Chats and agents can read a Home Assistant instance and, if the person
allows it, switch things in it.
Read tools: server summary, areas, entity search, state, history,
logbook and the catalogue of callable services. Results are bounded,
marked as untrusted data, and stripped of pictures, access tokens,
secrets and locations.
Write tools: call-service for quiet services (lights, switches, input
booleans, media transport) follows the write mode of the connection;
call-physical-service always needs a confirmation. A deny-by-default
allowlist decides which services a model may call. A hard exclusion
list that no setting can lift covers locks, alarms, sirens, valves,
cameras, garage-type covers, restarts, reloads and shell, system and
add-on management. Calls name entities one by one, up to a cap.
Entities can be excluded by domain, area, pattern or label.
One connection is one instance: the token is the credential and the
address is its one allowed resource, so the host refuses any other
address before the add-on runs. The add-on speaks only to that address,
refuses redirects, verifies TLS, and accepts a self-signed certificate
only through a pinned SHA-256 fingerprint.
The policy lives in the add-on data folder and is edited on the add-on
page by an administrator. For that, the host no longer asks a
credential for a uiOnly tool of a credentialed add-on, since the page
has no chat to name a connection.
Assisted-by: Claude:claude-sonnet-5-5 go node
Ettore Di Giacinto
6be3a96083