Install Lightsage MCP in ChatGPT - Lightsage

Install Lightsage MCP in ChatGPT

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.

Steps to Connect

  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:

    1. Sign in with your Lightsage account (the same login you use for the dashboard).
    2. Choose the organization this connection should access.
    3. 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. See Connect from ChatGPT and Apps SDK authentication.