fix(api): honor custom model IDs for OpenAI-compatible providers

src/api/providers/__tests__/base-openai-compatible-provider.spec.ts

@@ -3,7 +3,7 @@
 import { Anthropic } from "@anthropic-ai/sdk"
 import OpenAI from "openai"
 
-import type { ModelInfo } from "@roo-code/types"
+import { type ModelInfo, openAiModelInfoSaneDefaults } from "@roo-code/types"
 
 import { BaseOpenAiCompatibleProvider } from "../base-openai-compatible-provider"
 import { asyncStreamFrom, collectStream } from "../../../test-utils/stream"
@@ -25,18 +25,20 @@ vi.mock("openai", () => ({
 	}),
 }))
 
+const TEST_MODEL_INFO: ModelInfo = {
+	maxTokens: 4096,
+	contextWindow: 128000,
+	supportsImages: false,
+	supportsPromptCache: false,
+	inputPrice: 0.5,
+	outputPrice: 1.5,
+}
+
 // Create a concrete test implementation of the abstract base class
 class TestOpenAiCompatibleProvider extends BaseOpenAiCompatibleProvider<"test-model"> {
-	constructor(apiKey: string) {
+	constructor(apiKey: string, options?: { apiModelId?: string; modelMaxTokens?: number }) {
 		const testModels: Record<"test-model", ModelInfo> = {
-			"test-model": {
-				maxTokens: 4096,
-				contextWindow: 128000,
-				supportsImages: false,
-				supportsPromptCache: false,
-				inputPrice: 0.5,
-				outputPrice: 1.5,
-			},
+			"test-model": TEST_MODEL_INFO,
 		}
 
 		super({
@@ -45,6 +47,7 @@ class TestOpenAiCompatibleProvider extends BaseOpenAiCompatibleProvider<"test-mo
 			defaultProviderModelId: "test-model",
 			providerModels: testModels,
 			apiKey,
+			...options,
 		})
 	}
 }
@@ -297,6 +300,64 @@ describe("BaseOpenAiCompatibleProvider", () => {
 		})
 	})
 
+	describe("getModel", () => {
+		it("returns the provider default when no model id is configured", () => {
+			const model = handler.getModel()
+			expect(model.id).toBe("test-model")
+			expect(model.info).toEqual(TEST_MODEL_INFO)
+		})
+
+		it("returns the predefined metadata for a known model id", () => {
+			const knownHandler = new TestOpenAiCompatibleProvider("test-api-key", { apiModelId: "test-model" })
+			const model = knownHandler.getModel()
+			expect(model.id).toBe("test-model")
+			expect(model.info).toEqual(TEST_MODEL_INFO)
+		})
+
+		it("honors a custom model id that is not in the predefined list", () => {
+			// Regression: a user-supplied custom id must not be silently swapped for the
+			// provider default (which previously caused wrong-model requests / 404s).
+			const customHandler = new TestOpenAiCompatibleProvider("test-api-key", {
+				apiModelId: "some/custom-model-not-in-list",
+			})
+			const model = customHandler.getModel()
+			expect(model.id).toBe("some/custom-model-not-in-list")
+			expect(model.id).not.toBe("test-model")
+			// Falls back to sane default metadata so the rest of the pipeline works.
+			expect(model.info).toEqual(openAiModelInfoSaneDefaults)
+		})
+
+		it("sends the custom model id verbatim to the API", async () => {
+			mockCreate.mockImplementationOnce(() => asyncStreamFrom([]))
+
+			const customHandler = new TestOpenAiCompatibleProvider("test-api-key", {
+				apiModelId: "some/custom-model-not-in-list",
+			})
+
+			const stream = customHandler.createMessage("system prompt", [])
+			await collectStream(stream)
+
+			expect(mockCreate).toHaveBeenCalledWith(
+				expect.objectContaining({ model: "some/custom-model-not-in-list" }),
+				undefined,
+			)
+		})
+
+		it("completePrompt sends the custom model id verbatim to the API", async () => {
+			mockCreate.mockResolvedValueOnce({ choices: [{ message: { content: "ok" } }] })
+
+			const customHandler = new TestOpenAiCompatibleProvider("test-api-key", {
+				apiModelId: "some/custom-model-not-in-list",
+			})
+
+			await customHandler.completePrompt("hello")
+
+			expect(mockCreate).toHaveBeenCalledWith(
+				expect.objectContaining({ model: "some/custom-model-not-in-list" }),
+			)
+		})
+	})
+
 	describe("Tool call handling", () => {
 		it("should yield tool_call_end events when finish_reason is tool_calls", async () => {
 			mockCreate.mockImplementationOnce(() =>

src/api/providers/base-openai-compatible-provider.ts

@@ -1,7 +1,7 @@
 import { Anthropic } from "@anthropic-ai/sdk"
 import OpenAI from "openai"
 
-import type { ModelInfo } from "@roo-code/types"
+import { type ModelInfo, openAiModelInfoSaneDefaults } from "@roo-code/types"
 
 import { type ApiHandlerOptions, getModelMaxOutputTokens } from "../../shared/api"
 import { TagMatcher } from "../../utils/tag-matcher"
@@ -243,11 +243,27 @@ export abstract class BaseOpenAiCompatibleProvider<ModelName extends string>
 	}
 
 	override getModel() {
-		const id =
-			this.options.apiModelId && this.options.apiModelId in this.providerModels
-				? (this.options.apiModelId as ModelName)
-				: this.defaultProviderModelId
+		const requestedId = this.options.apiModelId
 
-		return { id, info: this.providerModels[id] }
+		// A known model: use its predefined metadata.
+		if (requestedId && requestedId in this.providerModels) {
+			const id = requestedId as ModelName
+			return { id, info: this.providerModels[id] }
+		}
+
+		// A user-supplied custom model that isn't in our static list (e.g. a newly
+		// released Fireworks model). Honor the exact id the user configured instead
+		// of silently falling back to the provider default, which would send the
+		// wrong model to the API and can surface as a confusing "model not found"
+		// error. Provide sane default metadata so the rest of the pipeline works.
+		if (requestedId) {
+			return {
+				id: requestedId as ModelName,
+				info: { ...openAiModelInfoSaneDefaults },
+			}
+		}
+
+		// No model configured: use the provider default.
+		return { id: this.defaultProviderModelId, info: this.providerModels[this.defaultProviderModelId] }
 	}
 }

webview-ui/src/components/ui/hooks/__tests__/useSelectedModel.spec.ts

@@ -1413,7 +1413,9 @@ describe("useSelectedModel", () => {
 			expect(result.current.info).toEqual(getZAiModels("international_api")["glm-5.3"])
 		})
 
-		it("falls back when GLM-5.3 is unavailable on the China API", () => {
+		it("displays the configured model ID with sane defaults when it is not in the API line catalog", () => {
+			expect(getZAiModels("china_api")["glm-5.3"]).toBeUndefined()
+
 			const apiConfiguration: ProviderSettings = {
 				apiProvider: providerIdentifiers.zai,
 				apiModelId: "glm-5.3",
@@ -1422,6 +1424,43 @@ describe("useSelectedModel", () => {
 
 			const { result } = renderHook(() => useSelectedModel(apiConfiguration), { wrapper: createWrapper() })
 
+			expect(result.current.id).toBe("glm-5.3")
+			expect(result.current.info).toEqual(openAiModelInfoSaneDefaults)
+		})
+
+		it("displays a custom model ID that is in no Z.ai catalog", () => {
+			const apiConfiguration: ProviderSettings = {
+				apiProvider: providerIdentifiers.zai,
+				apiModelId: "glm-custom-preview",
+			}
+
+			const { result } = renderHook(() => useSelectedModel(apiConfiguration), { wrapper: createWrapper() })
+
+			expect(result.current.id).toBe("glm-custom-preview")
+			expect(result.current.info).toEqual(openAiModelInfoSaneDefaults)
+		})
+
+		it("falls back to the API line default when no model is configured", () => {
+			const apiConfiguration: ProviderSettings = {
+				apiProvider: providerIdentifiers.zai,
+				zaiApiLine: "china_api",
+			}
+
+			const { result } = renderHook(() => useSelectedModel(apiConfiguration), { wrapper: createWrapper() })
+
+			expect(result.current.id).toBe(mainlandZAiDefaultModelId)
+			expect(result.current.info).toEqual(getZAiModels("china_api")[mainlandZAiDefaultModelId])
+		})
+
+		it("falls back to the API line default when the configured model ID is empty", () => {
+			const apiConfiguration: ProviderSettings = {
+				apiProvider: providerIdentifiers.zai,
+				apiModelId: "",
+				zaiApiLine: "china_api",
+			}
+
+			const { result } = renderHook(() => useSelectedModel(apiConfiguration), { wrapper: createWrapper() })
+
 			expect(result.current.id).toBe(mainlandZAiDefaultModelId)
 			expect(result.current.info).toEqual(getZAiModels("china_api")[mainlandZAiDefaultModelId])
 		})

webview-ui/src/components/ui/hooks/useSelectedModel.ts

@@ -326,9 +326,11 @@ function getSelectedModel({
 			const isChina = zaiApiLineConfigs[apiLine].isChina
 			const models = getZAiModels(apiLine)
 			const defaultModelId = getProviderDefaultModelId(provider, { isChina })
-			const id = getValidatedModelId(apiConfiguration.apiModelId, models, defaultModelId)
-			const info = models[id]
-			return { id, info }
+			const configuredId = apiConfiguration.apiModelId
+			if (configuredId) {
+				return { id: configuredId, info: models[configuredId] ?? openAiModelInfoSaneDefaults }
+			}
+			return { id: defaultModelId, info: models[defaultModelId] }
 		}
 		case providerIdentifiers.openaiNative: {
 			const id = apiConfiguration.apiModelId ?? defaultModelId