Jev changelog

Model releases, pricing changes, SDK updates, and access changes, newest first. Every entry links to its source. Also available as an RSS feed.

1. Sep 18, 2026

   Python SDK 0.7.0 switches to Pydantic

   Breaking change: the SDK now uses Pydantic instead of msgspec for serialization. system_one() gains a response_model argument that parses answers into your own Pydantic model. Also fixes str subclasses being serialized as lists of characters.

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2. Sep 17, 2026

   TypeSafe documents Jev 1.13's known weak spots

   A new docs page lists nine failure modes of jev-1.13, including literal reading of instructions, arithmetic and counting, date comparison, multi-hop indirection, large distracting state, adversarial content, and text generation, with a recommended workaround for each.

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3. Sep 15, 2026

   TypeSafe launches Jev, the first System One model

   TypeSafe AI announced Jev, a model that returns typed decisions (Choice, Score, and Noul) with calibrated probabilities instead of generated text. Access opened through an early-access waitlist. Pricing is $0.042 per million input tokens, and output tokens are free.

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4. Sep 15, 2026

   JavaScript SDK 0.6.0

   Breaking change: Score criteria are now passed as an ordered array instead of an object keyed by integers. Install with npm install @typesafe-ai/sdk.

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5. Sep 15, 2026

   TypeSafe AI emerges from stealth with a $40M seed round

   The round was led by DCVC. TypeSafe was founded in 2024 by Diogo Almeida (formerly of OpenAI), Erik Gafni, and Sasha Sheng, and is based in San Francisco.

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