feat: add WebSocket transport type

Author: pyadav

src/commands/mcp.ts

@@ -21,7 +21,7 @@ export function createMCPCommand(): Command {
     .argument("<name>", "Server name")
     .option(
       "-t, --transport <type>",
-      "Transport type: stdio | sse | streamable-http (alias: http)",
+      "Transport type: stdio | sse | ws | streamable-http (alias: http)",
       "stdio",
     )
     .option(
@@ -33,7 +33,7 @@ export function createMCPCommand(): Command {
       "Arguments for the server command (for stdio transport)",
       [],
     )
-    .option("-u, --url <url>", "URL for SSE/HTTP transport")
+    .option("-u, --url <url>", "URL for SSE/HTTP/WS transport")
     .option("-e, --env [envs...]", "Environment variables (KEY=VALUE)")
     .option("-H, --header [headers...]", "HTTP headers (KEY=VALUE)")
     .option("--timeout <ms>", "Operation timeout in ms", (v) => parseInt(v, 10))
@@ -60,6 +60,14 @@ export function createMCPCommand(): Command {
             enabled: opts.enabled,
           };
           break;
+        case TRANSPORT_TYPES.WS:
+          config = {
+            type: TRANSPORT_TYPES.WS,
+            url: opts.url,
+            timeout: opts.timeout,
+            enabled: opts.enabled,
+          };
+          break;
         case TRANSPORT_TYPES.HTTP:
         case TRANSPORT_TYPES.STREAMABLE_HTTP:
           config = {

src/mcp/constants.ts

@@ -3,6 +3,7 @@ export const TRANSPORT_TYPES = {
   STDIO: "stdio",
   SSE: "sse",
   HTTP: "http",
+  WS: "ws",
   STREAMABLE_HTTP: "streamable-http",
 } as const;
 

src/mcp/transports.ts

@@ -9,7 +9,9 @@ import type {
   SSEServerConfig,
   StdioServerConfig,
   StreamableHttpServerConfig,
+  WebSocketServerConfig,
 } from "./types.js";
+import { WebSocketClientTransport } from "@modelcontextprotocol/sdk/client/websocket.js";
 
 interface TransportFactory {
   create(config: MCPServerConfig): Promise<Transport>;
@@ -51,11 +53,18 @@ class StreamableHttpTransportFactory implements TransportFactory {
     );
   }
 }
+class WebSocketTransportFactory implements TransportFactory {
+  async create(config: WebSocketServerConfig): Promise<Transport> {
+    if (!config.url) throw new Error("URL is required for WebSocket transport");
+    return new WebSocketClientTransport(new URL(config.url));
+  }
+}
 
 const factories: Record<string, TransportFactory> = {
   [TRANSPORT_TYPES.STDIO]: new StdioTransportFactory(),
   [TRANSPORT_TYPES.SSE]: new SSETransportFactory(),
   [TRANSPORT_TYPES.STREAMABLE_HTTP]: new StreamableHttpTransportFactory(),
+  [TRANSPORT_TYPES.WS]: new WebSocketTransportFactory(),
 };
 
 export async function createTransport(

src/mcp/types.ts

@@ -11,7 +11,7 @@ import type {
  * List of all MCP client transport types.
  * Which define the communication protocol used to connect MCP servers.
  */
-export type TransportType = "stdio" | "sse" | "http" | "streamable-http";
+export type TransportType = "stdio" | "sse" | "http" | "streamable-http" | "ws";
 
 export interface BaseServerConfig {
   type: TransportType;
@@ -37,11 +37,16 @@ export interface StreamableHttpServerConfig extends BaseServerConfig {
   url: string;
   headers?: Record<string, string>;
 }
+export interface WebSocketServerConfig extends BaseServerConfig {
+  type: "ws";
+  url: string;
+}
 
 export type MCPServerConfig =
   | StdioServerConfig
   | SSEServerConfig
-  | StreamableHttpServerConfig;
+  | StreamableHttpServerConfig
+  | WebSocketServerConfig;
 
 export type ServerConfigs = Record<string, MCPServerConfig>;