# cuelang/cue

CUE has moved to https://github.com/cue-lang/cue

Repository: https://github.com/cuelang/cue
Canonical: https://ross.abutalabs.com/products/cuelang-cue
Homepage: https://cuelang.org
Language: Go
License: Apache-2.0
License Family: permissive
Topics: language-specification
Archived: true
Last push: 2021-07-14T16:31:41+00:00

## Health v2 (maintenance only)
Score: 10/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 0, release rhythm 8, longevity 100
- inputs: {"age_days": 2774, "days_push": 1876, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: archived
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 3056, forks 168 (observed 2026-08-28T04:07:39.754569+00:00)

## What it is
CUE is an open-source data validation language and inference engine, rooted in logic programming, that merges types and values into a single lattice hierarchy. It ships with the `cue` CLI and Go APIs for validating, generating, and unifying configuration and data in formats like JSON, YAML, Protobuf, and OpenAPI. Note: this repository (cuelang/cue) is a legacy mirror; development has moved to cue-lang/cue.

## Use cases
- validate json and yaml files against a schema
- reduce boilerplate in large-scale configuration files
- generate openapi or protobuf definitions from a single schema
- unify configuration values from multiple sources
- write policies and constraints for kubernetes-style configs
- template and export configuration as yaml or json
- script data transformations without writing a custom tool

## When to choose
- you need powerful, composable data validation across JSON/YAML/CUE files
- you manage large configuration estates with repetition and policy requirements
- you want a single source of truth generating multiple schema formats
- you want incremental adoption - validate existing files without changing other tooling

## When to avoid
- you need a general-purpose programming language - CUE is deliberately not one
- your team is unwilling to learn a new constraint-based language
- you only need simple one-off JSON schema validation with existing mature tools
- you require long-term support from this specific legacy repository rather than cue-lang/cue

## Facets
- artifact type: cli-tool
- maturity: active
- function: configuration-management, data-science, templating, cli, parser
- domain: programming-languages, developer-tools
- platform: windows, go, cli, cross-platform
- tags: cue-language, data-validation, schema, unification, json-yaml, openapi, protobuf, logic-programming, moved-repo, code-generation, configuration, data-engineering, devops, linux, macos, docker

## Member repositories
- cuelang/cue (main) score 10

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:07:39.754569+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T07:28:49.815227+00:00, confidence not recorded.
  - readme: https://github.com/cuelang/cue (fetched 2026-08-28T04:07:39.754569+00:00, sha b49c841017d7)
  - homepage: https://cuelang.org (fetched 2026-08-29T09:43:57.366925+00:00, sha aeaf25911f08)
  - site_page: https://cuelang.org/docs (fetched 2026-08-29T09:43:57.376582+00:00, sha 8eab7a42df00)
  - site_page: https://cuelang.org/docs/introduction/installation (fetched 2026-08-29T09:43:57.379006+00:00, sha bc5d05c491cf)
  - site_page: https://cuelang.org/docs/introduction (fetched 2026-08-29T09:43:57.380875+00:00, sha 033a0de989fc)
  - site_page: https://cuelang.org/docs/tour (fetched 2026-08-29T09:43:57.383278+00:00, sha 0ab50ead8ceb)
  - site_page: https://cuelang.org/docs/concept/how-cue-enables-data-validation (fetched 2026-08-29T09:43:57.385334+00:00, sha 08674ebfe924)
  - site_page: https://cuelang.org/docs/concept/how-cue-enables-configuration (fetched 2026-08-29T09:43:57.387907+00:00, sha 9cb23837c593)
  - site_page: https://cuelang.org/docs/concept/how-cue-enables-boilerplate-removal (fetched 2026-08-29T09:43:57.390224+00:00, sha 18d215abe06a)
  - site_page: https://cuelang.org/docs/reference/command/cue-help-cmd (fetched 2026-08-29T09:43:57.392207+00:00, sha 8ab8acbc0987)
- Data as of 2026-08-30T08:39:29.467469+00:00.