cats-effect prelude

build.sbt

// ...

lazy val prelude = (project in file("prelude"))
  .settings(commonSettings)
  .settings(
    name := "my-application-prelude",
    libraryDependencies ++= Seq(
      "co.fs2" %% "fs2-core" % V.Fs2,
      "org.typelevel" %% "cats-effect" % V.CatsEffect,
      "org.typelevel" %% "log4cats-core" % V.Log4Cats,
    )
  )

// ...

val preludeImport =
  scalacOptions ++= Seq("-Yimports:java.lang,scala,scala.Predef,com.myproject.prelude.Prelude")

// ...

lazy val root = (project in file("."))
  .settings(preludeImport)
  .dependsOn(prelude)

// ...

Prelude.scala

package com.myproject.prelude

import cats.syntax.{AllSyntaxBinCompat => CatsSyntax}
import cats.effect.syntax.{AllSyntax => CESyntax}
import cats.effect.instances.{AllInstances => CEInstances}

/** Custom prelude for importing with -Yimport
  *
  * This means we never need to import cats syntax or stream explicitly
  */
object Prelude extends CatsSyntax with CESyntax with CEInstances {
  val Stream = fs2.Stream
  type Stream[+F[_], +O] = fs2.Stream[F, O]

  val IO = cats.effect.IO
  type IO[+A] = cats.effect.IO[A]

  val Deferred = cats.effect.Deferred
  type Deferred[F[_], A] = cats.effect.Deferred[F, A]

  val Resource = cats.effect.Resource
  type Resource[F[_], +A] = cats.effect.Resource[F, A]

  type Sync[F[_]] = cats.effect.Sync[F]
  val Sync = cats.effect.Sync

  type Async[F[_]] = cats.effect.Async[F]
  val Async = cats.effect.Async

  type Ref[F[_], A] = cats.effect.Ref[F, A]
  val Ref = cats.effect.Ref

  type Logger[F[_]] = org.typelevel.log4cats.Logger[F]
  val Logger = org.typelevel.log4cats.Logger

  type Console[F[_]] = cats.effect.std.Console[F]
  val Console = cats.effect.std.Console
}