Let's Encrypt client written in PHP


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Note: This project is in beta but follow a strict BC policy, even in beta (see the Backward Compatibility policy of Acme PHP for more informations).

Acme PHP is a simple yet very extensible CLI client for Let's Encrypt that will help you get and renew free HTTPS certificates.

Acme PHP is also an initiative to bring a robust, stable and powerful implementation of the ACME protocol in PHP. Using the Acme PHP library and core components, you will be able to deeply integrate the management of your certificates directly in your application (for instance, renew your certificates from your web interface).

Why should I use Acme PHP when I have an official client?

Acme PHP provides several major improvements over the default clients:

  • Acme PHP comes by nature as a single binary file: a single download and you are ready to start working ;
  • Acme PHP is based on a configuration file (~/.acmephp/acmephp.conf) instead command line arguments. Thus, the configuration is much more expressive and the same setup is used at every renewal ;
  • Acme PHP can monitor your CRONs and can send you alerts in many differents places: E-mail, Slack, HipChat, Flowdock, Fleep (thanks to Monolog!)
  • Acme PHP is very extensible it to create the certificate files structure you need for your webserver. It brings several default formatters to create classical file structures (nginx, nginx-proxy, haproxy, etc.) but you can very easily create your own if you need to ;
  • Acme PHP follows a strict BC policy preventing errors in your scripts or CRON even if you update it (see the Backward Compatibility policy of Acme PHP for more informations) ;


Read the official Acme PHP documentation.

Backward Compatibility policy

Acme PHP follows a strict BC policy by sticking carefully to semantic versioning. This means your scripts, your CRON tasks and your code will keep working properly even when you update Acme PHP (either the CLI tool or the library), as long as you keep the same major version (1.X.X, 2.X.X, etc.).

In addition of semantic versioning of stable versions for the CLI and the library, Acme PHP also follows certain rules for the CLI only:

  • an alpha release can break BC with previous alpha releases of the same version (1.1.0-alpha2 can break BC with features introduced by 1.1.0-alpha1 but can't break BC with 1.0.0 features).
  • a beta release cannot break BC with previous beta releases (1.1.0-beta4 have to be BC with 1.1.0-beta3, 1.1.0-beta2, 1.1.0-beta1 and 1.0.0). New features can be added in beta as long as they don't break BC.

Launch the Test suite

The Acme PHP test suite uses the Docker Boulder image to create an ACME server. To launch the test suite, you need to setup the proper Docker environment for the suite. Useful scripts are available under the tests directory: in the Acme PHP root directory, execute the following:

# Create the Docker environment required for the suite
sudo tests/

# Run the tests

# Clean the docker environment

Note: you may have boulder errors sometimes in tests. Simply ignore them and rerun the suite, they are due to an issue in the container DNS.

Warning: as the acmephp/testing-ca Docker image needs to be mapped to the host network, you may have ports conflicts. See for more informations.