fix(litellm): merge only native tool defaults with router models

daniel-lxs · daniel-lxs · commit 4d9964b9e5bc · 2025-12-18T11:17:55.000-05:00
Only merges supportsNativeTools and defaultToolProtocol from litellmDefaultModelInfo,
not prices or other model-specific info that could be incorrect for different models.
diff --git a/webview-ui/src/components/ui/hooks/__tests__/useSelectedModel.spec.ts b/webview-ui/src/components/ui/hooks/__tests__/useSelectedModel.spec.ts
@@ -616,7 +616,7 @@ describe("useSelectedModel", () => {
 			expect(result.current.info?.supportsNativeTools).toBe(true)
 		})
 
-		it("should use model info from routerModels when model exists", () => {
+		it("should merge only native tool defaults with routerModels when model exists", () => {
 			const customModelInfo: ModelInfo = {
 				maxTokens: 16384,
 				contextWindow: 128000,
@@ -650,9 +650,15 @@ describe("useSelectedModel", () => {
 
 			expect(result.current.provider).toBe("litellm")
 			expect(result.current.id).toBe("custom-model")
-			// Should use the model info from routerModels, not the fallback
-			expect(result.current.info).toEqual(customModelInfo)
+			// Should only merge native tool defaults, not prices or other model-specific info
+			// Router model values override the defaults
+			const nativeToolDefaults = {
+				supportsNativeTools: litellmDefaultModelInfo.supportsNativeTools,
+				defaultToolProtocol: litellmDefaultModelInfo.defaultToolProtocol,
+			}
+			expect(result.current.info).toEqual({ ...nativeToolDefaults, ...customModelInfo })
 			expect(result.current.info?.supportsNativeTools).toBe(true)
+			expect(result.current.info?.defaultToolProtocol).toBe("native")
 		})
 	})
 })
diff --git a/webview-ui/src/components/ui/hooks/useSelectedModel.ts b/webview-ui/src/components/ui/hooks/useSelectedModel.ts
@@ -166,7 +166,13 @@ function getSelectedModel({
 		}
 		case "litellm": {
 			const id = getValidatedModelId(apiConfiguration.litellmModelId, routerModels.litellm, defaultModelId)
-			const info = routerModels.litellm?.[id] ?? litellmDefaultModelInfo
+			const routerInfo = routerModels.litellm?.[id]
+			// Only merge native tool call defaults, not prices or other model-specific info
+			const nativeToolDefaults = {
+				supportsNativeTools: litellmDefaultModelInfo.supportsNativeTools,
+				defaultToolProtocol: litellmDefaultModelInfo.defaultToolProtocol,
+			}
+			const info = routerInfo ? { ...nativeToolDefaults, ...routerInfo } : litellmDefaultModelInfo
 			return { id, info }
 		}
 		case "xai": {
