mcp-endpoint.ts•1.63 kB
/**
* MCP Endpoint Utilities
*
* Helper functions for constructing MCP endpoint URLs with proper context path handling
* when behind reverse proxies.
*/
import { Request } from 'express';
/**
* Extract the context path from the request
* Checks X-Forwarded-Prefix header and PROXY_CONTEXT_PATH environment variable
*/
export function getContextPath(req: Request): string {
const forwardedPrefix = req.headers['x-forwarded-prefix'] as string;
const envPrefix = process.env.PROXY_CONTEXT_PATH;
return forwardedPrefix || envPrefix || '';
}
/**
* Build a full URL from request headers and path
* Useful for constructing SSE endpoint URLs
*/
export function buildFullUrl(req: Request, path: string): string {
const proto = (req.headers['x-forwarded-proto'] as string) || req.protocol;
const host = (req.headers['x-forwarded-host'] as string) || req.get('host') || 'localhost';
const contextPath = getContextPath(req);
const fullPath = contextPath + path;
return `${proto}://${host}${fullPath}`;
}
/**
* Validate session ID format
*/
export function isValidSessionId(sessionId: string): boolean {
// Session IDs should be alphanumeric with hyphens, between 8 and 128 characters
return /^[a-zA-Z0-9-_]{8,128}$/.test(sessionId);
}
/**
* Extract session ID from multiple sources (query, header, body)
* Returns the first valid session ID found
*/
export function extractSessionId(req: Request): string | undefined {
const sources = [
req.query.sessionId as string,
req.headers['x-session-id'] as string,
req.body?.sessionId as string,
];
return sources.find(id => id && typeof id === 'string');
}