🔐 acme.sh

An ACME Protocol Client Written Purely in Shell

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✨ Features

• 🐚 An ACME protocol client written purely in Shell (Unix shell) language
• 📜 Full ACME protocol implementation
• 🔑 Support ECDSA certificates
• 🌐 Support SAN and wildcard certificates
• ⚡ Simple, powerful and very easy to use — only 3 minutes to learn!
• 🔧 Compatible with Bash, dash and sh
• 🚫 No dependencies on Python
• 🔄 One script to issue, renew and install your certificates automatically
• 👤 DOES NOT require root/sudoer access
• 🐳 Docker ready
• 🌍 IPv6 ready
• 📧 Cron job notifications for renewal or error

💡 It's probably the easiest & smartest shell script to automatically issue & renew free certificates.

📚 Wiki • 🐳 Docker Guide • 🐦 Twitter

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🌏 中文说明

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🏆 Who Uses acme.sh?

• FreeBSD.org
• ruby-china.org
• Proxmox
• pfsense
• Loadbalancer.org
• discourse.org
• Centminmod
• splynx
• opnsense.org
• CentOS Web Panel
• lnmp.org
• more...

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🖥️ Tested OS

NO	Status	Platform
1		Mac OSX
2		Windows (cygwin with curl, openssl and crontab included)
3		FreeBSD
4		Solaris
5		Ubuntu
6	NA	pfsense
7		OpenBSD
8		NetBSD
9		DragonFlyBSD
10		MidnightBSD
11		Omnios
12		OpenIndiana
13		Debian
14		openSUSE
15		Alpine Linux (with curl)
16		Archlinux
17		fedora
18		Kali Linux
19		Oracle Linux
20		Mageia
21		Gentoo Linux
22	-----	Cloud Linux https://github.com/acmesh-official/acme.sh/issues/111
23	-----	OpenWRT: Tested and working. See wiki page
24		Proxmox: See Proxmox VE Wiki. Version 4.x, 5.0, 5.1, version 5.2 and up
25		Haiku OS
26		Tribblix
27		GhostBSD
28		GNU Hurd
29		openEuler
30		HardenedBSD
31		OPNsense

🧪 Check our testing project

🖥️ The testing VMs are supported by vmactions.org

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🏛️ Supported CA

CA	Status
ZeroSSL.com CA	⭐ Default
Letsencrypt.org CA	✅ Supported
SSL.com CA	✅ Supported
Google.com Public CA	✅ Supported
Actalis.com CA	✅ Supported
Pebble strict Mode	✅ Supported
Any RFC8555-compliant CA	✅ Supported

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⚙️ Supported Modes

Mode	Description
📁 Webroot mode	Use existing webroot directory
🖥️ Standalone mode	Built-in webserver on port 80
🔐 Standalone tls-alpn mode	Built-in webserver on port 443
🪶 Apache mode	Use Apache for verification
⚡ Nginx mode	Use Nginx for verification
🌐 DNS mode	Use DNS TXT records
🔗 DNS alias mode	Use DNS alias for verification
📡 Stateless mode	Stateless verification
📌 DNS persist mode	Persistent DNS TXT record (draft-ietf-acme-dns-persist-01)

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📖 Usage Guide

1️⃣ How to Install

📥 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

📦 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

💡 You don't have to be root then, although it is recommended.

📚 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

⚠️ After the installation, you must close the current terminal and reopen it to make the alias take effect.

✅ You are ready to issue certs now!

Show help message:

acme.sh -h

🔏 Verify a Release

Release tags from 3.1.5 on are signed with the maintainer's SSH key. The signing happens on the maintainer's machine, so the private key is never available to CI. The public half is allowed_signers in this repository. From a clone:

git config gpg.ssh.allowedSignersFile allowed_signers

git verify-tag 3.1.5

The signature covers the tag object, which pins the commit and therefore the whole tree, so a good signature verifies every file at that release and no separate tarball checksum is needed. Build a tarball from the verified tag:

git archive --format=tar.gz --prefix=acme.sh-3.1.5/ 3.1.5 > acme.sh-3.1.5.tar.gz

⚠️ Tags up to 3.1.4 predate the signing key and are unsigned.

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2️⃣ 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/

🔄 The certs will be renewed automatically every 30 days.

🔐 The certs will default to ECC certificates.

📚 More examples: https://github.com/acmesh-official/acme.sh/wiki/How-to-issue-a-cert

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3️⃣ 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.

⚠️ IMPORTANT: You MUST use this command to copy the certs to the target files. DO NOT use the certs files in ~/.acme.sh/ folder — they are for internal use only, the folder structure may change in the future.

🪶 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"

⚡ 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.

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

⚠️ 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.

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4️⃣ Use Standalone Server to Issue Certificate

🔐 Requires root/sudoer or permission to listen on port 80 (TCP)

⚠️ 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

📚 More examples: https://github.com/acmesh-official/acme.sh/wiki/How-to-issue-a-cert

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5️⃣ Use Standalone TLS Server to Issue Certificate

🔐 Requires root/sudoer or permission to listen on port 443 (TCP)

⚠️ 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

📚 More examples: https://github.com/acmesh-official/acme.sh/wiki/How-to-issue-a-cert

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6️⃣ Use Apache Mode

🔐 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

💡 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!

📚 More examples: https://github.com/acmesh-official/acme.sh/wiki/How-to-issue-a-cert

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7️⃣ Use Nginx Mode

🔐 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

💡 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!

📚 More examples: https://github.com/acmesh-official/acme.sh/wiki/How-to-issue-a-cert

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8️⃣ Automatic DNS API Integration

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

✨ You don't have to do anything manually!

📚 Currently acme.sh supports most DNS providers: https://github.com/acmesh-official/acme.sh/wiki/dnsapi

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9️⃣ 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

✅ Done!

⚠️ WARNING: This is DNS manual mode — 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.

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🔟 Use DNS Persist Mode

📖 Wiki: https://github.com/acmesh-official/acme.sh/wiki/DNS-persist-mode

📚 Spec: draft-ietf-acme-dns-persist-01

DNS persist mode lets you place a single, long‑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 — useful when DNS API access is not available but you still want unattended renewals.

🪄 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:

Flag	Description
--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-wildcard	Adds 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 — 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"

✍️ 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.

📜 Step 3: Issue the certificate

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

✅ Done! No challenge token is provisioned during issuance — the CA reads the persistent TXT record directly.

🔄 Renewals just work: acme.sh --renew -d example.com (or the cron job) reuses the same TXT record automatically — no further DNS edits needed.

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1️⃣1️⃣ 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 Length	Description
ec-256	prime256v1, "ECDSA P-256" ⭐ Default
ec-384	secp384r1, "ECDSA P-384"
ec-521	secp521r1, "ECDSA P-521" ⚠️ Not supported by Let's Encrypt yet
2048	RSA 2048-bit
3072	RSA 3072-bit
4096	RSA 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

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1️⃣2️⃣ 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

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1️⃣3️⃣ How to Renew Certificates

🔄 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

📡 ACME Renewal Information (ARI) — RFC 9773

📖 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 — no flag needed, no opt-in:

What	When	Why
🔍 Polls suggestedWindow	Every cron run, before deciding to skip	Lets the CA shift the renewal time forward in case of an incident (key compromise, mass revocation, etc.)
🎯 Picks a random renewal time inside the window	Right after a successful issuance/renewal	Disperses renewals across the network so all clients don't hit the CA at the same instant
🔗 Sends replaces=<certID> in newOrder	On renewal	Lets the CA correlate the new order with the certificate it supersedes (RFC 9773 §5)
↩️ Retries without replaces	If the CA rejects with alreadyReplaced or an ARI validation error	Robust 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'

💡 If your CA does not advertise renewalInfo, acme.sh falls back to the classic 30-day rule — no behavior change.

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1️⃣4️⃣ 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.

💡 You can remove the respective directory (e.g. ~/.acme.sh/example.com) manually.

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1️⃣5️⃣ How to Upgrade acme.sh

🚀 acme.sh is in constant development — 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

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1️⃣6️⃣ Issue a Certificate from an Existing CSR

📚 https://github.com/acmesh-official/acme.sh/wiki/Issue-a-cert-from-existing-CSR

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1️⃣7️⃣ Send Notifications in Cronjob

📚 https://github.com/acmesh-official/acme.sh/wiki/notify

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1️⃣8️⃣ Under the Hood

🔧 Speak ACME language using shell, directly to "Let's Encrypt".

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1️⃣9️⃣ Acknowledgments

Project	Link
🙏 Acme-tiny	https://github.com/diafygi/acme-tiny
📜 ACME protocol	https://github.com/ietf-wg-acme/acme

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👥 Contributors

💻 Code Contributors

This project exists thanks to all the people who contribute.

If you want to become a contributor make sure to read CONTRIBUTING.md.

💰 Financial Contributors

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

👤 Individuals

🏢 Organizations

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

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2️⃣0️⃣ License & Others

📄 License: GPLv3

⭐ Please Star and Fork this project!

🐛 Issues and 🔀 Pull Requests are welcome.

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2️⃣1️⃣ Donate

💝 Your donation makes acme.sh better!

Method	Link
PayPal / Alipay(支付宝) / Wechat(微信)	https://donate.acme.sh/

📜 Donate List

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2️⃣2️⃣ 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.