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.

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	⚠️ Experimental
caddy.fs	`fs.FS`	Virtual file system	⚠️ Experimental
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	⚠️ Experimental
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.CELLibraryProducer`	HTTP request matchers Support for CEL expressions	(Optional)
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	⚠️ Experimental
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	⚠️ Experimental
tls.get_certificate	`certmagic.Manager`	TLS certificate manager	⚠️ Experimental
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	⚠️ Experimental
tls.stek	`caddytls.STEKProvider`	TLS session ticket key source

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