What is openwhisk?

Apache OpenWhisk is an open source platform for running serverless functions. Serverless means you write small pieces of code called functions, and the platform handles all the infrastructure work of running them, such as deciding when to start a server, scaling up under load, and shutting things down when they are not needed. You do not manage servers directly. With OpenWhisk, you can write functions in multiple programming languages and deploy them to respond to events. An event might be an HTTP request arriving at an API endpoint, a message from a queue, a scheduled timer, or many other triggers. You can chain functions together into workflows and set up rules that connect events to specific functions. You can run OpenWhisk on your own machine for development using a standalone mode that starts as a single Java process, with functions running inside Docker containers. A browser-based playground starts automatically and lets you write and test functions without any additional setup. For larger deployments, OpenWhisk can run on Kubernetes, either on a managed cloud service or on hardware you control. The project is part of the Apache Software Foundation and is licensed under Apache 2.0. The codebase is split across multiple repositories covering different components, such as the core platform, language runtimes, and deployment tools. In late 2025 the project migrated from one internal framework to another called Apache Pekko, which is a breaking change that requires redeploying clusters rather than upgrading in place. Community support is available through GitHub issues and a public Slack workspace.