feat: add GPT-5 model support

packages/types/src/model.ts

@@ -10,6 +10,16 @@ export const reasoningEffortsSchema = z.enum(reasoningEfforts)
 
 export type ReasoningEffort = z.infer<typeof reasoningEffortsSchema>
 
+/**
+ * Verbosity
+ */
+
+export const verbosityLevels = ["low", "medium", "high"] as const
+
+export const verbosityLevelsSchema = z.enum(verbosityLevels)
+
+export type VerbosityLevel = z.infer<typeof verbosityLevelsSchema>
+
 /**
  * ModelParameter
  */

packages/types/src/provider-settings.ts

@@ -1,6 +1,6 @@
 import { z } from "zod"
 
-import { reasoningEffortsSchema, modelInfoSchema } from "./model.js"
+import { reasoningEffortsSchema, verbosityLevelsSchema, modelInfoSchema } from "./model.js"
 import { codebaseIndexProviderSchema } from "./codebase-index.js"
 
 /**
@@ -79,6 +79,9 @@ const baseProviderSettingsSchema = z.object({
 	reasoningEffort: reasoningEffortsSchema.optional(),
 	modelMaxTokens: z.number().optional(),
 	modelMaxThinkingTokens: z.number().optional(),
+
+	// Model verbosity.
+	verbosity: verbosityLevelsSchema.optional(),
 })
 
 // Several of the providers share common model config properties.

packages/types/src/providers/openai.ts

@@ -3,9 +3,42 @@ import type { ModelInfo } from "../model.js"
 // https://openai.com/api/pricing/
 export type OpenAiNativeModelId = keyof typeof openAiNativeModels
 
-export const openAiNativeDefaultModelId: OpenAiNativeModelId = "gpt-4.1"
+export const openAiNativeDefaultModelId: OpenAiNativeModelId = "gpt-5-2025-08-07"
 
 export const openAiNativeModels = {
+	"gpt-5-2025-08-07": {
+		maxTokens: 128000,
+		contextWindow: 400000,
+		supportsImages: true,
+		supportsPromptCache: true,
+		supportsReasoningEffort: true,
+		inputPrice: 1.25,
+		outputPrice: 10.0,
+		cacheReadsPrice: 0.13,
+		description: "GPT-5: The best model for coding and agentic tasks across domains",
+	},
+	"gpt-5-mini-2025-08-07": {
+		maxTokens: 128000,
+		contextWindow: 400000,
+		supportsImages: true,
+		supportsPromptCache: true,
+		supportsReasoningEffort: true,
+		inputPrice: 0.25,
+		outputPrice: 2.0,
+		cacheReadsPrice: 0.03,
+		description: "GPT-5 Mini: A faster, more cost-efficient version of GPT-5 for well-defined tasks",
+	},
+	"gpt-5-nano-2025-08-07": {
+		maxTokens: 128000,
+		contextWindow: 400000,
+		supportsImages: true,
+		supportsPromptCache: true,
+		supportsReasoningEffort: true,
+		inputPrice: 0.05,
+		outputPrice: 0.4,
+		cacheReadsPrice: 0.01,
+		description: "GPT-5 Nano: Fastest, most cost-efficient version of GPT-5",
+	},
 	"gpt-4.1": {
 		maxTokens: 32_768,
 		contextWindow: 1_047_576,

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

@@ -455,8 +455,162 @@ describe("OpenAiNativeHandler", () => {
 				openAiNativeApiKey: "test-api-key",
 			})
 			const modelInfo = handlerWithoutModel.getModel()
-			expect(modelInfo.id).toBe("gpt-4.1") // Default model
+			expect(modelInfo.id).toBe("gpt-5-2025-08-07") // Default model
 			expect(modelInfo.info).toBeDefined()
 		})
 	})
+
+	describe("GPT-5 models", () => {
+		it("should handle GPT-5 model with developer role", async () => {
+			handler = new OpenAiNativeHandler({
+				...mockOptions,
+				apiModelId: "gpt-5-2025-08-07",
+			})
+
+			const stream = handler.createMessage(systemPrompt, messages)
+			const chunks: any[] = []
+			for await (const chunk of stream) {
+				chunks.push(chunk)
+			}
+
+			// Verify developer role is used for GPT-5 with default parameters
+			expect(mockCreate).toHaveBeenCalledWith(
+				expect.objectContaining({
+					model: "gpt-5-2025-08-07",
+					messages: [{ role: "developer", content: expect.stringContaining(systemPrompt) }],
+					stream: true,
+					stream_options: { include_usage: true },
+					reasoning_effort: "minimal", // Default for GPT-5
+					verbosity: "medium", // Default verbosity
+				}),
+			)
+		})
+
+		it("should handle GPT-5-mini model", async () => {
+			handler = new OpenAiNativeHandler({
+				...mockOptions,
+				apiModelId: "gpt-5-mini-2025-08-07",
+			})
+
+			const stream = handler.createMessage(systemPrompt, messages)
+			const chunks: any[] = []
+			for await (const chunk of stream) {
+				chunks.push(chunk)
+			}
+
+			expect(mockCreate).toHaveBeenCalledWith(
+				expect.objectContaining({
+					model: "gpt-5-mini-2025-08-07",
+					messages: [{ role: "developer", content: expect.stringContaining(systemPrompt) }],
+					stream: true,
+					stream_options: { include_usage: true },
+					reasoning_effort: "minimal", // Default for GPT-5
+					verbosity: "medium", // Default verbosity
+				}),
+			)
+		})
+
+		it("should handle GPT-5-nano model", async () => {
+			handler = new OpenAiNativeHandler({
+				...mockOptions,
+				apiModelId: "gpt-5-nano-2025-08-07",
+			})
+
+			const stream = handler.createMessage(systemPrompt, messages)
+			const chunks: any[] = []
+			for await (const chunk of stream) {
+				chunks.push(chunk)
+			}
+
+			expect(mockCreate).toHaveBeenCalledWith(
+				expect.objectContaining({
+					model: "gpt-5-nano-2025-08-07",
+					messages: [{ role: "developer", content: expect.stringContaining(systemPrompt) }],
+					stream: true,
+					stream_options: { include_usage: true },
+					reasoning_effort: "minimal", // Default for GPT-5
+					verbosity: "medium", // Default verbosity
+				}),
+			)
+		})
+
+		it("should support verbosity control for GPT-5", async () => {
+			handler = new OpenAiNativeHandler({
+				...mockOptions,
+				apiModelId: "gpt-5-2025-08-07",
+				verbosity: "low", // Set verbosity through options
+			})
+
+			// Create a message to verify verbosity is passed
+			const stream = handler.createMessage(systemPrompt, messages)
+			const chunks: any[] = []
+			for await (const chunk of stream) {
+				chunks.push(chunk)
+			}
+
+			// Verify that verbosity is passed in the request
+			expect(mockCreate).toHaveBeenCalledWith(
+				expect.objectContaining({
+					model: "gpt-5-2025-08-07",
+					messages: expect.any(Array),
+					stream: true,
+					stream_options: { include_usage: true },
+					verbosity: "low",
+				}),
+			)
+		})
+
+		it("should support minimal reasoning effort for GPT-5", async () => {
+			handler = new OpenAiNativeHandler({
+				...mockOptions,
+				apiModelId: "gpt-5-2025-08-07",
+				reasoningEffort: "low",
+			})
+
+			const stream = handler.createMessage(systemPrompt, messages)
+			const chunks: any[] = []
+			for await (const chunk of stream) {
+				chunks.push(chunk)
+			}
+
+			// With low reasoning effort, the model should pass it through
+			expect(mockCreate).toHaveBeenCalledWith(
+				expect.objectContaining({
+					model: "gpt-5-2025-08-07",
+					messages: expect.any(Array),
+					stream: true,
+					stream_options: { include_usage: true },
+					reasoning_effort: "low",
+					verbosity: "medium", // Default verbosity
+				}),
+			)
+		})
+
+		it("should support both verbosity and reasoning effort together for GPT-5", async () => {
+			handler = new OpenAiNativeHandler({
+				...mockOptions,
+				apiModelId: "gpt-5-2025-08-07",
+				verbosity: "high", // Set verbosity through options
+				reasoningEffort: "low", // Set reasoning effort
+			})
+
+			const stream = handler.createMessage(systemPrompt, messages)
+			const chunks: any[] = []
+			for await (const chunk of stream) {
+				chunks.push(chunk)
+			}
+
+			// Verify both parameters are passed
+			expect(mockCreate).toHaveBeenCalledWith(
+				expect.objectContaining({
+					model: "gpt-5-2025-08-07",
+					messages: expect.any(Array),
+					stream: true,
+					stream_options: { include_usage: true },
+					reasoning_effort: "low",
+					verbosity: "high",
+				}),
+			)
+		})
+	})
 })