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Connect ChatGPT Desktop to CMX so requests from the ChatGPT Desktop app pass through the local gateway. CMX compresses eligible context in the background, reducing your provider token usage across longer sessions, without requiring any changes to how you use ChatGPT Desktop.
Prerequisites: CMX must be installed and signed in on your device. ChatGPT Desktop must already be installed and signed in. CMX does not replace your OpenAI account; you continue signing in through ChatGPT Desktop as usual.
1

Set Up CMX

Run the guided setup command to sign in, start the local gateway, and detect your coding agents:
Follow the browser sign-in prompt. Once setup completes, the CMX gateway starts at 127.0.0.1:17322 and is ready to accept connections.
2

Connect ChatGPT Desktop

Open the CMX terminal UI and connect ChatGPT Desktop:
  1. Navigate to CONFIG → ChatGPT Desktop.
  2. Refresh the provider list to make sure your configured provider appears.
  3. Select the provider you use in ChatGPT Desktop.
  4. Click Connect.
  5. Quit and reopen ChatGPT Desktop so it picks up the new routing through CMX.
ChatGPT Desktop will now send eligible requests through the CMX gateway instead of directly to your provider.
3

Verify the Connection

Confirm that ChatGPT Desktop is routing through CMX correctly:
Send a request from ChatGPT Desktop as you normally would. Then check CMX for activity:
New requests should appear in the stats output. If you see activity, the connection is working.
Short conversations may show little or no compression. Savings grow with longer sessions as eligible older context accumulates. Compare stats across a full session to get a representative picture.

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Troubleshooting

If requests from ChatGPT Desktop are not appearing in cmx stats after a session:
  1. Quit and reopen ChatGPT Desktop so the new routing takes effect.
  2. Check the selected connection by opening CONFIG in CMX and confirming the correct provider is connected.
  3. Run the diagnostics command:
For more detailed guidance, see the troubleshooting guide. If the issue persists, contact support with your CMX version, OS, and a description of what happened. Using a tool that is not listed under Providers? See Connect Any OpenAI or Anthropic Agent to CMX for instructions on connecting other tools via a custom base URL, or suggest a provider for us to integrate next.
Last modified on September 22, 2026