Versioning

Wysp has two separate versioning concepts:

Model Snapshots - govern the behavior of the system (including underlying models and related runtime behavior)

API Versions - govern the shape of the integration interfaces

Data is not versioned

Ground truth mapping data and other Wysp data layers update on a variety of schedules (mostly daily, some hourly, some realtime).

Evals should be designed with this in mind.

Model Versioning

Current Version: wysp-2026-02-20

Model versions are behavior snapshots of the system (including underlying models and related runtime behavior).

When model version is omitted from requests (or set explicitly to wysp-latest) the latest snapshot will be used.

Default model (wysp-latest)

curl https://api.wysp.com/v1/some-endpoint

You can pin to a snapshot using the X-Wysp-Model HTTP header:

Pinned model snapshot

curl https://api.wysp.com/v1/some-endpoint \
  -H "X-Wysp-Model: wysp-2026-02-20"

API Versioning

Current Version: 1.0.47

API major version is specified in the URL path (for example, /v1/).

Expect major versions to be infrequent, with the following guaranteed to be stable within a major version:

• Authentication scheme and token types
• Required request fields and their meaning
• Existing response field meaning and type
• Existing endpoint paths and HTTP methods
• Error envelope shape and top-level error semantics

Client implementations must be tolerant of the following changes within a major version:

• New optional request fields and parameters
• New response fields
• Additional enum values
• Reordered JSON object keys
• Additional headers in requests/responses