# http4s

Scala library for typeful, functional and streaming HTTP servers and clients, built on FS2 and cats-effect.


Source: https://findsoftware.frbit.cloud/http4s/
Last reviewed: 2026-10-26
Listed since: 2026-10-26

## Record

### Links

- home: https://http4s.org/
- repository: https://github.com/http4s/http4s
- docs: https://http4s.org/v0.23/docs/quickstart.html
- discord: https://discord.gg/XF3CXcMzqD

### Identity

- status: active
- maintainer: http4s
- maintainerType: unknown
- parent: unknown
- firstRelease: 2014
- hqCountry: unknown

### Kind

- category: framework
- hosting: java
- language: scala
- runtime: jvm
- runtimeMin: unknown
- basedOn: unknown

### Content

- contentStore: unknown
- databases: unknown
- adminUi: unknown
- headlessApi: unknown
- templating: unknown
- i18n: unknown

### Rendering and deploy

- runsAs: always-on
- renderingModes: unknown
- installMethod: sbt dependency

### License

- licenseModel: open-source
- license: Apache 2.0, Apache-2.0, Apache 2

### Releases

- currentMajor: 0
- latestReleaseDate: 2026-09-29

### Adoption

- githubStargazers: 2627
- packagistDownloads: not applicable
- npmWeeklyDownloads: not applicable
- contributors: 335
- pluginCount: unknown
- packagistMonthlyDownloads: unknown
- ecosystemsMonthlyDownloads: unknown
- httpArchiveSites: unknown
- wordpressActiveInstalls: unknown
- dependentRepos: unknown
- dependentPackages: unknown

### Sources

- urls: https://http4s.org/ (read 2026-10-26)
- urls: https://api.github.com/repos/http4s/http4s (read 2026-10-26)
- urls: https://http4s.org/v0.23/docs/quickstart.html (read 2026-10-26)
- category: https://http4s.org/ (read 2026-10-26)
- maintainer: https://github.com/http4s/http4s/blob/series/0.23/README.md (read 2026-10-26)
- language: https://api.github.com/repos/http4s/http4s (read 2026-10-26)
- runtime: https://github.com/http4s/http4s/blob/series/0.23/README.md (read 2026-10-26)
- installMethod: https://http4s.org/v0.23/docs/quickstart.html (read 2026-10-26)
- installMethod: https://http4s.org/v0.23/docs/quickstart.html (read 2026-10-26)
- installMethod: https://http4s.org/v0.23/docs/deployment.html (read 2026-10-26)
- license: https://http4s.org/ (read 2026-10-26)
- license: https://api.github.com/repos/http4s/http4s (read 2026-10-26)
- license: https://github.com/http4s/http4s/blob/series/0.23/README.md (read 2026-10-26)
- license: https://http4s.org/changelog.html (read 2026-10-26)
- runsAs: https://http4s.org/v0.23/docs/quickstart.html (read 2026-10-26)
- licenseModel: https://github.com/http4s/http4s/blob/series/0.23/README.md (read 2026-10-26)
- firstRelease: https://http4s.org/changelog.html (read 2026-10-26)
- currentMajor: https://api.github.com/repos/http4s/http4s/releases (read 2026-10-26)
- latestReleaseDate: https://api.github.com/repos/http4s/http4s/releases (read 2026-10-26)
- githubStargazers: https://api.github.com/repos/http4s/http4s (read 2026-10-26)
- contributors: https://api.github.com/repos/http4s/http4s/contributors?per_page=1 (read 2026-10-26)

## Notes

http4s is a Scala library for HTTP servers and clients written as typed, functional and streaming code. It is built on FS2, manages its effects through cats-effect, and runs on the JVM. Its quickstart adds the Ember client and server modules to an sbt build through libraryDependencies, and its deployment page packages a service as an assembled jar that runs with `java -jar`.

## Worth knowing

The README states that the blaze backend needs a JDK newer than 8u252. The quickstart runs the service as a server on a port, so it needs a host that keeps a process running.

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Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Attributes are recorded, never scored; absent means unknown.
Credit, in full: FindSoftware, CC BY 4.0