feat: Added openrouter provider

packages/llm/src/config.ts

@@ -2,6 +2,7 @@ import { z } from "zod";
 
 const LLMConfigSchema = z.object({
   GOOGLE_API_KEY: z.string().optional(),
+  OPENROUTER_API_KEY: z.string().optional(),
 });
 
 export const llmConfig = LLMConfigSchema.parse(process.env);

packages/llm/src/index.ts

@@ -2,3 +2,4 @@ export * from "./llm.js";
 export * from "./config.js";
 export * from "./providers/google-genai.js";
 export * from "./providers/mock.js";
+export * from "./providers/openrouter.js";

packages/llm/src/providers/openrouter.ts

@@ -0,0 +1,31 @@
+import { z } from "zod";
+import { ChatOpenRouter } from "@langchain/openrouter";
+import { ILLMProvider, LLMRequest, LLMResponse } from "../llm.js";
+import { llmConfig } from "../config.js";
+
+export class OpenRouterProvider implements ILLMProvider {
+  providerName = "OpenRouter";
+  private model: ChatOpenRouter;
+
+  constructor(apiKey?: string, modelName: string = "google/gemini-2.5-flash") {
+    const key = apiKey || llmConfig.OPENROUTER_API_KEY;
+    if (!key) {
+      throw new Error("OPENROUTER_API_KEY is required to initialize OpenRouterProvider");
+    }
+    this.model = new ChatOpenRouter({
+      apiKey: key,
+      model: modelName,
+    });
+  }
+
+  async generateStructuredResponse<T extends z.ZodTypeAny>(
+    request: LLMRequest<T>,
+  ): Promise<LLMResponse<z.infer<T>>> {
+    const structuredModel = this.model.withStructuredOutput(request.schema);
+    const result = await structuredModel.invoke([
+      { role: "system", content: request.systemPrompt },
+      { role: "user", content: request.userContext },
+    ]);
+    return { success: true, data: result as z.infer<T> };
+  }
+}

packages/llm/tests/openrouter.test.ts

@@ -0,0 +1,81 @@
+import { describe, test, expect, vi } from "vitest";
+import { z } from "zod";
+import { OpenRouterProvider } from "../src/providers/openrouter.js";
+import { llmConfig } from "../src/config.js";
+
+// Mock the ChatOpenRouter class
+vi.mock("@langchain/openrouter", () => {
+  return {
+    ChatOpenRouter: class {
+      config: unknown;
+      constructor(config: unknown) {
+        this.config = config;
+      }
+      withStructuredOutput = vi.fn().mockImplementation(() => {
+        return {
+          invoke: vi.fn().mockImplementation(async () => {
+            // Return a mock output that matches a sample schema
+            return {
+              name: "mocked response",
+              success: true,
+            };
+          }),
+        };
+      });
+    },
+  };
+});
+
+describe("OpenRouterProvider Unit Tests (Tier 1)", () => {
+  test("initializes successfully with a provided apiKey", () => {
+    const provider = new OpenRouterProvider("dummy-key");
+    expect(provider.providerName).toBe("OpenRouter");
+  });
+
+  test("initializes successfully with apiKey from config", () => {
+    // Save current config
+    const originalKey = llmConfig.OPENROUTER_API_KEY;
+    llmConfig.OPENROUTER_API_KEY = "env-dummy-key";
+    
+    try {
+      const provider = new OpenRouterProvider();
+      expect(provider.providerName).toBe("OpenRouter");
+    } finally {
+      llmConfig.OPENROUTER_API_KEY = originalKey;
+    }
+  });
+
+  test("throws error if no API key is provided or in config", () => {
+    // Save current config
+    const originalKey = llmConfig.OPENROUTER_API_KEY;
+    llmConfig.OPENROUTER_API_KEY = undefined;
+
+    try {
+      expect(() => new OpenRouterProvider()).toThrow(
+        "OPENROUTER_API_KEY is required to initialize OpenRouterProvider"
+      );
+    } finally {
+      llmConfig.OPENROUTER_API_KEY = originalKey;
+    }
+  });
+
+  test("generateStructuredResponse invokes the model with structured output", async () => {
+    const provider = new OpenRouterProvider("dummy-key");
+    const TestSchema = z.object({
+      name: z.string(),
+      success: z.boolean(),
+    });
+
+    const response = await provider.generateStructuredResponse({
+      systemPrompt: "system prompt",
+      userContext: "user context",
+      schema: TestSchema,
+    });
+
+    expect(response.success).toBe(true);
+    expect(response.data).toEqual({
+      name: "mocked response",
+      success: true,
+    });
+  });
+});