diff --git a/google/genai/_gaos/types/interactions/agentoption.py b/google/genai/_gaos/types/interactions/agentoption.py
index 270727eb3..00618642b 100644
--- a/google/genai/_gaos/types/interactions/agentoption.py
+++ b/google/genai/_gaos/types/interactions/agentoption.py
@@ -29,6 +29,8 @@
         "deep-research-preview-04-2026",
         # Gemini Deep Research Max Agent
         "deep-research-max-preview-04-2026",
+        # Use the Antigravity managed agent to perform multi-step tasks that require reasoning, file operations, and tool use.
+        "antigravity-preview-05-2026",
     ],
     UnrecognizedStr,
 ]
diff --git a/google/genai/_gaos/types/interactions/model.py b/google/genai/_gaos/types/interactions/model.py
index 7273d7f2b..1201e3eef 100644
--- a/google/genai/_gaos/types/interactions/model.py
+++ b/google/genai/_gaos/types/interactions/model.py
@@ -59,6 +59,8 @@
         "gemini-3.1-flash-lite-preview",
         # Gemini 3.1 Flash TTS: Powerful, low-latency speech generation. Enjoy natural outputs, steerable prompts, and new expressive audio tags for precise narration control.
         "gemini-3.1-flash-tts-preview",
+        # Our most intelligent model for sustained frontier performance in agentic and coding tasks.
+        "gemini-3.5-flash",
         # Our low-latency, music generation model optimized for high-fidelity audio clips and precise rhythmic control.
         "lyria-3-clip-preview",
         # Our advanced, full-song generative model with deep compositional understanding, optimized for precise structural control and complex transitions across diverse musical styles.