Google Gen AI SDK v3.0.0
Google Gen AI SDK v3.0.0 is released with breaking changes: the default Gemini Developer API version updates to v1, the HTTP backend switches to httpx2 using the OS trust store, and CodeExecutionResultStep.result becomes a union type.
Why this signal matters
Google Gen AI SDK version 3.0.0 introduces several key breaking changes and features. The default Gemini Developer API version is updated to v1 (Vertex AI / Enterprise defaults remain v1beta1), configurable via GOOGLE GENAI API VERSION or HttpOptions(api version=...). The default HTTP client is changed from httpx to httpx2, which now verifies certificates using the OS trust store rather than certifi by default; httpx is no longer installed by default. In interactions, CodeExecutionResultStep.result has changed from a string to the CodeExecutionResultStepResult union to support multimodal execution results. Additional changes include disabling GenerateVideos for Gemini API, adding MALFORMED RESPONSE to FinishReason, setting gemini-3.5-transcribe as the CLI transcription default, and bug fixes for interaction retries and Gemini API file upload versioning.
Actionable summary
BREAKING: Google Gen AI SDK v3.0.0 defaults Developer API to 'v1' (was 'v1beta'), transitions default HTTP client to 'httpx2' (using OS certificate store), and changes CodeExecutionResultStep.result from a string to the CodeExecutionResultStepResult union. GenerateVideos is disabled for Gemini API.
- Agent usefulness
- 96/100
- Confidence
- 96%
- Canonical data
- JSON + Markdown
What builders should check
- Review API calls if relying on features exclusive to v1beta; set GOOGLE GENAI API VERSION=v1beta or configure HttpOptions(api version='v1beta') if legacy behavior is needed.
- Update code handling CodeExecutionResultStep.result to inspect the CodeExecutionResultStepResult union rather than treating it as a raw string.
- Verify compatibility with httpx2 and OS certificate trust store behavior; install google-genai httpx and set GOOGLE GENAI HTTP CLIENT=httpx if httpx is required.
- Update transport-specific exception handling and HttpOptions arguments to align with httpx2 types.