Jev Changelog: Model Versions, Aliases and SDK Releases

Last checked Sep 19, 2026 · Independent guide, not affiliated with TypeSafe AI

ANSWER

As of September 19, 2026 there is one Jev model, Jev 1.13 (jev-1.13.0). The aliases jev-latest and jev-preview both point to it. The Python SDK is at 0.7.0 (released September 18) and the JavaScript SDK at 0.6.0 (September 15). Pin jev-1.13.0 if you tune thresholds, because the aliases will move when a new version ships.

This page tracks what changed and when. We update it when TypeSafe ships a new model or SDK version, or when a platform adds Jev.

Current model

Name	Resolves to	Notes
`jev-1.13.0`	Jev 1.13	The versioned ID. Use it when you need answers to stay stable
`jev-latest`	`jev-1.13.0`	Most recent official release; the SDK default
`jev-preview`	`jev-1.13.0`	Most recent release, official or not; TypeSafe says no preview build exists yet

We confirmed on September 19, 2026 that all three names return "model": "jev-1.13.0". GET /v1/models lists only the two aliases, with release dates of September 10, 2026, five days before the public launch. The shortened name jev-1.13 is rejected with “Unknown model”.

Model timeline

Date	Change
Sep 10, 2026	Release date listed by the API for the `jev-latest` and `jev-preview` aliases
Sep 15, 2026	Public launch of Jev (1.13) in early access; Vercel AI Gateway lists `typesafe-ai/jev`
Sep 17, 2026	TypeSafe’s “Jev 1.13 jaggedness” page (known weaknesses) last reviewed
Sep 18, 2026	OpenRouter lists `typesafe/jev-1.13`; its API reference shows a dated build, `jev-1.13-20260917`
Sep 19, 2026	Cloudflare lists `typesafe/jev` in Workers AI

TypeSafe has not published release notes for the model itself. Its known-issues page for 1.13 says many of the listed weaknesses should be fixed in later versions.

Python SDK (`typesafe-sdk`)

Version	Date	What changed
0.7.0	Sep 18, 2026	Breaking: serialization moved from msgspec to pydantic. New `response_model` argument on `system_one` for typed responses. Fix: `str` subclasses now serialize as strings
0.6.0	Sep 15, 2026	Breaking: Score `criteria` is an ordered list instead of a dict keyed by integers. Better type hints, error messages with HTTP details, picklable exceptions
0.5.7	Sep 11-14, 2026	First public release (the changelog says Sep 14; PyPI shows the upload on Sep 11)

Install the current version with pip install -U typesafe-sdk. If pip reports no matching distribution for 0.7.0, your package index is probably a mirror that has not synced yet; see Python quickstart.

JavaScript SDK (`@typesafe-ai/sdk`)

Version	Date	What changed
0.6.0	Sep 15, 2026	Breaking: Score `criteria` is an ordered list instead of a map keyed by integers
0.5.7	Sep 11-12, 2026	First public release (changelog Sep 11; npm Sep 12)

Channel availability

Channel	Model name	Listed since
TypeSafe API	`jev-1.13.0`, `jev-latest`, `jev-preview`	Sep 15, 2026 (early access)
Vercel AI Gateway	`typesafe-ai/jev`	Sep 15, 2026
OpenRouter	`typesafe/jev-1.13`	Sep 18, 2026
Cloudflare Workers AI	`typesafe/jev`	Sep 19, 2026

Details per channel: Jev channels compared.

Pinning versus aliases

An alias moves when TypeSafe ships a new release, so answers can change without any change on your side. TypeSafe’s docs recommend pinning the versioned ID if you have tuned confidence thresholds against a specific version, and moving to a new version on your own schedule. Every response’s model field reports the exact version that answered; log it.

In practice:

Prototypes: jev-latest is fine.
Anything with thresholds or evaluations: pin jev-1.13.0, and re-run your evaluation set before switching.
Upgrading SDKs: both SDKs had a breaking change to Score criteria in 0.6.0, and Python changed its serialization library in 0.7.0. Read the changelog before upgrading a production service.