Systems and methods are described for a connection service that identifies connections for providing a data flow between a client computing device and a target computing device. A client computing device can send an API-based connection request to various servers hosting the connection service. The connection service processes the requests to determine a routing path for the connection. Advantageously, the connection service determines various routing paths and further identifies a connection for the data stream using that routing path. Finally, a control service provides control and relays requests to initiate data flows for resources configured for a data flow (e.g., a remote desktop session).