Abstract: Computer systems and methods are disclosed to implement a virtual server using a multitenant serverless execution service (MTSES) and a request labeling endpoint outside the MTSES to identify the virtual server to worker nodes in the service. The MTSES is configured to host multiple virtual servers, and forward requests for the different virtual servers to dynamically selected worker nodes. However, in embodiments, the MTSES is not configured to determine the virtual server targeted by the requests. Accordingly, to allow the MTSES to support virtual servers that require knowledge of their identity, for example to authorize incoming requests, a request labeling endpoint is provided outside the MTSES to forward requests to the MTSES and automatically label individual requests with an endpoint identifier associated with their target virtual servers. In this manner, nodes in the MTSES can dynamically determine the virtual server that they are to assume for each request.