Harmonyhub Py

License: MIT Python

harmonyhub-py talks directly to your hub over WebSocket on the local network — no Logitech cloud, no account, no internet required after the initial one-time provisioning.

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Features

• Pure local control — WebSocket on port 8088; provisioning POST is answered by the hub itself
• Async Python library — async with HarmonyHubClient("192.168.1.x") as hub: ...
• Rich CLI — human-readable tables or --json for scripts and pipes
• MCP server — expose your hub as tools to Claude or any MCP client
• Logical-key routing — maps volume_up, channel_down, ok, etc. to the right device automatically
• Hub discovery — SSDP M-SEARCH + parallel /24 port scan
• Simulator — fake hub for tests; no real hardware needed

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Installation

pip install harmonyhub-py

Requires Python 3.14+.

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Quick start

1. Discover your hub

harmony discover

           Discovered Harmony Hubs
┏━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━┳━━━━━━━━━━━┓
┃ Host           ┃ Friendly Name ┃ Remote ID ┃
┡━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━━━╇━━━━━━━━━━━┩
│ 192.168.178.50 │ Harmony Hub   │ 12345678  │
└────────────────┴───────────────┴───────────┘

2. Point the CLI at the hub

export HARMONY_HUB_HOST=192.168.178.50
harmony status

Activity: PowerOff
Last channel: 5 (source: library)
Connected: True

3. Use it

harmony activities list
harmony activities start "Watch TV"
harmony key volume-up
harmony channel 101

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CLI reference

harmony [--host IP] [--json]

Command	Description
harmony discover	Find hubs on the LAN via SSDP + /24 port scan
harmony info	Hub identity: remote ID, firmware, friendly name
harmony status	Current activity, last channel, connection state
harmony power-off	Run the PowerOff activity
harmony listen	Stream real-time hub events to stdout
harmony activities list/current/start	List, query, or switch activities
harmony devices list/commands	List devices and their IR commands
harmony device power-on/off <device>	Power a single device on or off
harmony key volume-up/down/mute/ok/back/digit	Send a logical key with automatic routing
harmony channel <n>	Switch channel (digits_then_enter or change_channel)
harmony send --device DEV --command CMD	Send a raw IR command to a specific device
harmony config pull/show/diff	Fetch, display, or diff the hub config
harmony sequence list/run	List and fire hub-defined macro sequences
harmony doctor	End-to-end diagnostic: network → provisioning → WebSocket → config

Use --json for machine-readable output on any read command. All log output goes to stderr; stdout stays scriptable.

For the full subcommand reference see docs/routing.md.

Exit codes

Code	Meaning
0	success
2	usage / validation error
10	hub unavailable on the network
11	protocol error (timeout, malformed payload)
12	command or alias not found
13	routing ambiguous — pass an explicit --device

Shell completions (zsh)

harmony --install-completion zsh
exec zsh

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Python library

import asyncio
from harmonyhub import HarmonyHubClient


async def main() -> None:
    async with HarmonyHubClient("192.168.178.50") as hub:
        info = await hub.get_info()
        print(f"Hub: {info.friendly_name} (remote-id: {info.remote_id})")

        for activity in await hub.list_activities():
            print(f"  {activity.label} (id={activity.id})")

        await hub.start_activity("Watch TV")
        await hub.send_key("volume_up")
        result = await hub.set_channel("101")
        print(f"Channel via {result.method}")


asyncio.run(main())

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MCP server

harmonyhub-py ships with an MCP server that exposes the hub as tools for Claude or any MCP-compatible client.

Claude Desktop

Add to claude_desktop_config.json:

{
  "mcpServers": {
    "harmony": {
      "command": "harmony-mcp",
      "args": [],
      "env": { "HARMONY_HUB_HOST": "192.168.178.50" }
    }
  }
}

VS Code (agent mode)

{
  "mcp": {
    "servers": {
      "harmony": {
        "command": "harmony-mcp",
        "type": "stdio",
        "env": { "HARMONY_HUB_HOST": "192.168.178.50" }
      }
    }
  }
}

Available MCP tools

harmony_get_status · harmony_list_activities · harmony_start_activity · harmony_power_off · harmony_list_devices · harmony_list_device_commands · harmony_device_power_on · harmony_device_power_off · harmony_send_key · harmony_send_command · harmony_set_channel · harmony_refresh_config

Resources: harmony://config · harmony://activities · harmony://devices · harmony://status

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Agent skill

skill/harmonyhub/SKILL.md follows the Agent Skills open standard and works across GitHub Copilot (VS Code, CLI, cloud agent), Claude Code, and Cursor — write once, use everywhere.

It teaches the model to translate voice-style requests ("schalte Pro7 ein", "lauter", "alles aus") into the matching MCP tool calls or harmony CLI invocations. Replies stay in the user's language — no tool names, no JSON.

Skill installation

Project skill (one repository):

cp -r skill/harmonyhub /your-project/.agents/skills/harmonyhub
# or keep in sync via symlink:
ln -s "$(pwd)/skill/harmonyhub" /your-project/.agents/skills/harmonyhub

Personal skill (every project on your machine):

cp -r skill/harmonyhub ~/.agents/skills/harmonyhub      # generic / Copilot
cp -r skill/harmonyhub ~/.claude/skills/harmonyhub       # Claude Code

[!TIP] If you cloned harmonyhub-py, the skill is already installed as .agents/skills/harmonyhub — no extra step needed.

See docs/skill.md for full installation notes.

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Configuration

Config file: ~/.config/harmony-local/config.toml

[hub]
host = "192.168.178.50"

[connection]
mode = "persistent"            # persistent | ondemand
protocol = "websocket"         # websocket | xmpp
keepalive_interval_s = 50
request_timeout_s = 10

[channel]
mode = "digits_then_enter"     # digits_then_enter | change_channel
inter_digit_delay_ms = 150
send_enter = true

[volume]
repeat = 1                     # IR presses per logical key (e.g. 4 → 2 dB steps on a Yamaha AVR)
hold_ms = 0                    # extra hold per press in ms
inter_press_delay_ms = 80      # gap between repeats when repeat > 1

[activity_routes."Watch TV"]
volume_device = "Denon AVR"
channel_device = "Vodafone Receiver"
navigation_device = "Vodafone Receiver"
number_device = "Vodafone Receiver"

Environment variable overrides:

Variable	Overrides
HARMONY_HUB_HOST	hub.host
HARMONY_PROTOCOL	connection.protocol
HARMONY_CONNECTION_MODE	connection.mode

Precedence: CLI flag > env var > config file > default.

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Limitations

The hub is a one-way IR transmitter for most operations, so the library is honest about what it cannot know:

Question	Verdict
Which activity is active?	Reliable — read directly from the hub
What is the current channel?	Unknown to the hub; tracked only when set via this library (last_channel_source flagged)
Is a specific device powered on?	Inferred from the active activity; unverified
Did the user press the original remote?	Invisible to the hub

Run harmony status to inspect what is actually known.

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Development

git clone https://github.com/jenreh/harmonyhub-py
cd harmonyhub-py
uv sync --extra dev
task test     # pytest with coverage
task lint     # ruff + mypy
task format   # ruff format

[!NOTE] A FakeHub simulator (harmonyhub.simulator) is included for use in tests — no real Harmony Hub required.

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Documentation

File	Summary
docs/protocol.md	Raw WebSocket/HTTP payloads; reverse-engineered hub wire format
docs/routing.md	How logical keys resolve to a device — precedence rules and config examples
docs/skill.md	Installation guide for the natural-language agent skill
docs/troubleshooting.md	Common errors (HTTP 401, timeout, provisioning failures) and fixes