Use case / connected tools
Control Home Assistant Devices with Hermes Agent
Hermes Agent ships a Home Assistant toolset: list entities, read an entity's state, list available services, and call a service. It activates as soon as a Home Assistant token is configured. That turns the assistant into a natural-language layer over a system you already run, and it makes the same channel that carries your work messages able to answer what the house is doing.
- 01
Create a long-lived access token
Generate a token in Home Assistant rather than reusing a user password. A dedicated token can be revoked without disturbing anyone's login.
- 02
Configure the token for the runtime
Set the Home Assistant token in the agent's environment so the toolset activates automatically. Nothing else needs to be enabled by hand.
- 03
Read state before you write state
Ask the agent to list entities and report the state of one device. This proves connectivity and shows you the entity names it will actually use.
- 04
Test one harmless service call
Turn a light on and off in a room nobody is in. The first call should be reversible and low consequence.
- 05
Decide what the agent may never control
Locks, alarms, and heating are the usual exclusions. Write the list down before the agent is reachable from a group channel.
Four-step path
How do you connect Home Assistant?
Create a scoped token, confirm the agent can read state, and only then allow service calls.
- Step 01
Create a long-lived access token
Generate a token in Home Assistant rather than reusing a user password. A dedicated token can be revoked without disturbing anyone's login.
- Step 02
Configure the token for the runtime
Set the Home Assistant token in the agent's environment so the toolset activates automatically. Nothing else needs to be enabled by hand.
- Step 03
Read state before you write state
Ask the agent to list entities and report the state of one device. This proves connectivity and shows you the entity names it will actually use.
- Step 04
Test one harmless service call
Turn a light on and off in a room nobody is in. The first call should be reversible and low consequence.
- Step 05
Decide what the agent may never control
Locks, alarms, and heating are the usual exclusions. Write the list down before the agent is reachable from a group channel.
Which Home Assistant tools does Hermes Agent give you?
Four: list entities, read an entity's state, list available services, and call a service. Together they cover discovery, reading, and acting.
- List entities, so the agent can find the right device name.
- Read state, so answers are based on the system rather than a guess.
- List services, so the agent calls a real service name instead of inventing one.
- Call a service, so the agent can actually change something.
How is the toolset activated?
The Home Assistant toolset turns on automatically once a Home Assistant token is configured, so there is no separate enablement step to forget.
That convenience is also the risk. The moment the token exists, the agent has home control from every channel connected to that runtime, so channel access and token scope have to be decided together.
How do you keep home control safe?
Scope the token, keep the assistant out of open group chats, and exclude anything irreversible from the allowed service list.
- Use a dedicated token that can be revoked on its own.
- Keep the assistant in direct messages or a private channel.
- Exclude locks, alarms, and anything with a physical consequence.
- Review the entity list after adding new devices, because new names appear automatically.
What are sensible first jobs for home control?
Read-only summaries and low-consequence actions: a status digest, turning a light off, or reporting which windows are open.
- A scheduled morning summary of temperatures and open sensors.
- Turning off lights in rooms that are empty.
- Answering what the state of a specific entity is right now.
Where does this fit with the rest of the deployment?
Home Assistant is one tool server among several. Connect it the same way you connect work systems, and keep the same review rules.
Which primary sources support this page?
Product behavior is checked against the current deployment flow. These external links provide the upstream project or channel documentation used for setup details.
Direct answers
Frequently asked questions
Does Hermes Agent support Home Assistant out of the box?
Yes. A Home Assistant toolset is built in and activates automatically when a Home Assistant token is configured, so no custom integration is required.
Can the agent control devices or only read them?
It can call services, which means control. Limit that deliberately by excluding irreversible devices and keeping the assistant out of open group chats.
How many Home Assistant tools are there?
Four: list entities, get state, list services, and call a service. That is enough for discovery, reading, and acting without a broader home-automation surface.
Key takeaways
- Hermes Agent ships a Home Assistant toolset: list entities, read an entity's state, list available services, and call a service. It activates as soon as a Home Assistant token is configured. That turns the assistant into a natural-language layer over a system you already run, and it makes the same channel that carries your work messages able to answer what the house is doing.
- Start with one model, one channel, and one controlled test conversation.
- Use managed hosting when deployment speed matters more than operating the server yourself.
Continue the setup
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