Home Assistant with Home MCP in ChatGPT and Codex

Hombee Free

Which OpenAI product this guide covers

Use this guide to add Hombee as a custom MCP app in ChatGPT developer mode. The separate Codex desktop application is now a historical product name: the current ChatGPT desktop application includes Codex as a mode. Custom MCP app availability still depends on the ChatGPT version, workspace policy and plan, so configure the connection where developer mode and custom apps.

Before you connect

You need:

  • access to a Hombee installation that includes the Home Assistant capabilities you want to use;
  • the public Hombee Home MCP URL ending in /mcp;
  • permission to enable developer mode and create an app in the relevant ChatGPT workspace.

Home MCP does not expose every Home Assistant entity. It presents selected, typed tools filtered by your Hombee account, installation and current capabilities.

Add Home MCP to ChatGPT

  1. Open ChatGPT settings and go to Apps and connectors.
  2. Open Advanced settings and enable developer mode if your workspace allows it.
  3. Choose the option to create a custom app or connector.
  4. Name it Hombee Home MCP and enter the public Home MCP URL ending in /mcp.
  5. Save the configuration and start the authorization flow.
  6. Sign in with the Hombee account that has access to the intended installation. Do not paste a session token into the app definition or chat.
  7. Open a new conversation and enable the Hombee app for that conversation.

The exact settings labels can change between ChatGPT releases. If your account does not show developer mode or custom apps, the feature is unavailable for that account or workspace; changing the MCP URL will not fix that limitation.

Verify Home Assistant access safely

Start with a read-only request that names the installation context:

Using Hombee Home MCP, list the rooms and summarize which Home Assistant capabilities are currently available. Do not change anything.

Check that ChatGPT shows a Hombee tool call, the expected installation and a result consistent with the Hombee app. A shorter tool list than another user sees is not necessarily an error: discovery is capability- and permission-aware.

Before a state-changing request, name the target explicitly and ask ChatGPT to explain the proposed action first. Confirm only after the room, device and consequence are correct.

Troubleshooting ChatGPT and Codex naming

  • No custom app controls: verify ChatGPT plan and workspace policy. Codex mode alone does not guarantee that the custom-app controls are available.
  • Authorization repeats: remove the incomplete Hombee app connection and create it again, then finish the browser flow with one Hombee account.
  • The app is connected but no tools appear: verify access to the intended Hombee installation and compare with the capabilities visible in the Hombee app.
  • A guide mentions the Codex app: treat that as the former name of the separate desktop application. Use the current ChatGPT app and its current settings.

For the security model behind the discovered tools, continue to the Home MCP capabilities and safety reference.

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