diff --git a/iris/service/build.sbt b/iris/service/build.sbt
index b534e2fe4f..2723fc860a 100644
--- a/iris/service/build.sbt
+++ b/iris/service/build.sbt
@@ -1,4 +1,5 @@
 import Dependencies._
+import sbtghpackages.GitHubPackagesPlugin.autoImport._
 
 ThisBuild / version := "0.1.0-SNAPSHOT"
 ThisBuild / scalaVersion := "3.1.3"
@@ -11,13 +12,22 @@ ThisBuild / apiBaseDirectory := baseDirectory.value / "../api"
 // Project definitions
 lazy val root = project
   .in(file("."))
-  .aggregate(core, sql, `api-server`)
+  .aggregate(core, sql, server)
 
 lazy val core = project
   .in(file("core"))
   .settings(
     name := "iris-core",
-    libraryDependencies ++= coreDependencies
+    githubTokenSource := TokenSource.Environment("ATALA_GITHUB_TOKEN"),
+    resolvers += Resolver
+      .githubPackages("input-output-hk", "atala-prism-sdk"),
+    // Needed for Kotlin coroutines that support new memory management mode
+    resolvers +=
+      "JetBrains Space Maven Repository" at "https://maven.pkg.jetbrains.space/public/p/kotlinx-coroutines/maven",
+    libraryDependencies ++= coreDependencies,
+    // gRPC settings
+    Compile / PB.targets := Seq(scalapb.gen() -> (Compile / sourceManaged).value / "scalapb"),
+    Compile / PB.protoSources := Seq(apiBaseDirectory.value / "grpc")
   )
 
 lazy val sql = project
@@ -28,13 +38,10 @@ lazy val sql = project
   )
   .dependsOn(core)
 
-lazy val `api-server` = project
-  .in(file("api-server"))
+lazy val server = project
+  .in(file("server"))
   .settings(
-    name := "iris-api-server",
+    name := "iris-server",
     libraryDependencies ++= apiServerDependencies,
-    // gRPC settings
-    Compile / PB.targets := Seq(scalapb.gen() -> (Compile / sourceManaged).value / "scalapb"),
-    Compile / PB.protoSources := Seq(apiBaseDirectory.value / "grpc")
   )
   .dependsOn(core, sql)
diff --git a/iris/service/core/src/main/scala/io/iohk/atala/iris/core/model/Models.scala b/iris/service/core/src/main/scala/io/iohk/atala/iris/core/model/Models.scala
index 89d3a8b44b..7fc22339cd 100644
--- a/iris/service/core/src/main/scala/io/iohk/atala/iris/core/model/Models.scala
+++ b/iris/service/core/src/main/scala/io/iohk/atala/iris/core/model/Models.scala
@@ -5,4 +5,3 @@ final case class IrisNotification(foo: String)
 
 final case class IrisOperationId(id: String)
 final case class IrisOperation(foo: String)
-final case class SignedIrisOperation(foo: String)
diff --git a/iris/service/core/src/main/scala/io/iohk/atala/iris/core/model/ledger/Funds.scala b/iris/service/core/src/main/scala/io/iohk/atala/iris/core/model/ledger/Funds.scala
new file mode 100644
index 0000000000..197ba8fd6f
--- /dev/null
+++ b/iris/service/core/src/main/scala/io/iohk/atala/iris/core/model/ledger/Funds.scala
@@ -0,0 +1,3 @@
+package io.iohk.atala.iris.core.model.ledger
+
+case class Funds(lovelaces: Int)
diff --git a/iris/service/core/src/main/scala/io/iohk/atala/iris/core/model/ledger/Ledger.scala b/iris/service/core/src/main/scala/io/iohk/atala/iris/core/model/ledger/Ledger.scala
new file mode 100644
index 0000000000..5cf93c7d9e
--- /dev/null
+++ b/iris/service/core/src/main/scala/io/iohk/atala/iris/core/model/ledger/Ledger.scala
@@ -0,0 +1,15 @@
+package io.iohk.atala.iris.core.model.ledger
+
+import enumeratum.{Enum, EnumEntry}
+
+import scala.collection.immutable.ArraySeq
+
+sealed trait Ledger extends EnumEntry
+
+object Ledger extends Enum[Ledger] {
+  val values = ArraySeq(InMemory, CardanoMainnet, CardanoTestnet)
+
+  case object InMemory extends Ledger
+  case object CardanoMainnet extends Ledger
+  case object CardanoTestnet extends Ledger
+}
diff --git a/iris/service/core/src/main/scala/io/iohk/atala/iris/core/model/ledger/TransactionDetails.scala b/iris/service/core/src/main/scala/io/iohk/atala/iris/core/model/ledger/TransactionDetails.scala
new file mode 100644
index 0000000000..a979b38dc3
--- /dev/null
+++ b/iris/service/core/src/main/scala/io/iohk/atala/iris/core/model/ledger/TransactionDetails.scala
@@ -0,0 +1,3 @@
+package io.iohk.atala.iris.core.model.ledger
+
+case class TransactionDetails(id: TransactionId, status: TransactionStatus)
diff --git a/iris/service/core/src/main/scala/io/iohk/atala/iris/core/model/ledger/TransactionId.scala b/iris/service/core/src/main/scala/io/iohk/atala/iris/core/model/ledger/TransactionId.scala
new file mode 100644
index 0000000000..40191ea26d
--- /dev/null
+++ b/iris/service/core/src/main/scala/io/iohk/atala/iris/core/model/ledger/TransactionId.scala
@@ -0,0 +1,18 @@
+package io.iohk.atala.iris.core.model.ledger
+
+import com.typesafe.config.ConfigMemorySize
+import io.iohk.atala.shared.{HashValueConfig, HashValueFrom}
+
+import scala.collection.immutable.ArraySeq
+
+case class TransactionId(hex: ArraySeq[Byte])
+
+object TransactionId extends HashValueFrom[TransactionId] {
+
+  override val config: HashValueConfig = HashValueConfig(
+    ConfigMemorySize.ofBytes(32)
+  )
+
+  override protected def constructor(value: ArraySeq[Byte]): TransactionId =
+    new TransactionId(value)
+}
diff --git a/iris/service/core/src/main/scala/io/iohk/atala/iris/core/model/ledger/TransactionStatus.scala b/iris/service/core/src/main/scala/io/iohk/atala/iris/core/model/ledger/TransactionStatus.scala
new file mode 100644
index 0000000000..ca09ec1c9f
--- /dev/null
+++ b/iris/service/core/src/main/scala/io/iohk/atala/iris/core/model/ledger/TransactionStatus.scala
@@ -0,0 +1,16 @@
+package io.iohk.atala.iris.core.model.ledger
+
+import enumeratum.{Enum, EnumEntry}
+import enumeratum.EnumEntry.Snakecase
+import scala.collection.immutable.ArraySeq
+
+sealed trait TransactionStatus extends EnumEntry with Snakecase
+
+object TransactionStatus extends Enum[TransactionStatus] {
+  val values = ArraySeq(InWalletMempool, Submitted, Expired, InLedger)
+
+  case object InWalletMempool extends TransactionStatus
+  case object Submitted extends TransactionStatus
+  case object Expired extends TransactionStatus
+  case object InLedger extends TransactionStatus
+}
diff --git a/iris/service/core/src/main/scala/io/iohk/atala/iris/core/repository/OperationsRepository.scala b/iris/service/core/src/main/scala/io/iohk/atala/iris/core/repository/OperationsRepository.scala
index 7cfc55cbba..5775e6954e 100644
--- a/iris/service/core/src/main/scala/io/iohk/atala/iris/core/repository/OperationsRepository.scala
+++ b/iris/service/core/src/main/scala/io/iohk/atala/iris/core/repository/OperationsRepository.scala
@@ -1,10 +1,10 @@
 package io.iohk.atala.iris.core.repository
 
-import io.iohk.atala.iris.core.model.{IrisOperation, IrisOperationId, SignedIrisOperation}
+import io.iohk.atala.iris.core.model as model
 import zio.*
 
 // TODO: replace with actual implementation
 trait OperationsRepository[F[_]] {
-  def getOperation(id: IrisOperationId): F[IrisOperation]
-  def saveOperations(ops: Seq[SignedIrisOperation]): F[Unit]
+  def getOperation(id: model.IrisOperationId): F[model.IrisOperation]
+  def saveOperations(ops: Seq[model.IrisOperation]): F[Unit]
 }
diff --git a/iris/service/core/src/main/scala/io/iohk/atala/iris/core/service/InmemoryUnderlyingLedgerService.scala b/iris/service/core/src/main/scala/io/iohk/atala/iris/core/service/InmemoryUnderlyingLedgerService.scala
new file mode 100644
index 0000000000..fc18acaab9
--- /dev/null
+++ b/iris/service/core/src/main/scala/io/iohk/atala/iris/core/service/InmemoryUnderlyingLedgerService.scala
@@ -0,0 +1,105 @@
+package io.iohk.atala.iris.core.service
+
+import io.iohk.atala.iris.core.model.ledger.TransactionStatus.{InWalletMempool, InLedger}
+import io.iohk.atala.iris.core.model.ledger.{Funds, TransactionDetails, TransactionId}
+import io.iohk.atala.iris.core.service.InmemoryUnderlyingLedgerService.{CardanoBlock, CardanoTransaction, Config}
+import io.iohk.atala.iris.proto.service.IrisOperation
+import zio.{Duration as ZDuration, *}
+import zio.stm.*
+import io.iohk.atala.iris.proto.dlt_operations as proto_dlt
+import io.iohk.atala.iris.proto.service as proto_service
+import io.iohk.atala.prism.crypto.Sha256
+
+import scala.concurrent.duration.Duration
+
+object InmemoryUnderlyingLedgerService {
+  case class Config(blockEvery: Duration, initialFunds: Funds, txFee: Funds)
+
+  case class CardanoTransaction(operations: Seq[proto_service.IrisOperation]) {
+    lazy val transactionId: TransactionId = {
+      val objectBytes = proto_dlt.AtalaObject(operations).toByteArray
+      val hash = Sha256.compute(objectBytes)
+      TransactionId
+        .from(hash.getValue)
+        .getOrElse(throw new RuntimeException("Unexpected invalid hash"))
+    }
+  }
+
+  case class CardanoBlock(txs: List[CardanoTransaction])
+
+  def layer(config: Config): ULayer[UnderlyingLedgerService] = ZLayer.fromZIO {
+    for {
+      mempoolRef <- TRef.make(List[CardanoTransaction]()).commit
+      blocksRef <- TRef.make(List[CardanoBlock]()).commit
+      initialBalance <- TRef.make(config.initialFunds).commit
+      srv = InmemoryUnderlyingLedgerService(config, mempoolRef, blocksRef, initialBalance)
+      _ <- srv.startBackgroundProcess()
+    } yield srv
+  }
+}
+
+class InmemoryUnderlyingLedgerService(
+                                       config: Config,
+                                       mempoolRef: TRef[List[CardanoTransaction]],
+                                       blocksRef: TRef[List[CardanoBlock]],
+                                       balanceRef: TRef[Funds]
+                                     ) extends UnderlyingLedgerService {
+
+  def startBackgroundProcess(): UIO[Unit] = STM.atomically {
+    for {
+      // Craft a new block from mempool transactions
+      txs <- mempoolRef.modify(old => (old, List.empty))
+      _ <- blocksRef.update(CardanoBlock(txs) :: _)
+    } yield ()
+  }
+    .repeat(Schedule.spaced(ZDuration.fromScala(config.blockEvery)))
+    .fork.map(_ => ())
+
+  override def publish(operations: Seq[proto_service.IrisOperation]): IO[LedgerError, Unit] =
+    STM.atomically {
+      for {
+        curFunds <- balanceRef.get
+        newFunds <- STM.cond(
+          curFunds.lovelaces >= config.txFee.lovelaces,
+          Funds(curFunds.lovelaces - config.txFee.lovelaces),
+          LedgerError("Insufficient wallet balance")
+        )
+        _ <- balanceRef.set(newFunds)
+        _ <- mempoolRef.update(CardanoTransaction(operations) :: _)
+      } yield ()
+    }
+
+  override def getTransactionDetails(transactionId: TransactionId): IO[LedgerError, TransactionDetails] =
+    STM.atomically {
+      for {
+        mempool <- mempoolRef.get
+        blockchain <- blocksRef.get
+        tdetails <- STM.fromOption {
+          mempool.find(_.transactionId == transactionId)
+            .map(_ => TransactionDetails(transactionId, InWalletMempool))
+        }.orElse {
+          STM.fromOption {
+            blockchain.find(block => block.txs.exists(t => t.transactionId == transactionId))
+              .map(_ => TransactionDetails(transactionId, InLedger))
+          }
+        }
+          .orElseFail(LedgerError(s"Couldn't find tx $transactionId"))
+      } yield tdetails
+    }
+
+  override def deleteTransaction(transactionId: TransactionId): IO[LedgerError, Unit] = STM.atomically {
+    for {
+      mempool <- mempoolRef.get
+      _ <- STM.cond(mempool.exists(_.transactionId == transactionId),
+        (),
+        LedgerError(s"Transaction $transactionId not found in the mempool")
+      )
+      _ <- mempoolRef.update(m => m.filter {
+        _.transactionId != transactionId
+      })
+      _ <- balanceRef.update(b => Funds(b.lovelaces + config.txFee.lovelaces))
+    } yield ()
+  }
+
+  override def getWalletBalance: IO[LedgerError, Funds] = balanceRef.get.commit
+}
diff --git a/iris/service/core/src/main/scala/io/iohk/atala/iris/core/service/PublishingService.scala b/iris/service/core/src/main/scala/io/iohk/atala/iris/core/service/PublishingService.scala
index 37c2141fd3..23cc753dbe 100644
--- a/iris/service/core/src/main/scala/io/iohk/atala/iris/core/service/PublishingService.scala
+++ b/iris/service/core/src/main/scala/io/iohk/atala/iris/core/service/PublishingService.scala
@@ -1,17 +1,17 @@
 package io.iohk.atala.iris.core.service
 
-import io.iohk.atala.iris.core.model.SignedIrisOperation
+import io.iohk.atala.iris.proto.service as proto
 import zio.*
 
 // TODO: replace with actual implementation
 trait PublishingService {
-  def publishOperations(op: SignedIrisOperation): UIO[Unit]
+  def publishOperation(op: proto.IrisOperation): UIO[Unit] = ???
 }
 
 object MockPublishingService {
   val layer: ULayer[PublishingService] = ZLayer.succeed {
     new PublishingService {
-      override def publishOperations(op: SignedIrisOperation): UIO[Unit] = ZIO.unit
+      override def publishOperation(op: proto.IrisOperation): UIO[Unit] = ZIO.unit
     }
   }
 }
diff --git a/iris/service/core/src/main/scala/io/iohk/atala/iris/core/service/UnderlyingLedgerService.scala b/iris/service/core/src/main/scala/io/iohk/atala/iris/core/service/UnderlyingLedgerService.scala
new file mode 100644
index 0000000000..f0b8259bc7
--- /dev/null
+++ b/iris/service/core/src/main/scala/io/iohk/atala/iris/core/service/UnderlyingLedgerService.scala
@@ -0,0 +1,20 @@
+package io.iohk.atala.iris.core.service
+
+import io.iohk.atala.iris.proto.{service => proto}
+import io.iohk.atala.iris.core.model.IrisOperation
+import io.iohk.atala.iris.core.model.ledger.{Funds, TransactionDetails, TransactionId}
+import zio.{IO, UIO}
+
+case class LedgerError(msg: String) extends RuntimeException(msg)
+
+trait UnderlyingLedgerService {
+//  def getType: Ledger
+
+  def publish(operations: Seq[proto.IrisOperation]): IO[LedgerError, Unit]
+
+  def getTransactionDetails(transactionId: TransactionId): IO[LedgerError, TransactionDetails]
+
+  def deleteTransaction(transactionId: TransactionId): IO[LedgerError, Unit]
+
+  def getWalletBalance: IO[LedgerError, Funds]
+}
diff --git a/iris/service/core/src/main/scala/io/iohk/atala/iris/core/worker/PublishingScheduler.scala b/iris/service/core/src/main/scala/io/iohk/atala/iris/core/worker/PublishingScheduler.scala
index fdd1b6206d..167d3dc36e 100644
--- a/iris/service/core/src/main/scala/io/iohk/atala/iris/core/worker/PublishingScheduler.scala
+++ b/iris/service/core/src/main/scala/io/iohk/atala/iris/core/worker/PublishingScheduler.scala
@@ -1,17 +1,16 @@
 package io.iohk.atala.iris.core.worker
 
-import io.iohk.atala.iris.core.model.SignedIrisOperation
-import io.iohk.atala.iris.core.service.PublishingService
+import io.iohk.atala.iris.proto.service as proto
 import zio.{UIO, ULayer, ZIO, ZLayer}
 
 trait PublishingScheduler {
-  def scheduleOperations(op: SignedIrisOperation): UIO[Unit]
+  def scheduleOperations(op: proto.IrisOperation): UIO[Unit]
 }
 
 object MockPublishingScheduler {
   val layer: ULayer[PublishingScheduler] = ZLayer.succeed {
     new PublishingScheduler {
-      def scheduleOperations(op: SignedIrisOperation): UIO[Unit] = ZIO.unit
+      def scheduleOperations(op: proto.IrisOperation): UIO[Unit] = ZIO.unit
     }
   }
 }
diff --git a/iris/service/project/Dependencies.scala b/iris/service/project/Dependencies.scala
index 8a750ca5c4..ee0413cee4 100644
--- a/iris/service/project/Dependencies.scala
+++ b/iris/service/project/Dependencies.scala
@@ -7,6 +7,9 @@ object Dependencies {
     val akkaHttp = "10.2.9"
     val doobie = "1.0.0-RC2"
     val zioCatsInterop = "3.3.0"
+    val prismSdk = "v1.3.3-snapshot-1657194253-992dd96"
+    val shared = "0.1.0"
+    val enumeratum = "1.7.0"
   }
 
   private lazy val zio = "dev.zio" %% "zio" % Versions.zio
@@ -25,15 +28,25 @@ object Dependencies {
 
   private lazy val doobiePostgres = "org.tpolecat" %% "doobie-postgres" % Versions.doobie
   private lazy val doobieHikari = "org.tpolecat" %% "doobie-hikari" % Versions.doobie
+  // We have to exclude bouncycastle since for some reason bitcoinj depends on bouncycastle jdk15to18
+  // (i.e. JDK 1.5 to 1.8), but we are using JDK 11
+  private lazy val prismCrypto = "io.iohk.atala" % "prism-crypto-jvm" % Versions.prismSdk excludeAll
+    ExclusionRule(
+      organization = "org.bouncycastle"
+    )
+
+  private lazy val shared = "io.iohk.atala" % "shared" % Versions.shared
+
+  private lazy val enumeratum = ("com.beachape" %% "enumeratum" % Versions.enumeratum).cross(CrossVersion.for3Use2_13)
 
   // Dependency Modules
-  private lazy val baseDependencies: Seq[ModuleID] = Seq(zio)
+  private lazy val baseDependencies: Seq[ModuleID] = Seq(zio, prismCrypto, shared, enumeratum)
   private lazy val akkaHttpDependencies: Seq[ModuleID] = Seq(akkaTyped, akkaStream, akkaHttp, akkaSprayJson).map(_.cross(CrossVersion.for3Use2_13))
   private lazy val grpcDependencies: Seq[ModuleID] = Seq(grpcNetty, grpcServices, scalaPbProto, scalaPbGrpc)
   private lazy val doobieDependencies: Seq[ModuleID] = Seq(doobiePostgres, doobieHikari)
 
   // Project Dependencies
-  lazy val coreDependencies: Seq[ModuleID] = baseDependencies
+  lazy val coreDependencies: Seq[ModuleID] = baseDependencies ++ grpcDependencies
   lazy val sqlDependencies: Seq[ModuleID] = baseDependencies ++ doobieDependencies ++ Seq(zioCatsInterop)
-  lazy val apiServerDependencies: Seq[ModuleID] = baseDependencies ++ akkaHttpDependencies ++ grpcDependencies
+  lazy val apiServerDependencies: Seq[ModuleID] = baseDependencies ++ akkaHttpDependencies
 }
diff --git a/iris/service/project/build.sbt b/iris/service/project/build.sbt
index 2625ab2264..83adafa3f1 100644
--- a/iris/service/project/build.sbt
+++ b/iris/service/project/build.sbt
@@ -1,3 +1 @@
 addSbtPlugin("org.scalameta" % "sbt-scalafmt" % "2.4.6")
-
-libraryDependencies ++= Seq("org.openapitools" % "openapi-generator" % "6.0.0")
diff --git a/iris/service/project/plugins.sbt b/iris/service/project/plugins.sbt
new file mode 100644
index 0000000000..54f54acbe0
--- /dev/null
+++ b/iris/service/project/plugins.sbt
@@ -0,0 +1 @@
+addSbtPlugin("com.codecommit" % "sbt-github-packages" % "0.5.3")
diff --git a/iris/service/api-server/src/main/scala/io/iohk/atala/iris/apiserver/Main.scala b/iris/service/server/src/main/scala/io/iohk/atala/iris/server/Main.scala
similarity index 69%
rename from iris/service/api-server/src/main/scala/io/iohk/atala/iris/apiserver/Main.scala
rename to iris/service/server/src/main/scala/io/iohk/atala/iris/server/Main.scala
index 1bdac42323..fb6cb3f94f 100644
--- a/iris/service/api-server/src/main/scala/io/iohk/atala/iris/apiserver/Main.scala
+++ b/iris/service/server/src/main/scala/io/iohk/atala/iris/server/Main.scala
@@ -1,4 +1,4 @@
-package io.iohk.atala.iris.apiserver
+package io.iohk.atala.iris.server
 
 import zio.*
 
diff --git a/iris/service/api-server/src/main/scala/io/iohk/atala/iris/apiserver/Modules.scala b/iris/service/server/src/main/scala/io/iohk/atala/iris/server/Modules.scala
similarity index 91%
rename from iris/service/api-server/src/main/scala/io/iohk/atala/iris/apiserver/Modules.scala
rename to iris/service/server/src/main/scala/io/iohk/atala/iris/server/Modules.scala
index 4774d9cb5b..6532653db0 100644
--- a/iris/service/api-server/src/main/scala/io/iohk/atala/iris/apiserver/Modules.scala
+++ b/iris/service/server/src/main/scala/io/iohk/atala/iris/server/Modules.scala
@@ -1,12 +1,12 @@
-package io.iohk.atala.iris.apiserver
+package io.iohk.atala.iris.server
 
 import akka.actor.typed.ActorSystem
 import akka.actor.typed.scaladsl.Behaviors
 import akka.http.scaladsl.server.Route
 import cats.effect.std.Dispatcher
 import doobie.util.transactor.Transactor
-import io.iohk.atala.iris.apiserver.grpc.service.IrisServiceGrpcImpl
-import io.iohk.atala.iris.apiserver.grpc.{GrpcServer, GrpcServices}
+import io.iohk.atala.iris.server.grpc.service.IrisServiceGrpcImpl
+import io.iohk.atala.iris.server.grpc.{GrpcServer, GrpcServices}
 import io.iohk.atala.iris.core.repository.OperationsRepository
 import io.iohk.atala.iris.core.service.*
 import io.iohk.atala.iris.core.worker.{MockPublishingScheduler, PublishingScheduler}
diff --git a/iris/service/api-server/src/main/scala/io/iohk/atala/iris/apiserver/grpc/GrpcServer.scala b/iris/service/server/src/main/scala/io/iohk/atala/iris/server/grpc/GrpcServer.scala
similarity index 96%
rename from iris/service/api-server/src/main/scala/io/iohk/atala/iris/apiserver/grpc/GrpcServer.scala
rename to iris/service/server/src/main/scala/io/iohk/atala/iris/server/grpc/GrpcServer.scala
index c0423b8ab1..b3e9203464 100644
--- a/iris/service/api-server/src/main/scala/io/iohk/atala/iris/apiserver/grpc/GrpcServer.scala
+++ b/iris/service/server/src/main/scala/io/iohk/atala/iris/server/grpc/GrpcServer.scala
@@ -1,4 +1,4 @@
-package io.iohk.atala.iris.apiserver.grpc
+package io.iohk.atala.iris.server.grpc
 
 import io.grpc.{ServerBuilder, ServerServiceDefinition}
 import io.grpc.protobuf.services.ProtoReflectionService
diff --git a/iris/service/api-server/src/main/scala/io/iohk/atala/iris/apiserver/grpc/GrpcServices.scala b/iris/service/server/src/main/scala/io/iohk/atala/iris/server/grpc/GrpcServices.scala
similarity index 91%
rename from iris/service/api-server/src/main/scala/io/iohk/atala/iris/apiserver/grpc/GrpcServices.scala
rename to iris/service/server/src/main/scala/io/iohk/atala/iris/server/grpc/GrpcServices.scala
index f4ef958a81..65838def92 100644
--- a/iris/service/api-server/src/main/scala/io/iohk/atala/iris/apiserver/grpc/GrpcServices.scala
+++ b/iris/service/server/src/main/scala/io/iohk/atala/iris/server/grpc/GrpcServices.scala
@@ -1,4 +1,4 @@
-package io.iohk.atala.iris.apiserver.grpc
+package io.iohk.atala.iris.server.grpc
 
 import akka.actor.typed.ActorSystem
 import io.grpc.ServerServiceDefinition
diff --git a/iris/service/api-server/src/main/scala/io/iohk/atala/iris/apiserver/grpc/service/IrisServiceGrpcImpl.scala b/iris/service/server/src/main/scala/io/iohk/atala/iris/server/grpc/service/IrisServiceGrpcImpl.scala
similarity index 97%
rename from iris/service/api-server/src/main/scala/io/iohk/atala/iris/apiserver/grpc/service/IrisServiceGrpcImpl.scala
rename to iris/service/server/src/main/scala/io/iohk/atala/iris/server/grpc/service/IrisServiceGrpcImpl.scala
index 19464c4bf7..8b488ad463 100644
--- a/iris/service/api-server/src/main/scala/io/iohk/atala/iris/apiserver/grpc/service/IrisServiceGrpcImpl.scala
+++ b/iris/service/server/src/main/scala/io/iohk/atala/iris/server/grpc/service/IrisServiceGrpcImpl.scala
@@ -1,4 +1,4 @@
-package io.iohk.atala.iris.apiserver.grpc.service
+package io.iohk.atala.iris.server.grpc.service
 
 import com.google.protobuf.ByteString
 import io.iohk.atala.iris.core.service.PublishingService
diff --git a/iris/service/sql/src/main/scala/io/iohk/atala/iris/sql/repository/JdbcOperationsRepository.scala b/iris/service/sql/src/main/scala/io/iohk/atala/iris/sql/repository/JdbcOperationsRepository.scala
index dd7fecb8c8..75ac5c5017 100644
--- a/iris/service/sql/src/main/scala/io/iohk/atala/iris/sql/repository/JdbcOperationsRepository.scala
+++ b/iris/service/sql/src/main/scala/io/iohk/atala/iris/sql/repository/JdbcOperationsRepository.scala
@@ -2,7 +2,7 @@ package io.iohk.atala.iris.sql.repository
 
 import doobie.*
 import doobie.implicits.*
-import io.iohk.atala.iris.core.model.{IrisOperation, IrisOperationId, SignedIrisOperation}
+import io.iohk.atala.iris.core.model as model
 import io.iohk.atala.iris.core.repository.OperationsRepository
 import io.iohk.atala.iris.sql.repository.JdbcOperationsRepository
 import zio.*
@@ -11,17 +11,17 @@ import zio.interop.catz.*
 // TODO: replace with actual implementation
 class JdbcOperationsRepository(xa: Transactor[Task]) extends OperationsRepository[Task] {
 
-  override def getOperation(id: IrisOperationId): Task[IrisOperation] = {
+  override def getOperation(id: model.IrisOperationId): Task[model.IrisOperation] = {
     val cxnIO = sql"""
          |SELECT foo FROM public.iris_operations
          |""".stripMargin.query[String].unique
 
     cxnIO
       .transact(xa)
-      .map(IrisOperation.apply)
+      .map(model.IrisOperation.apply)
   }
 
-  override def saveOperations(ops: Seq[SignedIrisOperation]): Task[Unit] = ZIO.unit
+  override def saveOperations(ops: Seq[model.IrisOperation]): Task[Unit] = ZIO.unit
 }
 
 object JdbcOperationsRepository {
diff --git a/shared/README.md b/shared/README.md
new file mode 100644
index 0000000000..3b85b855ca
--- /dev/null
+++ b/shared/README.md
@@ -0,0 +1,3 @@
+## shared
+
+Contains a stateless utility code which might be reused across all the building blocks.
diff --git a/shared/build.sbt b/shared/build.sbt
new file mode 100644
index 0000000000..486f3da97b
--- /dev/null
+++ b/shared/build.sbt
@@ -0,0 +1,17 @@
+import sbtbuildinfo.BuildInfoPlugin
+import sbtbuildinfo.BuildInfoPlugin.autoImport._
+import Dependencies._
+
+ThisBuild / version := "0.1.0"
+
+ThisBuild / scalaVersion := "3.1.3"
+
+lazy val root = (project in file("."))
+  .settings(
+    organization := "io.iohk.atala",
+    organizationName := "Input Output HK",
+    buildInfoPackage := "io.iohk.atala.shared",
+    name := "shared",
+    crossPaths := false,
+    libraryDependencies ++= dependencies
+  ).enablePlugins(BuildInfoPlugin)
diff --git a/shared/project/Dependencies.scala b/shared/project/Dependencies.scala
new file mode 100644
index 0000000000..d70c3dd4c1
--- /dev/null
+++ b/shared/project/Dependencies.scala
@@ -0,0 +1,11 @@
+import sbt._
+
+object Dependencies {
+  object Versions {
+    val typesafeConfig = "1.4.2"
+  }
+
+  private lazy val typesafeConfig = "com.typesafe" % "config" % Versions.typesafeConfig
+
+  lazy val dependencies: Seq[ModuleID] = Seq(typesafeConfig)
+}
diff --git a/shared/project/build.properties b/shared/project/build.properties
new file mode 100644
index 0000000000..d738b858c8
--- /dev/null
+++ b/shared/project/build.properties
@@ -0,0 +1 @@
+sbt.version = 1.7.1
diff --git a/shared/project/plugins.sbt b/shared/project/plugins.sbt
new file mode 100644
index 0000000000..78bb5eba38
--- /dev/null
+++ b/shared/project/plugins.sbt
@@ -0,0 +1,2 @@
+addSbtPlugin("org.jetbrains.scala" % "sbt-ide-settings" % "1.1.1")
+addSbtPlugin("com.eed3si9n" % "sbt-buildinfo" % "0.11.0")
diff --git a/shared/src/main/scala/io/iohk/atala/shared/HashValue.scala b/shared/src/main/scala/io/iohk/atala/shared/HashValue.scala
new file mode 100644
index 0000000000..26387349a8
--- /dev/null
+++ b/shared/src/main/scala/io/iohk/atala/shared/HashValue.scala
@@ -0,0 +1,51 @@
+package io.iohk.atala.shared
+
+import java.util.Locale
+import com.typesafe.config.ConfigMemorySize
+import io.iohk.atala.shared.utils.BytesOps
+
+import scala.collection.immutable.ArraySeq
+import scala.util.matching.Regex
+
+trait HashValue extends Any {
+
+  def value: ArraySeq[Byte]
+
+  override def toString: String = {
+    BytesOps.bytesToHex(value)
+  }
+}
+
+trait HashValueFrom[A] {
+  protected val config: HashValueConfig
+
+  protected def constructor(value: ArraySeq[Byte]): A
+
+  def from(string: String): Option[A] = {
+    val lowercaseString = string.toLowerCase(Locale.ROOT)
+
+    lowercaseString match {
+      case config.HexPattern() =>
+        val bytes = lowercaseString
+          .grouped(2)
+          .toList
+          .map { hex =>
+            Integer.parseInt(hex, 16).asInstanceOf[Byte]
+          }
+        Some(constructor(ArraySeq.from(bytes)))
+      case _ => None
+    }
+  }
+
+  def from(bytes: Iterable[Byte]): Option[A] = {
+    if (bytes.size == config.size.toBytes) {
+      Some(constructor(ArraySeq.from(bytes)))
+    } else {
+      None
+    }
+  }
+}
+
+case class HashValueConfig(size: ConfigMemorySize) {
+  private[shared] val HexPattern: Regex = s"^[a-f0-9]{${2 * size.toBytes}}$$".r
+}
diff --git a/shared/src/main/scala/io/iohk/atala/shared/utils/Base64.scala b/shared/src/main/scala/io/iohk/atala/shared/utils/Base64.scala
new file mode 100644
index 0000000000..de3c217d4d
--- /dev/null
+++ b/shared/src/main/scala/io/iohk/atala/shared/utils/Base64.scala
@@ -0,0 +1,18 @@
+package io.iohk.atala.shared.utils
+
+import java.nio.charset.StandardCharsets
+import java.util.Base64
+
+object Base64Utils {
+  def encodeURL(bytes: Array[Byte]): String = {
+    Base64.getUrlEncoder.encodeToString(bytes)
+  }
+
+  def decodeUrlToString(encodedStr: String): String = {
+    new String(Base64.getUrlDecoder.decode(encodedStr), StandardCharsets.UTF_8)
+  }
+
+  def decodeURL(string: String): Array[Byte] = {
+    Base64.getUrlDecoder.decode(string)
+  }
+}
diff --git a/shared/src/main/scala/io/iohk/atala/shared/utils/BytesOps.scala b/shared/src/main/scala/io/iohk/atala/shared/utils/BytesOps.scala
new file mode 100644
index 0000000000..afc5c4dabc
--- /dev/null
+++ b/shared/src/main/scala/io/iohk/atala/shared/utils/BytesOps.scala
@@ -0,0 +1,28 @@
+package io.iohk.atala.shared.utils
+
+import java.nio.charset.StandardCharsets
+
+object BytesOps {
+  private val HexArray = "0123456789abcdef".getBytes(StandardCharsets.US_ASCII);
+
+  // Converts hex string to bytes representation
+  def hexToBytes(hexEncoded: String): Array[Byte] = {
+    require(hexEncoded.length % 2 == 0, "Hex length needs to be even")
+    hexEncoded.grouped(2).toVector.map(hexToByte).toArray
+  }
+
+  // Converts bytes to hex string representation
+  def bytesToHex(bytes: Iterable[Byte]): String = {
+    val hexChars = new Array[Byte](bytes.size * 2)
+    for ((byte, i) <- bytes.zipWithIndex) {
+      val v = byte & 0xff
+      hexChars(i * 2) = HexArray(v >>> 4)
+      hexChars(i * 2 + 1) = HexArray(v & 0x0f)
+    }
+    new String(hexChars, StandardCharsets.UTF_8)
+  }
+
+  private def hexToByte(h: String): Byte = {
+    Integer.parseInt(h, 16).toByte
+  }
+}