v0.39.0
HyNetworks/hysteriav0.39.0Jun 19, 2026by github-actions[bot]
AI Summary
This release introduces significant architectural changes to the agent system, including a new sans-IO state machine and deterministic tool registration, alongside new AI provider support and various stability improvements.
Key Highlights
- Added VoyageAI rerank provider support
- Breaking change: sans-IO AgentRun state machine implementation
- Breaking change: deterministic and duplicate-safe tool registration
- Added Gemini Nano Banana image generation
- Fixed context document ordering and streaming reasoning history
Breaking Changes
- sans-IO AgentRun state machine; both agent loops become thin drivers
- deterministic, duplicate-safe tool registration + cassette tests
New Features
- VoyageAI rerank support
- Gemini Nano Banana image generation
- Gemini mid-stream disruption token-counting example
- ToolSet backed by IndexMap instead of HashMap
Full Release Notes
### Added - *(providers)* add VoyageAI rerank support ([#1917](https://github.com/0xPlaygrounds/rig/pull/1917)) (by @sergiomeneses) - *(agent)* [**breaking**] sans-IO AgentRun state machine; both agent loops become thin drivers ([#1899](https://github.com/0xPlaygrounds/rig/pull/1899)) (by @gold-silver-copper) ### Fixed - correct possessive pronoun typo in CONTRIBUTING.md ([#1865](https://github.com/0xPlaygrounds/rig/pull/1865)) (by @abhicris) - #1865 - *(tool)* [**breaking**] deterministic, duplicate-safe tool registration + cassette tests ([#1913](https://github.com/0xPlaygrounds/rig/pull/1913)) (by @gold-silver-copper) ### Other - *(deps)* bump uuid from 1.23.1 to 1.23.3 ([#1907](https://github.com/0xPlaygrounds/rig/pull/1907)) (by @dependabot[bot]) - *(deps)* bump lopdf from 0.40.0 to 0.41.0 ([#1877](https://github.com/0xPlaygrounds/rig/pull/1877)) (by @dependabot[bot]) - *(deps)* bump http from 1.4.0 to 1.4.2 ([#1909](https://github.com/0xPlaygrounds/rig/pull/1909)) (by @dependabot[bot]) - *(deps)* bump futures-timer from 3.0.3 to 3.0.4 ([#1908](https://github.com/0xPlaygrounds/rig/pull/1908)) (by @dependabot[bot]) - *(examples)* add Gemini mid-stream disruption token-counting example ([#1918](https://github.com/0xPlaygrounds/rig/pull/1918)) (by @gold-silver-copper) - *(tool)* back ToolSet with an IndexMap instead of HashMap + order Vec ([#1916](https://github.com/0xPlaygrounds/rig/pull/1916)) (by @gold-silver-copper) - de-flake tracing span tests and deepseek permission_control race ([#1915](https://github.com/0xPlaygrounds/rig/pull/1915)) (by @gold-silver-copper) - #1915 - *(agent)* cassette-backed AgentRun coverage against real Gemini turns ([#1901](https://github.com/0xPlaygrounds/rig/pull/1901)) (by @gold-silver-copper) - Fix streaming reasoning history order ([#1898](https://github.com/0xPlaygrounds/rig/pull/1898)) (by @gold-silver-copper) - #1898 - Fix context document ordering ([#1893](https://github.com/0xPlaygrounds/rig/pull/1893)) (by @gold-silver-copper) - #1893 - Point ecosystem link to awesome-rig ([#1895](https://github.com/0xPlaygrounds/rig/pull/1895)) (by @gold-silver-copper) - #1895 - Add Gemini Nano Banana image generation ([#1889](https://github.com/0xPlaygrounds/rig/pull/1889)) (by @gold-silver-copper) - #1889 ### Contributors * @dependabot[bot] * @abhicris * @gold-silver-copper * @sergiomeneses