breaking shared apart

src/client.ts

@@ -14,7 +14,8 @@ import { Client } from '@modelcontextprotocol/sdk/client/index.js'
 import { SSEClientTransport } from '@modelcontextprotocol/sdk/client/sse.js'
 import { ListResourcesResultSchema, ListToolsResultSchema } from '@modelcontextprotocol/sdk/types.js'
 import { UnauthorizedError } from '@modelcontextprotocol/sdk/client/auth.js'
-import { NodeOAuthClientProvider, setupOAuthCallbackServer, parseCommandLineArgs, setupSignalHandlers } from './shared'
+import { NodeOAuthClientProvider } from './lib/node-oauth-client-provider'
+import { parseCommandLineArgs, setupOAuthCallbackServer, setupSignalHandlers } from './lib/utils'
 
 /**
  * Main function to run the client

src/lib/node-oauth-client-provider.ts

@@ -1,15 +1,8 @@
-/**
+import crypto from 'crypto'
- * Shared utilities for MCP OAuth clients and proxies.
- * Contains common functionality for authentication, file storage, and proxying.
- */
-
-import express from 'express'
-import open from 'open'
-import fs from 'fs/promises'
 import path from 'path'
 import os from 'os'
-import crypto from 'crypto'
+import fs from 'fs/promises'
-import net from 'net'
+import open from 'open'
 import { OAuthClientProvider } from '@modelcontextprotocol/sdk/client/auth.js'
 import {
   OAuthClientInformation,
@@ -18,7 +11,7 @@ import {
   OAuthTokens,
   OAuthTokensSchema,
 } from '@modelcontextprotocol/sdk/shared/auth.js'
-import { OAuthCallbackServerOptions, OAuthProviderOptions } from './lib/types'
+import type { OAuthProviderOptions } from './types'
 
 /**
  * Implements the OAuthClientProvider interface for Node.js environments.
@@ -204,131 +197,3 @@ export class NodeOAuthClientProvider implements OAuthClientProvider {
     return await this.readTextFile('code_verifier.txt')
   }
 }
-
-/**
- * Sets up an Express server to handle OAuth callbacks
- * @param options The server options
- * @returns An object with the server, authCode, and waitForAuthCode function
- */
-export function setupOAuthCallbackServer(options: OAuthCallbackServerOptions) {
-  let authCode: string | null = null
-  const app = express()
-
-  app.get(options.path, (req, res) => {
-    const code = req.query.code as string | undefined
-    if (!code) {
-      res.status(400).send('Error: No authorization code received')
-      return
-    }
-
-    authCode = code
-    res.send('Authorization successful! You may close this window and return to the CLI.')
-
-    // Notify main flow that auth code is available
-    options.events.emit('auth-code-received', code)
-  })
-
-  const server = app.listen(options.port, () => {
-    console.error(`OAuth callback server running at http://127.0.0.1:${options.port}`)
-  })
-
-  /**
-   * Waits for the OAuth authorization code
-   * @returns A promise that resolves with the authorization code
-   */
-  const waitForAuthCode = (): Promise<string> => {
-    return new Promise((resolve) => {
-      if (authCode) {
-        resolve(authCode)
-        return
-      }
-
-      options.events.once('auth-code-received', (code) => {
-        resolve(code)
-      })
-    })
-  }
-
-  return { server, authCode, waitForAuthCode }
-}
-
-/**
- * Finds an available port on the local machine
- * @param preferredPort Optional preferred port to try first
- * @returns A promise that resolves to an available port number
- */
-export async function findAvailablePort(preferredPort?: number): Promise<number> {
-  return new Promise((resolve, reject) => {
-    const server = net.createServer()
-
-    server.on('error', (err: NodeJS.ErrnoException) => {
-      if (err.code === 'EADDRINUSE') {
-        // If preferred port is in use, get a random port
-        server.listen(0)
-      } else {
-        reject(err)
-      }
-    })
-
-    server.on('listening', () => {
-      const { port } = server.address() as net.AddressInfo
-      server.close(() => {
-        resolve(port)
-      })
-    })
-
-    // Try preferred port first, or get a random port
-    server.listen(preferredPort || 0)
-  })
-}
-
-/**
- * Parses command line arguments for MCP clients and proxies
- * @param args Command line arguments
- * @param defaultPort Default port for the callback server if specified port is unavailable
- * @param usage Usage message to show on error
- * @returns A promise that resolves to an object with parsed serverUrl and callbackPort
- */
-export async function parseCommandLineArgs(args: string[], defaultPort: number, usage: string) {
-  const serverUrl = args[0]
-  const specifiedPort = args[1] ? parseInt(args[1]) : undefined
-
-  if (!serverUrl) {
-    console.error(usage)
-    process.exit(1)
-  }
-
-  const url = new URL(serverUrl)
-  const isLocalhost = (url.hostname === 'localhost' || url.hostname === '127.0.0.1') && url.protocol === 'http:'
-
-  if (!(url.protocol == 'https:' || isLocalhost)) {
-    console.error(usage)
-    process.exit(1)
-  }
-
-  // Use the specified port, or find an available one
-  const callbackPort = specifiedPort || (await findAvailablePort(defaultPort))
-
-  if (specifiedPort) {
-    console.error(`Using specified callback port: ${callbackPort}`)
-  } else {
-    console.error(`Using automatically selected callback port: ${callbackPort}`)
-  }
-
-  return { serverUrl, callbackPort }
-}
-
-/**
- * Sets up signal handlers for graceful shutdown
- * @param cleanup Cleanup function to run on shutdown
- */
-export function setupSignalHandlers(cleanup: () => Promise<void>) {
-  process.on('SIGINT', async () => {
-    console.error('\nShutting down...')
-    await cleanup()
-    process.exit(0)
-  })
-
-  // Keep the process alive
-  process.stdin.resume()
-}

src/lib/utils.ts

@@ -1,6 +1,9 @@
 import { OAuthClientProvider, UnauthorizedError } from '@modelcontextprotocol/sdk/client/auth.js'
 import { SSEClientTransport } from '@modelcontextprotocol/sdk/client/sse.js'
 import { Transport } from '@modelcontextprotocol/sdk/shared/transport.js'
+import { OAuthCallbackServerOptions } from './types'
+import express from 'express'
+import net from 'net'
 
 const pid = process.pid
 
@@ -99,3 +102,131 @@ export async function connectToRemoteServer(
     }
   }
 }
+
+/**
+ * Sets up an Express server to handle OAuth callbacks
+ * @param options The server options
+ * @returns An object with the server, authCode, and waitForAuthCode function
+ */
+export function setupOAuthCallbackServer(options: OAuthCallbackServerOptions) {
+  let authCode: string | null = null
+  const app = express()
+
+  app.get(options.path, (req, res) => {
+    const code = req.query.code as string | undefined
+    if (!code) {
+      res.status(400).send('Error: No authorization code received')
+      return
+    }
+
+    authCode = code
+    res.send('Authorization successful! You may close this window and return to the CLI.')
+
+    // Notify main flow that auth code is available
+    options.events.emit('auth-code-received', code)
+  })
+
+  const server = app.listen(options.port, () => {
+    console.error(`OAuth callback server running at http://127.0.0.1:${options.port}`)
+  })
+
+  /**
+   * Waits for the OAuth authorization code
+   * @returns A promise that resolves with the authorization code
+   */
+  const waitForAuthCode = (): Promise<string> => {
+    return new Promise((resolve) => {
+      if (authCode) {
+        resolve(authCode)
+        return
+      }
+
+      options.events.once('auth-code-received', (code) => {
+        resolve(code)
+      })
+    })
+  }
+
+  return { server, authCode, waitForAuthCode }
+}
+
+/**
+ * Finds an available port on the local machine
+ * @param preferredPort Optional preferred port to try first
+ * @returns A promise that resolves to an available port number
+ */
+export async function findAvailablePort(preferredPort?: number): Promise<number> {
+  return new Promise((resolve, reject) => {
+    const server = net.createServer()
+
+    server.on('error', (err: NodeJS.ErrnoException) => {
+      if (err.code === 'EADDRINUSE') {
+        // If preferred port is in use, get a random port
+        server.listen(0)
+      } else {
+        reject(err)
+      }
+    })
+
+    server.on('listening', () => {
+      const { port } = server.address() as net.AddressInfo
+      server.close(() => {
+        resolve(port)
+      })
+    })
+
+    // Try preferred port first, or get a random port
+    server.listen(preferredPort || 0)
+  })
+}
+
+/**
+ * Parses command line arguments for MCP clients and proxies
+ * @param args Command line arguments
+ * @param defaultPort Default port for the callback server if specified port is unavailable
+ * @param usage Usage message to show on error
+ * @returns A promise that resolves to an object with parsed serverUrl and callbackPort
+ */
+export async function parseCommandLineArgs(args: string[], defaultPort: number, usage: string) {
+  const serverUrl = args[0]
+  const specifiedPort = args[1] ? parseInt(args[1]) : undefined
+
+  if (!serverUrl) {
+    console.error(usage)
+    process.exit(1)
+  }
+
+  const url = new URL(serverUrl)
+  const isLocalhost = (url.hostname === 'localhost' || url.hostname === '127.0.0.1') && url.protocol === 'http:'
+
+  if (!(url.protocol == 'https:' || isLocalhost)) {
+    console.error(usage)
+    process.exit(1)
+  }
+
+  // Use the specified port, or find an available one
+  const callbackPort = specifiedPort || (await findAvailablePort(defaultPort))
+
+  if (specifiedPort) {
+    console.error(`Using specified callback port: ${callbackPort}`)
+  } else {
+    console.error(`Using automatically selected callback port: ${callbackPort}`)
+  }
+
+  return { serverUrl, callbackPort }
+}
+
+/**
+ * Sets up signal handlers for graceful shutdown
+ * @param cleanup Cleanup function to run on shutdown
+ */
+export function setupSignalHandlers(cleanup: () => Promise<void>) {
+  process.on('SIGINT', async () => {
+    console.error('\nShutting down...')
+    await cleanup()
+    process.exit(0)
+  })
+
+  // Keep the process alive
+  process.stdin.resume()
+}

src/proxy.ts

@@ -11,8 +11,8 @@
 
 import { EventEmitter } from 'events'
 import { StdioServerTransport } from '@modelcontextprotocol/sdk/server/stdio.js'
-import { NodeOAuthClientProvider, setupOAuthCallbackServer, parseCommandLineArgs, setupSignalHandlers } from './shared'
+import { connectToRemoteServer, mcpProxy, parseCommandLineArgs, setupOAuthCallbackServer, setupSignalHandlers } from './lib/utils'
-import { connectToRemoteServer, mcpProxy } from './lib/utils'
+import { NodeOAuthClientProvider } from './lib/node-oauth-client-provider'
 
 /**
  * Main function to run the proxy