API error type
Feature unavailable
HTTP 503 · https://errors.driftstack.dev/feature-unavailable
What it means
The feature exists but is disabled in this deployment (an activation gate is off — e.g. billing, agent sessions, or avatar upload without its bucket).
How to fix it
The `detail` explains what is missing and any self-serve option. Cloud features come online per the changelog; self-hosted operators enable the relevant env config.
Where it appears
In the type field of the RFC 9457 application/problem+json error body, alongside title, status, detail, and an instance correlation id.