fix(ai): finalize cloudflare gateway provider support

packages/ai/test/openai-completions-empty-tools.test.ts

@@ -9,10 +9,15 @@ import { streamSimple } from "../src/stream.js";
 
 const mockState = vi.hoisted(() => ({
 	lastParams: undefined as unknown,
+	lastClientOptions: undefined as unknown,
 }));
 
 vi.mock("openai", () => {
 	class FakeOpenAI {
+		constructor(options: unknown) {
+			mockState.lastClientOptions = options;
+		}
+
 		chat = {
 			completions: {
 				create: (params: unknown) => {
@@ -52,6 +57,7 @@ vi.mock("openai", () => {
 describe("openai-completions empty tools handling", () => {
 	beforeEach(() => {
 		mockState.lastParams = undefined;
+		mockState.lastClientOptions = undefined;
 	});
 
 	it("omits tools field when context.tools is an empty array", async () => {
@@ -87,6 +93,79 @@ describe("openai-completions empty tools handling", () => {
 		expect("tools" in (params as object)).toBe(false);
 	});
 
+	it("uses conservative OpenAI-compatible fields for Cloudflare AI Gateway /compat models", async () => {
+		process.env.CLOUDFLARE_ACCOUNT_ID = "account-id";
+		process.env.CLOUDFLARE_GATEWAY_ID = "gateway-id";
+		const model = getModel("cloudflare-ai-gateway", "workers-ai/@cf/moonshotai/kimi-k2.6")!;
+
+		await streamSimple(
+			model,
+			{
+				systemPrompt: "You are helpful.",
+				messages: [{ role: "user", content: "hi", timestamp: Date.now() }],
+			},
+			{ apiKey: "test", reasoning: "high" },
+		).result();
+
+		const params = mockState.lastParams as {
+			messages: Array<{ role: string }>;
+			max_tokens?: number;
+			max_completion_tokens?: number;
+			reasoning_effort?: string;
+			store?: boolean;
+		};
+		expect(params.messages[0].role).toBe("system");
+		expect(params.max_tokens).toBeDefined();
+		expect(params.max_completion_tokens).toBeUndefined();
+		expect(params.reasoning_effort).toBeUndefined();
+		expect(params.store).toBeUndefined();
+
+		const clientOptions = mockState.lastClientOptions as {
+			baseURL?: string;
+			defaultHeaders?: Record<string, unknown>;
+		};
+		expect(clientOptions.baseURL).toBe("https://gateway.ai.cloudflare.com/v1/account-id/gateway-id/compat");
+		expect(clientOptions.defaultHeaders?.Authorization).toBeNull();
+		expect(clientOptions.defaultHeaders?.["cf-aig-authorization"]).toBe("Bearer test");
+	});
+
+	it("preserves inline upstream Authorization for Cloudflare AI Gateway BYOK requests", async () => {
+		process.env.CLOUDFLARE_ACCOUNT_ID = "account-id";
+		process.env.CLOUDFLARE_GATEWAY_ID = "gateway-id";
+		const model = getModel("cloudflare-ai-gateway", "gpt-5.1")!;
+
+		await streamSimple(
+			model,
+			{
+				messages: [{ role: "user", content: "hi", timestamp: Date.now() }],
+			},
+			{ apiKey: "cf-token", headers: { Authorization: "Bearer upstream-token" } },
+		).result();
+
+		const clientOptions = mockState.lastClientOptions as { defaultHeaders?: Record<string, unknown> };
+		expect(clientOptions.defaultHeaders?.Authorization).toBe("Bearer upstream-token");
+		expect(clientOptions.defaultHeaders?.["cf-aig-authorization"]).toBe("Bearer cf-token");
+	});
+
+	it("sends session affinity headers for Workers AI through Cloudflare AI Gateway", async () => {
+		process.env.CLOUDFLARE_ACCOUNT_ID = "account-id";
+		process.env.CLOUDFLARE_GATEWAY_ID = "gateway-id";
+		const workersModel = getModel("cloudflare-ai-gateway", "workers-ai/@cf/moonshotai/kimi-k2.6")!;
+
+		await streamSimple(
+			workersModel,
+			{
+				messages: [{ role: "user", content: "hi", timestamp: Date.now() }],
+			},
+			{ apiKey: "test", sessionId: "session-1" },
+		).result();
+
+		const clientOptions = mockState.lastClientOptions as { defaultHeaders?: Record<string, string> };
+		expect(clientOptions.defaultHeaders?.session_id).toBe("session-1");
+		expect(clientOptions.defaultHeaders?.["x-client-request-id"]).toBe("session-1");
+		expect(clientOptions.defaultHeaders?.["x-session-affinity"]).toBe("session-1");
+	});
+
 	it("still emits tools: [] for Anthropic/LiteLLM proxy when conversation has tool history", async () => {
 		const { compat: _compat, ...baseModel } = getModel("openai", "gpt-4o-mini")!;
 		const model = { ...baseModel, api: "openai-completions" } as const;