> ## Documentation Index
> Fetch the complete documentation index at: https://docs.osmosis.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Changelog

> Follow user-visible changes to the Osmosis Python SDK and CLI

This changelog highlights the SDK and CLI changes that affect how you install,
build, evaluate, and train rollouts. It is more task-oriented than the canonical
[SDK changelog](https://github.com/Osmosis-AI/osmosis-sdk-python/blob/main/CHANGELOG.md),
which remains the complete repository record.

<Info>
  Release candidates remain in this timeline as incremental release records.
  Each stable release provides a complete summary from the previous stable
  version, so you do not need to read every release-candidate entry before
  upgrading.
</Info>

<Update
  label="July 28, 2026"
  description="0.3.0rc1"
  rss={{
title: "Osmosis Python SDK 0.3.0rc1",
description: "A single-sample rollout contract and rollout-scoped model and callback routing.",
}}
>
  Version `0.3.0rc1` introduces the 0.3 rollout protocol. A workflow execution
  now produces exactly one `RolloutSample`, and its grader assigns exactly one
  reward.

  ### What changed

  * `GraderContext.samples` is now `GraderContext.sample`, and
    `set_sample_reward(sample_id, reward)` is now `set_reward(reward)`.
  * Custom integrations register one source with `set_sample_source()` and read
    it with `get_sample()`.
  * `RolloutSample.id` and `MultiTurnMode` were removed. The rollout URL now
    supplies execution identity.
  * Model and callback requests use rollout-scoped URLs. Integrations no longer
    attach per-call sample or rollout routing headers.
  * Backends exchange `sample.json` and a single-value
    `reward.json` (`{"reward": <float>}`).
  * Strands and OpenAI Agents integrations enforce one registered agent or
    session per workflow execution.

  ### Who needs to act

  Update custom graders, custom sample sources, backend adapters, or workflows
  that create more than one registered Strands agent or OpenAI Agents session.
  Evaluation and training can still request multiple independent executions for
  the same prompt.

  Follow [Migrate from v0.2 to v0.3](/migration-guides/v0-3) for before-and-after
  code and verification steps.

  [SDK changelog](https://github.com/Osmosis-AI/osmosis-sdk-python/blob/main/CHANGELOG.md#030rc1---2026-07-28)
  · [GitHub release](https://github.com/Osmosis-AI/osmosis-sdk-python/releases/tag/v0.3.0rc1)
  · [Full diff](https://github.com/Osmosis-AI/osmosis-sdk-python/compare/v0.2.30...v0.3.0rc1)
</Update>