import { JSONRPCMessage } from '@modelcontextprotocol/sdk/types.js';
import type { ClientInfo } from '@src/types/context.js';
/**
* Extract client information from MCP initialize request
*/
export class ClientInfoExtractor {
private static extractedClientInfo: ClientInfo | null = null;
private static initializeReceived = false;
/**
* Extract client information from initialize request
*/
static extractFromInitializeRequest(message: JSONRPCMessage): ClientInfo | null {
// Return null if we've already processed an initialize request
if (this.initializeReceived) {
return null;
}
// Check if this is an initialize request
if (
message &&
typeof message === 'object' &&
'method' in message &&
message.method === 'initialize' &&
'params' in message &&
typeof message.params === 'object' &&
message.params !== null &&
'clientInfo' in message.params
) {
const params = message.params as { clientInfo?: unknown };
const clientInfo = params.clientInfo;
// Validate required fields
if (
clientInfo &&
typeof clientInfo === 'object' &&
'name' in clientInfo &&
typeof (clientInfo as { name: unknown }).name === 'string' &&
'version' in clientInfo &&
typeof (clientInfo as { version: unknown }).version === 'string'
) {
const typedClientInfo = clientInfo as {
name: string;
version: string;
title?: unknown;
};
this.extractedClientInfo = {
name: typedClientInfo.name,
version: typedClientInfo.version,
title: typedClientInfo.title && typeof typedClientInfo.title === 'string' ? typedClientInfo.title : undefined,
};
this.initializeReceived = true;
return this.extractedClientInfo;
}
}
return null;
}
/**
* Get the extracted client information (if available)
*/
static getExtractedClientInfo(): ClientInfo | null {
return this.extractedClientInfo;
}
/**
* Check if initialize request has been received
*/
static hasReceivedInitialize(): boolean {
return this.initializeReceived;
}
/**
* Reset the extractor state (for new connections)
*/
static reset(): void {
this.extractedClientInfo = null;
this.initializeReceived = false;
}
}
