What is Fission used for?

Fission is an open source, Kubernetes-native framework for running serverless functions, with fast cold-start and support for multiple languages. It is a good fit for running serverless functions on Kubernetes, deploying functions triggered by HTTP requests or events and building portable Lambda-like services.

Is Fission open source?

Yes. Fission is open source under the Apache-2.0 licence. Its source code is on GitHub at fission/fission and is written mainly in Go.

Yes. Fission is open source, so the software itself is free to use.

Can I self-host Fission?

Yes. Fission can be self-hosted on your own server or infrastructure.

What is Fission an alternative to?

Fission is an open-source alternative to Modal, AWS Lambda, Azure Functions and Firebase Remote Config. Other open-source alternatives to Modal include OpenFaaS, Fn and Nuclio.

Is Fission actively maintained?

Yes. The most recent commit to Fission was on 12 October 2026, and the latest release is v1.27.0, published on 22 June 2026. The project has 8.9k stars on GitHub.

Fission: open-source alternative to Modal, AWS Lambda

About Fission

Fission is a framework for serverless functions on Kubernetes. It allows developers to write short-lived functions in any language and map them to HTTP requests or other event triggers. Functions can be deployed instantly with one command, without building containers or managing Docker registries.

Fission is open source under the Apache license and works on any Kubernetes cluster, whether on a laptop, public cloud, or private data center. It aims to simplify operations by integrating with Fluentd for logs and Prometheus for metrics, and supports Istio for service mesh integration.

Key features

Kubernetes-native: runs on any Kubernetes cluster
Fast cold-start: maintains a configurable pool of containers for low latency (~100ms)
Declarative application specifications: define functions and triggers in source control
Administration simplicity: logs via Fluentd, metrics via Prometheus
Istio service-mesh integration for monitoring and tracing
Wide language support: Python, NodeJS, Go, Rust, C#, PHP

Good fit for

Running serverless functions on Kubernetes
Deploying functions triggered by HTTP requests or events
Building portable Lambda-like services

Built with: Go tools; Kubernetes tools; Docker tools
Tags: serverless; kubernetes; functions; open-source; apache-license

Fission: questions and answers

What is Fission used for?: Fission is an open source, Kubernetes-native framework for running serverless functions, with fast cold-start and support for multiple languages. It is a good fit for running serverless functions on Kubernetes, deploying functions triggered by HTTP requests or events and building portable Lambda-like services.
Is Fission open source?: Yes. Fission is open source under the Apache-2.0 licence. Its source code is on GitHub at fission/fission and is written mainly in Go.
Is Fission free?: Yes. Fission is open source, so the software itself is free to use.
Can I self-host Fission?: Yes. Fission can be self-hosted on your own server or infrastructure.
What is Fission an alternative to?: Fission is an open-source alternative to Modal, AWS Lambda, Azure Functions and Firebase Remote Config. Other open-source alternatives to Modal include OpenFaaS, Fn and Nuclio.
Is Fission actively maintained?: Yes. The most recent commit to Fission was on 12 October 2026, and the latest release is v1.27.0, published on 22 June 2026. The project has 8.9k stars on GitHub.