{"issuer":"https://mcp.squareup.com","authorization_endpoint":"https://mcp.squareup.com/authorize","token_endpoint":"https://mcp.squareup.com/token","registration_endpoint":"https://mcp.squareup.com/register","response_types_supported":["code"],"response_modes_supported":["query"],"grant_types_supported":["authorization_code","refresh_token"],"token_endpoint_auth_methods_supported":["client_secret_basic","client_secret_post","none"],"revocation_endpoint":"https://mcp.squareup.com/token","code_challenge_methods_supported":["plain","S256"]}