Infinite possibilities

CUE is an open source language, with a rich set of APIs and tooling, for defining, generating, and validating all kinds of data: configuration, APIs, database schemas, code, ... just name it!

Data validation

Validate text-based data like JSON or YAML using CUE's powerful and flexible constraints

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Validate existing configurations ⊚ Check JSON, YAML and CUE config files ⊚ Reduce boilerplate in large-scale configurations ⊚ & more

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Schema definition

Validate text-based data files or programmatic data such as incoming RPCs or database documents

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Automate the use of your data without writing yet another tool

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Generate code and schema

Keep validation code in sync across code bases, Protobuf definitions, and OpenAPI definitions

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Find the locations of instances of CUE types and values in data

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CUE integrations

CUE works with a wide range of tools and formats that you're already using ...


    Read about how CUE’s Go API brings its power and flexibility into your programs, and lets you convert Go types to CUE schemas.
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    CUE might look a bit like JSON, but that’s where the similarity ends. Discover how CUE helps you tame your static JSON data files.
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    Love YAML’s “anchors”? No.
    No, you don’t - no-one does … and for good reason! Learn about how CUE reads and writes YAML, whilst delivering a much better referencing system!
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    CUE has first class support for OpenAPI’s data schemas, using them to validate data directly. See how CUE makes OpenAPI easier to handle and understand.
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    JSON Schema

    JSON Schema can be used as if it were CUE - and can be converted to CUE just as easily. Find out more about CUE’s native support for JSON Schema.
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    Protocol Buffers

    CUE understands Protocol Buffers, extending Protobuf’s capabilities by validating data values and not just the data schema. Find out how …
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CUE users

Organizations in every industry use CUE to power their software and services

Supporters of CUE

Organizations actively supporting CUE