Public | Automated Build

Last pushed: 2 years ago
Short Description
An automated build of the official letsencrypt repo (
Full Description

.. notice for github users


The Let's Encrypt Client is BETA SOFTWARE. It contains plenty of bugs and
rough edges, and should be tested thoroughly in staging environments before use
on production systems.

For more information regarding the status of the project, please see Be sure to checkout the
Frequently Asked Questions (FAQ) <>_.

About the Let's Encrypt Client

The Let's Encrypt Client is a fully-featured, extensible client for the Let's
Encrypt CA (or any other CA that speaks the ACME <>_
protocol) that can automate the tasks of obtaining certificates and
configuring webservers to use them.


If letsencrypt is packaged for your OS, you can install it from there, and
run it by typing letsencrypt. Because not all operating systems have
packages yet, we provide a temporary solution via the letsencrypt-auto
wrapper script, which obtains some dependencies from your OS and puts others
in a python virtual environment::

user@webserver:~$ git clone
user@webserver:~$ cd letsencrypt
user@webserver:~/letsencrypt$ ./letsencrypt-auto --help

Or for full command line help, type::

./letsencrypt-auto --help all

letsencrypt-auto updates to the latest client release automatically. And
since letsencrypt-auto is a wrapper to letsencrypt, it accepts exactly
the same command line flags and arguments. More details about this script and
other installation methods can be found in the User Guide <>_.

How to run the client

In many cases, you can just run letsencrypt-auto or letsencrypt, and the
client will guide you through the process of obtaining and installing certs

You can also tell it exactly what you want it to do from the command line.
For instance, if you want to obtain a cert for,, and, using the Apache plugin to both
obtain and install the certs, you could do this::

./letsencrypt-auto --apache -d -d -d

(The first time you run the command, it will make an account, and ask for an
email and agreement to the Let's Encrypt Subscriber Agreement; you can
automate those with --email and --agree-tos)

If you want to use a webserver that doesn't have full plugin support yet, you
can still use "standalone" or "webroot" plugins to obtain a certificate::

./letsencrypt-auto certonly --standalone --email -d -d -d

Understanding the client in more depth

To understand what the client is doing in detail, it's important to
understand the way it uses plugins. Please see the explanation of plugins <>_ in
the User Guide.



Software project:

Notes for developers:

Main Website:

IRC Channel: #letsencrypt on Freenode_


Mailing list: client-dev_ (to subscribe without a Google account, send an
email to

|build-status| |coverage| |docs| |container|

.. |build-status| image::
:alt: Travis CI status

.. |coverage| image::
:alt: Coverage status

.. |docs| image::
:alt: Documentation status

.. |container| image::
:alt: Docker Repository on

.. _installation instructions:

.. _watch demo video:

System Requirements

The Let's Encrypt Client presently only runs on Unix-ish OSes that include
Python 2.6 or 2.7; Python 3.x support will be added after the Public Beta
launch. The client requires root access in order to write to
/etc/letsencrypt, /var/log/letsencrypt, /var/lib/letsencrypt; to
bind to ports 80 and 443 (if you use the standalone plugin) and to read and
modify webserver configurations (if you use the apache or nginx
plugins). If none of these apply to you, it is theoretically possible to run
without root privileges, but for most users who want to avoid running an ACME
client as root, either letsencrypt-nosudo <>_ or simp_le <>_ are more appropriate choices.

The Apache plugin currently requires a Debian-based OS with augeas version
1.0; this includes Ubuntu 12.04+ and Debian 7+.

Current Features

  • Supports multiple web servers:

    • apache/2.x (working on Debian 8+ and Ubuntu 12.04+)
    • standalone (runs its own simple webserver to prove you control a domain)
    • webroot (adds files to webroot directories in order to prove control of
      domains and obtain certs)
    • nginx/0.8.48+ (highly experimental, not included in letsencrypt-auto)
  • The private key is generated locally on your system.

  • Can talk to the Let's Encrypt CA or optionally to other ACME
    compliant services.
  • Can get domain-validated (DV) certificates.
  • Can revoke certificates.
  • Adjustable RSA key bit-length (2048 (default), 4096, ...).
  • Can optionally install a http -> https redirect, so your site effectively
    runs https only (Apache only)
  • Fully automated.
  • Configuration changes are logged and can be reverted.
  • Supports ncurses and text (-t) UI, or can be driven entirely from the
    command line.
  • Free and Open Source Software, made with Python.

.. _Freenode:
.. _client-dev:!forum/client-dev

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