Upgrading to 3.0.0 changes the default Gemini Developer API version to v1 and swaps the HTTP client from httpx to httpx2. Set GOOGLE_GENAI_API_VERSION or api_version to keep the old behavior.
Key takeaways · AI-distilled
Gemini Developer API clients in google-genai 3.0.0 now default to API version v1 instead of v1beta, while Vertex AI clients (vertexai=True) still default to v1beta1. Setting GOOGLE_GENAI_API_VERSION=beta restores the old beta defaults without code changes.
The SDK's default HTTP client is now httpx2, and httpx is no longer installed. Switching back requires both the google-genai[httpx] extra and GOOGLE_GENAI_HTTP_CLIENT=httpx; per the release notes, installing the extra alone only makes httpx importable.
When SSL_CERT_FILE and SSL_CERT_DIR are unset, httpx2 verifies certificates against the operating system's trust store instead of certifi, so TLS trust now follows the machine's configured certificates.
Objects passed via HttpOptions client_args (Timeout, Limits, transports, custom Auth) and transport exceptions caught from client calls, such as TimeoutException, must match the active HTTP client. The notes say switching imports to httpx2 as httpx is usually enough.
In the Interactions API, CodeExecutionResultStep.result changes from a string to a union that can carry multimodalA model that works with more than text — reading images, audio, or video, and sometimes generating them too.Full definition → content, so code reading it as a string must check the variant; text-only JSON is unchanged. The release also disables GenerateVideos for the Gemini API.
Terms in this piece · Glossary
multimodal — A model that works with more than text — reading images, audio, or video, and sometimes generating them too.
