# Versioning and deprecation

The path pins the major version; a dated header pins behaviour within it.

```
SciSpace-Version: 2026-08-01
```

Omit the header and you get the version pinned to your account at first use. Pin it explicitly in
production.

## What we may change without a version bump

- Adding a new endpoint, resource, or optional parameter
- Adding a field to a response
- Adding a value to a non-exhaustive enum — `publication_type`, `tone`, citation styles, `subjects`. `status`, `depth`, and `error.type` are exhaustive and will not gain values without a version date
- Improving answer quality within a `depth`

Write clients that tolerate unknown fields and unknown enum values.

## What requires a new version date

- Removing or renaming a field or parameter
- Changing a type, default, or required-ness
- Changing pagination, error shapes, or status semantics

## Deprecation policy

- Each version date is supported for **at least 12 months** after its successor ships
- Removals get **90 days notice**, announced in the changelog and emailed to organization owners
- Deprecated endpoints return a `SciSpace-Deprecation: <sunset-date>` response header for the whole notice period
- New version dates are published at most quarterly

## Related

conventions · changelog