feat: allow custom models for Anthropic provider with custom base URLs

src/api/providers/__tests__/anthropic.custom-models.spec.ts

@@ -0,0 +1,159 @@
+import { describe, it, expect, vi, beforeEach } from "vitest"
+import { Anthropic } from "@anthropic-ai/sdk"
+
+import { AnthropicHandler } from "../anthropic"
+import { ANTHROPIC_DEFAULT_MAX_TOKENS } from "@roo-code/types"
+
+// Mock the Anthropic SDK
+vi.mock("@anthropic-ai/sdk", () => ({
+	Anthropic: vi.fn().mockImplementation(() => ({
+		messages: {
+			create: vi.fn(),
+			countTokens: vi.fn(),
+		},
+	})),
+}))
+
+describe("AnthropicHandler - Custom Models", () => {
+	let handler: AnthropicHandler
+	let mockClient: any
+
+	beforeEach(() => {
+		vi.clearAllMocks()
+		mockClient = {
+			messages: {
+				create: vi.fn().mockResolvedValue({
+					content: [{ type: "text", text: "Test response" }],
+				}),
+				countTokens: vi.fn().mockResolvedValue({ input_tokens: 100 }),
+			},
+		}
+		;(Anthropic as any).mockImplementation(() => mockClient)
+	})
+
+	describe("getModel", () => {
+		it("should use predefined model when no custom base URL is set", () => {
+			handler = new AnthropicHandler({
+				apiKey: "test-key",
+				apiModelId: "claude-3-opus-20240229",
+			} as any)
+
+			const model = handler.getModel()
+
+			expect(model.id).toBe("claude-3-opus-20240229")
+			expect(model.info).toBeDefined()
+			expect(model.info.maxTokens).toBe(4096) // Predefined model's max tokens
+		})
+
+		it("should fallback to default model when invalid model is provided without custom base URL", () => {
+			handler = new AnthropicHandler({
+				apiKey: "test-key",
+				apiModelId: "custom-model-xyz",
+			} as any)
+
+			const model = handler.getModel()
+
+			expect(model.id).toBe("claude-sonnet-4-20250514") // Default model
+			expect(model.info).toBeDefined()
+		})
+
+		it("should allow custom model when custom base URL is set", () => {
+			handler = new AnthropicHandler({
+				apiKey: "test-key",
+				apiModelId: "glm-4.6-cc-max",
+				anthropicBaseUrl: "https://api.z.ai/api/anthropic",
+			} as any)
+
+			const model = handler.getModel()
+
+			expect(model.id).toBe("glm-4.6-cc-max")
+			expect(model.info).toBeDefined()
+			expect(model.info.maxTokens).toBe(ANTHROPIC_DEFAULT_MAX_TOKENS) // Default for custom models
+			expect(model.info.contextWindow).toBe(200_000) // Default context window
+			expect(model.info.supportsImages).toBe(false) // Conservative default
+			expect(model.info.supportsPromptCache).toBe(false) // Conservative default
+		})
+
+		it("should still use predefined model info when using known model with custom base URL", () => {
+			handler = new AnthropicHandler({
+				apiKey: "test-key",
+				apiModelId: "claude-3-opus-20240229",
+				anthropicBaseUrl: "https://api.z.ai/api/anthropic",
+			} as any)
+
+			const model = handler.getModel()
+
+			expect(model.id).toBe("claude-3-opus-20240229")
+			expect(model.info.maxTokens).toBe(4096) // Should use predefined model's settings
+			expect(model.info.supportsImages).toBe(true) // From predefined model
+			expect(model.info.supportsPromptCache).toBe(true) // From predefined model
+		})
+
+		it("should handle custom models with special characters", () => {
+			handler = new AnthropicHandler({
+				apiKey: "test-key",
+				apiModelId: "glm-4.5v",
+				anthropicBaseUrl: "https://api.z.ai/api/anthropic",
+			} as any)
+
+			const model = handler.getModel()
+
+			expect(model.id).toBe("glm-4.5v")
+			expect(model.info).toBeDefined()
+		})
+
+		it("should use auth token when anthropicUseAuthToken is true", () => {
+			const handler = new AnthropicHandler({
+				apiKey: "test-token",
+				apiModelId: "custom-model",
+				anthropicBaseUrl: "https://api.z.ai/api/anthropic",
+				anthropicUseAuthToken: true,
+			} as any)
+
+			// Verify the Anthropic client was created with authToken instead of apiKey
+			expect(Anthropic).toHaveBeenCalledWith({
+				baseURL: "https://api.z.ai/api/anthropic",
+				authToken: "test-token",
+			})
+		})
+	})
+
+	describe("completePrompt with custom models", () => {
+		it("should use custom model ID when making API calls", async () => {
+			handler = new AnthropicHandler({
+				apiKey: "test-key",
+				apiModelId: "glm-4.6-cc-max",
+				anthropicBaseUrl: "https://api.z.ai/api/anthropic",
+			} as any)
+
+			await handler.completePrompt("Test prompt")
+
+			expect(mockClient.messages.create).toHaveBeenCalledWith(
+				expect.objectContaining({
+					model: "glm-4.6-cc-max",
+					messages: [{ role: "user", content: "Test prompt" }],
+				}),
+			)
+		})
+	})
+
+	describe("countTokens with custom models", () => {
+		it("should use custom model ID for token counting", async () => {
+			handler = new AnthropicHandler({
+				apiKey: "test-key",
+				apiModelId: "glm-4.6-cc-max",
+				anthropicBaseUrl: "https://api.z.ai/api/anthropic",
+			} as any)
+
+			const content = [{ type: "text" as const, text: "Test content" }]
+			await handler.countTokens(content)
+
+			expect(mockClient.messages.countTokens).toHaveBeenCalledWith(
+				expect.objectContaining({
+					model: "glm-4.6-cc-max",
+					messages: [{ role: "user", content }],
+				}),
+			)
+		})
+	})
+})

src/api/providers/anthropic.ts

@@ -245,21 +245,48 @@ export class AnthropicHandler extends BaseProvider implements SingleCompletionHa
 
 	getModel() {
 		const modelId = this.options.apiModelId
-		let id = modelId && modelId in anthropicModels ? (modelId as AnthropicModelId) : anthropicDefaultModelId
-		let info: ModelInfo = anthropicModels[id]
-
-		// If 1M context beta is enabled for Claude Sonnet 4 or 4.5, update the model info
-		if ((id === "claude-sonnet-4-20250514" || id === "claude-sonnet-4-5") && this.options.anthropicBeta1MContext) {
-			// Use the tier pricing for 1M context
-			const tier = info.tiers?.[0]
-			if (tier) {
-				info = {
-					...info,
-					contextWindow: tier.contextWindow,
-					inputPrice: tier.inputPrice,
-					outputPrice: tier.outputPrice,
-					cacheWritesPrice: tier.cacheWritesPrice,
-					cacheReadsPrice: tier.cacheReadsPrice,
+
+		// When using a custom base URL, allow any model ID to be used
+		// This enables compatibility with services like z.ai that provide
+		// Anthropic-compatible endpoints with custom models
+		const isUsingCustomBaseUrl = !!this.options.anthropicBaseUrl
+
+		let id: string
+		let info: ModelInfo
+
+		if (isUsingCustomBaseUrl && modelId && !(modelId in anthropicModels)) {
+			// Custom model with custom base URL - use the model ID as-is
+			// and provide default model info since we don't know the specifics
+			id = modelId
+			info = {
+				maxTokens: ANTHROPIC_DEFAULT_MAX_TOKENS,
+				contextWindow: 200_000, // Default context window
+				supportsImages: false, // Conservative default
+				supportsPromptCache: false, // Conservative default
+				inputPrice: 0, // Unknown pricing
+				outputPrice: 0, // Unknown pricing
+			}
+		} else {
+			// Standard Anthropic model or no custom base URL
+			id = modelId && modelId in anthropicModels ? (modelId as AnthropicModelId) : anthropicDefaultModelId
+			info = anthropicModels[id as AnthropicModelId]
+
+			// If 1M context beta is enabled for Claude Sonnet 4 or 4.5, update the model info
+			if (
+				(id === "claude-sonnet-4-20250514" || id === "claude-sonnet-4-5") &&
+				this.options.anthropicBeta1MContext
+			) {
+				// Use the tier pricing for 1M context
+				const tier = info.tiers?.[0]
+				if (tier) {
+					info = {
+						...info,
+						contextWindow: tier.contextWindow,
+						inputPrice: tier.inputPrice,
+						outputPrice: tier.outputPrice,
+						cacheWritesPrice: tier.cacheWritesPrice,
+						cacheReadsPrice: tier.cacheReadsPrice,
+					}
 				}
 			}
 		}

webview-ui/src/components/settings/ApiOptions.tsx

@@ -689,66 +689,68 @@ const ApiOptions = ({
 				<Featherless apiConfiguration={apiConfiguration} setApiConfigurationField={setApiConfigurationField} />
 			)}
 
-			{selectedProviderModels.length > 0 && (
-				<>
-					<div>
-						<label className="block font-medium mb-1">{t("settings:providers.model")}</label>
-						<Select
-							value={selectedModelId === "custom-arn" ? "custom-arn" : selectedModelId}
-							onValueChange={(value) => {
-								setApiConfigurationField("apiModelId", value)
-
-								// Clear custom ARN if not using custom ARN option.
-								if (value !== "custom-arn" && selectedProvider === "bedrock") {
-									setApiConfigurationField("awsCustomArn", "")
-								}
-
-								// Clear reasoning effort when switching models to allow the new model's default to take effect
-								// This is especially important for GPT-5 models which default to "medium"
-								if (selectedProvider === "openai-native") {
-									setApiConfigurationField("reasoningEffort", undefined)
-								}
-							}}>
-							<SelectTrigger className="w-full">
-								<SelectValue placeholder={t("settings:common.select")} />
-							</SelectTrigger>
-							<SelectContent>
-								{selectedProviderModels.map((option) => (
-									<SelectItem key={option.value} value={option.value}>
-										{option.label}
-									</SelectItem>
-								))}
-								{selectedProvider === "bedrock" && (
-									<SelectItem value="custom-arn">{t("settings:labels.useCustomArn")}</SelectItem>
-								)}
-							</SelectContent>
-						</Select>
-					</div>
+			{/* Don't show model selector for Anthropic when using custom base URL - it's handled in the Anthropic component */}
+			{selectedProviderModels.length > 0 &&
+				!(selectedProvider === "anthropic" && apiConfiguration?.anthropicBaseUrl) && (
+					<>
+						<div>
+							<label className="block font-medium mb-1">{t("settings:providers.model")}</label>
+							<Select
+								value={selectedModelId === "custom-arn" ? "custom-arn" : selectedModelId}
+								onValueChange={(value) => {
+									setApiConfigurationField("apiModelId", value)
+
+									// Clear custom ARN if not using custom ARN option.
+									if (value !== "custom-arn" && selectedProvider === "bedrock") {
+										setApiConfigurationField("awsCustomArn", "")
+									}
+
+									// Clear reasoning effort when switching models to allow the new model's default to take effect
+									// This is especially important for GPT-5 models which default to "medium"
+									if (selectedProvider === "openai-native") {
+										setApiConfigurationField("reasoningEffort", undefined)
+									}
+								}}>
+								<SelectTrigger className="w-full">
+									<SelectValue placeholder={t("settings:common.select")} />
+								</SelectTrigger>
+								<SelectContent>
+									{selectedProviderModels.map((option) => (
+										<SelectItem key={option.value} value={option.value}>
+											{option.label}
+										</SelectItem>
+									))}
+									{selectedProvider === "bedrock" && (
+										<SelectItem value="custom-arn">{t("settings:labels.useCustomArn")}</SelectItem>
+									)}
+								</SelectContent>
+							</Select>
+						</div>
 
-					{/* Show error if a deprecated model is selected */}
-					{selectedModelInfo?.deprecated && (
-						<ApiErrorMessage errorMessage={t("settings:validation.modelDeprecated")} />
-					)}
+						{/* Show error if a deprecated model is selected */}
+						{selectedModelInfo?.deprecated && (
+							<ApiErrorMessage errorMessage={t("settings:validation.modelDeprecated")} />
+						)}
 
-					{selectedProvider === "bedrock" && selectedModelId === "custom-arn" && (
-						<BedrockCustomArn
-							apiConfiguration={apiConfiguration}
-							setApiConfigurationField={setApiConfigurationField}
-						/>
-					)}
+						{selectedProvider === "bedrock" && selectedModelId === "custom-arn" && (
+							<BedrockCustomArn
+								apiConfiguration={apiConfiguration}
+								setApiConfigurationField={setApiConfigurationField}
+							/>
+						)}
 
-					{/* Only show model info if not deprecated */}
-					{!selectedModelInfo?.deprecated && (
-						<ModelInfoView
-							apiProvider={selectedProvider}
-							selectedModelId={selectedModelId}
-							modelInfo={selectedModelInfo}
-							isDescriptionExpanded={isDescriptionExpanded}
-							setIsDescriptionExpanded={setIsDescriptionExpanded}
-						/>
-					)}
-				</>
-			)}
+						{/* Only show model info if not deprecated */}
+						{!selectedModelInfo?.deprecated && (
+							<ModelInfoView
+								apiProvider={selectedProvider}
+								selectedModelId={selectedModelId}
+								modelInfo={selectedModelInfo}
+								isDescriptionExpanded={isDescriptionExpanded}
+								setIsDescriptionExpanded={setIsDescriptionExpanded}
+							/>
+						)}
+					</>
+				)}
 
 			<ThinkingBudget
 				key={`${selectedProvider}-${selectedModelId}`}