chatgpt.md
Install Lightsage MCP in ChatGPT
Connect ChatGPT developer mode to Lightsage MCP with a preconfigured public OAuth client.
You can connect ChatGPT to Lightsage MCP with Lightsage's public OAuth client. You will sign in with your Lightsage account and choose which organization the connection can access. You do not need a Lightsage API key or an OAuth client secret.
1. Enable developer mode
Open Settings → Security and login and turn on Developer mode.
2. Open the New Plugin dialog
Click Create a new ChatGPT plugin to open the New Plugin dialog directly.
3. Enter the Lightsage MCP server
Set Name to Lightsage MCP and enter this MCP Server URL:
https://mcp.lightsage.com/mcp
Set Authentication to OAuth.
4. Configure the public OAuth client
Open Advanced OAuth settings and configure:
| Setting | Value |
|---|---|
| Registration method | User-Defined OAuth Client |
| Client ID | ilCry2skQZh8vKo4 |
| Client secret | Leave blank |
| Token endpoint authentication method | none |
Select these default scopes:
openid
profile
email
offline_access
Leave the discovered authorization, token, resource, and OpenID endpoints unchanged.
The client ID is a public identifier, not a secret. Do not enter a client secret.
5. Verify the callback URL
Confirm that ChatGPT displays this callback URL in Advanced OAuth settings:
https://chatgpt.com/connector/oauth/ZbWk4_OZH9yn
If ChatGPT displays a different callback URL, do not create the connector. Contact Lightsage support so the callback can be added to the OAuth client.
6. Create the connector
Check I understand and want to continue, then click Create.
7. Sign in and authorize
ChatGPT opens a Lightsage sign-in window:
- Sign in with your Lightsage account (the same login you use for the dashboard).
- Choose the organization this connection should access.
- Review the requested permissions and approve.
ChatGPT receives an access token scoped to the organization you selected. The connection can only act on that organization.
8. Test the connection
Enable the Lightsage connector in a chat, then run a read-only prompt:
Use the Lightsage MCP server to check my Lightsage auth status.
Lightsage is also preparing a published ChatGPT plugin that will remove the manual OAuth configuration steps.