The connection uses MCP, an open standard that most AI apps support. ChatGPT acts as you and sees exactly what you can see in Loctax, nothing more. You don't need an API key.
1. Copy the URL in Loctax
Open the organization menu, select My profile, then Assistant external access. On the MCP tab, select Copy URL.
2. Add it to ChatGPT
Open Plugins, select Add, then Add custom MCP server.
Name it Loctax, add a short description and paste the URL.
Keep OAuth as the authentication.
Read the risk notice, check I understand and want to continue, and select Create as a plugin.
3. Connect and confirm in Loctax
Select Connect Loctax.
Loctax asks you to confirm: select Continue, check the organization and select Allow access. ChatGPT now lists Loctax under Installed.
Good to know
In Loctax, ChatGPT shows under Your connected apps, with the date it was last used. Select Disconnect to end its access at any time.
ChatGPT's menus change from time to time. If you don't see Plugins, look for Apps or Connectors in ChatGPT's settings: the URL and the Loctax sign-in stay the same.
For Claude Code, copy the command shown on the page. Tools that can't sign in, such as Cursor, need a personal API key from the API tab. Keep that key out of shared files.