feat(ai): add OpenAI Codex OAuth + responses provider

packages/ai/test/openai-codex-stream.test.ts

@@ -0,0 +1,132 @@
+import { mkdtempSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { streamOpenAICodexResponses } from "../src/providers/openai-codex-responses.js";
+import type { Context, Model } from "../src/types.js";
+
+const originalFetch = global.fetch;
+const originalAgentDir = process.env.PI_CODING_AGENT_DIR;
+
+afterEach(() => {
+	global.fetch = originalFetch;
+	if (originalAgentDir === undefined) {
+		delete process.env.PI_CODING_AGENT_DIR;
+	} else {
+		process.env.PI_CODING_AGENT_DIR = originalAgentDir;
+	}
+	vi.restoreAllMocks();
+});
+
+describe("openai-codex streaming", () => {
+	it("streams SSE responses into AssistantMessageEventStream", async () => {
+		const tempDir = mkdtempSync(join(tmpdir(), "pi-codex-stream-"));
+		process.env.PI_CODING_AGENT_DIR = tempDir;
+
+		const payload = Buffer.from(
+			JSON.stringify({ "https://api.openai.com/auth": { chatgpt_account_id: "acc_test" } }),
+			"utf8",
+		).toString("base64");
+		const token = `aaa.${payload}.bbb`;
+
+		const sse = `${[
+			`data: ${JSON.stringify({
+				type: "response.output_item.added",
+				item: { type: "message", id: "msg_1", role: "assistant", status: "in_progress", content: [] },
+			})}`,
+			`data: ${JSON.stringify({ type: "response.content_part.added", part: { type: "output_text", text: "" } })}`,
+			`data: ${JSON.stringify({ type: "response.output_text.delta", delta: "Hello" })}`,
+			`data: ${JSON.stringify({
+				type: "response.output_item.done",
+				item: {
+					type: "message",
+					id: "msg_1",
+					role: "assistant",
+					status: "completed",
+					content: [{ type: "output_text", text: "Hello" }],
+				},
+			})}`,
+			`data: ${JSON.stringify({
+				type: "response.completed",
+				response: {
+					status: "completed",
+					usage: {
+						input_tokens: 5,
+						output_tokens: 3,
+						total_tokens: 8,
+						input_tokens_details: { cached_tokens: 0 },
+					},
+				},
+			})}`,
+		].join("\n\n")}\n\n`;
+
+		const encoder = new TextEncoder();
+		const stream = new ReadableStream<Uint8Array>({
+			start(controller) {
+				controller.enqueue(encoder.encode(sse));
+				controller.close();
+			},
+		});
+
+		const fetchMock = vi.fn(async (input: string | URL, init?: RequestInit) => {
+			const url = typeof input === "string" ? input : input.toString();
+			if (url === "https://api.github.com/repos/openai/codex/releases/latest") {
+				return new Response(JSON.stringify({ tag_name: "rust-v0.0.0" }), { status: 200 });
+			}
+			if (url.startsWith("https://raw.githubusercontent.com/openai/codex/")) {
+				return new Response("PROMPT", { status: 200, headers: { etag: '"etag"' } });
+			}
+			if (url === "https://chatgpt.com/backend-api/codex/responses") {
+				const headers = init?.headers instanceof Headers ? init.headers : undefined;
+				expect(headers?.get("Authorization")).toBe(`Bearer ${token}`);
+				expect(headers?.get("chatgpt-account-id")).toBe("acc_test");
+				expect(headers?.get("OpenAI-Beta")).toBe("responses=experimental");
+				expect(headers?.get("originator")).toBe("codex_cli_rs");
+				expect(headers?.get("accept")).toBe("text/event-stream");
+				expect(headers?.has("x-api-key")).toBe(false);
+				return new Response(stream, {
+					status: 200,
+					headers: { "content-type": "text/event-stream" },
+				});
+			}
+			return new Response("not found", { status: 404 });
+		});
+
+		global.fetch = fetchMock as typeof fetch;
+
+		const model: Model<"openai-codex-responses"> = {
+			id: "gpt-5.1-codex",
+			name: "GPT-5.1 Codex",
+			api: "openai-codex-responses",
+			provider: "openai-codex",
+			baseUrl: "https://chatgpt.com/backend-api",
+			reasoning: true,
+			input: ["text"],
+			cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
+			contextWindow: 400000,
+			maxTokens: 128000,
+		};
+
+		const context: Context = {
+			systemPrompt: "You are a helpful assistant.",
+			messages: [{ role: "user", content: "Say hello", timestamp: Date.now() }],
+		};
+
+		const streamResult = streamOpenAICodexResponses(model, context, { apiKey: token });
+		let sawTextDelta = false;
+		let sawDone = false;
+
+		for await (const event of streamResult) {
+			if (event.type === "text_delta") {
+				sawTextDelta = true;
+			}
+			if (event.type === "done") {
+				sawDone = true;
+				expect(event.message.content.find((c) => c.type === "text")?.text).toBe("Hello");
+			}
+		}
+
+		expect(sawTextDelta).toBe(true);
+		expect(sawDone).toBe(true);
+	});
+});