Compatibility shim. Implementation lives in llm.sdk.providers.gemini.native.

Vertex AI image-generation adapter.

Google discontinued the Imagen prediction endpoints on 2026-06-30.
The :vertex-imagen SDK identity now targets the documented replacement,
Gemini image generation over Vertex generateContent.

Gemini Native API transport adapter.
Handles thought signatures, streaming deltas, safety metadata.
Preserves provider-specific replay state.

Vertex AI Gemini transport adapter.

Builds on Gemini native with different auth (GCP OAuth) and endpoint
structure. Auth resolution follows the standard GCP ADC chain via
llm.sdk.gcp-auth: request opts → GOOGLE_OAUTH_ACCESS_TOKEN env →
`gcloud auth print-access-token` → GOOGLE_APPLICATION_CREDENTIALS
service-account JSON (RS256-signed JWT exchanged at
oauth2.googleapis.com/token).

Project resolution: request opts → profile quirks →
GOOGLE_CLOUD_PROJECT env → SA JSON project_id.