# circe/circe

Yet another JSON library for Scala

Repository: https://github.com/circe/circe
Canonical: https://ross.abutalabs.com/products/circe
Homepage: http://circe.io/circe/
Language: Scala
License: Apache-2.0
License Family: permissive
Topics: json, generic-derivation, scala
Last push: 2026-07-23T08:36:23+00:00

## Health v2 (maintenance only)
Score: 90/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 94, release rhythm 78, longevity 100
- inputs: {"age_days": 4051, "days_push": 41, "days_rel": 70, "gap_med": 80.5, "n_releases_24m": 7}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 2542, forks 546 (observed 2026-08-28T04:06:59.437080+00:00)

## What it is
circe is a JSON library for Scala and Scala.js providing a JSON AST, encoders/decoders (codecs), and automatic derivation for case classes and sealed traits. It builds on cats and uses Jawn or Jackson for fast parsing and printing.

## Use cases
- serialize case classes to JSON in Scala
- parse JSON responses into typed Scala models
- auto-derive JSON codecs for case classes and sealed traits
- handle JSON in Scala.js browser apps
- high-throughput JSON processing in Scala services

## When to choose
- you're writing Scala or Scala.js and need idiomatic, type-safe JSON handling
- you want automatic codec derivation without runtime reflection
- you need fast parsing for high-throughput services
- your project already uses cats

## When to avoid
- you're not on the JVM/Scala ecosystem
- you need a minimal JSON library without cats dependency
- you work in a non-Scala JVM language like Java or Kotlin

## Facets
- artifact type: library
- maturity: stable
- function: serialization, parser
- domain: developer-tools, web-development, apis
- platform: jvm, wasm
- tags: scala, codec-derivation, cats, scala-js

## Member repositories
- circe/circe (main) score 90

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:06:59.437080+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 2026-08-30T02:25:06.636187+00:00, confidence not recorded.
  - readme: https://github.com/circe/circe (fetched 2026-08-28T04:06:59.437080+00:00, sha b9b212dd417f)
  - homepage: http://circe.io/circe/ (fetched 2026-08-29T10:07:05.439066+00:00, sha 740a53098268)
  - site_page: http://circe.io/circe/quickstart.html (fetched 2026-08-29T10:07:05.448255+00:00, sha eecc60b97310)
- Data as of 2026-08-30T08:39:29.467469+00:00.