fix: add mock OpenAI server for E2E tests

.github/workflows/e2e.yml

@@ -28,6 +28,7 @@ jobs:
 
       - name: Run E2E tests
         env:
+          MOCK: true
           OPENAI_API_KEY: ${{ secrets.OPENAI_API_KEY }}
           OPENAI_BASE_URL: ${{ secrets.OPENAI_BASE_URL }}
           OPENAI_MODEL: ${{ secrets.OPENAI_MODEL }}

packages/agent/__tests__/e2e/react-loop.e2e.test.ts

@@ -5,7 +5,8 @@
  * receives a question, invokes a tool, receives the tool result, and
  * produces a final text answer.
  *
- * Skipped when OPENAI_API_KEY is not set (uses OpenAI-compatible adapter).
+ * Skipped when OPENAI_API_KEY is not set (uses OpenAI-compatible adapter),
+ * unless MOCK=true.
  * Falls back to ANTHROPIC_API_KEY if OPENAI_API_KEY is unavailable.
  *
  * Environment variables (OpenAI-compatible):
@@ -17,9 +18,11 @@
  *   ANTHROPIC_API_KEY   — API key
  *   ANTHROPIC_BASE_URL  — Base URL
  *   ANTHROPIC_MODEL     — Model name
+ *
+ *   MOCK — Set to "true" to use a mock server (no real API needed)
  */
 
-import { describe, it, expect } from "vitest";
+import { describe, it, expect, beforeAll, afterAll } from "vitest";
 import {
   registerProvider,
   createModel,
@@ -29,28 +32,50 @@ import {
 } from "@openlinkos/ai";
 import { createAgent } from "../../src/index.js";
 import type { ToolDefinition } from "../../src/types.js";
+import { createMockOpenAI } from "../helpers/mock-openai-server.js";
+import type { MockOpenAI } from "../helpers/mock-openai-server.js";
 
 const OPENAI_KEY = process.env.OPENAI_API_KEY;
 const ANTHROPIC_KEY = process.env.ANTHROPIC_API_KEY;
-const HAS_PROVIDER = !!(OPENAI_KEY || ANTHROPIC_KEY);
+const USE_MOCK = process.env.MOCK === "true";
+const HAS_PROVIDER = !!(OPENAI_KEY || ANTHROPIC_KEY || USE_MOCK);
+
+describe.skipIf(!HAS_PROVIDER)("Agent ReAct loop E2E", () => {
+  let mockServer: MockOpenAI | null = null;
+
+  beforeAll(async () => {
+    if (USE_MOCK) {
+      mockServer = await createMockOpenAI();
+    }
+  }, 30_000);
 
-function setupModel() {
-  clearProviders();
-  if (OPENAI_KEY) {
-    registerProvider(createOpenAIProvider());
-    const modelName = process.env.OPENAI_MODEL ?? "gpt-4o-mini";
-    return createModel(`openai:${modelName}`, {
-      ...(process.env.OPENAI_BASE_URL ? { baseURL: process.env.OPENAI_BASE_URL } : {}),
+  afterAll(() => {
+    mockServer?.close();
+  });
+
+  function setupModel() {
+    clearProviders();
+    if (USE_MOCK && mockServer) {
+      registerProvider(createOpenAIProvider());
+      return createModel("openai:mock-model", {
+        baseURL: mockServer.url,
+        apiKey: "mock-key",
+      });
+    }
+    if (OPENAI_KEY) {
+      registerProvider(createOpenAIProvider());
+      const modelName = process.env.OPENAI_MODEL ?? "gpt-4o-mini";
+      return createModel(`openai:${modelName}`, {
+        ...(process.env.OPENAI_BASE_URL ? { baseURL: process.env.OPENAI_BASE_URL } : {}),
+      });
+    }
+    registerProvider(createAnthropicProvider());
+    const modelName = process.env.ANTHROPIC_MODEL ?? "claude-sonnet-4-20250514";
+    return createModel(`anthropic:${modelName}`, {
+      ...(process.env.ANTHROPIC_BASE_URL ? { baseURL: process.env.ANTHROPIC_BASE_URL } : {}),
     });
   }
-  registerProvider(createAnthropicProvider());
-  const modelName = process.env.ANTHROPIC_MODEL ?? "claude-sonnet-4-20250514";
-  return createModel(`anthropic:${modelName}`, {
-    ...(process.env.ANTHROPIC_BASE_URL ? { baseURL: process.env.ANTHROPIC_BASE_URL } : {}),
-  });
-}
 
-describe.skipIf(!HAS_PROVIDER)("Agent ReAct loop E2E", () => {
   it("completes a full ReAct cycle: question → tool call → answer", async () => {
     const model = setupModel();
 

packages/agent/__tests__/e2e/tool-calling.e2e.test.ts

@@ -4,7 +4,8 @@
  * Verifies that the agent correctly invokes tools with the right parameters,
  * receives results, and incorporates them into the final response.
  *
- * Skipped when OPENAI_API_KEY is not set (uses OpenAI-compatible adapter).
+ * Skipped when OPENAI_API_KEY is not set (uses OpenAI-compatible adapter),
+ * unless MOCK=true.
  * Falls back to ANTHROPIC_API_KEY if OPENAI_API_KEY is unavailable.
  *
  * Environment variables (OpenAI-compatible):
@@ -16,9 +17,11 @@
  *   ANTHROPIC_API_KEY   — API key
  *   ANTHROPIC_BASE_URL  — Base URL
  *   ANTHROPIC_MODEL     — Model name
+ *
+ *   MOCK — Set to "true" to use a mock server (no real API needed)
  */
 
-import { describe, it, expect } from "vitest";
+import { describe, it, expect, beforeAll, afterAll } from "vitest";
 import {
   registerProvider,
   createModel,
@@ -28,28 +31,50 @@ import {
 } from "@openlinkos/ai";
 import { createAgent } from "../../src/index.js";
 import type { ToolDefinition } from "../../src/types.js";
+import { createMockOpenAI } from "../helpers/mock-openai-server.js";
+import type { MockOpenAI } from "../helpers/mock-openai-server.js";
 
 const OPENAI_KEY = process.env.OPENAI_API_KEY;
 const ANTHROPIC_KEY = process.env.ANTHROPIC_API_KEY;
-const HAS_PROVIDER = !!(OPENAI_KEY || ANTHROPIC_KEY);
-
-function setupModel() {
-  clearProviders();
-  if (OPENAI_KEY) {
-    registerProvider(createOpenAIProvider());
-    const modelName = process.env.OPENAI_MODEL ?? "gpt-4o-mini";
-    return createModel(`openai:${modelName}`, {
-      ...(process.env.OPENAI_BASE_URL ? { baseURL: process.env.OPENAI_BASE_URL } : {}),
+const USE_MOCK = process.env.MOCK === "true";
+const HAS_PROVIDER = !!(OPENAI_KEY || ANTHROPIC_KEY || USE_MOCK);
+
+describe.skipIf(!HAS_PROVIDER)("Agent tool-calling E2E", () => {
+  let mockServer: MockOpenAI | null = null;
+
+  beforeAll(async () => {
+    if (USE_MOCK) {
+      mockServer = await createMockOpenAI();
+    }
+  }, 30_000);
+
+  afterAll(() => {
+    mockServer?.close();
+  });
+
+  function setupModel() {
+    clearProviders();
+    if (USE_MOCK && mockServer) {
+      registerProvider(createOpenAIProvider());
+      return createModel("openai:mock-model", {
+        baseURL: mockServer.url,
+        apiKey: "mock-key",
+      });
+    }
+    if (OPENAI_KEY) {
+      registerProvider(createOpenAIProvider());
+      const modelName = process.env.OPENAI_MODEL ?? "gpt-4o-mini";
+      return createModel(`openai:${modelName}`, {
+        ...(process.env.OPENAI_BASE_URL ? { baseURL: process.env.OPENAI_BASE_URL } : {}),
+      });
+    }
+    registerProvider(createAnthropicProvider());
+    const modelName = process.env.ANTHROPIC_MODEL ?? "claude-sonnet-4-20250514";
+    return createModel(`anthropic:${modelName}`, {
+      ...(process.env.ANTHROPIC_BASE_URL ? { baseURL: process.env.ANTHROPIC_BASE_URL } : {}),
     });
   }
-  registerProvider(createAnthropicProvider());
-  const modelName = process.env.ANTHROPIC_MODEL ?? "claude-sonnet-4-20250514";
-  return createModel(`anthropic:${modelName}`, {
-    ...(process.env.ANTHROPIC_BASE_URL ? { baseURL: process.env.ANTHROPIC_BASE_URL } : {}),
-  });
-}
 
-describe.skipIf(!HAS_PROVIDER)("Agent tool-calling E2E", () => {
   it("passes correct parameters to tool and uses result", async () => {
     const model = setupModel();
     let receivedParams: Record<string, unknown> | undefined;