Merge pull request #111 from kernel/browser-utilities-mcp-tool

Add browser utility tools to MCP

Author: IlyaasK

src/lib/mcp/register.ts

@@ -3,6 +3,7 @@ import { registerKernelPrompts } from "@/lib/mcp/prompts";
 import { registerAPIKeyCapabilities } from "@/lib/mcp/tools/api-keys";
 import { registerAppCapabilities } from "@/lib/mcp/tools/apps";
 import { registerBrowserPoolCapabilities } from "@/lib/mcp/tools/browser-pools";
+import { registerBrowserCurlTool } from "@/lib/mcp/tools/browser-curl";
 import { registerBrowserCapabilities } from "@/lib/mcp/tools/browsers";
 import { registerComputerActionTool } from "@/lib/mcp/tools/computer-action";
 import { registerDocsTools } from "@/lib/mcp/tools/docs";
@@ -22,6 +23,7 @@ const mcpToolRegistrations = [
   ["projects", registerProjectCapabilities],
   ["api_keys", registerAPIKeyCapabilities],
   ["browser_pools", registerBrowserPoolCapabilities],
+  ["browser_curl", registerBrowserCurlTool],
   ["proxies", registerProxyTools],
   ["extensions", registerExtensionTools],
   ["apps", registerAppCapabilities],

src/lib/mcp/tools/browser-curl.ts

@@ -0,0 +1,65 @@
+import type { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
+import { z } from "zod";
+import { createKernelClient, type KernelClient } from "@/lib/mcp/kernel-client";
+import { errorResponse, jsonResponse } from "@/lib/mcp/responses";
+
+type BrowserCurlParams = Parameters<KernelClient["browsers"]["curl"]>[1];
+
+function curlUrlValidationError(url: string) {
+  const parsed = new URL(url);
+  if (parsed.protocol !== "http:" && parsed.protocol !== "https:") {
+    return "url must use http or https.";
+  }
+}
+
+export function registerBrowserCurlTool(server: McpServer) {
+  server.tool(
+    "browser_curl",
+    "Send an HTTP request through an existing Kernel browser session's Chrome network stack.",
+    {
+      session_id: z.string().describe("Browser session ID."),
+      url: z.string().url().describe("Target http or https URL."),
+      method: z
+        .enum(["GET", "HEAD", "POST", "PUT", "PATCH", "DELETE", "OPTIONS"])
+        .describe("HTTP method. Defaults to GET.")
+        .optional(),
+      headers: z
+        .record(z.string(), z.string())
+        .describe("Custom headers merged with browser defaults.")
+        .optional(),
+      body: z
+        .string()
+        .describe("Request body for POST, PUT, or PATCH requests.")
+        .optional(),
+      response_encoding: z
+        .enum(["utf8", "base64"])
+        .describe("Response body encoding. Use base64 for binary content.")
+        .optional(),
+      timeout_ms: z
+        .number()
+        .int()
+        .describe("Request timeout in milliseconds.")
+        .optional(),
+    },
+    async (params, extra) => {
+      if (!extra.authInfo) throw new Error("Authentication required");
+      const client = createKernelClient(extra.authInfo.token);
+
+      try {
+        const curlRequest: { session_id: string } & BrowserCurlParams = params;
+        const { session_id, ...curlParams } = curlRequest;
+        const urlError = curlUrlValidationError(curlParams.url);
+        if (urlError) return errorResponse(`Error: ${urlError}`);
+
+        const response = await client.browsers.curl(session_id, curlParams);
+        return jsonResponse(response);
+      } catch (error) {
+        return errorResponse(
+          `Error in browser_curl: ${
+            error instanceof Error ? error.message : String(error)
+          }`,
+        );
+      }
+    },
+  );
+}