Conditional Grounding Pattern

Inject Google Search grounding only when the model and modality support it.

Capability Set

Supported models:

• gemini-3-flash-preview
• gemini-3-pro-preview
• gemini-3-pro-image-preview

Not supported in this pipeline:

• audio modality requests
• TTS models (gemini-2.5-*-tts)

Helper Function

const config = withGoogleSearchGrounding(modelId, existingConfig);

Behavior:

• Returns original config if unsupported.
• Appends { googleSearch: {} } to tools if supported.
• Avoids duplicate googleSearch tool entries.

Why Centralize

• Prevents per-call drift.
• Keeps capabilities explicit.
• Makes grounding behavior testable.