feat(openai): add setting to disable native tool calling

packages/types/src/provider-settings.ts

@@ -244,6 +244,7 @@ const openAiSchema = baseProviderSettingsSchema.extend({
 	openAiApiKey: z.string().optional(),
 	openAiLegacyFormat: z.boolean().optional(),
 	openAiR1FormatEnabled: z.boolean().optional(),
+	openAiDisableNativeTools: z.boolean().optional(),
 	openAiModelId: z.string().optional(),
 	openAiCustomModelInfo: modelInfoSchema.nullish(),
 	openAiUseAzure: z.boolean().optional(),

src/api/providers/__tests__/openai.spec.ts

@@ -585,6 +585,56 @@ describe("OpenAiHandler", () => {
 			expect(model.id).toBe("")
 			expect(model.info).toBeDefined()
 		})
+
+		it("should default to supportsNativeTools true for standard models", () => {
+			const model = handler.getModel()
+			expect(model.info.supportsNativeTools).toBe(true)
+		})
+
+		it("should disable native tools when openAiDisableNativeTools is true", () => {
+			const handlerWithDisabledTools = new OpenAiHandler({
+				...mockOptions,
+				openAiDisableNativeTools: true,
+			})
+			const model = handlerWithDisabledTools.getModel()
+			expect(model.info.supportsNativeTools).toBe(false)
+		})
+
+		it("should disable native tools for deepseek-r1 model", () => {
+			const handlerWithDeepSeekR1 = new OpenAiHandler({
+				...mockOptions,
+				openAiModelId: "deepseek-r1",
+			})
+			const model = handlerWithDeepSeekR1.getModel()
+			expect(model.info.supportsNativeTools).toBe(false)
+		})
+
+		it("should disable native tools for deepseek-reasoner model", () => {
+			const handlerWithDeepSeekReasoner = new OpenAiHandler({
+				...mockOptions,
+				openAiModelId: "deepseek-reasoner",
+			})
+			const model = handlerWithDeepSeekReasoner.getModel()
+			expect(model.info.supportsNativeTools).toBe(false)
+		})
+
+		it("should disable native tools when openAiR1FormatEnabled is true", () => {
+			const handlerWithR1Format = new OpenAiHandler({
+				...mockOptions,
+				openAiR1FormatEnabled: true,
+			})
+			const model = handlerWithR1Format.getModel()
+			expect(model.info.supportsNativeTools).toBe(false)
+		})
+
+		it("should disable native tools for deepseek-r1 variants (e.g., deepseek-r1-distill-qwen-32b)", () => {
+			const handlerWithDeepSeekR1Variant = new OpenAiHandler({
+				...mockOptions,
+				openAiModelId: "deepseek-r1-distill-qwen-32b",
+			})
+			const model = handlerWithDeepSeekR1Variant.getModel()
+			expect(model.info.supportsNativeTools).toBe(false)
+		})
 	})
 
 	describe("Azure AI Inference Service", () => {

src/api/providers/openai.ts

@@ -292,12 +292,23 @@ export class OpenAiHandler extends BaseProvider implements SingleCompletionHandl
 
 	override getModel() {
 		const id = this.options.openAiModelId ?? ""
+		const enabledR1Format = this.options.openAiR1FormatEnabled ?? false
+		const disableNativeTools = this.options.openAiDisableNativeTools ?? false
+
+		// Detect DeepSeek reasoner models that don't support native tool calling
+		const isDeepSeekReasoner =
+			id.includes("deepseek-reasoner") || id.includes("deepseek-r1") || enabledR1Format
+
 		// Ensure OpenAI-compatible models default to supporting native tool calling.
 		// This is required for [`Task.attemptApiRequest()`](src/core/task/Task.ts:3817) to
 		// include tool definitions in the request.
+		// However, disable native tools for DeepSeek reasoner models or when explicitly disabled
+		// by the user, as these models don't support function calling and will return 400 errors.
 		const info: ModelInfo = {
 			...NATIVE_TOOL_DEFAULTS,
 			...(this.options.openAiCustomModelInfo ?? openAiModelInfoSaneDefaults),
+			// Override: Disable native tools if user setting is enabled or model is a DeepSeek reasoner
+			...((disableNativeTools || isDeepSeekReasoner) && { supportsNativeTools: false }),
 		}
 		const params = getModelParams({ format: "openai", modelId: id, model: info, settings: this.options })
 		return { id, info, ...params }

webview-ui/src/components/settings/providers/OpenAICompatible.tsx

@@ -155,6 +155,18 @@ export const OpenAICompatible = ({
 				onChange={handleInputChange("openAiR1FormatEnabled", noTransform)}
 				openAiR1FormatEnabled={apiConfiguration?.openAiR1FormatEnabled ?? false}
 			/>
+			<div>
+				<div className="flex items-center gap-1">
+					<Checkbox
+						checked={apiConfiguration?.openAiDisableNativeTools ?? false}
+						onChange={handleInputChange("openAiDisableNativeTools", noTransform)}>
+						<span className="font-medium">{t("settings:modelInfo.disableNativeTools")}</span>
+					</Checkbox>
+				</div>
+				<p className="text-vscode-descriptionForeground text-sm mt-0 ml-6">
+					{t("settings:modelInfo.disableNativeToolsTips")}
+				</p>
+			</div>
 			<div>
 				<Checkbox
 					checked={openAiLegacyFormatSelected}

webview-ui/src/i18n/locales/en/settings.json

@@ -869,6 +869,8 @@
 		"enableStreaming": "Enable streaming",
 		"enableR1Format": "Enable R1 model parameters",
 		"enableR1FormatTips": "Must be enabled when using R1 models such as QWQ to prevent 400 errors",
+		"disableNativeTools": "Disable native tool calling",
+		"disableNativeToolsTips": "Enable this if your model does not support function calling (tool use). When disabled, Roo will use XML-based tool definitions instead. Required for DeepSeek-R1 and similar models.",
 		"useAzure": "Use Azure",
 		"azureApiVersion": "Set Azure API version",
 		"gemini": {