ACME-CLIENT.CONF(5) | File Formats Manual | ACME-CLIENT.CONF(5)

# NAME

`acme-client.conf` — acme-client configuration file

# DESCRIPTION

The `acme-client.conf` file is divided into the following main sections:

Macros
  Definitions of variables that can be used later, simplifying the configuration file.
Authorities
  Certificate authorities (CAs) that can be contacted via ACME.
Domains
  Certificate specifications.

Additional configuration files can be included with the `include` keyword, for example:

    include "/etc/acme-client.sub.conf"

The current line can be extended over multiple lines using a backslash (‘\’). Comments can be put anywhere in the file using a hash mark (‘#’), and extend to the end of the current line. Care should be taken when commenting out multi-line text: the comment is effective until the end of the entire block.

Argument names not beginning with a letter, digit, underscore, or '/' must be quoted.

## Macros

A macro is defined with a command of the form name=value. The macro name can contain letters, digits, and underscores and cannot be a reserved word. Within unquoted arguments, the string $name is later expanded to value.

For example:

    api_url="https://acme-v02.api.letsencrypt.org/directory"
    authority letsencrypt {
    	api url $api_url
    	account key "/etc/acme/letsencrypt-privkey.pem"
    }

## Authorities

The configured certificate authorities.

Each authority section starts with a declaration of the name identifying a certificate authority.

`authority` name {...}
  The name is a string used to reference this certificate authority.

It is followed by a block of options enclosed in curly brackets:

`account key` file [keytype]
  Specify a file used to identify the user of this certificate authority. keytype can be `rsa` or `ecdsa`. It defaults to `rsa`.
`api url` url
  Specify the url under which the ACME API is reachable.
`contact` contact
  Optional contact URLs that the authority can use to contact the client for issues related to this account.

## Domains

The certificates to be obtained through ACME.

`domain` handle {...}
  Each domain section begins with the `domain` keyword followed by an identifier for this domain block.

It is followed by a block of options enclosed in curly brackets:

`domain name` name
  The name to be used as the common name component of the subject of the X.509 certificate. This is optional. If not specified, the handle of the domain block will be used as common name.
`alternative names` {...}
  A list of alternative names, comma or space separated, for which the certificate will be valid. The common name is included automatically if this option is present, but there is no automatic conversion/inclusion between "www." and plain domain name forms.
`domain key` file [keytype]
  The private key file for which the certificate will be obtained. keytype can be `rsa` or `ecdsa`. It defaults to `rsa`. If the key file does not exist, acme-client(1) will generate a key itself (4096-bit for `rsa` or secp384r1 for `ecdsa`).
`domain certificate` file
  The filename of the certificate that will be issued. This is optional if domain full chain certificate is specified. A backup with name file.1 is created if file exists.
`domain chain certificate` file
  The filename in which to store the certificate chain that will be returned by the certificate authority. It needs to be in the same directory as the domain certificate (or in a subdirectory) and can be specified as a relative or absolute path. This setting is optional. A backup with name file.1 is created if file exists.
`domain full chain certificate` file
  The filename in which to store the full certificate chain that will be returned by the certificate authority. It needs to be in the same directory as the domain certificate (or in a subdirectory) and can be specified as a relative or absolute path. This is a combination of the domain certificate and the domain chain certificate in one file, and is required by most browsers. This is optional if domain certificate is specified. A backup with name file.1 is created if file exists.
`profile` profile
  The certificate profile to be requested. If this setting is absent, no profile request is made.
`sign with` authority
  The certificate authority (as declared above in the Authorities section) to use. If this setting is absent, the first authority specified is used.
`challengedir` path
  The directory in which the challenge file will be stored. If it is not specified, a default of /var/www/acme will be used.

# FILES

/etc/acme-client.conf
  acme-client(1) configuration file.
/etc/examples/acme-client.conf
  Example configuration file.

# SEE ALSO

acme-client(1)

# HISTORY

The `acme-client.conf` file format first appeared in OpenBSD 6.1.

September 16, 2025 | Debian