Entity Discovery

HA NOVA Entity Discovery

Scope

Use for:

• listing entities by domain
• searching entities by user phrase
• bulk inventory by prefix, domain, area, or label
• resolving likely targets before writes

Read-only behavior.

• No POST, PUT, PATCH, or DELETE relay writes.
• If the user moves from discovery to mutation, stop after resolution and hand off to the write-capable skill.

Bootstrap (once per session)

Verify relay CLI: ha-nova relay health If this fails: ha-nova setup

Relay Contract

Use file-based relay requests by default:

• ha-nova relay ws --data-file
• ha-nova relay core --method --path --body-file when a body is needed
• --jq-file for non-trivial filters; keep inline --jq for short selectors only
• --out for large reads
• On Windows PowerShell, never chain commands with && or ||; run separate shell commands instead.
• Never call external jq; use relay-native filters or ha-nova relay jq --file ....

Flow

Step 1: Search entity registry

Entity registry uses compact abbreviated keys: ei=entityid, en=name, ai=areaid.

Search both entity_id and name. Use short keyword stems to handle spelling variants. Always limit to 20 results.

For bulk selectors, follow skills/ha-nova/bulk-patterns.md.

• prefix: case-insensitive prefix match on the entity_id suffix and display name
• domain: exact domain filter
• area: resolve the area, then use search/related as the primary shortlist source; use ai only as optional extra evidence when present
• label: escalate to the full registry only when label evidence is required; config/entity_registry/list returns the entity array directly in .data
• helper + area: not a first-class bulk selector contract; do not imply room-owned helper discovery unless live helper-area semantics are explicitly defined

For domain counts or domain shortlists:

• count only the requested domain unless the user explicitly asks for heuristics or related domains
• use --jq-file for the count filter
• if you need a follow-up count from a saved file, use ha-nova relay jq --file length

Create ` with {"type":"config/entityregistry/listfor_display"}`, then run:

ha-nova relay ws --data-file  --jq-file 

Write `` with:

[.data.entities[] | select((.ei + " " + (.en // "")) | test("KEYWORD";"i")) | {entity_id: .ei, name: .en, area_id: .ai}] | .[0:20]

This generic test("KEYWORD";"i") example is for free-text search, not explicit prefix matching. For an explicit prefix selector, match the suffix and display name with startswith(...), not loose substring search.

If 0 results: try synonyms, alternative terms, or shorter keyword stems. Use OR for multiple variants: test("kw1|kw2|kw3";"i"). If too many: narrow with AND: test("kw1";"i") and test("kw2";"i"). Never dump entire domains without a user-intent keyword.

When the task is multi-target inventory:

• save the shortlist with --out
• do not trim to 20 inside the initial selector filter
• dedupe first, then sort deterministically, then compute the exact matched count, then apply the 20-row display cap
• keep ordering deterministic: domain, then entity_id
• return the exact matched count separately from the displayed rows

Step 2: Get state or config

# State
ha-nova relay core --method GET --path /api/states/{entity_id}

# Automation/script config — always resolve unique_id first (see relay-api.md → ID Types)
ha-nova relay ws --data-file  --out 
ha-nova relay jq -r --file  '.data.unique_id'
ha-nova relay core --method GET --path /api/config/automation/config/{unique_id} --jq-file  --out 
# For scripts: use script.{slug} and /api/config/script/config/{unique_id}

Write `` with:

if .ok then .data.body else error("relay error: \(.error.message // "unknown")") end

Step 3: Find automations related to a device or area

Automations rarely have reliable direct area_id data in the compact registry. When user asks "automations for X in room Y":

1. Resolve room name to area_id:

ha-nova relay ws --data-file then filter by name with --jq

1. Query the area directly:

{"type":"search/related","item_type":"area","item_id":""}

1. Treat the response as a keyed object, not an array:

• automation discovery uses .data.automation
• script discovery uses .data.script
• entity discovery uses .data.entity

1. If automation/script keys are absent and only area entities are present, use search/related on those entities to derive the automation/script shortlist:

``text ha-nova relay ws --data-file ``

This is more reliable than keyword search or assuming .ai is populated for room-based queries.

Step 4: Return shortlist

• entity_id, friendly_name, state (if fetched), short relevance reason
• for bulk inventory: filter used, matched count, displayed rows
• do not fetch full YAML for every matched item in one response

IMPORTANT: Never dump raw get_states — it returns thousands of entities with full attributes.

Matching Rules

• area-first bulk discovery by room/area uses search/related on the resolved area before keyword heuristics
• exact entity_id match wins
• keyword match on entity_id + name second

If ambiguity remains: present top candidates (max 10), ask one selection question.

Safety

• Read-only — this skill never modifies Home Assistant state or config.
• No POST, PUT, PATCH, or DELETE relay writes.
• All communication with Home Assistant goes through ha-nova relay exclusively.

Guardrails

• never guess entity IDs
• cap displayed shortlist rows at 20 only after exact matched-count computation for bulk inventory
• no writes
• no proactive doctor before real failure

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: markusleben
• Source: markusleben/ha-nova
• License: MIT
• Homepage: https://github.com/markusleben/ha-nova

Install and usage instructions live in the source repository linked above.