From b217e0800739674caa896ad1191f1348029dfe95 Mon Sep 17 00:00:00 2001
From: Jeremy Morrell <jmorrell@cloudflare.com>
Date: Mon, 24 Mar 2025 12:08:33 -0700
Subject: [PATCH] Add VPN warning

---
 README.md        | 30 ++++++++++++++++++++++++++++++
 package.json     |  1 +
 src/cli/proxy.ts | 22 ++++++++++++++++++++++
 3 files changed, 53 insertions(+)

diff --git a/README.md b/README.md
index 7aebd26..12f14e1 100644
--- a/README.md
+++ b/README.md
@@ -20,3 +20,33 @@ E.g: Claude Desktop or Windsurf
 Cursor:
 
 ![image](https://github.com/user-attachments/assets/14338bfa-a779-4e8a-a477-71f72cc5d99d)
+
+
+## Debugging
+
+### Restart Claude
+
+When modifying `claude_desktop_config.json` it can helpful to completely restart Claude
+
+### VPN Certs
+
+You may run into issues if you are behind a VPN, you can try setting the `NODE_EXTRA_CA_CERTS`
+environment variable to point to the CA certificate file. If using `claude_desktop_config.json`,
+this might look like:
+
+```json
+{
+ "mcpServers": {
+    "remote-example": {
+      "command": "npx",
+      "args": [
+        "mcp-remote",
+        "https://remote.mcp.server/sse"
+      ],
+      "env": {
+        "NODE_EXTRA_CA_CERTS": "\${your CA certificate file path}.pem"
+      }
+    }
+  }
+}
+```
diff --git a/package.json b/package.json
index 1dd36a3..5cf09a2 100644
--- a/package.json
+++ b/package.json
@@ -18,6 +18,7 @@
     }
   },
   "scripts": {
+    "dev": "tsup --watch",
     "build": "tsup",
     "check": "prettier --check . && tsc"
   },
diff --git a/src/cli/proxy.ts b/src/cli/proxy.ts
index 60f4966..d705b35 100644
--- a/src/cli/proxy.ts
+++ b/src/cli/proxy.ts
@@ -63,6 +63,28 @@ async function runProxy(serverUrl: string, callbackPort: number) {
     setupSignalHandlers(cleanup)
   } catch (error) {
     console.error('Fatal error:', error)
+    if (error instanceof Error && error.message.includes('self-signed certificate in certificate chain')) {
+      console.error(`You may be behind a VPN!
+
+If you are behind a VPN, you can try setting the NODE_EXTRA_CA_CERTS environment variable to point
+to the CA certificate file. If using claude_desktop_config.json, this might look like:
+
+{
+  "mcpServers": {
+    "\${mcpServerName}": {
+      "command": "npx",
+      "args": [
+        "mcp-remote",
+        "https://remote.mcp.server/sse"
+      ],
+      "env": {
+        "NODE_EXTRA_CA_CERTS": "\${your CA certificate file path}.pem"
+      }
+    }
+  }
+}
+        `)
+    }
     server.close()
     process.exit(1)
   }