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a project
Every site on HTTPS
Caddy is an extensible server platform that uses TLS by default.
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Features
Install
Build from source
For development
With version information and/or plugins
Quick start
Overview
Full documentation
Getting help
About
Features
Easy configuration with the Caddyfile
Powerful configuration with its native JSON config
Dynamic configuration with the JSON API
Config adapters if you don't like JSON
Automatic HTTPS by default
ZeroSSL and Let's Encrypt for public names
Fully-managed local CA for internal names & IPs
Can coordinate with other Caddy instances in a cluster
Multi-issuer fallback
Encrypted ClientHello (ECH) support
Stays up when other servers go down due to TLS/OCSP/certificate-related issues
Production-ready after serving trillions of requests and managing millions of TLS certificates
Scales to hundreds of thousands of sites as proven in production
HTTP/1.1, HTTP/2, and HTTP/3 all supported by default
Highly extensible modular architecture lets Caddy do anything without bloat
Runs anywhere with no external dependencies (not even libc)
Written in Go, a language with higher memory safety guarantees than other servers
Actually fun to use
So much more to discover
Install
The simplest, cross-platform way to get started is to download Caddy from GitHub Releases and place the executable file in your PATH.
See our online documentation for other install instructions.
Build from source
Requirements:
Go 1.26.0 or newer
For development
Note: These steps will not embed proper version information. For that, please follow the instructions in the next section.
$ git clone "https://github.com/caddyserver/caddy.git"
$ cd caddy/cmd/caddy/
$ go build
When you run Caddy, it may try to bind to low ports unless otherwise specified in your config. If your OS requires elevated privileges for this, you will need to give your new binary permission to do so. On Linux, this can be done easily with: sudo setcap cap_net_bind_service=+ep ./caddy
If you prefer to use go run which only creates temporary binaries, you can still do this with the included setcap.sh like so:
$ go run -exec ./setcap.sh main.go
If you don't want to type your password for setcap, use sudo visudo to edit your sudoers file and allow your user account to run that command without a password, for example:
username ALL=(ALL:ALL) NOPASSWD: /usr/sbin/setcap
replacing username with your actual username. Please be careful and only do this if you know what you are doing! We are only qualified to document how to use Caddy, not Go tooling or your computer, and we are providing these instructions for convenience only; please learn how to use your own computer at your own risk and make any needful adjustments.
Then you can run the tests in all modules or a specific one:
$ go test ./...
$ go test ./modules/caddyhttp/tracing/
With version information and/or plugins
Using our builder tool, xcaddy...
$ xcaddy build
...the following steps are automated:
Create a new folder: mkdir caddy
Change into it: cd caddy
Copy Caddy's main.go into the empty folder. Add imports for any custom plugins you want to add.
Initialize a Go module: go mod init caddy
(Optional) Pin Caddy version: go get github.com/caddyserver/caddy/v2@version replacing version with a git tag, commit, or branch name.
(Optional) Add plugins by adding their import: _ "import/path/here"
Compile: go build -tags=nobadger,nomysql,nopgx
Quick start
The Caddy website has documentation that includes tutorials, quick-start guides, reference, and more.
We recommend that all users -- regardless of experience level -- do our Getting Started guide to become familiar with using Caddy.
If you've only got a minute, the website has several quick-start tutorials to choose from! However, after finishing a quick-start tutorial, please read more documentation to understand how the software works. 🙂
Overview
Caddy is most often used as an HTTPS server, but it is suitable for any long-running Go program. First and foremost, it is a platform to run Go applications. Caddy "apps" are just Go programs that are implemented as Caddy modules. Two apps -- tls and http -- ship standard with Caddy.
Caddy apps instantly benefit from automated documentation, graceful on-line config changes via API, and unification with other Caddy apps.
Although JSON is Caddy's native config language, Caddy can accept input from config adapters which can essentially convert any config format of your choice into JSON: Caddyfile, JSON 5, YAML, TOML, NGINX config, and more.
The primary way to configure Caddy is through its API, but if you prefer config files, the command-line interface supports those too.
Caddy exposes an unprecedented level of control compared to any web server in existence. In Caddy, you are usually setting the actual values of the initialized types in memory that power everything from your HTTP handlers and TLS handshakes to your storage medium. Caddy is also ridiculously extensible, with a powerful plugin system that makes vast improvements over other web servers.
To wield the power of this design, you need to know how the config document is structured. Please see our documentation site for details about Caddy's config structure.
Nearly all of Caddy's configuration is contained in a single config document, rather than being scattered across CLI flags and env variables and a configuration file as with other web servers. This makes managing your server config more straightforward and reduces hidden variables/factors.
Full documentation
Our website has complete documentation:
https://caddyserver.com/docs/
The docs are also open source. You can contribute to them here: https://github.com/caddyserver/website
Getting help
We advise companies using Caddy to
Read the full README on GitHub