README.md

May 6, 2026 ยท View on GitHub

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๐Ÿ” acme.sh

An ACME Protocol Client Written Purely in Shell

FreeBSD OpenBSD NetBSD MacOS Ubuntu Windows Solaris DragonFlyBSD MidnightBSD Omnios OpenIndiana Haiku

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โœจ Features

  • ๐Ÿš An ACME protocol client written purely in Shell (Unix shell) language
  • ๐Ÿ“œ Full ACME protocol implementation
  • ๐Ÿ”‘ Support ECDSA certificates
  • ๐ŸŒ Support SAN and wildcard certificates
  • โšก Simple, powerful and very easy to use โ€” only 3 minutes to learn!
  • ๐Ÿ”ง Compatible with Bash, dash and sh
  • ๐Ÿšซ No dependencies on Python
  • ๐Ÿ”„ One script to issue, renew and install your certificates automatically
  • ๐Ÿ‘ค DOES NOT require root/sudoer access
  • ๐Ÿณ Docker ready
  • ๐ŸŒ IPv6 ready
  • ๐Ÿ“ง Cron job notifications for renewal or error

๐Ÿ’ก It's probably the easiest & smartest shell script to automatically issue & renew free certificates.

๐Ÿ“š Wiki โ€ข ๐Ÿณ Docker Guide โ€ข ๐Ÿฆ Twitter


๐ŸŒ ไธญๆ–‡่ฏดๆ˜Ž


๐Ÿ† Who Uses acme.sh?


๐Ÿ–ฅ๏ธ Tested OS

NOStatusPlatform
1MacOSMac OSX
2WindowsWindows (cygwin with curl, openssl and crontab included)
3FreeBSDFreeBSD
4SolarisSolaris
5UbuntuUbuntu
6NApfsense
7OpenBSDOpenBSD
8NetBSDNetBSD
9DragonFlyBSDDragonFlyBSD
10MidnightBSDMidnightBSD
11OmniosOmnios
12OpenIndianaOpenIndiana
13LinuxDebian
14LinuxopenSUSE
15LinuxAlpine Linux (with curl)
16LinuxArchlinux
17Linuxfedora
18LinuxKali Linux
19LinuxOracle Linux
20LinuxMageia
21LinuxGentoo Linux
22-----Cloud Linux https://github.com/acmesh-official/acme.sh/issues/111
23-----OpenWRT: Tested and working. See wiki page
24Proxmox: See Proxmox VE Wiki. Version 4.x, 5.0, 5.1, version 5.2 and up
25HaikuHaiku OS

๐Ÿงช Check our testing project

๐Ÿ–ฅ๏ธ The testing VMs are supported by vmactions.org


๐Ÿ›๏ธ Supported CA

CAStatus
ZeroSSL.com CAโญ Default
Letsencrypt.org CAโœ… Supported
SSL.com CAโœ… Supported
Google.com Public CAโœ… Supported
Actalis.com CAโœ… Supported
Pebble strict Modeโœ… Supported
Any RFC8555-compliant CAโœ… Supported

โš™๏ธ Supported Modes

ModeDescription
๐Ÿ“ Webroot modeUse existing webroot directory
๐Ÿ–ฅ๏ธ Standalone modeBuilt-in webserver on port 80
๐Ÿ” Standalone tls-alpn modeBuilt-in webserver on port 443
๐Ÿชถ Apache modeUse Apache for verification
โšก Nginx modeUse Nginx for verification
๐ŸŒ DNS modeUse DNS TXT records
๐Ÿ”— DNS alias modeUse DNS alias for verification
๐Ÿ“ก Stateless modeStateless verification
๐Ÿ“Œ DNS persist modePersistent DNS TXT record (draft-ietf-acme-dns-persist-01)

๐Ÿ“– Usage Guide

1๏ธโƒฃ How to Install

๐Ÿ“ฅ Install Online

Check this project: https://github.com/acmesh-official/get.acme.sh

curl https://get.acme.sh | sh -s email=my@example.com

Or:

wget -O -  https://get.acme.sh | sh -s email=my@example.com

๐Ÿ“ฆ Install from Git

Clone this project and launch installation:

git clone https://github.com/acmesh-official/acme.sh.git
cd ./acme.sh
./acme.sh --install -m my@example.com

๐Ÿ’ก You don't have to be root then, although it is recommended.

๐Ÿ“š Advanced Installation: https://github.com/acmesh-official/acme.sh/wiki/How-to-install

The installer will perform 3 actions:

  1. Create and copy acme.sh to your home dir ($HOME): ~/.acme.sh/. All certs will be placed in this folder too.
  2. Create alias for: acme.sh=~/.acme.sh/acme.sh.
  3. Create daily cron job to check and renew the certs if needed.

Cron entry example:

0 0 * * * "/home/user/.acme.sh"/acme.sh --cron --home "/home/user/.acme.sh" > /dev/null

โš ๏ธ After the installation, you must close the current terminal and reopen it to make the alias take effect.

โœ… You are ready to issue certs now!

Show help message:

acme.sh -h

2๏ธโƒฃ Issue a Certificate

Example 1: Single domain.

acme.sh --issue -d example.com -w /home/wwwroot/example.com

or:

acme.sh --issue -d example.com -w /home/username/public_html

or:

acme.sh --issue -d example.com -w /var/www/html

Example 2: Multiple domains in the same cert.

acme.sh --issue -d example.com -d www.example.com -d cp.example.com -w /home/wwwroot/example.com

The parameter /home/wwwroot/example.com or /home/username/public_html or /var/www/html is the web root folder where you host your website files. You MUST have write access to this folder.

Second argument "example.com" is the main domain you want to issue the cert for. You must have at least one domain there.

You must point and bind all the domains to the same webroot dir: /home/wwwroot/example.com.

The certs will be placed in ~/.acme.sh/example.com/

๐Ÿ”„ The certs will be renewed automatically every 30 days.

๐Ÿ” The certs will default to ECC certificates.

๐Ÿ“š More examples: https://github.com/acmesh-official/acme.sh/wiki/How-to-issue-a-cert


3๏ธโƒฃ Install the Certificate to Apache/Nginx

After the cert is generated, you probably want to install/copy the cert to your Apache/Nginx or other servers.

โš ๏ธ IMPORTANT: You MUST use this command to copy the certs to the target files. DO NOT use the certs files in ~/.acme.sh/ folder โ€” they are for internal use only, the folder structure may change in the future.

๐Ÿชถ Apache Example:

acme.sh --install-cert -d example.com \
--cert-file      /path/to/certfile/in/apache/cert.pem  \
--key-file       /path/to/keyfile/in/apache/key.pem  \
--fullchain-file /path/to/fullchain/certfile/apache/fullchain.pem \
--reloadcmd     "service apache2 force-reload"

โšก Nginx Example:

acme.sh --install-cert -d example.com \
--key-file       /path/to/keyfile/in/nginx/key.pem  \
--fullchain-file /path/to/fullchain/nginx/cert.pem \
--reloadcmd     "service nginx force-reload"

Only the domain is required, all the other parameters are optional.

The ownership and permission info of existing files are preserved. You can pre-create the files to define the ownership and permission.

Install/copy the cert/key to the production Apache or Nginx path.

๐Ÿ”„ The cert will be renewed every 30 days by default (configurable). Once renewed, the Apache/Nginx service will be reloaded automatically.

โš ๏ธ IMPORTANT: The reloadcmd is very important. The cert can be automatically renewed, but without a correct reloadcmd, the cert may not be flushed to your server (like nginx or apache), then your website will not be able to show the renewed cert.


4๏ธโƒฃ Use Standalone Server to Issue Certificate

๐Ÿ” Requires root/sudoer or permission to listen on port 80 (TCP)

โš ๏ธ Port 80 (TCP) MUST be free to listen on, otherwise you will be prompted to free it and try again.

acme.sh --issue --standalone -d example.com -d www.example.com -d cp.example.com

๐Ÿ“š More examples: https://github.com/acmesh-official/acme.sh/wiki/How-to-issue-a-cert


5๏ธโƒฃ Use Standalone TLS Server to Issue Certificate

๐Ÿ” Requires root/sudoer or permission to listen on port 443 (TCP)

โš ๏ธ Port 443 (TCP) MUST be free to listen on, otherwise you will be prompted to free it and try again.

acme.sh --issue --alpn -d example.com -d www.example.com -d cp.example.com

๐Ÿ“š More examples: https://github.com/acmesh-official/acme.sh/wiki/How-to-issue-a-cert


6๏ธโƒฃ Use Apache Mode

๐Ÿ” Requires root/sudoer to interact with Apache server

If you are running a web server, it is recommended to use the Webroot mode.

Particularly, if you are running an Apache server, you can use Apache mode instead. This mode doesn't write any files to your web root folder.

acme.sh --issue --apache -d example.com -d www.example.com -d cp.example.com

๐Ÿ’ก Note: This Apache mode is only to issue the cert, it will not change your Apache config files. You will need to configure your website config files to use the cert by yourself. We don't want to mess with your Apache server, don't worry!

๐Ÿ“š More examples: https://github.com/acmesh-official/acme.sh/wiki/How-to-issue-a-cert


7๏ธโƒฃ Use Nginx Mode

๐Ÿ” Requires root/sudoer to interact with Nginx server

If you are running a web server, it is recommended to use the Webroot mode.

Particularly, if you are running an Nginx server, you can use Nginx mode instead. This mode doesn't write any files to your web root folder.

It will configure Nginx server automatically to verify the domain and then restore the Nginx config to the original version. So, the config is not changed.

acme.sh --issue --nginx -d example.com -d www.example.com -d cp.example.com

๐Ÿ’ก Note: This Nginx mode is only to issue the cert, it will not change your Nginx config files. You will need to configure your website config files to use the cert by yourself. We don't want to mess with your Nginx server, don't worry!

๐Ÿ“š More examples: https://github.com/acmesh-official/acme.sh/wiki/How-to-issue-a-cert


8๏ธโƒฃ Automatic DNS API Integration

If your DNS provider supports API access, we can use that API to automatically issue the certs.

โœจ You don't have to do anything manually!

๐Ÿ“š Currently acme.sh supports most DNS providers: https://github.com/acmesh-official/acme.sh/wiki/dnsapi


9๏ธโƒฃ Use DNS Manual Mode

See: https://github.com/acmesh-official/acme.sh/wiki/dns-manual-mode first.

If your dns provider doesn't support any api access, you can add the txt record by hand.

acme.sh --issue --dns -d example.com -d www.example.com -d cp.example.com

You should get an output like below:

Add the following txt record:
Domain:_acme-challenge.example.com
Txt value:9ihDbjYfTExAYeDs4DBUeuTo18KBzwvTEjUnSwd32-c

Add the following txt record:
Domain:_acme-challenge.www.example.com
Txt value:9ihDbjxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Please add those txt records to the domains. Waiting for the dns to take effect.

Then just rerun with renew argument:

acme.sh --renew -d example.com

โœ… Done!

โš ๏ธ WARNING: This is DNS manual mode โ€” it cannot be renewed automatically. You will have to add a new TXT record to your domain manually when you renew your cert. Please use DNS API mode instead.


๐Ÿ”Ÿ Use DNS Persist Mode

๐Ÿ“– Wiki: https://github.com/acmesh-official/acme.sh/wiki/DNS-persist-mode

๐Ÿ“š Spec: draft-ietf-acme-dns-persist-01

DNS persist mode lets you place a single, longโ€‘lived _validation-persist TXT record in your zone and reuse it for every subsequent issuance and renewal. There is no per-issuance challenge token, so renewals require no DNS edits โ€” useful when DNS API access is not available but you still want unattended renewals.

๐Ÿช„ Step 1: Print the TXT record value

acme.sh --make-dns-persist-value -d example.com [--server letsencrypt] [--dns-persist-wildcard] [--dns-persist-ca-name "sectigo.com"] [--dns-persist-days 365]

Options:

FlagDescription
--server <ca>Pick the CA (default is your configured default). The account is registered automatically if you have not used this CA before.
--dns-persist-wildcardAdds policy=wildcard to the record so it also authorizes wildcard / subdomain certs.
--dns-persist-ca-name <name>Use a specific CA identity domain (e.g. sectigo.com). If omitted, identities are read from the ACME directory's caaIdentities field and one record per identity is printed โ€” you only need to add any one of them.
--dns-persist-days <N>Adds persistUntil=<unix-timestamp> to the record, set to N days from now. The CA will refuse new validations against the record after that time. Omit for a record with no expiry.

You should get an output like:

TXT persist domain:_validation-persist.example.com
TXT persist value :"letsencrypt.org; accounturi=https://acme-v02.api.letsencrypt.org/acme/acct/123456789"

โœ๏ธ Step 2: Add the TXT record to your DNS

Add the printed TXT persist domain / TXT persist value pair as a TXT record at your DNS provider, then wait for it to propagate.

๐Ÿ“œ Step 3: Issue the certificate

acme.sh --issue -d example.com --dns-persist

โœ… Done! No challenge token is provisioned during issuance โ€” the CA reads the persistent TXT record directly.

๐Ÿ”„ Renewals just work: acme.sh --renew -d example.com (or the cron job) reuses the same TXT record automatically โ€” no further DNS edits needed.


1๏ธโƒฃ1๏ธโƒฃ Issue Certificates of Different Key Types (ECC or RSA)

Just set the keylength to a valid, supported value.

Valid values for the keylength parameter:

Key LengthDescription
ec-256prime256v1, "ECDSA P-256" โญ Default
ec-384secp384r1, "ECDSA P-384"
ec-521secp521r1, "ECDSA P-521" โš ๏ธ Not supported by Let's Encrypt yet
2048RSA 2048-bit
3072RSA 3072-bit
4096RSA 4096-bit

Examples:

Single domain with ECDSA P-384 certificate

acme.sh --issue -w /home/wwwroot/example.com -d example.com --keylength ec-384

SAN multi domain with RSA4096 certificate

acme.sh --issue -w /home/wwwroot/example.com -d example.com -d www.example.com --keylength 4096

1๏ธโƒฃ2๏ธโƒฃ Issue Wildcard Certificates

It's simple! Just give a wildcard domain as the -d parameter:

acme.sh --issue -d example.com -d '*.example.com' --dns dns_cf

1๏ธโƒฃ3๏ธโƒฃ How to Renew Certificates

๐Ÿ”„ No need to renew manually! All certs will be renewed automatically every 30 days, or earlier when the CA's ARI says so (see below).

However, you can force a renewal:

acme.sh --renew -d example.com --force

For ECC cert:

acme.sh --renew -d example.com --force --ecc

๐Ÿ“ก ACME Renewal Information (ARI) โ€” RFC 9773

๐Ÿ“– Wiki: https://github.com/acmesh-official/acme.sh/wiki/ARI

If the CA exposes a renewalInfo endpoint in its ACME directory (Let's Encrypt, ZeroSSL, etc.), acme.sh follows RFC 9773 automatically โ€” no flag needed, no opt-in:

WhatWhenWhy
๐Ÿ” Polls suggestedWindowEvery cron run, before deciding to skipLets the CA shift the renewal time forward in case of an incident (key compromise, mass revocation, etc.)
๐ŸŽฏ Picks a random renewal time inside the windowRight after a successful issuance/renewalDisperses renewals across the network so all clients don't hit the CA at the same instant
๐Ÿ”— Sends replaces=<certID> in newOrderOn renewalLets the CA correlate the new order with the certificate it supersedes (RFC 9773 ยง5)
โ†ฉ๏ธ Retries without replacesIf the CA rejects with alreadyReplaced or an ARI validation errorRobust against edge cases (e.g. switching CAs, retired issuers)

Renewal trigger logic: the cert is renewed if any one of the following becomes true:

  1. --force is given
  2. The CA's ARI suggestedWindow has started
  3. The cached Le_NextRenewTime has passed (default fallback for CAs without ARI)

You can see the resulting next renewal time (already ARI-picked when applicable) in:

acme.sh --info -d example.com
# Look for: Le_NextRenewTimeStr=...

For the live ARI window the CA is currently advertising, run with --debug 2:

acme.sh --renew -d example.com --debug 2 2>&1 | grep -i 'ARI suggestedWindow'

๐Ÿ’ก If your CA does not advertise renewalInfo, acme.sh falls back to the classic 30-day rule โ€” no behavior change.


1๏ธโƒฃ4๏ธโƒฃ How to Stop Certificate Renewal

To stop renewal of a cert, you can execute the following to remove the cert from the renewal list:

acme.sh --remove -d example.com [--ecc]

The cert/key file is not removed from the disk.

๐Ÿ’ก You can remove the respective directory (e.g. ~/.acme.sh/example.com) manually.


1๏ธโƒฃ5๏ธโƒฃ How to Upgrade acme.sh

๐Ÿš€ acme.sh is in constant development โ€” it's strongly recommended to use the latest code.

Update to latest:

acme.sh --upgrade

Enable auto upgrade:

acme.sh --upgrade --auto-upgrade

Disable auto upgrade:

acme.sh --upgrade --auto-upgrade 0

1๏ธโƒฃ6๏ธโƒฃ Issue a Certificate from an Existing CSR

๐Ÿ“š https://github.com/acmesh-official/acme.sh/wiki/Issue-a-cert-from-existing-CSR


1๏ธโƒฃ7๏ธโƒฃ Send Notifications in Cronjob

๐Ÿ“š https://github.com/acmesh-official/acme.sh/wiki/notify


1๏ธโƒฃ8๏ธโƒฃ Under the Hood

๐Ÿ”ง Speak ACME language using shell, directly to "Let's Encrypt".


1๏ธโƒฃ9๏ธโƒฃ Acknowledgments

ProjectLink
๐Ÿ™ Acme-tinyhttps://github.com/diafygi/acme-tiny
๐Ÿ“œ ACME protocolhttps://github.com/ietf-wg-acme/acme

๐Ÿ‘ฅ Contributors

๐Ÿ’ป Code Contributors

This project exists thanks to all the people who contribute.

๐Ÿ’ฐ Financial Contributors

Become a financial contributor and help us sustain our community. [Contribute]

๐Ÿ‘ค Individuals

๐Ÿข Organizations

Support this project with your organization. Your logo will show up here with a link to your website. [Contribute]


2๏ธโƒฃ0๏ธโƒฃ License & Others

๐Ÿ“„ License: GPLv3

โญ Please Star and Fork this project!

๐Ÿ› Issues and ๐Ÿ”€ Pull Requests are welcome.


2๏ธโƒฃ1๏ธโƒฃ Donate

๐Ÿ’ Your donation makes acme.sh better!

MethodLink
PayPal / Alipay(ๆ”ฏไป˜ๅฎ) / Wechat(ๅพฎไฟก)https://donate.acme.sh/

๐Ÿ“œ Donate List


2๏ธโƒฃ2๏ธโƒฃ About This Repository

Note

This repository is officially maintained by ZeroSSL as part of our commitment to providing secure and reliable SSL/TLS solutions. We welcome contributions and feedback from the community!
For more information about our services, including free and paid SSL/TLS certificates, visit https://zerossl.com.

All donations made through this repository go directly to the original independent maintainer (Neil Pang), not to ZeroSSL.

ZeroSSL