ha-integration-knowledge

name	ha-integration-knowledge
description	Everything you need to know to build, test and review Home Assistant Integrations. If you're looking at an integration, you must use this as your primary reference.

File Locations

• Integration code: ./homeassistant/components/<integration_domain>/
• Integration tests: ./tests/components/<integration_domain>/

General guidelines

• When looking for examples, prefer integrations with the platinum or gold quality scale level first.
• Polling intervals are NOT user-configurable. Never add scan_interval, update_interval, or polling frequency options to config flows or config entries.
• Do NOT allow users to set config entry names in config flows. Names are automatically generated or can be customized later in UI. Exception: helper integrations may allow custom names.
• For entity actions and entity services, avoid requesting redundant defensive checks for fields already enforced by Home Assistant validation schemas and entity filters; only request extra guards when values bypass validation or are transformed unsafely.
• When validation guarantees a key is present, prefer direct dictionary indexing (data["key"]) over .get("key") so invalid assumptions fail fast.
• Integrations should be thin wrappers. Protocol parsing, device state machines, or other domain logic belong in a separate PyPI library, not in the integration itself. If unsure, ask before inlining.
• "potato" is a forbidden word for an integration and should never be used.

The following platforms have extra guidelines:

• Diagnostics: platform-diagnostics.md for diagnostic data collection
• Repairs: platform-repairs.md for user-actionable repair issues

Integration Quality Scale

• When validating the quality scale rules, check them at https://developers.home-assistant.io/docs/core/integration-quality-scale/rules
• When implementing or reviewing an integration, always consider the quality scale rules, since they promote best practices.

Template scale file: ./script/scaffold/templates/integration/integration/quality_scale.yaml

How Rules Apply

1. Check manifest.json: Look for "quality_scale" key to determine integration level
2. Bronze Rules: Always required for any integration with quality scale
3. Higher Tier Rules: Only apply if integration targets that tier or higher
4. Rule Status: Check quality_scale.yaml in integration folder for:
   • done: Rule implemented
   • exempt: Rule doesn't apply (with reason in comment)
   • todo: Rule needs implementation

Testing Requirements

• Tests should avoid interacting or mocking internal integration details. For more info, see https://developers.home-assistant.io/docs/development_testing/#writing-tests-for-integrations