[devj]

# Fast, portable, non-Turing complete expression evaluation

Common Expression Language (CEL) is a non-Turing complete language designed for simplicity, speed, safety, and portability. CEL is designed to be evaluated without a sandbox, making it ideal for use within latency critical applications.

## Features

  - Familiar C-like syntax common to C++, Go, Java, and TypeScript.

  - Gradual typing with first-class support for Protobuf and JSON types.

  - High performance evaluators in C++ and Go with a rich set of standard operators.

## How Google uses Common Expression Language

Google uses CEL as the expression component of IAM and Firebase security policies, as well as within Istio Mixer configs.