Hi , I'm setting this to Closed - Already Available as the automation of deployment and task/workflow execution exists in Compose / QEM.
Compose provides a CLI to automate deployment of projects. While this is not a REST API, it does have a number of features (like for auto-generation / validation of the dw / dm and ETL tasks, environment variable management, secure password deployment etc.).
Please review and comment if you feel this doesn't support your use case or requirements, but a number of customers are leveraging these features for deployment automation and task execution.