Starts an OpenID Connect (OIDC) login by redirecting the browser to the provider's authorization endpoint. Open it in the browser; don't call it with fetch. No authentication is required. The endpoint adds the provider's client_id and scope, plus response_type=code, state, redirect_uri and, if you sent one, nonce. The authorization endpoint comes from the provider's configuration or its discovery document. Without redirect_uri, the provider returns the user to https://{host}/auth/oidc/callback. An unknown or disabled provider returns 404, and so does a provider whose IP allowlist excludes the caller, so that the response doesn't reveal which providers exist. To list the providers a login page can offer, use /oidc-providers/public.
Request
Query Params
Responses
🔵302Found
Redirect to the provider. The Location header holds the provider's authorization URL with the query parameters filled in.