import { createMcpHandler } from 'mcp-handler';
import { initializeMcpServer } from '../src/mcp-handler.js';
/**
* Vercel Function entry point for MCP server
*
* This handler is automatically deployed as a Vercel Function and provides
* Streamable HTTP transport for the MCP protocol.
*
* Supports URL query parameters (100% compatible with production mcp.exa.ai):
* - ?exaApiKey=YOUR_KEY - Pass API key via URL
* - ?tools=web_search_exa,get_code_context_exa - Enable specific tools
* - ?debug=true - Enable debug logging
*
* Also supports environment variables:
* - EXA_API_KEY: Your Exa AI API key
* - DEBUG: Enable debug logging (true/false)
* - ENABLED_TOOLS: Comma-separated list of tools to enable
*
* URL query parameters take precedence over environment variables.
*
* ARCHITECTURE NOTE:
* The mcp-handler library creates a single server instance and doesn't pass
* the request to the initializeServer callback. To support per-request
* configuration via URL params (like ?tools=... and ?exaApiKey=...), we
* create a fresh handler for each request. This ensures:
* 1. Feature parity with the production Smithery-based deployment at mcp.exa.ai
* 2. Each request gets its own configuration (no API key leakage between users)
* 3. Users can specify different tools and API keys per request
*/
/**
* Extract configuration from request URL or environment variables
* URL parameters take precedence over environment variables
*/
function getConfigFromUrl(url: string) {
let exaApiKey = process.env.EXA_API_KEY;
let enabledTools: string[] | undefined;
let debug = process.env.DEBUG === 'true';
try {
const parsedUrl = new URL(url);
const params = parsedUrl.searchParams;
// Support ?exaApiKey=YOUR_KEY (query param takes precedence)
if (params.has('exaApiKey')) {
const keyFromUrl = params.get('exaApiKey');
if (keyFromUrl) {
exaApiKey = keyFromUrl;
}
}
// Support ?tools=tool1,tool2 (query param takes precedence)
if (params.has('tools')) {
const toolsParam = params.get('tools');
if (toolsParam) {
enabledTools = toolsParam
.split(',')
.map(t => t.trim())
.filter(t => t.length > 0);
}
}
// Support ?debug=true
if (params.has('debug')) {
debug = params.get('debug') === 'true';
}
} catch (error) {
// URL parsing failed, will use env vars
if (debug) {
console.error('Failed to parse request URL:', error);
}
}
// Fall back to env vars if no query params were found
if (!enabledTools && process.env.ENABLED_TOOLS) {
enabledTools = process.env.ENABLED_TOOLS
.split(',')
.map(t => t.trim())
.filter(t => t.length > 0);
}
return { exaApiKey, enabledTools, debug };
}
/**
* Create a fresh handler for the given configuration
* We create a new handler per request to ensure each request gets its own
* configuration (tools and API key). This prevents API key leakage between
* different users who might pass different keys via URL.
*/
function createHandler(config: { exaApiKey?: string; enabledTools?: string[]; debug: boolean }) {
return createMcpHandler(
(server: any) => {
initializeMcpServer(server, config);
},
{}, // Server options
{ basePath: '/api' } // Config - basePath for Vercel Functions
);
}
/**
* Main request handler that extracts config from URL and creates
* a fresh handler for each request
*/
async function handleRequest(request: Request): Promise<Response> {
// Extract configuration from the request URL
const config = getConfigFromUrl(request.url);
if (config.debug) {
console.log(`[EXA-MCP] Request URL: ${request.url}`);
console.log(`[EXA-MCP] Enabled tools: ${config.enabledTools?.join(', ') || 'default'}`);
console.log(`[EXA-MCP] API key provided: ${config.exaApiKey ? 'yes' : 'no (using env var)'}`);
}
// Create a fresh handler for this request's configuration
const handler = createHandler(config);
// Delegate to the handler
return handler(request);
}
// Export handlers for Vercel Functions
export { handleRequest as GET, handleRequest as POST, handleRequest as DELETE };
