# JAX v0.8.2 — JAX v0.8.2

- Product: JAX (https://whatsnew.fyi/product/jax)
- Vendor: Google
- Date: 2025-12-18
- Version: v0.8.2
- Original notes: https://github.com/jax-ml/jax/releases/tag/jax-v0.8.2
- Permalink: https://whatsnew.fyi/product/jax/releases/v0.8.2

What's New is an index, not a publisher: every entry below links to the vendor's own release notes, which are the authoritative source. Entries are labelled where they are hand-curated sample data, pre-releases, or drawn from a secondary source such as a developer blog.

Reuse: the summaries, labels and curation here are © What's New. Quote freely with attribution and a link back; wholesale republication of the corpus is not permitted — terms: https://whatsnew.fyi/terms. The vendors' own release notes remain their publishers'.

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- **deprecated** — jax.lax.pvary has been deprecated; use jax.lax.pcast(..., to='varying') as the replacement
- **deprecated** — Complex arguments passed to jax.numpy.arange now result in a deprecation warning
- **deprecated** — From jax.core, the following symbols are newly deprecated: call_impl, get_aval, mapped_aval, subjaxprs, set_current_trace, take_current_trace, traverse_jaxpr_params, unmapped_aval, AbstractToken, and TraceTag
- **deprecated** — All symbols in jax.interpreters.pxla are deprecated
- **changed** — jax's Tracer no longer inherits from jax.Array at runtime, but jax.Array now uses a custom metaclass such that isinstance(x, Array) is true if an object x represents a traced Array
- **removed** — jax.experimental.si_vjp has been deleted; use jax.vjp instead

* Deprecations
  * `jax.lax.pvary` has been deprecated.
    Please use `jax.lax.pcast(..., to='varying')` as the replacement.
  * Complex arguments passed to `jax.numpy.arange` now result in a
    deprecation warning, because the output is poorly-defined.
  * From `jax.core` a number of symbols are newly deprecated including:
    `call_impl`, `get_aval`, `mapped_aval`, `subjaxprs`, `set_current_trace`,
    `take_current_trace`, `traverse_jaxpr_params`, `unmapped_aval`,
    `AbstractToken`,  and `TraceTag`.
  * All symbols in `jax.interpreters.pxla` are deprecated. These are
    primarily JAX internal APIs, and users should not rely on them.

* Changes:
  * jax's `Tracer` no longer inherits from `jax.Array` at runtime. However,
    `jax.Array` now uses a custom metaclass such `isinstance(x, Array)` is true
    if an object `x` represents a traced `Array`. Only some `Tracer`s represent
    `Array`s, so it is not correct for `Tracer` to inherit from `Array`.

    For the moment, during Python type checking, we continue to declare `Tracer`
    as a subclass of `Array`, however we expect to remove this in a future
    release.
  * `jax.experimental.si_vjp` has been deleted.
    `jax.vjp` subsumes it's functionality.