Running as a zio-http server
The tapir-zio
module defines type aliases and extension methods which make it more ergonomic to work with
ZIO and tapir. Moreover, tapir-zio-http-server
contains an interpreter useful when
exposing the endpoints using the ZIO Http server.
The *-zio
modules depend on ZIO 2.x. For ZIO 1.x support, use modules with the *-zio1
suffix.
You’ll need the following dependency for the ZServerEndpoint
type alias and helper classes:
"com.softwaremill.sttp.tapir" %% "tapir-zio" % "1.6.3"
or just add the zio-http integration which already depends on tapir-zio
:
"com.softwaremill.sttp.tapir" %% "tapir-zio-http-server" % "1.6.3"
Next, instead of the usual import sttp.tapir._
, you should import (or extend the ZTapir
trait, see MyTapir):
import sttp.tapir.ztapir._
This brings into scope all the basic input/output descriptions, which can be used to define an endpoint.
Note
You should have only one of these imports in your source file. Otherwise, you’ll get naming conflicts. The
import sttp.tapir.ztapir._
import is meant as a complete replacement of import sttp.tapir._
.
Exposing endpoints
import sttp.tapir.server.ziohttp.ZioHttpInterpreter
The ZioHttpInterpreter
objects contains the toHttp
method, which requires a ZServerEndpoint
(see below). For
example:
import sttp.tapir.PublicEndpoint
import sttp.tapir.ztapir._
import sttp.tapir.server.ziohttp.ZioHttpInterpreter
import zio.http.{HttpApp, Request, Response}
import zio._
def countCharacters(s: String): ZIO[Any, Nothing, Int] =
ZIO.succeed(s.length)
val countCharactersEndpoint: PublicEndpoint[String, Unit, Int, Any] =
endpoint.in(stringBody).out(plainBody[Int])
val countCharactersHttp: HttpApp[Any, Throwable] =
ZioHttpInterpreter().toHttp(countCharactersEndpoint.zServerLogic(countCharacters))
Note
A single ZIO-Http application can contain both tapir-managed and ZIO-Http-managed routes. However, because of the routing implementation in ZIO Http, the shape of the paths that tapir and other ZIO Http handlers serve should not overlap. The shape of the path includes exact path segments, single- and multi-wildcards. Otherwise, request handling will throw an exception. We don’t expect users to encounter this as a problem, however the implementation here diverges a bit comparing to other interpreters.
Server logic
When defining the business logic for an endpoint, the following methods are available, which replace the standard ones:
def zServerLogic[R](logic: I => ZIO[R, E, O]): ZServerEndpoint[R, C]
for public endpointsdef zServerSecurityLogic[R, U](f: A => ZIO[R, E, U]): ZPartialServerEndpoint[R, A, U, I, E, O, C]
for secure endpoints
The first defines complete server logic, while the second and third allow defining server logic in parts.
Note
When using Scala 3, it’s best to provide the type of the environment explicitly to avoid type inferencing issues.
E.g.: myEndpoint.zServerLogic[Any](...)
.
Streaming
The zio-http interpreter accepts streaming bodies of type Stream[Throwable, Byte]
, as described by the ZioStreams
capability. Both response bodies and request bodies can be streamed. Usage: streamBody(ZioStreams)(schema, format)
.
The capability can be added to the classpath independently of the interpreter through the
"com.softwaremill.sttp.shared" %% "zio"
dependency.
Configuration
The interpreter can be configured by providing an ZioHttpServerOptions
value, see
server options for details.