diff --git a/apps/aether-gateway/src/ai_serving/planner/standard/openai/chat/decision/request.rs b/apps/aether-gateway/src/ai_serving/planner/standard/openai/chat/decision/request.rs
index 4bfa07dea..ce719f126 100644
--- a/apps/aether-gateway/src/ai_serving/planner/standard/openai/chat/decision/request.rs
+++ b/apps/aether-gateway/src/ai_serving/planner/standard/openai/chat/decision/request.rs
@@ -2763,7 +2763,7 @@ mod tests {
             payload.provider_request_body["userAgent"],
             "vscode/1.X.X (Antigravity/4.3.0)"
         );
-        assert_eq!(payload.provider_request_body["requestType"], "agent");
+        assert!(payload.provider_request_body.get("requestType").is_none());
         assert!(payload.provider_request_body.get("contents").is_none());
         assert!(payload.provider_request_body["request"]
             .get("contents")
diff --git a/apps/aether-gateway/src/tests/ai_execute/finalize_local.rs b/apps/aether-gateway/src/tests/ai_execute/finalize_local.rs
index 3bac90c5d..dd8c0350a 100644
--- a/apps/aether-gateway/src/tests/ai_execute/finalize_local.rs
+++ b/apps/aether-gateway/src/tests/ai_execute/finalize_local.rs
@@ -1972,7 +1972,7 @@ async fn gateway_executes_openai_chat_antigravity_cross_format_sync_via_local_fi
         seen_execution_runtime_request.user_agent,
         aether_provider_transport::antigravity::ANTIGRAVITY_REQUEST_USER_AGENT
     );
-    assert_eq!(seen_execution_runtime_request.request_type, "agent");
+    assert_eq!(seen_execution_runtime_request.request_type, "");
     assert_eq!(seen_execution_runtime_request.contents_len, 1);
     assert!(!seen_execution_runtime_request.request_has_model);
 
diff --git a/apps/aether-gateway/src/tests/ai_execute/finalize_local_cli/cross_format.rs b/apps/aether-gateway/src/tests/ai_execute/finalize_local_cli/cross_format.rs
index 0cedf3111..f199ee5f3 100644
--- a/apps/aether-gateway/src/tests/ai_execute/finalize_local_cli/cross_format.rs
+++ b/apps/aether-gateway/src/tests/ai_execute/finalize_local_cli/cross_format.rs
@@ -1570,7 +1570,7 @@ async fn gateway_executes_openai_responses_antigravity_cross_format_upstream_str
         seen_remote_execution_runtime_request.user_agent,
         aether_provider_transport::antigravity::ANTIGRAVITY_REQUEST_USER_AGENT
     );
-    assert_eq!(seen_remote_execution_runtime_request.request_type, "agent");
+    assert_eq!(seen_remote_execution_runtime_request.request_type, "");
     assert_eq!(seen_remote_execution_runtime_request.contents_len, 1);
     assert!(!seen_remote_execution_runtime_request.request_has_model);
 
diff --git a/apps/aether-gateway/src/tests/ai_execute/finalize_local_provider/gemini.rs b/apps/aether-gateway/src/tests/ai_execute/finalize_local_provider/gemini.rs
index 7c3575c2f..6a84c0e24 100644
--- a/apps/aether-gateway/src/tests/ai_execute/finalize_local_provider/gemini.rs
+++ b/apps/aether-gateway/src/tests/ai_execute/finalize_local_provider/gemini.rs
@@ -2155,7 +2155,7 @@ async fn gateway_executes_antigravity_gemini_cli_sync_upstream_stream_via_local_
         seen_remote_execution_runtime_request.user_agent,
         aether_provider_transport::antigravity::ANTIGRAVITY_REQUEST_USER_AGENT
     );
-    assert_eq!(seen_remote_execution_runtime_request.request_type, "agent");
+    assert_eq!(seen_remote_execution_runtime_request.request_type, "");
     assert_eq!(seen_remote_execution_runtime_request.contents_len, 0);
     assert!((seen_remote_execution_runtime_request.exact_temperature - 0.2).abs() < f64::EPSILON);
     assert!(!seen_remote_execution_runtime_request.request_has_model);
diff --git a/apps/aether-gateway/src/tests/ai_execute/stream_provider_gemini/local_cli.rs b/apps/aether-gateway/src/tests/ai_execute/stream_provider_gemini/local_cli.rs
index 5c5d26cd0..603ba0d64 100644
--- a/apps/aether-gateway/src/tests/ai_execute/stream_provider_gemini/local_cli.rs
+++ b/apps/aether-gateway/src/tests/ai_execute/stream_provider_gemini/local_cli.rs
@@ -2060,7 +2060,7 @@ async fn gateway_executes_antigravity_gemini_cli_stream_via_local_decision_gate_
         seen_execution_runtime_request.user_agent,
         aether_provider_transport::antigravity::ANTIGRAVITY_REQUEST_USER_AGENT
     );
-    assert_eq!(seen_execution_runtime_request.request_type, "agent");
+    assert_eq!(seen_execution_runtime_request.request_type, "");
     assert_eq!(seen_execution_runtime_request.contents_len, 0);
     assert!((seen_execution_runtime_request.exact_temperature - 0.2).abs() < f64::EPSILON);
     assert!(!seen_execution_runtime_request.request_has_model);
diff --git a/apps/aether-gateway/src/tests/ai_execute/sync/gemini/cli.rs b/apps/aether-gateway/src/tests/ai_execute/sync/gemini/cli.rs
index 8abd3a094..bf491eef1 100644
--- a/apps/aether-gateway/src/tests/ai_execute/sync/gemini/cli.rs
+++ b/apps/aether-gateway/src/tests/ai_execute/sync/gemini/cli.rs
@@ -2374,7 +2374,7 @@ async fn gateway_executes_antigravity_gemini_cli_sync_via_local_decision_gate_af
         seen_execution_runtime_request.user_agent,
         aether_provider_transport::antigravity::ANTIGRAVITY_REQUEST_USER_AGENT
     );
-    assert_eq!(seen_execution_runtime_request.request_type, "agent");
+    assert_eq!(seen_execution_runtime_request.request_type, "");
     assert_eq!(seen_execution_runtime_request.contents_len, 0);
     assert!((seen_execution_runtime_request.exact_temperature - 0.2).abs() < f64::EPSILON);
     assert!(!seen_execution_runtime_request.request_has_model);
diff --git a/crates/aether-provider/transport/src/antigravity/request.rs b/crates/aether-provider/transport/src/antigravity/request.rs
index b0ddc5b9b..c25a1cb97 100644
--- a/crates/aether-provider/transport/src/antigravity/request.rs
+++ b/crates/aether-provider/transport/src/antigravity/request.rs
@@ -83,17 +83,21 @@ pub fn build_antigravity_safe_v1internal_request(
         let request_id = non_empty_string_field(source, "requestId").unwrap_or(request_id);
         let user_agent =
             non_empty_string_field(source, "userAgent").unwrap_or(ANTIGRAVITY_REQUEST_USER_AGENT);
-        let request_type =
-            existing_v1internal_request_type(source).unwrap_or_else(|| request_type.as_str());
+        let existing_request_type = existing_v1internal_request_type(source);
 
-        return AntigravityRequestEnvelopeSupport::Supported(serde_json::json!({
+        let mut envelope = serde_json::json!({
             "project": auth.project_id,
             "requestId": request_id,
             "request": Value::Object(inner_request),
             "model": model,
             "userAgent": user_agent,
-            "requestType": request_type,
-        }));
+        });
+        if let Some(existing_request_type) = existing_request_type {
+            envelope["requestType"] = Value::String(existing_request_type.to_string());
+        } else if request_type != AntigravityEnvelopeRequestType::Agent {
+            envelope["requestType"] = Value::String(request_type.as_str().to_string());
+        }
+        return AntigravityRequestEnvelopeSupport::Supported(envelope);
     }
 
     let mut inner_request: Map<String, Value> = source.clone();
@@ -103,14 +107,17 @@ pub fn build_antigravity_safe_v1internal_request(
     normalize_antigravity_builtin_tool_names(&mut inner_request);
     normalize_antigravity_function_declaration_parameters(&mut inner_request);
 
-    AntigravityRequestEnvelopeSupport::Supported(serde_json::json!({
+    let mut envelope = serde_json::json!({
         "project": auth.project_id,
         "requestId": request_id,
         "request": Value::Object(inner_request),
         "model": model,
         "userAgent": ANTIGRAVITY_REQUEST_USER_AGENT,
-        "requestType": request_type.as_str(),
-    }))
+    });
+    if request_type != AntigravityEnvelopeRequestType::Agent {
+        envelope["requestType"] = Value::String(request_type.as_str().to_string());
+    }
+    AntigravityRequestEnvelopeSupport::Supported(envelope)
 }
 
 /// Antigravity's private v1internal Gemini surface still uses the legacy
@@ -298,7 +305,7 @@ mod tests {
         assert_eq!(envelope["requestId"], "request-ant-agent-123");
         assert_eq!(envelope["model"], "gemini-3.5-flash-low");
         assert_eq!(envelope["userAgent"], ANTIGRAVITY_REQUEST_USER_AGENT);
-        assert_eq!(envelope["requestType"], "agent");
+        assert!(envelope.get("requestType").is_none());
         assert!(envelope["request"].get("model").is_none());
         assert!(envelope["request"].get("safetySettings").is_none());
         assert_eq!(