MCP hub
Connect ChatGPT and other MCP clients to Backplane's resource-bound tool gateway.
https://backplane.gsmlg.net/mcp is the canonical Streamable HTTP endpoint. An unauthenticated request returns a WWW-Authenticate challenge that points to https://backplane.gsmlg.net/.well-known/oauth-protected-resource/mcp.
Assign the same MCP tool scopes to the predefined client and the signing-in user. Backplane exposes permitted tools with stable prefix::tool names.
Setup
- Copy the exact callback URI shown in the ChatGPT app-management page. It has a shape such as https://chatgpt.com/connector/oauth/<callback_id>. Do not change the callback ID or add a trailing slash.
- Create a predefined confidential Backplane OAuth client, keep PKCE S256 enabled, and register that exact callback URI. Copy the generated $CLIENT_ID and one-time client secret into $CLIENT_SECRET when it is shown; Backplane will not show it again.
- Enable MCP (/mcp), assign matching tool scopes to the client, and grant matching scopes to the signing-in user.
- Configure ChatGPT's MCP server URL as https://backplane.gsmlg.net/mcp. Enter $CLIENT_ID and $CLIENT_SECRET in ChatGPT's OAuth settings, then test the connection.
Examples
Discover MCP OAuth
curl -i https://backplane.gsmlg.net/mcp
# Follow the WWW-Authenticate resource_metadata challenge directly:
curl https://backplane.gsmlg.net/.well-known/oauth-protected-resource/mcp
ChatGPT endpoint values
MCP_SERVER_URL=https://backplane.gsmlg.net/mcp
OAUTH_CLIENT_ID=$CLIENT_ID
OAUTH_CLIENT_SECRET=$CLIENT_SECRET
Reference
POST /mcp
GET /mcp
DELETE /mcp
GET /.well-known/oauth-protected-resource/mcp