pac4j / http4s-pac4j   4.3.0

Apache License 2.0 GitHub

Security library for http4s

Scala versions: 3.x 2.13 2.12

The http4s-pac4j project is an easy and powerful security library for http4s web applications and web services which supports authentication and authorization, but also logout and advanced features like session fixation and CSRF protection. It's based on Http4s 0.23 and on the pac4j security engine v5. The library is cross-built for Scala 2.12 and 2.13. It's available under the Apache 2 license.

Main concepts and components:

  1. A client represents an authentication mechanism. It performs the login process and returns a user profile. An indirect client is for web application authentication while a direct client is for web services authentication:

▸ OAuth - SAML - CAS - OpenID Connect - HTTP - Google App Engine - LDAP - SQL - JWT - MongoDB - CouchDB - Kerberos - IP address - Kerberos (SPNEGO) - REST API

  1. An authorizer is meant to check authorizations on the authenticated user profile(s) or on the current web context:

▸ Roles / permissions - Anonymous / remember-me / (fully) authenticated - Profile type, attribute - CORS - CSRF - Security headers - IP address, HTTP method

  1. The SecurityFilterMiddleware protects an url by checking that the user is authenticated and that the authorizations are valid, according to the clients and authorizers configuration. If the user is not authenticated, it performs authentication for direct clients or starts the login process for indirect clients

  2. The CallbackService finishes the login process for an indirect client

  3. The LogoutService logs out the user from the application and triggers the logout at the identity provider level.


  1. Add the required dependencies

  2. Define:

  1. Apply security

  2. Get the authenticated user profiles


The demo webapp for http4s-pac4j: http4s-pac4j-demo is available for tests and implements many authentication mechanisms: Facebook, Twitter, form, basic auth, CAS, SAML, OpenID Connect, JWT...


The latest released version is the Maven Central, available in the Maven central repository. The next version is under development.

See the release notes. Learn more by browsing the pac4j documentation and the http4s-pac4j Javadoc.

See the migration guide as well.

Need help?

You can use the mailing lists or the commercial support.


Thanks to for the Session implementation