{"adoption": {"forks": 1245, "observed_at": "2026-08-28T04:09:19.330069+00:00", "stars": 5456}, "canonical_url": "https://ross.abutalabs.com/products/cats", "card": {"archived": false, "artifact_type": "library", "description": "Lightweight, modular, and extensible library for functional programming.", "domain": ["programming-languages", "developer-tools"], "enriched": true, "function": ["type-system", "developer-tools"], "health_score": 90, "homepage": "https://typelevel.org/cats/", "language": "Scala", "license": "NOASSERTION", "license_family": "other", "maturity": "stable", "member_repos": ["typelevel/cats"], "name": "typelevel/cats", "platform": ["jvm", "cross-platform"], "pushed_at": "2026-08-21T12:13:32+00:00", "repo": "typelevel/cats", "stars": 5456, "tags": ["functional-programming", "typeclasses", "category-theory", "scala", "scalajs", "scala-native", "pure-fp", "algorithms"], "topics": [], "urls": [], "use_cases": ["use type classes like Monad and Functor in Scala", "write pure functional Scala code", "model errors with validated and Either", "build a pure FP library ecosystem on a stable core", "learn functional programming abstractions in Scala", "replace Scalaz with a modular FP foundation"], "what_it_is": "Cats is a lightweight, modular, and extensible Scala library providing abstractions for functional programming, such as type classes (Functor, Monad, Applicative) and pure data types. It aims to be a stable, binary-compatible foundation for an ecosystem of pure, typeful Scala libraries, running on JVM, Scala.js, and Scala Native.", "when_to_avoid": ["you want a batteries-included FP standard library with IO/Task included (look at Cats Effect or ZIO)", "your project is imperative/OO Scala with no interest in FP abstractions", "you need a runtime effect system rather than pure abstractions"], "when_to_choose": ["you are doing functional programming in Scala and want lawful, modular type classes", "you need a stable, binary-compatible FP core for Scala libraries", "you want cross-building support across JVM, Scala.js, and Scala Native"]}, "data_as_of": "2026-08-30T08:39:29.467469+00:00", "members": [{"path": "/products/cats", "repo": "typelevel/cats", "role": "main", "score": 67}], "provenance": {"archived": {"kind": "observed", "observed_at": "2026-08-28T04:09:19.330069+00:00", "source": "github"}, "artifact_type": {"confidence": null, "enriched_at": "2026-08-29T17:56:48.003852+00:00", "kind": "inferred", "prompt_version": 1, "sources": [{"content_hash": "6c86cb87ecd54b9f4e4957e29943984eda99e268ea4f0c1b6f7faa428705e85c", "fetched_at": "2026-08-28T04:09:19.330069+00:00", "kind": "readme", "missing": false, "url": "https://github.com/typelevel/cats"}, {"content_hash": "1bdd2ce73551036913c72b93a876884647b17d0f2c1f7b9756960908eced4d81", "fetched_at": "2026-08-29T08:51:51.336633+00:00", "kind": "homepage", "missing": false, "url": "https://typelevel.org/cats/"}, {"content_hash": "a0fbc9776983898eb5e8a4054fbff9e153ce94a4e798b5c644579850611801c0", "fetched_at": "2026-08-29T08:51:51.345690+00:00", "kind": "site_page", "missing": false, "url": "https://typelevel.org/cats/faq.html"}], "taxonomy_version": 1}, "description": {"kind": "observed", "observed_at": "2026-08-28T04:09:19.330069+00:00", "source": "github"}, "domain": {"confidence": null, "enriched_at": "2026-08-29T17:56:48.003852+00:00", "kind": "inferred", "prompt_version": 1, "sources": [{"content_hash": "6c86cb87ecd54b9f4e4957e29943984eda99e268ea4f0c1b6f7faa428705e85c", "fetched_at": "2026-08-28T04:09:19.330069+00:00", "kind": "readme", "missing": false, "url": "https://github.com/typelevel/cats"}, {"content_hash": "1bdd2ce73551036913c72b93a876884647b17d0f2c1f7b9756960908eced4d81", "fetched_at": "2026-08-29T08:51:51.336633+00:00", "kind": "homepage", "missing": false, "url": "https://typelevel.org/cats/"}, {"content_hash": "a0fbc9776983898eb5e8a4054fbff9e153ce94a4e798b5c644579850611801c0", "fetched_at": "2026-08-29T08:51:51.345690+00:00", "kind": "site_page", "missing": false, "url": "https://typelevel.org/cats/faq.html"}], "taxonomy_version": 1}, "enriched": {"inputs": [], "kind": "computed", "method": "enrichment_status"}, "function": {"confidence": null, "enriched_at": "2026-08-29T17:56:48.003852+00:00", "kind": "inferred", "prompt_version": 1, "sources": [{"content_hash": "6c86cb87ecd54b9f4e4957e29943984eda99e268ea4f0c1b6f7faa428705e85c", "fetched_at": "2026-08-28T04:09:19.330069+00:00", "kind": "readme", "missing": false, "url": "https://github.com/typelevel/cats"}, {"content_hash": "1bdd2ce73551036913c72b93a876884647b17d0f2c1f7b9756960908eced4d81", "fetched_at": "2026-08-29T08:51:51.336633+00:00", "kind": "homepage", "missing": false, "url": "https://typelevel.org/cats/"}, {"content_hash": "a0fbc9776983898eb5e8a4054fbff9e153ce94a4e798b5c644579850611801c0", "fetched_at": "2026-08-29T08:51:51.345690+00:00", "kind": "site_page", "missing": false, "url": "https://typelevel.org/cats/faq.html"}], "taxonomy_version": 1}, "health_score": {"inputs": ["days_since_push", "days_since_release", "archived"], "kind": "computed", "method": "health_v1"}, "homepage": {"kind": "observed", "observed_at": "2026-08-28T04:09:19.330069+00:00", "source": "github"}, "language": {"kind": "observed", "observed_at": "2026-08-28T04:09:19.330069+00:00", "source": "github"}, "license": {"kind": "observed", "observed_at": "2026-08-28T04:09:19.330069+00:00", "source": "github"}, "license_family": {"inputs": ["license"], "kind": "computed", "method": "license_family"}, "maturity": {"confidence": null, "enriched_at": "2026-08-29T17:56:48.003852+00:00", "kind": "inferred", "prompt_version": 1, "sources": [{"content_hash": "6c86cb87ecd54b9f4e4957e29943984eda99e268ea4f0c1b6f7faa428705e85c", "fetched_at": "2026-08-28T04:09:19.330069+00:00", "kind": "readme", "missing": false, "url": "https://github.com/typelevel/cats"}, {"content_hash": "1bdd2ce73551036913c72b93a876884647b17d0f2c1f7b9756960908eced4d81", "fetched_at": "2026-08-29T08:51:51.336633+00:00", "kind": "homepage", "missing": false, "url": "https://typelevel.org/cats/"}, {"content_hash": "a0fbc9776983898eb5e8a4054fbff9e153ce94a4e798b5c644579850611801c0", "fetched_at": "2026-08-29T08:51:51.345690+00:00", "kind": "site_page", "missing": false, "url": "https://typelevel.org/cats/faq.html"}], "taxonomy_version": 1}, "member_repos": {"kind": "observed", "observed_at": "2026-08-28T04:09:19.330069+00:00", "source": "github"}, "name": {"kind": "observed", "observed_at": "2026-08-28T04:09:19.330069+00:00", "source": "github"}, "platform": {"confidence": null, "enriched_at": "2026-08-29T17:56:48.003852+00:00", "kind": "inferred", "prompt_version": 1, "sources": [{"content_hash": "6c86cb87ecd54b9f4e4957e29943984eda99e268ea4f0c1b6f7faa428705e85c", "fetched_at": "2026-08-28T04:09:19.330069+00:00", "kind": "readme", "missing": false, "url": "https://github.com/typelevel/cats"}, {"content_hash": "1bdd2ce73551036913c72b93a876884647b17d0f2c1f7b9756960908eced4d81", "fetched_at": "2026-08-29T08:51:51.336633+00:00", "kind": "homepage", "missing": false, "url": "https://typelevel.org/cats/"}, {"content_hash": "a0fbc9776983898eb5e8a4054fbff9e153ce94a4e798b5c644579850611801c0", "fetched_at": "2026-08-29T08:51:51.345690+00:00", "kind": "site_page", "missing": false, "url": "https://typelevel.org/cats/faq.html"}], "taxonomy_version": 1}, "pushed_at": {"kind": "observed", "observed_at": "2026-08-28T04:09:19.330069+00:00", "source": "github"}, "repo": {"kind": "observed", "observed_at": "2026-08-28T04:09:19.330069+00:00", "source": "github"}, "stars": {"kind": "observed", "observed_at": "2026-08-28T04:09:19.330069+00:00", "source": "github"}, "tags": {"confidence": null, "enriched_at": "2026-08-29T17:56:48.003852+00:00", "kind": "inferred", "prompt_version": 1, "sources": [{"content_hash": "6c86cb87ecd54b9f4e4957e29943984eda99e268ea4f0c1b6f7faa428705e85c", "fetched_at": "2026-08-28T04:09:19.330069+00:00", "kind": "readme", "missing": false, "url": "https://github.com/typelevel/cats"}, {"content_hash": "1bdd2ce73551036913c72b93a876884647b17d0f2c1f7b9756960908eced4d81", "fetched_at": "2026-08-29T08:51:51.336633+00:00", "kind": "homepage", "missing": false, "url": "https://typelevel.org/cats/"}, {"content_hash": "a0fbc9776983898eb5e8a4054fbff9e153ce94a4e798b5c644579850611801c0", "fetched_at": "2026-08-29T08:51:51.345690+00:00", "kind": "site_page", "missing": false, "url": "https://typelevel.org/cats/faq.html"}], "taxonomy_version": 1}, "topics": {"kind": "observed", "observed_at": "2026-08-28T04:09:19.330069+00:00", "source": "github"}, "urls": {"kind": "observed", "observed_at": "2026-08-28T04:09:19.330069+00:00", "source": "github"}, "use_cases": {"confidence": null, "enriched_at": "2026-08-29T17:56:48.003852+00:00", "kind": "inferred", "prompt_version": 1, "sources": [{"content_hash": "6c86cb87ecd54b9f4e4957e29943984eda99e268ea4f0c1b6f7faa428705e85c", "fetched_at": "2026-08-28T04:09:19.330069+00:00", "kind": "readme", "missing": false, "url": "https://github.com/typelevel/cats"}, {"content_hash": "1bdd2ce73551036913c72b93a876884647b17d0f2c1f7b9756960908eced4d81", "fetched_at": "2026-08-29T08:51:51.336633+00:00", "kind": "homepage", "missing": false, "url": "https://typelevel.org/cats/"}, {"content_hash": "a0fbc9776983898eb5e8a4054fbff9e153ce94a4e798b5c644579850611801c0", "fetched_at": "2026-08-29T08:51:51.345690+00:00", "kind": "site_page", "missing": false, "url": "https://typelevel.org/cats/faq.html"}], "taxonomy_version": 1}, "what_it_is": {"confidence": null, "enriched_at": "2026-08-29T17:56:48.003852+00:00", "kind": "inferred", "prompt_version": 1, "sources": [{"content_hash": "6c86cb87ecd54b9f4e4957e29943984eda99e268ea4f0c1b6f7faa428705e85c", "fetched_at": "2026-08-28T04:09:19.330069+00:00", "kind": "readme", "missing": false, "url": "https://github.com/typelevel/cats"}, {"content_hash": "1bdd2ce73551036913c72b93a876884647b17d0f2c1f7b9756960908eced4d81", "fetched_at": "2026-08-29T08:51:51.336633+00:00", "kind": "homepage", "missing": false, "url": "https://typelevel.org/cats/"}, {"content_hash": "a0fbc9776983898eb5e8a4054fbff9e153ce94a4e798b5c644579850611801c0", "fetched_at": "2026-08-29T08:51:51.345690+00:00", "kind": "site_page", "missing": false, "url": "https://typelevel.org/cats/faq.html"}], "taxonomy_version": 1}, "when_to_avoid": {"confidence": null, "enriched_at": "2026-08-29T17:56:48.003852+00:00", "kind": "inferred", "prompt_version": 1, "sources": [{"content_hash": "6c86cb87ecd54b9f4e4957e29943984eda99e268ea4f0c1b6f7faa428705e85c", "fetched_at": "2026-08-28T04:09:19.330069+00:00", "kind": "readme", "missing": false, "url": "https://github.com/typelevel/cats"}, {"content_hash": "1bdd2ce73551036913c72b93a876884647b17d0f2c1f7b9756960908eced4d81", "fetched_at": "2026-08-29T08:51:51.336633+00:00", "kind": "homepage", "missing": false, "url": "https://typelevel.org/cats/"}, {"content_hash": "a0fbc9776983898eb5e8a4054fbff9e153ce94a4e798b5c644579850611801c0", "fetched_at": "2026-08-29T08:51:51.345690+00:00", "kind": "site_page", "missing": false, "url": "https://typelevel.org/cats/faq.html"}], "taxonomy_version": 1}, "when_to_choose": {"confidence": null, "enriched_at": "2026-08-29T17:56:48.003852+00:00", "kind": "inferred", "prompt_version": 1, "sources": [{"content_hash": "6c86cb87ecd54b9f4e4957e29943984eda99e268ea4f0c1b6f7faa428705e85c", "fetched_at": "2026-08-28T04:09:19.330069+00:00", "kind": "readme", "missing": false, "url": "https://github.com/typelevel/cats"}, {"content_hash": "1bdd2ce73551036913c72b93a876884647b17d0f2c1f7b9756960908eced4d81", "fetched_at": "2026-08-29T08:51:51.336633+00:00", "kind": "homepage", "missing": false, "url": "https://typelevel.org/cats/"}, {"content_hash": "a0fbc9776983898eb5e8a4054fbff9e153ce94a4e798b5c644579850611801c0", "fetched_at": "2026-08-29T08:51:51.345690+00:00", "kind": "site_page", "missing": false, "url": "https://typelevel.org/cats/faq.html"}], "taxonomy_version": 1}}, "score": {"components": {"activity": 98, "longevity": 100, "rhythm": 8}, "computed_at": "2026-09-03T02:20:16.233290+00:00", "flags": ["no_license"], "formula": "round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)", "inputs": {"age_days": 4235, "days_push": 12, "days_rel": 590, "gap_med": null, "n_releases_24m": 1}, "score": 67, "version": 2}, "staleness": {"enrichment_outdated": false, "low_confidence": false, "scrape_days": 9, "stale_scrape": false}}