caddy-website/src/docs/markdown/caddyfile/directives/acme_server.md

---
title: acme_server (Caddyfile directive)
---

# acme_server

An embedded [ACME protocol](https://tools.ietf.org/html/rfc8555) server handler. This allows a Caddy instance to issue certificates for any other ACME-compatible software (including other Caddy instances).

When enabled, requests matching the path `/acme/*` will be handled by the ACME server.


## Client configuration

Using ACME server defaults, ACME clients should simply be configured to use `https://localhost/acme/local/directory` as their ACME endpoint. (`local` is the ID of Caddy's default CA.)


## Syntax

```caddy-d
acme_server [<matcher>] {
	ca       <id>
	lifetime <duration>
}
```

- **ca** specifies the ID of the certificate authority with which to sign certificates. The default is `local`, which is Caddy's default CA, intended for locally-used, self-signed certificates, which is most common in dev environments. For broader use, it is recommended to specify a different CA to avoid confusion. If the CA with the given ID does not already exist, it will be created. See the [PKI app global options](/docs/caddyfile/options#pki-options) to configure alternate CAs.
- **lifetime** (Default: `12h`) is a [duration](/docs/conventions#durations) which specifies the validity period for issued certificates. This value must be less than the lifetime of the [intermediate certificate](/docs/caddyfile/options#intermediate-lifetime) used for signing. It is not recommended to change this unless absolutely necessary.