Scala library that provides a functional and idiomatic interface for working with MongoDB. Built on top of the official MongoDB Java driver, mongo4cats integrates seamlessly with functional programming libraries like Cats-Effect/FS2 and ZIO, making it a great choice for Scala developers who prefer functional programming paradigms.
Available for Scala 2.12, 2.13 and 3.3.
Documentation is available on the mongo4cats microsite.
Add this to your build.sbt (depends on cats-effect and FS2):
libraryDependencies += "io.github.kirill5k" %% "mongo4cats-core" % "<version>"
libraryDependencies += "io.github.kirill5k" %% "mongo4cats-embedded" % "<version>" % TestAlternatively, for ZIO 2, add this:
libraryDependencies += "io.github.kirill5k" %% "mongo4cats-zio" % "<version>"
libraryDependencies += "io.github.kirill5k" %% "mongo4cats-zio-embedded" % "<version>" % TestOptional support for circe or zio-json can be enabled with:
// circe
libraryDependencies += "io.github.kirill5k" %% "mongo4cats-circe" % "<version>"
// zio-json
libraryDependencies += "io.github.kirill5k" %% "mongo4cats-zio-json" % "<version>"import cats.effect.{IO, IOApp}
import mongo4cats.client.MongoClient
import mongo4cats.operations.{Filter, Projection}
import mongo4cats.bson.Document
import mongo4cats.bson.syntax._
object Quickstart extends IOApp.Simple {
override val run: IO[Unit] =
MongoClient.fromConnectionString[IO]("mongodb://localhost:27017").use { client =>
for {
db <- client.getDatabase("my-db")
coll <- db.getCollection("docs")
_ <- coll.insertMany((0 to 100).map(i => Document("name" := s"doc-$i", "index" := i)))
docs <- coll.find
.filter(Filter.gte("index", 10) && Filter.regex("name", "doc-[1-9]0"))
.projection(Projection.excludeId)
.sortByDesc("name")
.limit(5)
.all
_ <- IO.println(docs.mkString("[\n", ",\n", "\n]"))
} yield ()
}
}import mongo4cats.bson.Document
import mongo4cats.bson.syntax._
import mongo4cats.operations.{Filter, Projection}
import mongo4cats.zio.{ZMongoClient, ZMongoCollection, ZMongoDatabase}
import zio._
object Zio extends ZIOAppDefault {
val client = ZLayer.scoped[Any](ZMongoClient.fromConnectionString("mongodb://localhost:27017"))
val database = ZLayer.fromZIO(ZIO.serviceWithZIO[ZMongoClient](_.getDatabase("my-db")))
val collection = ZLayer.fromZIO(ZIO.serviceWithZIO[ZMongoDatabase](_.getCollection("docs")))
val program = for {
coll <- ZIO.service[ZMongoCollection[Document]]
_ <- coll.insertMany((0 to 100).map(i => Document("name" := s"doc-$i", "index" := i)))
docs <- coll.find
.filter(Filter.gte("index", 10) && Filter.regex("name", "doc-[1-9]0"))
.projection(Projection.excludeId)
.sortByDesc("name")
.limit(5)
.all
_ <- Console.printLine(docs.mkString("[\n", ",\n", "\n]"))
} yield ()
override def run = program.provide(client, database, collection)
}If you find this library useful, consider giving it a ⭐!