Patent attributes
Systems and methods are described for utilizing cross-account access to tasks on an on-demand code execution environment or other distributed code execution environment to implement an application programming interface (API) on a network-accessible service. An on-demand code execution environment can utilize pre-initialized virtual machine instances to enable execution of user-specified code in a rapid manner, without delays typically caused by initialization of the virtual machine instances. While users may generally execute their own code, the present application enables code of a first user to be executed by a second user, while maintaining the privacy and security of the code and associated accounts. Further, the present application enables a set of tasks to be grouped together as an API, enabling any user to create an API for a service, while the on-demand code execution environment manages execution of the tasks and allocation of underlying computing resources.