Claude Desktop

Connect Claude Desktop through a custom connector or the claude_desktop_config.json file, and what the app can and cannot do with the prompts.

Claude Desktop adds remote MCP servers as custom connectors, and local ones through its config file.

Option 1: custom connector

Settings, Connectors, Add custom connector.
Name Vulnetix, URL https://mcp.vulnetix.com/mcp.
If the dialog offers custom request headers, add Authorization with ApiKey <orgId>:<hex>.
Save, then quit Claude Desktop fully and reopen it.

The server has no OAuth authorization server, so leave any OAuth client fields empty. If your build’s connector dialog has no header field, the connector will list the tools but every VDB tool returns a credential error; use option 2.

Option 2: config file with the stdio bridge

claude_desktop_config.json launches local commands. The mcp-remote package bridges stdio to the remote endpoint and adds the header. It needs Node.js.

OS	Path
macOS	`~/Library/Application Support/Claude/claude_desktop_config.json`
Windows	`%APPDATA%\Claude\claude_desktop_config.json`

{
  "mcpServers": {
    "vulnetix": {
      "command": "npx",
      "args": [
        "-y", "mcp-remote",
        "https://mcp.vulnetix.com/mcp",
        "--header", "Authorization:${VULNETIX_AUTH_HEADER}"
      ],
      "env": {
        "VULNETIX_AUTH_HEADER": "ApiKey <orgId>:<hex>"
      }
    }
  }
}

Keep the value in env and the --header argument free of spaces: mcp-remote substitutes ${VAR} from env, and a space inside an argument breaks on some platforms.

Check it

The tools menu in the message box lists the Vulnetix tools. Then:

Look up CVE-2021-44228 and tell me whether it is in the CISA KEV catalogue.

Claude asks before the first tool call in a chat.

What works in Claude Desktop

Feature	Works
All 31 tools	Yes
Prompts, from the + menu under the server name	Listed, but every one needs a shell and a repository, which Claude Desktop does not have
MCP Apps (KEV board, triage queue, CVE card)	Listed by the MCP Apps client matrix as supported; not yet tested in a real host

Use Claude Code or another agent with a terminal for the prompts.

Troubleshooting

Symptom	Fix
Connector saved but never connects	Quit fully and reopen
“Could not attach to MCP server”	URL must end in `/mcp`; check for a TLS-inspecting proxy
Every VDB tool says no credential was supplied	No header reached the server; use option 2
`npx` not found (option 2)	Install Node.js, or give the full path to `npx` in `command`