Home Assistant MCP Server

Home Assistant MCP Server – Overview

The Home Assistant MCP Server bridges the gap between conversational AI assistants and your smart‑home ecosystem. By exposing Home Assistant’s RESTful API through the Model Context Protocol, it allows language models such as Claude to read device states, trigger automations, and retrieve historical data—all through natural‑language prompts. This eliminates the need for custom integration code, enabling developers and hobbyists to prototype voice‑controlled or chat‑based home‑automation workflows quickly.

At its core, the server translates MCP tool calls into Home Assistant service requests. When an LLM issues a command like “turn on the living‑room light,” the server resolves the entity identifier, authenticates with a long‑lived access token, and forwards the appropriate service call. It also supports querying entity states () and listing available services or lights, providing a rich set of tools that cover most day‑to‑day home‑automation tasks. The server’s design focuses on safety: every request is authenticated, and optional mock mode lets developers test interactions without a live Home Assistant instance.

Key capabilities include:

• State Management – Retrieve current values of any entity () and list all light entities ().
• Service Calls – Execute arbitrary Home Assistant services () or control individual lights ().
• Historical Data – Pull past state changes for analysis or reporting ().
• Transport Flexibility – Operate over HTTP/SSE for remote clients or stdio for local, process‑bound interactions.
• Demo Mode – Run with mock data when Home Assistant is offline, simplifying onboarding and demonstration.

Typical use cases span from building a chat‑based home‑automation assistant that can answer questions about current temperatures to integrating voice commands into existing LLM workflows. Developers can embed the server in CI pipelines to test automations, or expose it through a local agent so that Claude Desktop can query and control devices directly. The unique advantage lies in its zero‑code integration: once the server is running, any MCP‑compatible client can leverage Home Assistant’s full feature set without writing custom adapters.

In summary, the Home Assistant MCP Server transforms a standard LLM into a powerful smart‑home controller, providing secure, flexible, and feature‑rich access to Home Assistant’s ecosystem through a standardized protocol.