Integration

Hermes Agent Home Assistant Integration: Smart Home Control and State Checks

Q: What token does Hermes need for Home Assistant?

A Home Assistant long-lived access token, stored as `HASS_TOKEN` in the Hermes environment.

Connect Hermes Agent to Home Assistant with a long-lived token so the agent can query entities, inspect state, and control devices safely.

Quick answer

Hermes integrates with Home Assistant through a long-lived access token. That enables smart-home tools for listing entities, reading state, listing services, and calling services, plus gateway event workflows when you want state changes to trigger agent runs.

Skip the setup → Deploy in 60 seconds

Managed cloud · API costs included · No gateway maintenance

Best for

Operators who want a practical agent workflow, not only a chat demo.

Teams that need a clear setup path, smoke test, and permission boundary.

Workflows that should connect Hermes to other tools such as GitHub, Linear, Notion, Telegram, Slack, or email.

Self-hosted users who need to understand what runs locally and what credentials are required.

Features

✓Long-lived access token setup with HASS_TOKEN
✓Optional HASS_URL for local or remote Home Assistant instances
✓Entity discovery by domain or room, such as lights, sensors, climate, switches, and media players
✓Detailed state inspection before taking action
✓Service listing so Hermes can see what actions each device supports
✓Controlled service calls for device automation and smart-home routines

Setup path

1Create a Home Assistant long-lived access token from your Home Assistant profile.
2Add HASS_TOKEN to ~/.hermes/.env and set HASS_URL if the default URL is not correct.
3Restart Hermes or the gateway so the Home Assistant toolset becomes available.
4Ask Hermes to list entities before allowing control commands.
5Run one harmless test, such as reading a sensor state or listing lights in one room.
6Only then allow actions like turning on lights, changing climate settings, or running automations.

Two integration modes

Home Assistant can be used as a tool surface and as an event source. Tool use is what you want for questions and direct commands. Event handling is what you want when a device state change should trigger an agent workflow.

•Tool mode: “What is the thermostat set to?” or “turn off kitchen lights.”
•Event mode: respond when a door opens, a sensor crosses a threshold, or an automation fires.
•Keep destructive or security-sensitive actions behind confirmation until you trust the setup.

Safety rules for smart-home agents

Smart-home control is physical-world automation. The agent should read state before changing state and should avoid broad commands like “turn everything off” unless you explicitly want that behavior.

•Start with read-only prompts.
•Use room/domain filters to reduce accidental device matches.
•Require approval for locks, alarms, garage doors, heating, and anything safety-critical.

Common setup issues

The integration appears enabled but nothing happens — restart the Hermes gateway or start a fresh Hermes session after config changes.
Credentials work in one shell but not in the gateway — check the active Hermes profile and where the gateway process reads its environment.
The workflow is too broad — split it into smaller routes, skills, or prompts with one expected outcome each.