CUE Has a Free API: A Data Constraint Language for Validating Kubernetes, Terraform, and APIs

CUE (Configure, Unify, Execute) is a language by a former Google engineer designed to validate, generate, and transform structured data. Think of it as JSON Schema on steroids with a proper type system. Why CUE Matters YAML and JSON have no built-in validation. You write a Kubernetes manifest, deploy it, and only discover typos in production. CUE catches these at authoring time with constraints that compose and scale. What you get for free: Validate any data format: JSON, YAML, Protobuf, OpenAPI Types ARE values — no separate schema language Constraints compose automatically Built-in Kubernetes, Terraform, and OpenAPI support Generate OpenAPI schemas from CUE definitions cue fmt — automatic formatting like gofmt Go API for embedding in applications Quick Start # Install go install cuelang.org/go/cmd/cue@latest # Validate YAML against CUE schema cue vet schema.cue data.yaml # Export CUE to JSON cue export config.cue # Export to YAML cue export config.cue --out yaml # Format CUE files cu