---

name: developer-extension description: "Guides contributors modifying or extending Viseron components, domains, reload behavior, entities, docs, tests, and source-root imports." metadata: disco-role: operating disable-model-invocation: true license: MIT

Developer Extension

Use this sub-skill when the task is to modify or extend Viseron backend code rather than only configure an existing camera, detector, recorder, or integration.

Route here for

• Adding or changing a component package, domain implementation, domain dependency, entity, event/data-stream publisher or subscriber, config schema, or unload hook.
• Diagnosing component/domain lifecycle states, DomainNotReady retries, hot reload behavior, or stale entities/listeners after reload.
• Updating schema-backed component documentation or choosing focused backend tests for a component/domain/reload change.
• Investigating source-root/import failures around subprocess workers and top-level manager.py.

Do not use for

• User-level Viseron configuration recipes, camera stream tuning, detector labels/zones, notification delivery, or deployment operations; route those to the corresponding sibling workflow sub-skill.
• Full release engineering, CI image maintenance, or container builds except as reference-only context.

Operating references

Read only the references needed for the current change:

1. Component and domain API for component shape, CONFIG_SCHEMA, setup()/setup_domains(), domain registration, RequireDomain/OptionalDomain, entities, events, and Viseron core APIs.
2. Reload and lifecycle for component/domain state transitions, unload order, hot reload rules, identifier-level changes, and retry behavior.
3. Docs, tests, and packaging for schema-derived docs, focused tests, safe schema inspection, and the source-root manager.py import caveat.
4. Troubleshooting for owned failure modes before proposing code changes.

Bundled helper

Use scripts/inspect_component_schema.py as a read-only helper to summarize one component's CONFIG_SCHEMA and, when requested, supported domain schemas. It prints to stdout and never writes Docusaurus files.