choices or planning new features.
-
-## security-auditor
-
-Use this agent when reviewing security-sensitive code.
-
-**Responsibilities:**
-- Review command execution paths for injection vulnerabilities
-- Validate input sanitization
-- Check allowlist/denylist implementations
-- Ensure proper authentication for MQTT commands
-- Review file system access patterns
-
-**Context:** Systant executes commands based on MQTT messages. This is a critical attack surface that requires careful security review.

CLAUDE.md

@@ -1,165 +1,79 @@
-# Systant
+# CLAUDE.md
 
-A system monitoring agent that collects metrics, monitors services, and reports to MQTT/Home Assistant; and responds to events over MQTT to trigger commands or other behavior.
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
 
-## Project Overview
+## Common Commands
-
-Systant is a lightweight CLI tool written in Bun/TypeScript that:
-- Collects system metrics (CPU, memory, disk, network)
-- Monitors service health
-- Publishes data to MQTT brokers
-- Supports Home Assistant auto-discovery
-- **Listens for MQTT commands** to trigger actions (run scripts, restart services, etc.)
-- **Responds to events** with configurable handlers
-- Runs as a daemon or one-shot command
-
-### Architecture
-
-```
-index.ts              # CLI entry point
-src/
-  config.ts           # TOML configuration loading
-  mqtt.ts             # MQTT client, publishing, and HA discovery
-  entities.ts         # Entity management (state polling, command handling)
-```
-
-### Entity System
-
-Systant uses a unified "entity" concept that combines state monitoring and command handling. Entity types:
-
-- **sensor**: Read-only numeric/string values (CPU usage, temperature, etc.)
-- **binary_sensor**: Read-only on/off states (service running, etc.)
-- **switch**: Controllable on/off with `on_command` and `off_command`
-- **light**: Same as switch, for display/monitor control
-- **button**: Press-only actions with `press_command`
-
-Each entity is defined in TOML with shell commands:
-
-```toml
-[entities.cpu_usage]
-type = "sensor"
-state_command = "awk '/^cpu / {print int(($2+$4)*100/($2+$4+$5))}' /proc/stat"
-unit = "%"
-icon = "mdi:chip"
-name = "CPU Usage"
-
-[entities.headphones]
-type = "switch"
-state_command = "pactl get-default-sink | grep -q usb && echo ON || echo OFF"
-on_command = "pactl set-default-sink alsa_output.usb-..."
-off_command = "pactl set-default-sink alsa_output.pci-..."
-```
-
-### MQTT Topics
-
-```
-systant/{hostname}/{entity_id}/state      # State updates
-systant/{hostname}/{entity_id}/set        # Commands (for switch/light)
-systant/{hostname}/{entity_id}/press      # Button presses
-systant/{hostname}/availability           # Online/offline status
-homeassistant/{type}/{hostname}_{id}/config  # HA auto-discovery
-```
-
-### Key Design Decisions
-
-- **Single binary**: Compiles to standalone executable via `bun build --compile`
-- **No external services**: Uses Bun built-ins (sqlite, file, etc.)
-- **Config-driven**: TOML configuration for flexibility
-- **Typed throughout**: Full TypeScript with strict mode
-
-## Tech Stack
-
-- **Runtime**: Bun (not Node.js)
-- **Config**: TOML (smol-toml)
-- **MQTT**: mqtt.js
-- **Packaging**: Nix flake with home-manager module
-
-### NixOS/Home Manager Integration
-
-```nix
-# flake.nix inputs
-inputs.systant.url = "git+ssh://...";
-
-# Add overlay for pkgs.systant
-nixpkgs.overlays = [ inputs.systant.overlays.default ];
-
-# Import home-manager module
-home-manager.sharedModules = [ inputs.systant.homeManagerModules.default ];
-
-# In user config
-services.systant = {
-  enable = true;
-  settings = { /* TOML as Nix attrset */ };
-  # or: configFile = ./systant.toml;
-};
-```
-
-## Bun Conventions
-
-Default to using Bun instead of Node.js.
-
-- Use `bun <file>` instead of `node <file>` or `ts-node <file>`
-- Use `bun test` instead of `jest` or `vitest`
-- Use `bun build <file.html|file.ts|file.css>` instead of `webpack` or `esbuild`
-- Use `bun install` instead of `npm install` or `yarn install` or `pnpm install`
-- Use `bun run <script>` instead of `npm run <script>`
-- Use `bunx <package> <command>` instead of `npx <package> <command>`
-- Bun automatically loads .env, so don't use dotenv.
-
-### Bun APIs
-
-- `Bun.serve()` for HTTP/WebSocket servers
-- `bun:sqlite` for SQLite (not better-sqlite3)
-- `Bun.file()` for file I/O (not node:fs readFile/writeFile)
-- `Bun.$\`cmd\`` for shell commands (not execa)
-- Native `WebSocket` (not ws)
-
-### Testing
-
-```ts
-import { test, expect, describe, beforeEach } from "bun:test";
-
-describe("MetricCollector", () => {
-  test("collects CPU metrics", async () => {
-    const metrics = await collectCPU();
-    expect(metrics.usage).toBeGreaterThanOrEqual(0);
-  });
-});
-```
-
-Run tests: `bun test`
-Run specific: `bun test src/metrics`
-Watch mode: `bun test --watch`
-
-## Code Style
-
-- Prefer `async/await` over callbacks
-- Use explicit return types on public functions
-- Prefer `interface` over `type` for object shapes
-- Use `const` by default, `let` only when reassignment needed
-- No classes unless state encapsulation is genuinely needed
-- Prefer pure functions and composition
-
-## Commands
 
+### Development
 ```bash
-# Development
+# Install dependencies
-bun run index.ts run --config systant.toml
+mix deps.get
 
-# Build standalone binary
+# Compile the project
-bun build index.ts --compile --outfile systant
+mix compile
 
-# Nix build
+# Run in development (non-halt mode)
-nix build .#systant
+mix run --no-halt
 
 # Run tests
-bun test
+mix test
+
+# Run specific test
+mix test test/systant_test.exs
+
+# Enter development shell (via Nix)
+nix develop
 ```
 
-## Planning Protocol
+### Production
+```bash
+# Build production release
+MIX_ENV=prod mix release
 
-When implementing features:
+# Run production release
-1. Discuss the approach before writing code
+_build/prod/rel/systant/bin/systant start
-2. Start with types/interfaces
+```
-3. Write tests alongside implementation
+
-4. Keep PRs focused and small
+## Architecture Overview
+
+This is an Elixir OTP application that serves as a systemd daemon for MQTT-based system monitoring, designed for deployment across multiple NixOS hosts to integrate with Home Assistant.
+
+### Core Components
+- **Systant.Application** (`lib/systant/application.ex`): OTP application supervisor that starts the MQTT client
+- **Systant.MqttClient** (`lib/systant/mqtt_client.ex`): GenServer that handles MQTT connection, publishes stats every 30 seconds, and listens for commands
+- **Configuration**: MQTT settings configurable via environment variables or config files
+
+### Key Libraries
+- **Tortoise**: MQTT client library for pub/sub functionality
+- **Jason**: JSON encoding/decoding for message payloads
+
+### MQTT Behavior
+- Publishes "Hello from systant" messages with timestamp and hostname to stats topic every 30 seconds
+- Subscribes to commands topic for incoming events that can trigger user-customizable actions
+- Uses randomized client ID to avoid conflicts across multiple hosts
+- Sends immediate hello message on startup
+
+### Default Configuration
+- **MQTT Host**: `mqtt.home` (not localhost)
+- **Stats Topic**: `systant/${hostname}/stats` (per-host topics)
+- **Command Topic**: `systant/${hostname}/commands` (per-host topics)
+- **Publish Interval**: 30 seconds
+
+### NixOS Deployment
+This project includes a complete Nix packaging and NixOS module:
+
+- **Package**: `nix/package.nix` - Builds the Elixir release using beamPackages.mixRelease
+- **Module**: `nix/nixos-module.nix` - Provides `services.systant` configuration options
+- **Development**: Use `nix develop` for development shell with Elixir/Erlang
+
+The NixOS module supports:
+- Configurable MQTT connection settings
+- Per-host topic naming using `${config.networking.hostName}`
+- Environment variable configuration for runtime settings
+- Systemd service with security hardening
+- Auto-restart and logging to systemd journal
+
+### Future Plans
+- Integration with Home Assistant via custom MQTT integration
+- Expandable command handling for host-specific automation
+- Multi-host deployment for comprehensive system monitoring

README.md

@@ -1,15 +1,60 @@
-# systant
+# Systant
 
-To install dependencies:
+An Elixir application that runs as a systemd daemon to:
+1. Publish system stats to MQTT every 30 seconds
+2. Listen for commands over MQTT and log them to syslog
 
-```bash
+## Configuration
-bun install
+
+Edit `config/config.exs` to configure MQTT connection:
+
+```elixir
+config :systant, Systant.MqttClient,
+  host: "localhost",
+  port: 1883,
+  client_id: "systant",
+  username: nil,
+  password: nil,
+  stats_topic: "system/stats",
+  command_topic: "system/commands",
+  publish_interval: 30_000
 ```
 
-To run:
+## Building
 
 ```bash
-bun run index.ts
+mix deps.get
+mix compile
 ```
 
-This project was created using `bun init` in bun v1.3.6. [Bun](https://bun.com) is a fast all-in-one JavaScript runtime.
+## Running
+
+```bash
+# Development
+mix run --no-halt
+
+# Production release
+MIX_ENV=prod mix release
+_build/prod/rel/systant/bin/systant start
+```
+
+## Systemd Installation
+
+1. Build production release
+2. Copy binary to `/usr/local/bin/`
+3. Copy `systant.service` to `/etc/systemd/system/`
+4. Enable and start:
+
+```bash
+sudo systemctl enable systant
+sudo systemctl start systant
+```
+
+## Features
+
+- Publishes "Hello from systant" stats every 30 seconds to `system/stats` topic
+- Listens on `system/commands` topic and logs received messages
+- Configurable MQTT connection settings
+- Runs as systemd daemon with auto-restart
+- Logs to system journal
+

bun.lock

@@ -1,152 +0,0 @@
-{
-  "lockfileVersion": 1,
-  "configVersion": 1,
-  "workspaces": {
-    "": {
-      "name": "systant",
-      "dependencies": {
-        "mqtt": "^5.14.1",
-        "smol-toml": "^1.6.0",
-        "yargs": "^18.0.0",
-      },
-      "devDependencies": {
-        "@types/bun": "latest",
-        "@types/yargs": "^17.0.35",
-      },
-      "peerDependencies": {
-        "typescript": "^5",
-      },
-    },
-  },
-  "packages": {
-    "@babel/runtime": ["@babel/runtime@7.28.6", "", {}, "sha512-05WQkdpL9COIMz4LjTxGpPNCdlpyimKppYNoJ5Di5EUObifl8t4tuLuUBBZEpoLYOmfvIWrsp9fCl0HoPRVTdA=="],
-
-    "@types/bun": ["@types/bun@1.3.6", "", { "dependencies": { "bun-types": "1.3.6" } }, "sha512-uWCv6FO/8LcpREhenN1d1b6fcspAB+cefwD7uti8C8VffIv0Um08TKMn98FynpTiU38+y2dUO55T11NgDt8VAA=="],
-
-    "@types/node": ["@types/node@25.0.9", "", { "dependencies": { "undici-types": "~7.16.0" } }, "sha512-/rpCXHlCWeqClNBwUhDcusJxXYDjZTyE8v5oTO7WbL8eij2nKhUeU89/6xgjU7N4/Vh3He0BtyhJdQbDyhiXAw=="],
-
-    "@types/readable-stream": ["@types/readable-stream@4.0.23", "", { "dependencies": { "@types/node": "*" } }, "sha512-wwXrtQvbMHxCbBgjHaMGEmImFTQxxpfMOR/ZoQnXxB1woqkUbdLGFDgauo00Py9IudiaqSeiBiulSV9i6XIPig=="],
-
-    "@types/ws": ["@types/ws@8.18.1", "", { "dependencies": { "@types/node": "*" } }, "sha512-ThVF6DCVhA8kUGy+aazFQ4kXQ7E1Ty7A3ypFOe0IcJV8O/M511G99AW24irKrW56Wt44yG9+ij8FaqoBGkuBXg=="],
-
-    "@types/yargs": ["@types/yargs@17.0.35", "", { "dependencies": { "@types/yargs-parser": "*" } }, "sha512-qUHkeCyQFxMXg79wQfTtfndEC+N9ZZg76HJftDJp+qH2tV7Gj4OJi7l+PiWwJ+pWtW8GwSmqsDj/oymhrTWXjg=="],
-
-    "@types/yargs-parser": ["@types/yargs-parser@21.0.3", "", {}, "sha512-I4q9QU9MQv4oEOz4tAHJtNz1cwuLxn2F3xcc2iV5WdqLPpUnj30aUuxt1mAxYTG+oe8CZMV/+6rU4S4gRDzqtQ=="],
-
-    "abort-controller": ["abort-controller@3.0.0", "", { "dependencies": { "event-target-shim": "^5.0.0" } }, "sha512-h8lQ8tacZYnR3vNQTgibj+tODHI5/+l06Au2Pcriv/Gmet0eaj4TwWH41sO9wnHDiQsEj19q0drzdWdeAHtweg=="],
-
-    "ansi-regex": ["ansi-regex@6.2.2", "", {}, "sha512-Bq3SmSpyFHaWjPk8If9yc6svM8c56dB5BAtW4Qbw5jHTwwXXcTLoRMkpDJp6VL0XzlWaCHTXrkFURMYmD0sLqg=="],
-
-    "ansi-styles": ["ansi-styles@6.2.3", "", {}, "sha512-4Dj6M28JB+oAH8kFkTLUo+a2jwOFkuqb3yucU0CANcRRUbxS0cP0nZYCGjcc3BNXwRIsUVmDGgzawme7zvJHvg=="],
-
-    "base64-js": ["base64-js@1.5.1", "", {}, "sha512-AKpaYlHn8t4SVbOHCy+b5+KKgvR4vrsD8vbvrbiQJps7fKDTkjkDry6ji0rUJjC0kzbNePLwzxq8iypo41qeWA=="],
-
-    "bl": ["bl@6.1.6", "", { "dependencies": { "@types/readable-stream": "^4.0.0", "buffer": "^6.0.3", "inherits": "^2.0.4", "readable-stream": "^4.2.0" } }, "sha512-jLsPgN/YSvPUg9UX0Kd73CXpm2Psg9FxMeCSXnk3WBO3CMT10JMwijubhGfHCnFu6TPn1ei3b975dxv7K2pWVg=="],
-
-    "broker-factory": ["broker-factory@3.1.13", "", { "dependencies": { "@babel/runtime": "^7.28.6", "fast-unique-numbers": "^9.0.26", "tslib": "^2.8.1", "worker-factory": "^7.0.48" } }, "sha512-H2VALe31mEtO/SRcNp4cUU5BAm1biwhc/JaF77AigUuni/1YT0FLCJfbUxwIEs9y6Kssjk2fmXgf+Y9ALvmKlw=="],
-
-    "buffer": ["buffer@6.0.3", "", { "dependencies": { "base64-js": "^1.3.1", "ieee754": "^1.2.1" } }, "sha512-FTiCpNxtwiZZHEZbcbTIcZjERVICn9yq/pDFkTl95/AxzD1naBctN7YO68riM/gLSDY7sdrMby8hofADYuuqOA=="],
-
-    "buffer-from": ["buffer-from@1.1.2", "", {}, "sha512-E+XQCRwSbaaiChtv6k6Dwgc+bx+Bs6vuKJHHl5kox/BaKbhiXzqQOwK4cO22yElGp2OCmjwVhT3HmxgyPGnJfQ=="],
-
-    "bun-types": ["bun-types@1.3.6", "", { "dependencies": { "@types/node": "*" } }, "sha512-OlFwHcnNV99r//9v5IIOgQ9Uk37gZqrNMCcqEaExdkVq3Avwqok1bJFmvGMCkCE0FqzdY8VMOZpfpR3lwI+CsQ=="],
-
-    "cliui": ["cliui@9.0.1", "", { "dependencies": { "string-width": "^7.2.0", "strip-ansi": "^7.1.0", "wrap-ansi": "^9.0.0" } }, "sha512-k7ndgKhwoQveBL+/1tqGJYNz097I7WOvwbmmU2AR5+magtbjPWQTS1C5vzGkBC8Ym8UWRzfKUzUUqFLypY4Q+w=="],
-
-    "commist": ["commist@3.2.0", "", {}, "sha512-4PIMoPniho+LqXmpS5d3NuGYncG6XWlkBSVGiWycL22dd42OYdUGil2CWuzklaJoNxyxUSpO4MKIBU94viWNAw=="],
-
-    "concat-stream": ["concat-stream@2.0.0", "", { "dependencies": { "buffer-from": "^1.0.0", "inherits": "^2.0.3", "readable-stream": "^3.0.2", "typedarray": "^0.0.6" } }, "sha512-MWufYdFw53ccGjCA+Ol7XJYpAlW6/prSMzuPOTRnJGcGzuhLn4Scrz7qf6o8bROZ514ltazcIFJZevcfbo0x7A=="],
-
-    "debug": ["debug@4.4.3", "", { "dependencies": { "ms": "^2.1.3" } }, "sha512-RGwwWnwQvkVfavKVt22FGLw+xYSdzARwm0ru6DhTVA3umU5hZc28V3kO4stgYryrTlLpuvgI9GiijltAjNbcqA=="],
-
-    "emoji-regex": ["emoji-regex@10.6.0", "", {}, "sha512-toUI84YS5YmxW219erniWD0CIVOo46xGKColeNQRgOzDorgBi1v4D71/OFzgD9GO2UGKIv1C3Sp8DAn0+j5w7A=="],
-
-    "escalade": ["escalade@3.2.0", "", {}, "sha512-WUj2qlxaQtO4g6Pq5c29GTcWGDyd8itL8zTlipgECz3JesAiiOKotd8JU6otB3PACgG6xkJUyVhboMS+bje/jA=="],
-
-    "event-target-shim": ["event-target-shim@5.0.1", "", {}, "sha512-i/2XbnSz/uxRCU6+NdVJgKWDTM427+MqYbkQzD321DuCQJUqOuJKIA0IM2+W2xtYHdKOmZ4dR6fExsd4SXL+WQ=="],
-
-    "events": ["events@3.3.0", "", {}, "sha512-mQw+2fkQbALzQ7V0MY0IqdnXNOeTtP4r0lN9z7AAawCXgqea7bDii20AYrIBrFd/Hx0M2Ocz6S111CaFkUcb0Q=="],
-
-    "fast-unique-numbers": ["fast-unique-numbers@9.0.26", "", { "dependencies": { "@babel/runtime": "^7.28.6", "tslib": "^2.8.1" } }, "sha512-3Mtq8p1zQinjGyWfKeuBunbuFoixG72AUkk4VvzbX4ykCW9Q4FzRaNyIlfQhUjnKw2ARVP+/CKnoyr6wfHftig=="],
-
-    "get-caller-file": ["get-caller-file@2.0.5", "", {}, "sha512-DyFP3BM/3YHTQOCUL/w0OZHR0lpKeGrxotcHWcqNEdnltqFwXVfhEBQ94eIo34AfQpo0rGki4cyIiftY06h2Fg=="],
-
-    "get-east-asian-width": ["get-east-asian-width@1.4.0", "", {}, "sha512-QZjmEOC+IT1uk6Rx0sX22V6uHWVwbdbxf1faPqJ1QhLdGgsRGCZoyaQBm/piRdJy/D2um6hM1UP7ZEeQ4EkP+Q=="],
-
-    "help-me": ["help-me@5.0.0", "", {}, "sha512-7xgomUX6ADmcYzFik0HzAxh/73YlKR9bmFzf51CZwR+b6YtzU2m0u49hQCqV6SvlqIqsaxovfwdvbnsw3b/zpg=="],
-
-    "ieee754": ["ieee754@1.2.1", "", {}, "sha512-dcyqhDvX1C46lXZcVqCpK+FtMRQVdIMN6/Df5js2zouUsqG7I6sFxitIC+7KYK29KdXOLHdu9zL4sFnoVQnqaA=="],
-
-    "inherits": ["inherits@2.0.4", "", {}, "sha512-k/vGaX4/Yla3WzyMCvTQOXYeIHvqOKtnqBduzTHpzpQZzAskKMhZ2K+EnBiSM9zGSoIFeMpXKxa4dYeZIQqewQ=="],
-
-    "ip-address": ["ip-address@10.1.0", "", {}, "sha512-XXADHxXmvT9+CRxhXg56LJovE+bmWnEWB78LB83VZTprKTmaC5QfruXocxzTZ2Kl0DNwKuBdlIhjL8LeY8Sf8Q=="],
-
-    "js-sdsl": ["js-sdsl@4.3.0", "", {}, "sha512-mifzlm2+5nZ+lEcLJMoBK0/IH/bDg8XnJfd/Wq6IP+xoCjLZsTOnV2QpxlVbX9bMnkl5PdEjNtBJ9Cj1NjifhQ=="],
-
-    "lru-cache": ["lru-cache@10.4.3", "", {}, "sha512-JNAzZcXrCt42VGLuYz0zfAzDfAvJWW6AfYlDBQyDV5DClI2m5sAmK+OIO7s59XfsRsWHp02jAJrRadPRGTt6SQ=="],
-
-    "minimist": ["minimist@1.2.8", "", {}, "sha512-2yyAR8qBkN3YuheJanUpWC5U3bb5osDywNB8RzDVlDwDHbocAJveqqj1u8+SVD7jkWT4yvsHCpWqqWqAxb0zCA=="],
-
-    "mqtt": ["mqtt@5.14.1", "", { "dependencies": { "@types/readable-stream": "^4.0.21", "@types/ws": "^8.18.1", "commist": "^3.2.0", "concat-stream": "^2.0.0", "debug": "^4.4.1", "help-me": "^5.0.0", "lru-cache": "^10.4.3", "minimist": "^1.2.8", "mqtt-packet": "^9.0.2", "number-allocator": "^1.0.14", "readable-stream": "^4.7.0", "rfdc": "^1.4.1", "socks": "^2.8.6", "split2": "^4.2.0", "worker-timers": "^8.0.23", "ws": "^8.18.3" }, "bin": { "mqtt_pub": "build/bin/pub.js", "mqtt_sub": "build/bin/sub.js", "mqtt": "build/bin/mqtt.js" } }, "sha512-NxkPxE70Uq3Ph7goefQa7ggSsVzHrayCD0OyxlJgITN/EbzlZN+JEPmaAZdxP1LsIT5FamDyILoQTF72W7Nnbw=="],
-
-    "mqtt-packet": ["mqtt-packet@9.0.2", "", { "dependencies": { "bl": "^6.0.8", "debug": "^4.3.4", "process-nextick-args": "^2.0.1" } }, "sha512-MvIY0B8/qjq7bKxdN1eD+nrljoeaai+qjLJgfRn3TiMuz0pamsIWY2bFODPZMSNmabsLANXsLl4EMoWvlaTZWA=="],
-
-    "ms": ["ms@2.1.3", "", {}, "sha512-6FlzubTLZG3J2a/NVCAleEhjzq5oxgHyaCU9yYXvcLsvoVaHJq/s5xXI6/XXP6tz7R9xAOtHnSO/tXtF3WRTlA=="],
-
-    "number-allocator": ["number-allocator@1.0.14", "", { "dependencies": { "debug": "^4.3.1", "js-sdsl": "4.3.0" } }, "sha512-OrL44UTVAvkKdOdRQZIJpLkAdjXGTRda052sN4sO77bKEzYYqWKMBjQvrJFzqygI99gL6Z4u2xctPW1tB8ErvA=="],
-
-    "process": ["process@0.11.10", "", {}, "sha512-cdGef/drWFoydD1JsMzuFf8100nZl+GT+yacc2bEced5f9Rjk4z+WtFUTBu9PhOi9j/jfmBPu0mMEY4wIdAF8A=="],
-
-    "process-nextick-args": ["process-nextick-args@2.0.1", "", {}, "sha512-3ouUOpQhtgrbOa17J7+uxOTpITYWaGP7/AhoR3+A+/1e9skrzelGi/dXzEYyvbxubEF6Wn2ypscTKiKJFFn1ag=="],
-
-    "readable-stream": ["readable-stream@4.7.0", "", { "dependencies": { "abort-controller": "^3.0.0", "buffer": "^6.0.3", "events": "^3.3.0", "process": "^0.11.10", "string_decoder": "^1.3.0" } }, "sha512-oIGGmcpTLwPga8Bn6/Z75SVaH1z5dUut2ibSyAMVhmUggWpmDn2dapB0n7f8nwaSiRtepAsfJyfXIO5DCVAODg=="],
-
-    "rfdc": ["rfdc@1.4.1", "", {}, "sha512-q1b3N5QkRUWUl7iyylaaj3kOpIT0N2i9MqIEQXP73GVsN9cw3fdx8X63cEmWhJGi2PPCF23Ijp7ktmd39rawIA=="],
-
-    "safe-buffer": ["safe-buffer@5.2.1", "", {}, "sha512-rp3So07KcdmmKbGvgaNxQSJr7bGVSVk5S9Eq1F+ppbRo70+YeaDxkw5Dd8NPN+GD6bjnYm2VuPuCXmpuYvmCXQ=="],
-
-    "smart-buffer": ["smart-buffer@4.2.0", "", {}, "sha512-94hK0Hh8rPqQl2xXc3HsaBoOXKV20MToPkcXvwbISWLEs+64sBq5kFgn2kJDHb1Pry9yrP0dxrCI9RRci7RXKg=="],
-
-    "smol-toml": ["smol-toml@1.6.0", "", {}, "sha512-4zemZi0HvTnYwLfrpk/CF9LOd9Lt87kAt50GnqhMpyF9U3poDAP2+iukq2bZsO/ufegbYehBkqINbsWxj4l4cw=="],
-
-    "socks": ["socks@2.8.7", "", { "dependencies": { "ip-address": "^10.0.1", "smart-buffer": "^4.2.0" } }, "sha512-HLpt+uLy/pxB+bum/9DzAgiKS8CX1EvbWxI4zlmgGCExImLdiad2iCwXT5Z4c9c3Eq8rP2318mPW2c+QbtjK8A=="],
-
-    "split2": ["split2@4.2.0", "", {}, "sha512-UcjcJOWknrNkF6PLX83qcHM6KHgVKNkV62Y8a5uYDVv9ydGQVwAHMKqHdJje1VTWpljG0WYpCDhrCdAOYH4TWg=="],
-
-    "string-width": ["string-width@7.2.0", "", { "dependencies": { "emoji-regex": "^10.3.0", "get-east-asian-width": "^1.0.0", "strip-ansi": "^7.1.0" } }, "sha512-tsaTIkKW9b4N+AEj+SVA+WhJzV7/zMhcSu78mLKWSk7cXMOSHsBKFWUs0fWwq8QyK3MgJBQRX6Gbi4kYbdvGkQ=="],
-
-    "string_decoder": ["string_decoder@1.3.0", "", { "dependencies": { "safe-buffer": "~5.2.0" } }, "sha512-hkRX8U1WjJFd8LsDJ2yQ/wWWxaopEsABU1XfkM8A+j0+85JAGppt16cr1Whg6KIbb4okU6Mql6BOj+uup/wKeA=="],
-
-    "strip-ansi": ["strip-ansi@7.1.2", "", { "dependencies": { "ansi-regex": "^6.0.1" } }, "sha512-gmBGslpoQJtgnMAvOVqGZpEz9dyoKTCzy2nfz/n8aIFhN/jCE/rCmcxabB6jOOHV+0WNnylOxaxBQPSvcWklhA=="],
-
-    "tslib": ["tslib@2.8.1", "", {}, "sha512-oJFu94HQb+KVduSUQL7wnpmqnfmLsOA/nAh6b6EH0wCEoK0/mPeXU6c3wKDV83MkOuHPRHtSXKKU99IBazS/2w=="],
-
-    "typedarray": ["typedarray@0.0.6", "", {}, "sha512-/aCDEGatGvZ2BIk+HmLf4ifCJFwvKFNb9/JeZPMulfgFracn9QFcAf5GO8B/mweUjSoblS5In0cWhqpfs/5PQA=="],
-
-    "typescript": ["typescript@5.9.3", "", { "bin": { "tsc": "bin/tsc", "tsserver": "bin/tsserver" } }, "sha512-jl1vZzPDinLr9eUt3J/t7V6FgNEw9QjvBPdysz9KfQDD41fQrC2Y4vKQdiaUpFT4bXlb1RHhLpp8wtm6M5TgSw=="],
-
-    "undici-types": ["undici-types@7.16.0", "", {}, "sha512-Zz+aZWSj8LE6zoxD+xrjh4VfkIG8Ya6LvYkZqtUQGJPZjYl53ypCaUwWqo7eI0x66KBGeRo+mlBEkMSeSZ38Nw=="],
-
-    "util-deprecate": ["util-deprecate@1.0.2", "", {}, "sha512-EPD5q1uXyFxJpCrLnCc1nHnq3gOa6DZBocAIiI2TaSCA7VCJ1UJDMagCzIkXNsUYfD1daK//LTEQ8xiIbrHtcw=="],
-
-    "worker-factory": ["worker-factory@7.0.48", "", { "dependencies": { "@babel/runtime": "^7.28.6", "fast-unique-numbers": "^9.0.26", "tslib": "^2.8.1" } }, "sha512-CGmBy3tJvpBPjUvb0t4PrpKubUsfkI1Ohg0/GGFU2RvA9j/tiVYwKU8O7yu7gH06YtzbeJLzdUR29lmZKn5pag=="],
-
-    "worker-timers": ["worker-timers@8.0.29", "", { "dependencies": { "@babel/runtime": "^7.28.6", "tslib": "^2.8.1", "worker-timers-broker": "^8.0.15", "worker-timers-worker": "^9.0.13" } }, "sha512-9jk0MWHhWAZ2xlJPXr45oe5UF/opdpfZrY0HtyPizWuJ+ce1M3IYk/4IIdGct3kn9Ncfs+tkZt3w1tU6KW2Fsg=="],
-
-    "worker-timers-broker": ["worker-timers-broker@8.0.15", "", { "dependencies": { "@babel/runtime": "^7.28.6", "broker-factory": "^3.1.13", "fast-unique-numbers": "^9.0.26", "tslib": "^2.8.1", "worker-timers-worker": "^9.0.13" } }, "sha512-Te+EiVUMzG5TtHdmaBZvBrZSFNauym6ImDaCAnzQUxvjnw+oGjMT2idmAOgDy30vOZMLejd0bcsc90Axu6XPWA=="],
-
-    "worker-timers-worker": ["worker-timers-worker@9.0.13", "", { "dependencies": { "@babel/runtime": "^7.28.6", "tslib": "^2.8.1", "worker-factory": "^7.0.48" } }, "sha512-qjn18szGb1kjcmh2traAdki1eiIS5ikFo+L90nfMOvSRpuDw1hAcR1nzkP2+Hkdqz5thIRnfuWx7QSpsEUsA6Q=="],
-
-    "wrap-ansi": ["wrap-ansi@9.0.2", "", { "dependencies": { "ansi-styles": "^6.2.1", "string-width": "^7.0.0", "strip-ansi": "^7.1.0" } }, "sha512-42AtmgqjV+X1VpdOfyTGOYRi0/zsoLqtXQckTmqTeybT+BDIbM/Guxo7x3pE2vtpr1ok6xRqM9OpBe+Jyoqyww=="],
-
-    "ws": ["ws@8.19.0", "", { "peerDependencies": { "bufferutil": "^4.0.1", "utf-8-validate": ">=5.0.2" }, "optionalPeers": ["bufferutil", "utf-8-validate"] }, "sha512-blAT2mjOEIi0ZzruJfIhb3nps74PRWTCz1IjglWEEpQl5XS/UNama6u2/rjFkDDouqr4L67ry+1aGIALViWjDg=="],
-
-    "y18n": ["y18n@5.0.8", "", {}, "sha512-0pfFzegeDWJHJIAmTLRP2DwHjdF5s7jo9tuztdQxAhINCdvS+3nGINqPd00AphqJR/0LhANUS6/+7SCb98YOfA=="],
-
-    "yargs": ["yargs@18.0.0", "", { "dependencies": { "cliui": "^9.0.1", "escalade": "^3.1.1", "get-caller-file": "^2.0.5", "string-width": "^7.2.0", "y18n": "^5.0.5", "yargs-parser": "^22.0.0" } }, "sha512-4UEqdc2RYGHZc7Doyqkrqiln3p9X2DZVxaGbwhn2pi7MrRagKaOcIKe8L3OxYcbhXLgLFUS3zAYuQjKBQgmuNg=="],
-
-    "yargs-parser": ["yargs-parser@22.0.0", "", {}, "sha512-rwu/ClNdSMpkSrUb+d6BRsSkLUq1fmfsY6TOpYzTwvwkg1/NRG85KBy3kq++A8LKQwX6lsu+aWad+2khvuXrqw=="],
-
-    "concat-stream/readable-stream": ["readable-stream@3.6.2", "", { "dependencies": { "inherits": "^2.0.3", "string_decoder": "^1.1.1", "util-deprecate": "^1.0.1" } }, "sha512-9u/sniCrY3D5WdsERHzHE4G2YCXqoG5FTHUiCC4SIbr6XcLZBY05ya9EKjYek9O5xOAwjGq+1JdGBAS7Q9ScoA=="],
-  }
-}

config/config.exs

@@ -0,0 +1,5 @@
+import Config
+
+config :logger, :console,
+  format: "$time $metadata[$level] $message\n",
+  metadata: [:request_id]

config/runtime.exs

@@ -0,0 +1,18 @@
+import Config
+
+# Get hostname for topic construction
+hostname = case :inet.gethostname() do
+  {:ok, hostname} -> List.to_string(hostname)
+  _ -> "unknown"
+end
+
+# Runtime configuration that can use environment variables
+config :systant, Systant.MqttClient,
+  host: System.get_env("SYSTANT_MQTT_HOST", "mqtt.home"),
+  port: String.to_integer(System.get_env("SYSTANT_MQTT_PORT", "1883")),
+  client_id: System.get_env("SYSTANT_CLIENT_ID", "systant"),
+  username: System.get_env("SYSTANT_MQTT_USERNAME"),
+  password: System.get_env("SYSTANT_MQTT_PASSWORD"),
+  stats_topic: System.get_env("SYSTANT_STATS_TOPIC", "systant/#{hostname}/stats"),
+  command_topic: System.get_env("SYSTANT_COMMAND_TOPIC", "systant/#{hostname}/commands"),
+  publish_interval: String.to_integer(System.get_env("SYSTANT_PUBLISH_INTERVAL", "30000"))

flake.lock

@@ -20,16 +20,16 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1768395095,
+        "lastModified": 1753939845,
-        "narHash": "sha256-ZhuYJbwbZT32QA95tSkXd9zXHcdZj90EzHpEXBMabaw=",
+        "narHash": "sha256-K2ViRJfdVGE8tpJejs8Qpvvejks1+A4GQej/lBk5y7I=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "13868c071cc73a5e9f610c47d7bb08e5da64fdd5",
+        "rev": "94def634a20494ee057c76998843c015909d6311",
         "type": "github"
       },
       "original": {
         "owner": "NixOS",
-        "ref": "nixpkgs-unstable",
+        "ref": "nixos-unstable",
         "repo": "nixpkgs",
         "type": "github"
       }

flake.nix

@@ -1,57 +1,44 @@
 {
-  description = "Systant - System monitoring agent with MQTT and Home Assistant integration";
+  description = "Elixir system monitor daemon";
 
-  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+  inputs = {
-  inputs.flake-utils.url = "github:numtide/flake-utils";
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
 
   outputs =
     {
       self,
       nixpkgs,
       flake-utils,
-      ...
     }:
-    {
-      # Home Manager module (system-independent)
-      homeManagerModules.default = import ./nix/nixos-module.nix;
-
-      # Overlay to add systant to pkgs
-      overlays.default = final: prev: {
-        systant = final.callPackage ./nix/package.nix { src = self; };
-      };
-    }
-    //
     flake-utils.lib.eachDefaultSystem (
       system:
       let
         pkgs = import nixpkgs {
-          inherit system;
+          system = system;
           config.allowUnfree = true;
-          overlays = [ self.overlays.default ];
         };
       in
       {
-        packages = {
-          systant = pkgs.systant;
-          default = pkgs.systant;
-        };
-
-        apps.default = {
-          type = "app";
-          program = "${pkgs.systant}/bin/systant";
-        };
-
         devShells.default = pkgs.mkShell {
           buildInputs = with pkgs; [
-            bashInteractive
+            elixir
-            glibcLocales
+            erlang
-            git
+            claude-code
-            bun
+            aider-chat
-            inotify-tools
+            nodejs_20
+            yarn
+            deno
+            python311
+            python311Packages.pip
+            python311Packages.ipython
+
           ];
 
           shellHook = ''
-            export PROJECT_ROOT=$PWD
+            echo "Elixir development environment loaded"
+            elixir --version
           '';
         };
       }

index.ts

@@ -1,130 +0,0 @@
-import yargs from "yargs";
-import { hideBin } from "yargs/helpers";
-import { loadConfig } from "./src/config";
-import { connect } from "./src/mqtt";
-import { createEntityManager } from "./src/entities";
-
-const DEFAULT_CONFIG_PATH = "./systant.toml";
-
-yargs(hideBin(process.argv))
-  .scriptName("systant")
-  .usage("$0 <cmd> [args]")
-
-  .command(
-    "run",
-    "Start the systant daemon",
-    (yargs) => {
-      return yargs.option("config", {
-        alias: "c",
-        type: "string",
-        default: DEFAULT_CONFIG_PATH,
-        describe: "Path to config file",
-      });
-    },
-    async (argv) => {
-      await run(argv.config);
-    }
-  )
-
-  .command(
-    "check",
-    "Check config and connectivity",
-    (yargs) => {
-      return yargs.option("config", {
-        alias: "c",
-        type: "string",
-        default: DEFAULT_CONFIG_PATH,
-        describe: "Path to config file",
-      });
-    },
-    async (argv) => {
-      await check(argv.config);
-    }
-  )
-
-  .command(
-    "once",
-    "Poll all entity states once, then exit",
-    (yargs) => {
-      return yargs.option("config", {
-        alias: "c",
-        type: "string",
-        default: DEFAULT_CONFIG_PATH,
-        describe: "Path to config file",
-      });
-    },
-    async (argv) => {
-      await once(argv.config);
-    }
-  )
-
-  .demandCommand(1, "\nError: You need to specify a command!")
-  .help()
-  .parse();
-
-async function run(configPath: string): Promise<void> {
-  const config = await loadConfig(configPath);
-
-  console.log(`Starting systant on ${config.systant.hostname}`);
-
-  const mqtt = await connect(config, config.systant.hostname);
-  const entities = createEntityManager(config, mqtt);
-
-  await entities.start();
-
-  // Handle shutdown
-  const shutdown = async () => {
-    console.log("\nShutting down...");
-    entities.stop();
-    await mqtt.disconnect();
-    process.exit(0);
-  };
-
-  process.on("SIGINT", shutdown);
-  process.on("SIGTERM", shutdown);
-
-  console.log("Systant running. Press Ctrl+C to stop.");
-}
-
-async function check(configPath: string): Promise<void> {
-  console.log(`Checking config: ${configPath}`);
-
-  try {
-    const config = await loadConfig(configPath);
-    const entityCount = Object.keys(config.entities).length;
-    console.log("Config loaded successfully");
-    console.log(`  MQTT broker: ${config.mqtt.broker}`);
-    console.log(`  Entities: ${entityCount} configured (default interval: ${config.systant.defaultInterval}s)`);
-    console.log(`  HA discovery: ${config.homeassistant.discovery}`);
-
-    console.log("\nTesting MQTT connection...");
-    const hostname = config.systant.hostname;
-    const mqtt = await connect(config, hostname);
-    console.log("MQTT connection successful");
-    await mqtt.disconnect();
-
-    console.log("\nAll checks passed!");
-  } catch (err) {
-    console.error("Check failed:", err instanceof Error ? err.message : err);
-    process.exit(1);
-  }
-}
-
-async function once(configPath: string): Promise<void> {
-  const config = await loadConfig(configPath);
-  const hostname = config.systant.hostname;
-
-  const mqtt = await connect(config, hostname);
-  const entities = createEntityManager(config, mqtt);
-
-  // Start will do initial poll of all entities
-  await entities.start();
-
-  // Wait a moment for the initial polls to complete
-  await new Promise((resolve) => setTimeout(resolve, 1000));
-
-  entities.stop();
-  await mqtt.disconnect();
-
-  console.log("Entity states published successfully");
-}

lib/systant.ex

@@ -0,0 +1,18 @@
+defmodule Systant do
+  @moduledoc """
+  Documentation for `Systant`.
+  """
+
+  @doc """
+  Hello world.
+
+  ## Examples
+
+      iex> Systant.hello()
+      :world
+
+  """
+  def hello do
+    :world
+  end
+end

lib/systant/application.ex

@@ -0,0 +1,19 @@
+defmodule Systant.Application do
+  # See https://hexdocs.pm/elixir/Application.html
+  # for more information on OTP Applications
+  @moduledoc false
+
+  use Application
+
+  @impl true
+  def start(_type, _args) do
+    children = [
+      {Systant.MqttClient, []}
+    ]
+
+    # See https://hexdocs.pm/elixir/Supervisor.html
+    # for other strategies and supported options
+    opts = [strategy: :one_for_one, name: Systant.Supervisor]
+    Supervisor.start_link(children, opts)
+  end
+end

lib/systant/mqtt_client.ex

@@ -0,0 +1,92 @@
+defmodule Systant.MqttClient do
+  use GenServer
+  require Logger
+
+  @moduledoc """
+  MQTT client for publishing system stats and handling commands
+  """
+
+  def start_link(opts) do
+    GenServer.start_link(__MODULE__, opts, name: __MODULE__)
+  end
+
+  def init(_opts) do
+    config = Application.get_env(:systant, __MODULE__)
+    Logger.info("Starting MQTT client with config: #{inspect(config)}")
+    
+    # Use a unique client ID to avoid conflicts
+    client_id = "#{config[:client_id]}_#{:rand.uniform(1000)}"
+    
+    connection_opts = [
+      client_id: client_id,
+      server: {Tortoise.Transport.Tcp, host: to_charlist(config[:host]), port: config[:port]},
+      handler: {Tortoise.Handler.Logger, []},
+      user_name: config[:username],
+      password: config[:password],
+      subscriptions: [{config[:command_topic], 0}]
+    ]
+
+    case Tortoise.Connection.start_link(connection_opts) do
+      {:ok, _pid} ->
+        Logger.info("MQTT client connected successfully")
+        
+        # Send immediate hello message
+        hello_msg = %{
+          message: "Hello - systant started",
+          timestamp: DateTime.utc_now() |> DateTime.to_iso8601(),
+          hostname: get_hostname()
+        }
+        Tortoise.publish(client_id, config[:stats_topic], Jason.encode!(hello_msg), qos: 0)
+        
+        schedule_stats_publish(config[:publish_interval])
+        {:ok, %{config: config, client_id: client_id}}
+        
+      {:error, reason} ->
+        Logger.error("Failed to connect to MQTT broker: #{inspect(reason)}")
+        {:stop, reason}
+    end
+  end
+
+  def handle_info(:publish_stats, state) do
+    publish_stats(state.config, state.client_id)
+    schedule_stats_publish(state.config[:publish_interval])
+    {:noreply, state}
+  end
+
+  def handle_info(_msg, state) do
+    {:noreply, state}
+  end
+
+  def terminate(reason, state) do
+    Logger.info("MQTT client terminating: #{inspect(reason)}")
+    :ok
+  end
+
+  defp publish_stats(config, client_id) do
+    stats = %{
+      message: "Hello from systant",
+      timestamp: DateTime.utc_now() |> DateTime.to_iso8601(),
+      hostname: get_hostname()
+    }
+    
+    payload = Jason.encode!(stats)
+    
+    case Tortoise.publish(client_id, config[:stats_topic], payload, qos: 0) do
+      :ok ->
+        Logger.info("Published stats: #{payload}")
+      {:error, reason} ->
+        Logger.error("Failed to publish stats: #{inspect(reason)}")
+    end
+  end
+
+  defp schedule_stats_publish(interval) do
+    Process.send_after(self(), :publish_stats, interval)
+  end
+
+  defp get_hostname do
+    case :inet.gethostname() do
+      {:ok, hostname} -> List.to_string(hostname)
+      _ -> "unknown"
+    end
+  end
+end

mix.exs

@@ -0,0 +1,41 @@
+defmodule SystemStatsDaemon.MixProject do
+  use Mix.Project
+
+  def project do
+    [
+      app: :systant,
+      version: "0.1.0",
+      elixir: "~> 1.18",
+      start_permanent: Mix.env() == :prod,
+      deps: deps(),
+      releases: releases()
+    ]
+  end
+
+  # Run "mix help compile.app" to learn about applications.
+  def application do
+    [
+      extra_applications: [:logger],
+      mod: {Systant.Application, []}
+    ]
+  end
+
+  # Run "mix help deps" to learn about dependencies.
+  defp deps do
+    [
+      {:tortoise, "~> 0.9.5"},
+      {:jason, "~> 1.4"}
+    ]
+  end
+
+  defp releases do
+    [
+      systant: [
+        include_executables_for: [:unix],
+        applications: [runtime_tools: :permanent],
+        include_erts: true,
+        strip_beams: false
+      ]
+    ]
+  end
+end

mix.lock

@@ -0,0 +1,10 @@
+%{
+  "cowlib": {:hex, :cowlib, "2.13.0", "db8f7505d8332d98ef50a3ef34b34c1afddec7506e4ee4dd4a3a266285d282ca", [:make, :rebar3], [], "hexpm", "e1e1284dc3fc030a64b1ad0d8382ae7e99da46c3246b815318a4b848873800a4"},
+  "emqtt": {:hex, :emqtt, "1.14.4", "f34fd1e612e3138e61e9a2d27b0f9674e1da87cc794d30b7916d96f6ee7eef71", [:rebar3], [{:cowlib, "2.13.0", [hex: :cowlib, repo: "hexpm", optional: false]}, {:getopt, "1.0.3", [hex: :getopt, repo: "hexpm", optional: false]}, {:gun, "2.1.0", [hex: :gun, repo: "hexpm", optional: false]}], "hexpm", "9065ba581ea899fde316b7eafd03f3c945044c151480bf3adabc6b62b0e60dad"},
+  "gen_state_machine": {:hex, :gen_state_machine, "3.0.0", "1e57f86a494e5c6b14137ebef26a7eb342b3b0070c7135f2d6768ed3f6b6cdff", [:mix], [], "hexpm", "0a59652574bebceb7309f6b749d2a41b45fdeda8dbb4da0791e355dd19f0ed15"},
+  "getopt": {:hex, :getopt, "1.0.3", "4f3320c1f6f26b2bec0f6c6446b943eb927a1e6428ea279a1c6c534906ee79f1", [:rebar3], [], "hexpm", "7e01de90ac540f21494ff72792b1e3162d399966ebbfc674b4ce52cb8f49324f"},
+  "gun": {:hex, :gun, "2.1.0", "b4e4cbbf3026d21981c447e9e7ca856766046eff693720ba43114d7f5de36e87", [:make, :rebar3], [{:cowlib, "2.13.0", [hex: :cowlib, repo: "hexpm", optional: false]}], "hexpm", "52fc7fc246bfc3b00e01aea1c2854c70a366348574ab50c57dfe796d24a0101d"},
+  "jason": {:hex, :jason, "1.4.4", "b9226785a9aa77b6857ca22832cffa5d5011a667207eb2a0ad56adb5db443b8a", [:mix], [{:decimal, "~> 1.0 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm", "c5eb0cab91f094599f94d55bc63409236a8ec69a21a67814529e8d5f6cc90b3b"},
+  "syslog": {:hex, :syslog, "1.1.0", "6419a232bea84f07b56dc575225007ffe34d9fdc91abe6f1b2f254fd71d8efc2", [:rebar3], [], "hexpm", "4c6a41373c7e20587be33ef841d3de6f3beba08519809329ecc4d27b15b659e1"},
+  "tortoise": {:hex, :tortoise, "0.9.9", "2e467570ef1d342d4de8fdc6ba3861f841054ab524080ec3d7052ee07c04501d", [:mix], [{:gen_state_machine, "~> 2.0 or ~> 3.0", [hex: :gen_state_machine, repo: "hexpm", optional: false]}], "hexpm", "4a316220b4b443c2497f42702f0c0616af3e4b2cbc6c150ebebb51657a773797"},
+}

nix/nixos-module.nix

@@ -1,88 +1,98 @@
 { config, lib, pkgs, ... }:
 
+with lib;
+
 let
   cfg = config.services.systant;
-  settingsFormat = pkgs.formats.toml { };
-  configFile =
-    if cfg.configFile != null
-    then cfg.configFile
-    else if cfg.settings != { }
-    then settingsFormat.generate "systant-config.toml" cfg.settings
-    else null;
 in
 {
   options.services.systant = {
-    enable = lib.mkEnableOption "systant system monitoring agent";
+    enable = mkEnableOption "Systant MQTT Daemon";
 
-    package = lib.mkOption {
+    package = mkOption {
-      type = lib.types.package;
+      type = types.package;
-      default = pkgs.systant;
+      description = "The systant package to use";
-      defaultText = lib.literalExpression "pkgs.systant";
-      description = "The systant package to use.";
     };
 
-    configFile = lib.mkOption {
+    mqttHost = mkOption {
-      type = lib.types.nullOr lib.types.path;
+      type = types.str;
+      default = "localhost";
+      description = "MQTT broker hostname";
+    };
+
+    mqttPort = mkOption {
+      type = types.int;
+      default = 1883;
+      description = "MQTT broker port";
+    };
+
+    mqttUsername = mkOption {
+      type = types.nullOr types.str;
       default = null;
-      description = ''
+      description = "MQTT username (null for no auth)";
-        Path to the systant configuration file (TOML).
-        If set, this takes precedence over the settings option.
-      '';
     };
 
-    settings = lib.mkOption {
+    mqttPassword = mkOption {
-      type = settingsFormat.type;
+      type = types.nullOr types.str;
-      default = { };
+      default = null;
-      description = ''
+      description = "MQTT password (null for no auth)";
-        Configuration for systant in Nix attribute set form.
+    };
-        Will be converted to TOML. Ignored if configFile is set.
+
-      '';
+    statsTopic = mkOption {
-      example = lib.literalExpression ''
+      type = types.str;
-        {
+      default = "systant/${config.networking.hostName}/stats";
-          mqtt = {
+      description = "MQTT topic for publishing stats";
-            broker = "mqtt://localhost:1883";
+    };
-            topicPrefix = "systant";
+
-          };
+    commandTopic = mkOption {
-          entities = {
+      type = types.str;
-            cpu_usage = {
+      default = "systant/${config.networking.hostName}/commands";
-              type = "sensor";
+      description = "MQTT topic for receiving commands";
-              state_command = "awk '/^cpu / {u=$2+$4; t=$2+$4+$5; print int(u*100/t)}' /proc/stat";
+    };
-              unit = "%";
+
-              icon = "mdi:cpu-64-bit";
+    publishInterval = mkOption {
-              name = "CPU Usage";
+      type = types.int;
-            };
+      default = 30000;
-          };
+      description = "Interval between stats publications (milliseconds)";
-          homeassistant = {
-            discovery = true;
-            discoveryPrefix = "homeassistant";
-          };
-        }
-      '';
     };
   };
 
-  config = lib.mkIf cfg.enable {
+  config = mkIf cfg.enable {
-    home.packages = [ cfg.package ];
+    systemd.services.systant = {
+      description = "Systant MQTT Daemon";
+      after = [ "network.target" ];
+      wantedBy = [ "multi-user.target" ];
 
-    systemd.user.services.systant = {
+      environment = {
-      Unit = {
+        SYSTANT_MQTT_HOST = cfg.mqttHost;
-        Description = "Systant system monitoring agent";
+        SYSTANT_MQTT_PORT = toString cfg.mqttPort;
-        After = [ "network-online.target" ];
+        SYSTANT_MQTT_USERNAME = mkIf (cfg.mqttUsername != null) cfg.mqttUsername;
-        Wants = [ "network-online.target" ];
+        SYSTANT_MQTT_PASSWORD = mkIf (cfg.mqttPassword != null) cfg.mqttPassword;
+        SYSTANT_STATS_TOPIC = cfg.statsTopic;
+        SYSTANT_COMMAND_TOPIC = cfg.commandTopic;
+        SYSTANT_PUBLISH_INTERVAL = toString cfg.publishInterval;
+        # Override RELEASE_COOKIE to bypass file reading
+        RELEASE_COOKIE = "systant-bypass-cookie";
       };
 
-      Service = {
+      serviceConfig = {
-        Type = "simple";
+        Type = "exec";
-        ExecStart =
+        User = "root";
-          if configFile != null
+        Group = "root";
-          then "${cfg.package}/bin/systant run --config ${configFile}"
+        ExecStart = "${cfg.package}/bin/systant start";
-          else "${cfg.package}/bin/systant run";
+        ExecStop = "${cfg.package}/bin/systant stop";
-        Restart = "on-failure";
+        Restart = "always";
-        RestartSec = "5s";
+        RestartSec = 5;
-      };
+        StandardOutput = "journal";
+        StandardError = "journal";
+        SyslogIdentifier = "systant";
+        WorkingDirectory = "${cfg.package}";
 
-      Install = {
+        # Security settings
-        WantedBy = [ "default.target" ];
+        NoNewPrivileges = true;
+        PrivateTmp = true;
+        ProtectHome = true;
+        ProtectSystem = false; # Need access to system stats
       };
     };
   };

nix/package.nix

@@ -1,66 +1,32 @@
 {
   lib,
-  stdenvNoCC,
+  beamPackages,
-  stdenv,
+  fetchgit,
-  bun,
-  cacert,
-  src,  # passed from flake.nix
 }:
 
-let
+beamPackages.mixRelease rec {
-  # Fixed-output derivation to fetch npm dependencies
-  # Update the hash when bun.lock changes by running:
-  #   nix build .#systant 2>&1 | grep 'got:'
-  deps = stdenvNoCC.mkDerivation {
-    pname = "systant-deps";
-    version = "0.1.0";
-
-    inherit src;
-
-    buildPhase = ''
-      export HOME=$TMPDIR
-      bun install --frozen-lockfile
-    '';
-
-    installPhase = ''
-      cp -r node_modules $out
-    '';
-
-    nativeBuildInputs = [ bun cacert ];
-
-    outputHashMode = "recursive";
-    outputHashAlgo = "sha256";
-    # To update: nix build .#systant 2>&1 | grep 'got:'
-    outputHash = "sha256-hQ1ZzOFOHHeaAtyfCXxX6jpqB7poFLwavgMW8yMwaHw=";
-  };
-in
-stdenv.mkDerivation {
   pname = "systant";
   version = "0.1.0";
 
-  inherit src;
+  src = fetchgit {
+    url = "https://git.ryanpandya.com/ryan/systant.git";
+    rev = "54f8d23945bcea17127631a81f8ac318bf7047a6";
+    sha256 = "sha256-1cRfSoH+JdO4a7q4hRZSkoDMk2wMCYRIyCIN56FSUgg=";
+  };
 
-  nativeBuildInputs = [ bun ];
+  # Mix dependencies will be automatically fetched and cached by Nix
+  mixFodDeps = beamPackages.fetchMixDeps {
+    pname = "systant-mix-deps";
+    inherit src version;
+    sha256 = "sha256-g8L/ZzCaXznrd+YLCMgvV94NVTKoFnK/Y/RXXPIMAjg=";
+  };
 
-  buildPhase = ''
-    export HOME=$TMPDIR
-    cp -r ${deps} node_modules
-    chmod -R u+w node_modules
-    bun build index.ts --compile --outfile systant
-  '';
-
-  installPhase = ''
-    mkdir -p $out/bin
-    cp systant $out/bin/systant
-  '';
-
-  # Bun's compiled binaries don't like being stripped
-  dontStrip = true;
 
   meta = with lib; {
-    description = "System monitoring agent with MQTT and Home Assistant integration";
+    description = "Systant - System stats MQTT daemon for monitoring system metrics";
     homepage = "https://git.ryanpandya.com/ryan/systant";
     license = licenses.mit;
+    maintainers = [ ];
     platforms = platforms.linux;
   };
 }

package.json

@@ -1,23 +0,0 @@
-{
-  "name": "systant",
-  "version": "0.1.0",
-  "module": "index.ts",
-  "devDependencies": {
-    "@types/bun": "latest",
-    "@types/yargs": "^17.0.35"
-  },
-  "peerDependencies": {
-    "typescript": "^5"
-  },
-  "private": true,
-  "scripts": {
-    "start": "bun run index.ts",
-    "dist": "bun build index.ts --compile --outfile dist/systant"
-  },
-  "type": "module",
-  "dependencies": {
-    "mqtt": "^5.14.1",
-    "smol-toml": "^1.6.0",
-    "yargs": "^18.0.0"
-  }
-}

rel/env.sh.eex

@@ -0,0 +1,6 @@
+#!/bin/sh
+
+# Configure environment for release
+export MIX_ENV=prod
+export RELEASE_DISTRIBUTION=none
+export RELEASE_NODE=nonode@nohost

src/config.ts

@@ -1,130 +0,0 @@
-import { parse } from "smol-toml";
-
-export interface SystantConfig {
-  hostname: string;
-  defaultInterval: number;
-}
-
-export interface MqttConfig {
-  broker: string;
-  username?: string;
-  password?: string;
-  clientId?: string;
-  topicPrefix: string;
-}
-
-export type EntityType = "sensor" | "binary_sensor" | "light" | "switch" | "button";
-
-export interface EntityConfig {
-  type: EntityType;
-  state_command?: string;   // for stateful entities (not button)
-  on_command?: string;      // for light/switch
-  off_command?: string;     // for light/switch
-  press_command?: string;   // for button
-  interval?: number;        // override default interval
-  unit?: string;            // for sensor
-  device_class?: string;    // for sensor (timestamp, etc.) or binary_sensor
-  icon?: string;
-  name?: string;
-  availability?: boolean;   // default true; set false to keep last value when offline
-}
-
-export interface HomeAssistantConfig {
-  discovery: boolean;
-  discoveryPrefix: string;
-}
-
-export interface Config {
-  systant: SystantConfig;
-  mqtt: MqttConfig;
-  entities: Record<string, EntityConfig>;
-  homeassistant: HomeAssistantConfig;
-}
-
-const defaults = {
-  systant: {
-    defaultInterval: 30,
-    hostname: process.env.HOSTNAME || require("os").hostname(),
-  },
-  mqtt: {
-    broker: "mqtt://localhost:1883",
-    topicPrefix: "systant",
-  },
-  homeassistant: {
-    discovery: true,
-    discoveryPrefix: "homeassistant",
-  },
-};
-
-export async function loadConfig(path: string): Promise<Config> {
-  const file = Bun.file(path);
-
-  if (!(await file.exists())) {
-    throw new Error(`Config file not found: ${path}`);
-  }
-
-  const content = await file.text();
-  const parsed = parse(content) as Record<string, unknown>;
-
-  return buildConfig(parsed);
-}
-
-function buildConfig(parsed: Record<string, unknown>): Config {
-  const config: Config = {
-    systant: { ...defaults.systant },
-    mqtt: { ...defaults.mqtt },
-    entities: {},
-    homeassistant: { ...defaults.homeassistant },
-  };
-
-  // MQTT settings
-  if (parsed.mqtt && typeof parsed.mqtt === "object") {
-    Object.assign(config.mqtt, parsed.mqtt);
-  }
-
-  // Systant settings
-  if (parsed.systant && typeof parsed.systant === "object") {
-    Object.assign(config.systant, parsed.systant);
-  }
-
-  // Entities
-  if (parsed.entities && typeof parsed.entities === "object") {
-    const entities = parsed.entities as Record<string, unknown>;
-    for (const [key, value] of Object.entries(entities)) {
-      if (key === "interval") continue; // skip the default interval
-      if (value && typeof value === "object" && "type" in value) {
-        const e = value as Record<string, unknown>;
-        const entityType = String(e.type) as EntityType;
-
-        // Buttons need press_command, others need state_command
-        const hasRequiredCommand = entityType === "button"
-          ? "press_command" in e
-          : "state_command" in e;
-
-        if (!hasRequiredCommand) continue;
-
-        config.entities[key] = {
-          type: entityType,
-          state_command: typeof e.state_command === "string" ? e.state_command : undefined,
-          on_command: typeof e.on_command === "string" ? e.on_command : undefined,
-          off_command: typeof e.off_command === "string" ? e.off_command : undefined,
-          press_command: typeof e.press_command === "string" ? e.press_command : undefined,
-          interval: typeof e.interval === "number" ? e.interval : undefined,
-          unit: typeof e.unit === "string" ? e.unit : undefined,
-          device_class: typeof e.device_class === "string" ? e.device_class : undefined,
-          icon: typeof e.icon === "string" ? e.icon : undefined,
-          name: typeof e.name === "string" ? e.name : undefined,
-          availability: typeof e.availability === "boolean" ? e.availability : true,
-        };
-      }
-    }
-  }
-
-  // Home Assistant
-  if (parsed.homeassistant && typeof parsed.homeassistant === "object") {
-    Object.assign(config.homeassistant, parsed.homeassistant);
-  }
-
-  return config;
-}
-

src/entities.ts

@@ -1,110 +0,0 @@
-import type { Config, EntityConfig } from "./config";
-import type { MqttConnection } from "./mqtt";
-
-export interface EntityManager {
-  start(): Promise<void>;
-  stop(): void;
-}
-
-export function createEntityManager(config: Config, mqtt: MqttConnection): EntityManager {
-  const timers: Timer[] = [];
-
-  async function setupStatefulEntity(id: string, entity: EntityConfig): Promise<void> {
-    const interval = entity.interval ?? config.systant.defaultInterval;
-    const isControllable = entity.type === "light" || entity.type === "switch";
-
-    if (!entity.state_command) return;
-
-    // State polling
-    const pollState = async () => {
-      try {
-        const output = await Bun.$`sh -c ${entity.state_command}`.text();
-        const value = output.trim();
-        console.debug(`[${id}] state: ${value}`);
-        await mqtt.publish(`${id}/state`, value, true); // retain state
-      } catch (err) {
-        console.error(`[${id}] state poll failed:`, err instanceof Error ? err.message : err);
-      }
-    };
-
-    // Initial state poll
-    await pollState();
-
-    // Schedule periodic polling
-    const timer = setInterval(pollState, interval * 1000);
-    timers.push(timer);
-
-    // Command subscription for controllable entities
-    if (isControllable && (entity.on_command || entity.off_command)) {
-      await mqtt.subscribe(`${id}/set`, async (_topic, payload) => {
-        const command = payload.toString().toUpperCase();
-        console.log(`[${id}] received command: ${command}`);
-
-        try {
-          if (command === "ON" && entity.on_command) {
-            await Bun.$`sh -c ${entity.on_command}`;
-            console.log(`[${id}] executed on_command`);
-          } else if (command === "OFF" && entity.off_command) {
-            await Bun.$`sh -c ${entity.off_command}`;
-            console.log(`[${id}] executed off_command`);
-          } else {
-            console.warn(`[${id}] unknown command or no handler: ${command}`);
-            return;
-          }
-
-          // Re-poll state after command execution
-          await new Promise((r) => setTimeout(r, 500)); // brief delay for state to settle
-          await pollState();
-        } catch (err) {
-          console.error(`[${id}] command failed:`, err instanceof Error ? err.message : err);
-        }
-      });
-    }
-
-    const typeLabel = isControllable ? `${entity.type} (controllable)` : entity.type;
-    console.log(`  ${id}: ${typeLabel}, poll every ${interval}s`);
-  }
-
-  async function setupButton(id: string, entity: EntityConfig): Promise<void> {
-    if (!entity.press_command) return;
-
-    await mqtt.subscribe(`${id}/press`, async (_topic, _payload) => {
-      console.log(`[${id}] button pressed`);
-
-      try {
-        await Bun.$`sh -c ${entity.press_command}`;
-        console.log(`[${id}] executed press_command`);
-      } catch (err) {
-        console.error(`[${id}] press_command failed:`, err instanceof Error ? err.message : err);
-      }
-    });
-
-    console.log(`  ${id}: button`);
-  }
-
-  return {
-    async start(): Promise<void> {
-      const entityCount = Object.keys(config.entities).length;
-      if (entityCount === 0) {
-        console.log("No entities configured");
-        return;
-      }
-
-      console.log(`Starting ${entityCount} entity manager(s):`);
-      for (const [id, entity] of Object.entries(config.entities)) {
-        if (entity.type === "button") {
-          await setupButton(id, entity);
-        } else {
-          await setupStatefulEntity(id, entity);
-        }
-      }
-    },
-
-    stop(): void {
-      for (const timer of timers) {
-        clearInterval(timer);
-      }
-      timers.length = 0;
-    },
-  };
-}

src/mqtt.ts

@@ -1,177 +0,0 @@
-import mqtt, { type MqttClient, type IClientOptions } from "mqtt";
-import type { Config, EntityConfig } from "./config";
-
-export interface MqttConnection {
-  client: MqttClient;
-  publish(topic: string, payload: string | object, retain?: boolean): Promise<void>;
-  subscribe(topic: string, handler: (topic: string, payload: Buffer) => void): Promise<void>;
-  disconnect(): Promise<void>;
-}
-
-export async function connect(config: Config, hostname: string): Promise<MqttConnection> {
-  const options: IClientOptions = {
-    clientId: config.mqtt.clientId || `systant-${hostname}`,
-    username: config.mqtt.username,
-    password: config.mqtt.password,
-    will: {
-      topic: `${config.mqtt.topicPrefix}/${hostname}/status`,
-      payload: Buffer.from("offline"),
-      qos: 1,
-      retain: true,
-    },
-  };
-
-  const client = mqtt.connect(config.mqtt.broker, options);
-  const handlers = new Map<string, (topic: string, payload: Buffer) => void>();
-
-  await new Promise<void>((resolve, reject) => {
-    client.on("connect", () => {
-      console.log(`Connected to MQTT broker: ${config.mqtt.broker}`);
-      resolve();
-    });
-    client.on("error", reject);
-  });
-
-  client.on("message", (topic, payload) => {
-    for (const [pattern, handler] of handlers) {
-      if (topicMatches(pattern, topic)) {
-        handler(topic, payload);
-      }
-    }
-  });
-
-  // Publish online status
-  await publishAsync(client, `${config.mqtt.topicPrefix}/${hostname}/status`, "online", true);
-
-  // Publish HA discovery if enabled
-  if (config.homeassistant.discovery) {
-    await publishDiscovery(client, config, hostname);
-  }
-
-  return {
-    client,
-
-    async publish(topic: string, payload: string | object, retain = false): Promise<void> {
-      const fullTopic = `${config.mqtt.topicPrefix}/${hostname}/${topic}`;
-      const data = typeof payload === "object" ? JSON.stringify(payload) : payload;
-      await publishAsync(client, fullTopic, data, retain);
-    },
-
-    async subscribe(topic: string, handler: (topic: string, payload: Buffer) => void): Promise<void> {
-      const fullTopic = `${config.mqtt.topicPrefix}/${hostname}/${topic}`;
-      handlers.set(fullTopic, handler);
-      await new Promise<void>((resolve, reject) => {
-        client.subscribe(fullTopic, { qos: 1 }, (err) => {
-          if (err) reject(err);
-          else resolve();
-        });
-      });
-      console.log(`Subscribed to: ${fullTopic}`);
-    },
-
-    async disconnect(): Promise<void> {
-      await publishAsync(client, `${config.mqtt.topicPrefix}/${hostname}/status`, "offline", true);
-      await new Promise<void>((resolve) => client.end(false, {}, () => resolve()));
-    },
-  };
-}
-
-function publishAsync(client: MqttClient, topic: string, payload: string, retain: boolean): Promise<void> {
-  return new Promise((resolve, reject) => {
-    client.publish(topic, payload, { qos: 1, retain }, (err) => {
-      if (err) reject(err);
-      else resolve();
-    });
-  });
-}
-
-function topicMatches(pattern: string, topic: string): boolean {
-  if (pattern === topic) return true;
-  if (pattern.endsWith("#")) {
-    return topic.startsWith(pattern.slice(0, -1));
-  }
-  return false;
-}
-
-async function publishDiscovery(client: MqttClient, config: Config, hostname: string): Promise<void> {
-  const prefix = config.homeassistant.discoveryPrefix;
-  const topicPrefix = config.mqtt.topicPrefix;
-
-  const entityCount = Object.keys(config.entities).length;
-  if (entityCount === 0) {
-    console.log("No entities configured, skipping HA discovery");
-    return;
-  }
-
-  for (const [id, entity] of Object.entries(config.entities)) {
-    const payload = buildDiscoveryPayload(id, entity, hostname, topicPrefix);
-    const discoveryTopic = `${prefix}/${entity.type}/${hostname}_${id}/config`;
-    await publishAsync(client, discoveryTopic, JSON.stringify(payload), true);
-  }
-
-  console.log(`Published Home Assistant discovery for ${entityCount} entity/entities`);
-}
-
-function buildDiscoveryPayload(
-  id: string,
-  entity: EntityConfig,
-  hostname: string,
-  topicPrefix: string
-): Record<string, unknown> {
-  const displayName = entity.name || id.replace(/_/g, " ");
-
-  const payload: Record<string, unknown> = {
-    name: displayName,
-    unique_id: `systant_${hostname}_${id}`,
-    device: {
-      identifiers: [`systant_${hostname}`],
-      name: `${hostname}`,
-      manufacturer: "Systant",
-    },
-  };
-
-  // Stateful entities have a state_topic (buttons don't)
-  if (entity.type !== "button") {
-    payload.state_topic = `${topicPrefix}/${hostname}/${id}/state`;
-  }
-
-  // Add availability tracking unless explicitly disabled
-  if (entity.availability !== false) {
-    payload.availability_topic = `${topicPrefix}/${hostname}/status`;
-    payload.payload_available = "online";
-    payload.payload_not_available = "offline";
-  }
-
-  // Common optional fields
-  if (entity.icon) payload.icon = entity.icon;
-
-  // Type-specific fields
-  switch (entity.type) {
-    case "sensor":
-      if (entity.unit) payload.unit_of_measurement = entity.unit;
-      if (entity.device_class) payload.device_class = entity.device_class;
-      break;
-
-    case "binary_sensor":
-      payload.payload_on = "ON";
-      payload.payload_off = "OFF";
-      if (entity.device_class) payload.device_class = entity.device_class;
-      break;
-
-    case "light":
-    case "switch":
-      payload.command_topic = `${topicPrefix}/${hostname}/${id}/set`;
-      payload.payload_on = "ON";
-      payload.payload_off = "OFF";
-      payload.state_on = "ON";
-      payload.state_off = "OFF";
-      break;
-
-    case "button":
-      payload.command_topic = `${topicPrefix}/${hostname}/${id}/press`;
-      payload.payload_press = "PRESS";
-      break;
-  }
-
-  return payload;
-}

systant.toml.example

@@ -1,75 +0,0 @@
-# Systant Configuration
-# Copy this to systant.toml and customize for your system
-
-[systant]
-# hostname = "myhost"  # defaults to system hostname
-
-[mqtt]
-broker = "mqtt://localhost:1883"
-# username = "user"
-# password = "secret"
-# clientId = "systant-myhost"  # defaults to systant-{hostname}
-topicPrefix = "systant"
-
-[entities]
-interval = 30  # default interval in seconds
-
-# Sensor examples
-[entities.cpu_usage]
-type = "sensor"
-state_command = "awk '/^cpu / {u=$2+$4; t=$2+$4+$5; print int(u*100/t)}' /proc/stat"
-unit = "%"
-icon = "mdi:cpu-64-bit"
-name = "CPU Usage"
-
-[entities.memory]
-type = "sensor"
-state_command = "awk '/MemTotal/{t=$2} /MemAvailable/{a=$2} END {print int((t-a)/t*100)}' /proc/meminfo"
-unit = "%"
-icon = "mdi:memory"
-name = "Memory Usage"
-
-[entities.last_seen]
-type = "sensor"
-state_command = "date -Iseconds"
-device_class = "timestamp"
-icon = "mdi:clock-check"
-name = "Last Seen"
-availability = false  # keeps last value when offline
-
-# Binary sensor example (read-only on/off)
-# [entities.service_running]
-# type = "binary_sensor"
-# state_command = "systemctl is-active myservice >/dev/null && echo ON || echo OFF"
-# device_class = "running"
-# icon = "mdi:cog"
-# name = "My Service"
-
-# Light example (controllable, for things like monitors)
-# [entities.screen]
-# type = "light"
-# state_command = "xrandr | grep -q 'connected primary' && echo ON || echo OFF"
-# on_command = "xrandr --output DP-1 --auto"
-# off_command = "xrandr --output DP-1 --off"
-# icon = "mdi:monitor"
-# name = "Screen"
-
-# Switch example (controllable on/off)
-# [entities.vpn]
-# type = "switch"
-# state_command = "systemctl is-active openvpn >/dev/null && echo ON || echo OFF"
-# on_command = "systemctl start openvpn"
-# off_command = "systemctl stop openvpn"
-# icon = "mdi:vpn"
-# name = "VPN"
-
-# Button example (just executes a command)
-# [entities.sync_time]
-# type = "button"
-# press_command = "ntpdate pool.ntp.org"
-# icon = "mdi:clock-sync"
-# name = "Sync Time"
-
-[homeassistant]
-discovery = true
-discoveryPrefix = "homeassistant"

test/systant_test.exs

@@ -0,0 +1,8 @@
+defmodule SystantTest do
+  use ExUnit.Case
+  doctest Systant
+
+  test "greets the world" do
+    assert Systant.hello() == :world
+  end
+end

test/test_helper.exs

@@ -0,0 +1 @@
+ExUnit.start()

tsconfig.json

@@ -1,29 +0,0 @@
-{
-  "compilerOptions": {
-    // Environment setup & latest features
-    "lib": ["ESNext"],
-    "target": "ESNext",
-    "module": "Preserve",
-    "moduleDetection": "force",
-    "jsx": "react-jsx",
-    "allowJs": true,
-
-    // Bundler mode
-    "moduleResolution": "bundler",
-    "allowImportingTsExtensions": true,
-    "verbatimModuleSyntax": true,
-    "noEmit": true,
-
-    // Best practices
-    "strict": true,
-    "skipLibCheck": true,
-    "noFallthroughCasesInSwitch": true,
-    "noUncheckedIndexedAccess": true,
-    "noImplicitOverride": true,
-
-    // Some stricter flags (disabled by default)
-    "noUnusedLocals": false,
-    "noUnusedParameters": false,
-    "noPropertyAccessFromIndexSignature": false
-  }
-}