Add basic fetch example extracted from wrapper repo

Author: subtleGradient

typescript/fetch/src/basic/example.ts

@@ -0,0 +1,111 @@
+/**
+ * Example: Using OpenRouter with raw fetch API
+ * 
+ * This example demonstrates how to make direct HTTP requests to OpenRouter's API
+ * using the native fetch API without any additional libraries.
+ * 
+ * To run: bun examples/basic/example-basic-fetch.ts
+ */
+
+// Make this a module
+export {};
+
+// OpenRouter API endpoint
+const OPENROUTER_API_URL = "https://openrouter.ai/api/v1/chat/completions";
+
+// Type definitions for the API response
+interface ChatCompletionResponse {
+  id: string;
+  model: string;
+  choices: Array<{
+    index: number;
+    message: {
+      role: string;
+      content: string;
+    };
+    finish_reason: string;
+  }>;
+  usage: {
+    prompt_tokens: number;
+    completion_tokens: number;
+    total_tokens: number;
+  };
+}
+
+// Request payload following OpenAI-compatible chat completions format
+const requestBody = {
+  model: "openai/gpt-4o-mini",
+  messages: [
+    {
+      role: "user",
+      content: "Write a haiku about TypeScript",
+    },
+  ],
+};
+
+console.log("=== OpenRouter Raw Fetch Example ===\n");
+console.log("Request:");
+console.log(`URL: ${OPENROUTER_API_URL}`);
+console.log("Model:", requestBody.model);
+console.log("Message:", requestBody.messages[0]?.content);
+console.log();
+
+try {
+  // Ensure API key is available
+  if (!process.env.OPENROUTER_API_KEY) {
+    throw new Error("OPENROUTER_API_KEY environment variable is not set");
+  }
+
+  // Make the HTTP POST request to OpenRouter
+  const response = await fetch(OPENROUTER_API_URL, {
+    method: "POST",
+    headers: {
+      // Required: Authorization header with your API key
+      "Authorization": `Bearer ${process.env.OPENROUTER_API_KEY}`,
+      // Required: Content type for JSON payload
+      "Content-Type": "application/json",
+      // Optional but recommended: Identify your app
+      "HTTP-Referer": "https://github.com/openrouter/examples",
+      "X-Title": "OpenRouter Fetch Example",
+    },
+    body: JSON.stringify(requestBody),
+  });
+
+  // Check if the request was successful
+  if (!response.ok) {
+    const errorText = await response.text();
+    throw new Error(
+      `HTTP error! status: ${response.status}, body: ${errorText}`
+    );
+  }
+
+  // Parse the JSON response
+  const data = await response.json() as ChatCompletionResponse;
+
+  // Display the response
+  console.log("Response:");
+  console.log("Status:", response.status, response.statusText);
+  console.log("Model used:", data.model);
+  console.log("\nGenerated content:");
+  console.log(data.choices[0]?.message?.content);
+  console.log("\nUsage stats:");
+  console.log("- Prompt tokens:", data.usage.prompt_tokens);
+  console.log("- Completion tokens:", data.usage.completion_tokens);
+  console.log("- Total tokens:", data.usage.total_tokens);
+
+  // Optional: Show raw response structure
+  if (process.env.DEBUG) {
+    console.log("\nFull response object:");
+    console.log(JSON.stringify(data, null, 2));
+  }
+} catch (error) {
+  console.error("Error making request to OpenRouter:");
+  
+  if (error instanceof Error) {
+    console.error("Error message:", error.message);
+  } else {
+    console.error("Unknown error:", error);
+  }
+  
+  process.exit(1);
+}