DefDex in Cursor

1. Add DefDex

Open Cursor Settings → MCP → Add new MCP server, or edit the file directly. Use ~/.cursor/mcp.json for every project, or .cursor/mcp.json for one:

{
  "mcpServers": {
    "defdex": {
      "url": "https://app.defdex.io/mcp",
      "headers": { "Authorization": "Bearer ${env:DEFDEX_API_KEY}" }
    }
  }
}

Cursor fills ${env:DEFDEX_API_KEY} from the environment it was started in. Export the variable in your shell profile, then quit and reopen Cursor (on macOS, launching it from a terminal with cursor . guarantees it sees the variable).

2. Verify

In Cursor Settings → MCP, defdex shows a green dot and its tools.

3. Try it

Use DefDex to find which companies supply rocket motors to DoD programs, with sources.

Troubleshooting

• 401 Unauthorized. Cursor sent the text ${env:DEFDEX_API_KEY} instead of the key, usually because it didn’t see the variable at launch. Restart Cursor from a terminal where the variable is set. If it still fails, put the key in place of ${env:DEFDEX_API_KEY} in your global ~/.cursor/mcp.json only, never in a project file you commit.
• Server shows red. Check the JSON is valid and the URL is exactly https://app.defdex.io/mcp.