Module Namespaces

Caddy guest modules are loaded generically as interface{} or any types. In order for the host modules to be able to use them, the loaded guest modules are usually type-asserted to a known type first. This page describes the mapping from module namespaces to Go types for all the standard modules.

Documentation for non-standard module namespaces can be found with the documentation for the host module that defines them.

<aside class="tip"> One way to read this table is, "If your module is in &lt;namespace&gt;, then it should compile as &lt;type&gt;." </aside> <style> .table-wrapper { padding-left: 0 !important; padding-right: 0 !important; } </style>

Namespace	Expected Interface Type	Description	Notes
	caddy.App	Caddy app
admin.api	caddy.AdminRouter

caddy.AdminHandler | Registers HTTP routes for admin

HTTP handler middleware | caddy.config_loaders | caddy.ConfigLoader | Loads a config | <i>⚠️ Experimental</i> caddy.fs | fs.FS | Virtual file system | <i>⚠️ Experimental</i> caddy.listeners | caddy.ListenerWrapper | Wrap network listeners caddy.logging.encoders | zapcore.Encoder | Log entry encoder caddy.logging.encoders.filter | logging.LogFieldFilter | Log field filter caddy.logging.writers | caddy.WriterOpener | Log writers caddy.storage | caddy.StorageConverter | Storage backends dns.providers | certmagic.DNSProvider | DNS challenge solver events.handlers | caddyevents.Handler | Event handlers | <i>⚠️ Experimental</i> http.authentication.hashes | caddyauth.Comparer

caddyauth.Hasher | Password comparers

Password hashers http.authentication.providers | caddyauth.Authenticator | HTTP authentication providers http.encoders | encode.Encoding

encode.Encoder | Creates an encoder (compression)

Encodes a data stream http.handlers | caddyhttp.MiddlewareHandler | HTTP handlers http.ip_sources | caddyhttp.IPRangeSource | IP ranges for trusted proxies http.matchers | caddyhttp.RequestMatcher

caddyhttp.RequestMatcherWithError

caddyhttp.CELLibraryProducer | Request matcher (use WithError instead)

Request matcher with error short-circuit

Support for CEL expressions | <i>⚠️ Deprecated</i>

<i>(Optional)</i> http.precompressed | encode.Precompressed | Supported precompress mappings http.reverse_proxy.circuit_breakers | reverseproxy.CircuitBreaker | Reverse proxy circuit breakers http.reverse_proxy.selection_policies | reverseproxy.Selector | Load balancing selection policies http.reverse_proxy.transport | http.RoundTripper | HTTP reverse proxy transports http.reverse_proxy.upstreams | reverseproxy.UpstreamSource | Dynamic upstream source | <i>⚠️ Experimental</i> tls.ca_pool.source | caddytls.CA | Source of trusted root certs tls.certificates | caddytls.CertificateLoader | TLS certificate source tls.client_auth | caddytls.ClientCertificateVerifier | Verifies client certificates tls.ech.publishers | caddytls.ECHPublisher | Publishes Encrypted ClientHello (ECH) configurations | <i>⚠️ Experimental</i> tls.get_certificate | certmagic.Manager | TLS certificate manager | <i>⚠️ Experimental</i> tls.handshake_match | caddytls.ConnectionMatcher | TLS connection matcher tls.issuance | certmagic.Issuer | TLS certificate issuer tls.leaf_cert_loader | caddytls.LeafCertificateLoader | Loads trusted leaf certs tls.permission | caddytls.OnDemandPermission | Whether to obtain a cert for a domain | <i>⚠️ Experimental</i> tls.stek | caddytls.STEKProvider | TLS session ticket key source tls.context | caddytls.HandshakeContext | Intercept GetCertificate context | <i>⚠️ Experimental</i>

Namespaces marked as "Experimental" are subject to change. (Please develop with them so we can finalize their interfaces!)