diff --git a/sample/src/main/java/com/trendyol/transmission/components/features/input/InputTransformer.kt b/sample/src/main/java/com/trendyol/transmission/components/features/input/InputTransformer.kt
index 2d8708c..477691d 100644
--- a/sample/src/main/java/com/trendyol/transmission/components/features/input/InputTransformer.kt
+++ b/sample/src/main/java/com/trendyol/transmission/components/features/input/InputTransformer.kt
@@ -1,7 +1,11 @@
 package com.trendyol.transmission.components.features.input
 
+import androidx.compose.ui.graphics.Color
 import com.trendyol.transmission.DefaultDispatcher
+import com.trendyol.transmission.ExperimentalTransmissionApi
+import com.trendyol.transmission.components.features.InputUiState
 import com.trendyol.transmission.components.features.colorpicker.ColorPickerEffect
+import com.trendyol.transmission.components.features.multioutput.multiOutputTransformerIdentity
 import com.trendyol.transmission.transformer.Transformer
 import com.trendyol.transmission.transformer.dataholder.dataHolder
 import com.trendyol.transmission.transformer.handler.Handlers
@@ -9,13 +13,13 @@ import com.trendyol.transmission.transformer.handler.createHandlers
 import com.trendyol.transmission.transformer.handler.onEffect
 import com.trendyol.transmission.transformer.handler.onSignal
 import com.trendyol.transmission.transformer.request.Contracts
+import com.trendyol.transmission.transformer.request.checkpointWithArgs
 import com.trendyol.transmission.transformer.request.computation
 import com.trendyol.transmission.transformer.request.computation.Computations
 import com.trendyol.transmission.transformer.request.computation.createComputations
 import com.trendyol.transmission.transformer.request.computation.register
 import com.trendyol.transmission.transformer.request.computationWithArgs
 import com.trendyol.transmission.transformer.request.dataHolder
-import com.trendyol.transmission.components.features.InputUiState
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.delay
 import javax.inject.Inject
@@ -37,20 +41,29 @@ class InputTransformer @Inject constructor(
         }
     }
 
+    @OptIn(ExperimentalTransmissionApi::class)
     override val handlers: Handlers = createHandlers {
         onSignal<InputSignal.InputUpdate> { signal ->
             holder.update { it.copy(writtenText = signal.value) }
+            val color = pauseOn(colorCheckpoint)
+            send(
+                effect = ColorPickerEffect.SelectedColorUpdate(color),
+                identity = multiOutputTransformerIdentity
+            )
             publish(effect = InputEffect.InputUpdate(signal.value))
         }
         onEffect<ColorPickerEffect.BackgroundColorUpdate> { effect ->
+            validate(colorCheckpoint, effect.color)
             holder.update { it.copy(backgroundColor = effect.color) }
         }
     }
 
+    @OptIn(ExperimentalTransmissionApi::class)
     companion object {
         val writtenInputWithArgs = Contracts.computationWithArgs<String, WrittenInput>()
         val writtenInputContract = Contracts.computation<WrittenInput>()
         val holderContract = Contracts.dataHolder<InputUiState>()
+        val colorCheckpoint = Contracts.checkpointWithArgs<Color>()
     }
 }
 
diff --git a/transmission-test/src/main/java/com/trendyol/transmissiontest/TransformerTestScope.kt b/transmission-test/src/main/java/com/trendyol/transmissiontest/TransformerTestScope.kt
index 3fbd639..b01f656 100644
--- a/transmission-test/src/main/java/com/trendyol/transmissiontest/TransformerTestScope.kt
+++ b/transmission-test/src/main/java/com/trendyol/transmissiontest/TransformerTestScope.kt
@@ -1,7 +1,6 @@
 package com.trendyol.transmissiontest
 
 import com.trendyol.transmission.Transmission
-import com.trendyol.transmission.effect.EffectWrapper
 
 interface TransformerTestScope {
     val dataStream: List<Transmission.Data>
diff --git a/transmission/src/main/java/com/trendyol/transmission/Annotations.kt b/transmission/src/main/java/com/trendyol/transmission/Annotations.kt
new file mode 100644
index 0000000..e9812b3
--- /dev/null
+++ b/transmission/src/main/java/com/trendyol/transmission/Annotations.kt
@@ -0,0 +1,16 @@
+package com.trendyol.transmission
+
+/**
+ * Marks internal declarations in Transmission. Internal declarations must not be used outside the library.
+ * There are no backward compatibility guarantees between different versions of Transmission.
+ */
+@RequiresOptIn(level = RequiresOptIn.Level.ERROR)
+@Retention(AnnotationRetention.BINARY)
+annotation class InternalTransmissionApi
+
+/**
+ * Marks experimental API in Transmission. An experimental API can be changed or removed at any time.
+ */
+@RequiresOptIn(level = RequiresOptIn.Level.WARNING)
+@Retention(AnnotationRetention.BINARY)
+annotation class ExperimentalTransmissionApi
diff --git a/transmission/src/main/java/com/trendyol/transmission/effect/EffectWrapper.kt b/transmission/src/main/java/com/trendyol/transmission/effect/EffectWrapper.kt
index dae229f..6994ed3 100644
--- a/transmission/src/main/java/com/trendyol/transmission/effect/EffectWrapper.kt
+++ b/transmission/src/main/java/com/trendyol/transmission/effect/EffectWrapper.kt
@@ -3,7 +3,7 @@ package com.trendyol.transmission.effect
 import com.trendyol.transmission.Transmission
 import com.trendyol.transmission.transformer.request.Contract
 
-data class EffectWrapper(
+internal data class EffectWrapper(
     val effect: Transmission.Effect,
     val identity: Contract.Identity? = null
 )
diff --git a/transmission/src/main/java/com/trendyol/transmission/identifier/IdentifierGenerator.kt b/transmission/src/main/java/com/trendyol/transmission/identifier/IdentifierGenerator.kt
index c6416b4..772cb20 100644
--- a/transmission/src/main/java/com/trendyol/transmission/identifier/IdentifierGenerator.kt
+++ b/transmission/src/main/java/com/trendyol/transmission/identifier/IdentifierGenerator.kt
@@ -3,9 +3,12 @@ package com.trendyol.transmission.identifier
 import kotlin.uuid.ExperimentalUuidApi
 import kotlin.uuid.Uuid
 
+/**
+ * Generates identifier for internal communication.
+ */
 @OptIn(ExperimentalUuidApi::class)
 internal object IdentifierGenerator {
     fun generateIdentifier(): String {
         return Uuid.random().toString()
     }
-}
\ No newline at end of file
+}
diff --git a/transmission/src/main/java/com/trendyol/transmission/router/RequestDelegate.kt b/transmission/src/main/java/com/trendyol/transmission/router/RequestDelegate.kt
index 2864e46..161e5ab 100644
--- a/transmission/src/main/java/com/trendyol/transmission/router/RequestDelegate.kt
+++ b/transmission/src/main/java/com/trendyol/transmission/router/RequestDelegate.kt
@@ -1,5 +1,3 @@
-@file:OptIn(ExperimentalUuidApi::class)
-
 package com.trendyol.transmission.router
 
 import com.trendyol.transmission.Transmission
@@ -20,7 +18,6 @@ import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.flow.receiveAsFlow
 import kotlinx.coroutines.flow.shareIn
 import kotlinx.coroutines.launch
-import kotlin.uuid.ExperimentalUuidApi
 
 internal class RequestDelegate(
     private val queryScope: CoroutineScope,
@@ -49,7 +46,7 @@ internal class RequestDelegate(
 
     // region process queries
 
-    private suspend fun processQuery(query: Query) = queryScope.launch {
+    private fun processQuery(query: Query) = queryScope.launch {
         when (query) {
             is Query.Computation -> processComputationQuery(query)
             is Query.Data -> processDataQuery(query)
@@ -60,7 +57,7 @@ internal class RequestDelegate(
     }
 
     private fun processDataQuery(
-        query: Query.Data
+        query: Query.Data,
     ) = queryScope.launch {
         val dataHolder = routerRef.transformerSet
             .filter { it.storage.isHolderStateInitialized() }
@@ -79,7 +76,7 @@ internal class RequestDelegate(
     }
 
     private fun processComputationQuery(
-        query: Query.Computation
+        query: Query.Computation,
     ) = queryScope.launch {
         val computationHolder = routerRef.transformerSet
             .find { it.storage.hasComputation(query.key) }
@@ -110,7 +107,7 @@ internal class RequestDelegate(
     }
 
     private fun <A : Any> processComputationQueryWithArgs(
-        query: Query.ComputationWithArgs<A>
+        query: Query.ComputationWithArgs<A>,
     ) = queryScope.launch {
         val computationHolder = routerRef.transformerSet
             .find { it.storage.hasComputation(query.key) }
@@ -145,7 +142,7 @@ internal class RequestDelegate(
     }
 
     private fun processExecution(
-        query: Query.Execution
+        query: Query.Execution,
     ) = queryScope.launch {
         val executionHolder = routerRef.transformerSet
             .find { it.storage.hasExecution(query.key) } ?: return@launch
@@ -180,7 +177,7 @@ internal class RequestDelegate(
     }
 
     private fun testDataQuery(
-        query: Query.Data
+        query: Query.Data,
     ) = queryScope.launch {
         val dataToSend = QueryResult.Data(
             owner = query.sender,
@@ -194,7 +191,7 @@ internal class RequestDelegate(
     }
 
     private fun testComputationQuery(
-        query: Query.Computation
+        query: Query.Computation,
     ) = queryScope.launch {
         val computationToSend = QueryResult.Computation(
             owner = query.sender,
@@ -206,7 +203,7 @@ internal class RequestDelegate(
     }
 
     private fun <A : Any> testComputationQueryWithArgs(
-        query: Query.ComputationWithArgs<A>
+        query: Query.ComputationWithArgs<A>,
     ) = queryScope.launch {
         val computationToSend = QueryResult.Computation(
             owner = query.sender,
@@ -236,7 +233,7 @@ internal class RequestDelegate(
 
     override suspend fun <C : Contract.Computation<D>, D : Any> compute(
         contract: C,
-        invalidate: Boolean
+        invalidate: Boolean,
     ): D? {
         val queryIdentifier = IdentifierGenerator.generateIdentifier()
         outGoingQuery.send(
@@ -256,7 +253,7 @@ internal class RequestDelegate(
     override suspend fun <C : Contract.ComputationWithArgs<A, D>, A : Any, D : Any> compute(
         contract: C,
         args: A,
-        invalidate: Boolean
+        invalidate: Boolean,
     ): D? {
         val queryIdentifier = IdentifierGenerator.generateIdentifier()
         outGoingQuery.send(
@@ -284,7 +281,7 @@ internal class RequestDelegate(
 
     override suspend fun <C : Contract.ExecutionWithArgs<A>, A : Any> execute(
         contract: C,
-        args: A
+        args: A,
     ) {
         outGoingQuery.send(
             Query.ExecutionWithArgs(
diff --git a/transmission/src/main/java/com/trendyol/transmission/router/TransmissionRouter.kt b/transmission/src/main/java/com/trendyol/transmission/router/TransmissionRouter.kt
index a0a22ee..3b824c5 100644
--- a/transmission/src/main/java/com/trendyol/transmission/router/TransmissionRouter.kt
+++ b/transmission/src/main/java/com/trendyol/transmission/router/TransmissionRouter.kt
@@ -5,6 +5,7 @@ import com.trendyol.transmission.effect.EffectWrapper
 import com.trendyol.transmission.router.builder.TransmissionRouterBuilderScope
 import com.trendyol.transmission.router.loader.TransformerSetLoader
 import com.trendyol.transmission.transformer.Transformer
+import com.trendyol.transmission.transformer.checkpoint.CheckpointTracker
 import com.trendyol.transmission.transformer.request.Contract
 import com.trendyol.transmission.transformer.request.RequestHandler
 import kotlinx.coroutines.CoroutineDispatcher
@@ -42,6 +43,8 @@ class TransmissionRouter internal constructor(
     private val dataBroadcast = routerScope.createBroadcast<Transmission.Data>()
     private val effectBroadcast = routerScope.createBroadcast<EffectWrapper>()
 
+    private val checkpointTracker = CheckpointTracker()
+
     val dataStream = dataBroadcast.output
     val effectStream: SharedFlow<Transmission.Effect> = effectBroadcast.output.map { it.effect }
         .shareIn(routerScope, SharingStarted.WhileSubscribed())
@@ -51,6 +54,7 @@ class TransmissionRouter internal constructor(
         routerRef = this@TransmissionRouter,
         registry = registryScope
     )
+
     val requestHelper: RequestHandler = _requestDelegate
 
     init {
@@ -97,6 +101,7 @@ class TransmissionRouter internal constructor(
         }
         transformerSet.forEach { transformer ->
             transformer.run {
+                bindCheckpointTracker(checkpointTracker)
                 startSignalCollection(incoming = signalBroadcast.output)
                 startDataPublishing(data = dataBroadcast.producer)
                 startEffectProcessing(
diff --git a/transmission/src/main/java/com/trendyol/transmission/transformer/CommunicationScopeBuilder.kt b/transmission/src/main/java/com/trendyol/transmission/transformer/CommunicationScopeBuilder.kt
index 5a15700..db6c627 100644
--- a/transmission/src/main/java/com/trendyol/transmission/transformer/CommunicationScopeBuilder.kt
+++ b/transmission/src/main/java/com/trendyol/transmission/transformer/CommunicationScopeBuilder.kt
@@ -1,5 +1,6 @@
 package com.trendyol.transmission.transformer
 
+import com.trendyol.transmission.ExperimentalTransmissionApi
 import com.trendyol.transmission.Transmission
 import com.trendyol.transmission.effect.EffectWrapper
 import com.trendyol.transmission.transformer.handler.CommunicationScope
@@ -7,6 +8,7 @@ import com.trendyol.transmission.transformer.request.Contract
 import com.trendyol.transmission.transformer.request.TransformerRequestDelegate
 import kotlinx.coroutines.channels.Channel
 
+@OptIn(ExperimentalTransmissionApi::class)
 internal class CommunicationScopeBuilder(
     private val effectChannel: Channel<EffectWrapper>,
     private val dataChannel: Channel<Transmission.Data>,
@@ -29,14 +31,14 @@ internal class CommunicationScopeBuilder(
     }
 
     override suspend fun <C : Contract.DataHolder<D>, D : Transmission.Data> getData(contract: C): D? {
-        return requestDelegate.interactor.getData(contract)
+        return requestDelegate.requestHandler.getData(contract)
     }
 
     override suspend fun <C : Contract.Computation<D>, D : Any> compute(
         contract: C,
         invalidate: Boolean
     ): D? {
-        return requestDelegate.interactor.compute(contract, invalidate)
+        return requestDelegate.requestHandler.compute(contract, invalidate)
     }
 
     override suspend fun <C : Contract.ComputationWithArgs<A, D>, A : Any, D : Any> compute(
@@ -44,17 +46,55 @@ internal class CommunicationScopeBuilder(
         args: A,
         invalidate: Boolean
     ): D? {
-        return requestDelegate.interactor.compute(contract, args, invalidate)
+        return requestDelegate.requestHandler.compute(contract, args, invalidate)
     }
 
     override suspend fun execute(contract: Contract.Execution) {
-        requestDelegate.interactor.execute(contract)
+        requestDelegate.requestHandler.execute(contract)
     }
 
     override suspend fun <C : Contract.ExecutionWithArgs<A>, A : Any> execute(
         contract: C,
         args: A
     ) {
-        requestDelegate.interactor.execute(contract, args)
+        requestDelegate.requestHandler.execute(contract, args)
+    }
+
+    @ExperimentalTransmissionApi
+    override suspend fun CommunicationScope.pauseOn(
+        contract: Contract.Checkpoint.Default
+    ) {
+        with(requestDelegate.checkpointHandler) {
+            pauseOn(contract)
+        }
+    }
+
+    @ExperimentalTransmissionApi
+    override suspend fun CommunicationScope.pauseOn(
+        vararg contract: Contract.Checkpoint.Default
+    ) {
+        with(requestDelegate.checkpointHandler) {
+            pauseOn(*contract)
+        }
+    }
+
+    @ExperimentalTransmissionApi
+    override suspend fun <C : Contract.Checkpoint.WithArgs<A>, A : Any> CommunicationScope.pauseOn(
+        contract: C
+    ): A {
+        return with(requestDelegate.checkpointHandler) {
+            pauseOn(contract)
+        }
+    }
+
+    override suspend fun validate(contract: Contract.Checkpoint.Default) {
+        requestDelegate.checkpointHandler.validate(contract)
+    }
+
+    override suspend fun <C : Contract.Checkpoint.WithArgs<A>, A : Any> validate(
+        contract: C,
+        args: A
+    ) {
+        requestDelegate.checkpointHandler.validate(contract, args)
     }
 }
diff --git a/transmission/src/main/java/com/trendyol/transmission/transformer/Transformer.kt b/transmission/src/main/java/com/trendyol/transmission/transformer/Transformer.kt
index 714374a..7aecaea 100644
--- a/transmission/src/main/java/com/trendyol/transmission/transformer/Transformer.kt
+++ b/transmission/src/main/java/com/trendyol/transmission/transformer/Transformer.kt
@@ -1,8 +1,10 @@
 package com.trendyol.transmission.transformer
 
+import com.trendyol.transmission.ExperimentalTransmissionApi
 import com.trendyol.transmission.Transmission
 import com.trendyol.transmission.effect.EffectWrapper
 import com.trendyol.transmission.effect.RouterEffect
+import com.trendyol.transmission.transformer.checkpoint.CheckpointTracker
 import com.trendyol.transmission.transformer.handler.CommunicationScope
 import com.trendyol.transmission.transformer.handler.ExtendedHandlers
 import com.trendyol.transmission.transformer.handler.Handlers
@@ -36,6 +38,7 @@ import kotlinx.coroutines.flow.receiveAsFlow
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.supervisorScope
 
+@OptIn(ExperimentalTransmissionApi::class)
 open class Transformer(
     identity: Contract.Identity = Contracts.identity(),
     dispatcher: CoroutineDispatcher = Dispatchers.Default,
@@ -51,7 +54,14 @@ open class Transformer(
     private val _identity: Contract.Identity = identity
 
     private val effectChannel: Channel<EffectWrapper> = Channel(capacity = Channel.BUFFERED)
-    private val requestDelegate = TransformerRequestDelegate(transformerScope, _identity)
+    private var checkpointProvider: () -> CheckpointTracker? = { null }
+    private val requestDelegate by lazy {
+        TransformerRequestDelegate(
+            scope = transformerScope,
+            checkpointTrackerProvider = checkpointProvider,
+            identity = _identity
+        )
+    }
     internal val dataChannel: Channel<Transmission.Data> = Channel(capacity = Channel.BUFFERED)
     internal val storage = TransformerStorage()
 
@@ -73,11 +83,18 @@ open class Transformer(
     var currentEffectProcessing: Job? = null
     var currentSignalProcessing: Job? = null
 
-    val communicationScope: CommunicationScope = CommunicationScopeBuilder(
-        effectChannel = effectChannel,
-        dataChannel = dataChannel,
-        requestDelegate = requestDelegate
-    )
+    val communicationScope: CommunicationScope by lazy {
+        CommunicationScopeBuilder(
+            effectChannel = effectChannel,
+            dataChannel = dataChannel,
+            requestDelegate = requestDelegate
+        )
+    }
+
+
+    internal fun bindCheckpointTracker(tracker: CheckpointTracker) {
+        checkpointProvider = { tracker }
+    }
 
     internal fun startSignalCollection(incoming: SharedFlow<Transmission.Signal>) {
         transformerScope.launch {
diff --git a/transmission/src/main/java/com/trendyol/transmission/transformer/checkpoint/CheckpointHandler.kt b/transmission/src/main/java/com/trendyol/transmission/transformer/checkpoint/CheckpointHandler.kt
new file mode 100644
index 0000000..f349db9
--- /dev/null
+++ b/transmission/src/main/java/com/trendyol/transmission/transformer/checkpoint/CheckpointHandler.kt
@@ -0,0 +1,54 @@
+package com.trendyol.transmission.transformer.checkpoint
+
+import com.trendyol.transmission.ExperimentalTransmissionApi
+import com.trendyol.transmission.transformer.handler.CommunicationScope
+import com.trendyol.transmission.transformer.request.Contract
+
+interface CheckpointHandler {
+
+    /**
+     * Pauses the processing of a [Transmission.Signal] or [Transmission.Effect] using
+     * the given [Contract.Checkpoint].
+     * @param contract Checkpoint to check for pause condition
+     * @return Unit after the [contract] is validated
+     */
+    @ExperimentalTransmissionApi
+    suspend fun CommunicationScope.pauseOn(
+        contract: Contract.Checkpoint.Default,
+    )
+
+    /**
+     * Pauses the processing of a [Transmission.Signal] or [Transmission.Effect] using
+     * the given [Contract.Checkpoint]s.
+     * @param contract Checkpoints to check for pause condition.
+     * @return Unit after the [contract]s are validated
+     * @throws IllegalStateException when no [Contract.Checkpoint] is supplied
+     */
+    @ExperimentalTransmissionApi
+    suspend fun CommunicationScope.pauseOn(
+        vararg contract: Contract.Checkpoint.Default,
+    )
+
+    /**
+     * Pauses the processing of a [Transmission.Signal] or [Transmission.Effect] using
+     * the given [Contract.CheckpointWithArgs]s.
+     * @param contract Checkpoint with Args to check for pause condition.
+     * @return the type of argument depicted in [contract] after the checkpoint is validated
+     */
+    @ExperimentalTransmissionApi
+    suspend fun <C : Contract.Checkpoint.WithArgs<A>, A : Any> CommunicationScope.pauseOn(
+        contract: C,
+    ): A
+
+    /**
+     * Validates the given [Contract.Checkpoint] and resumes the execution added with [pauseOn]
+     */
+    @ExperimentalTransmissionApi
+    suspend fun validate(contract: Contract.Checkpoint.Default)
+
+    /**
+     * Validates the given [Contract.CheckpointWithArgs] and resumes the execution added with [pauseOn]
+     */
+    @ExperimentalTransmissionApi
+    suspend fun <C : Contract.Checkpoint.WithArgs<A>, A : Any> validate(contract: C, args: A)
+}
diff --git a/transmission/src/main/java/com/trendyol/transmission/transformer/checkpoint/CheckpointTracker.kt b/transmission/src/main/java/com/trendyol/transmission/transformer/checkpoint/CheckpointTracker.kt
new file mode 100644
index 0000000..f542158
--- /dev/null
+++ b/transmission/src/main/java/com/trendyol/transmission/transformer/checkpoint/CheckpointTracker.kt
@@ -0,0 +1,43 @@
+package com.trendyol.transmission.transformer.checkpoint
+
+import com.trendyol.transmission.InternalTransmissionApi
+import com.trendyol.transmission.transformer.request.Contract
+import java.util.concurrent.ConcurrentHashMap
+import java.util.concurrent.ConcurrentMap
+
+@OptIn(InternalTransmissionApi::class)
+internal class CheckpointTracker {
+    private val tracker: ConcurrentMap<String, ArrayDeque<CheckpointValidator<*, *>>> =
+        ConcurrentHashMap()
+    private val contractTracker: ConcurrentMap<Contract.Checkpoint, String> = ConcurrentHashMap()
+
+    fun registerContract(contract: Contract.Checkpoint, identifier: String) {
+        contractTracker.put(contract, identifier)
+    }
+
+    fun <C : Contract.Checkpoint, A : Any> putOrCreate(
+        identifier: String,
+        validator: CheckpointValidator<C, A>
+    ) {
+        tracker
+            .putIfAbsent(identifier, ArrayDeque<CheckpointValidator<*, *>>().apply {
+                addLast(validator)
+            })?.addLast(validator)
+    }
+
+    fun <C : Contract.Checkpoint, A : Any> useValidator(contract: Contract.Checkpoint): CheckpointValidator<C, A>? {
+        val identifier = contractTracker[contract] ?: return null
+        return tracker[identifier]?.firstOrNull() as? CheckpointValidator<C, A>
+    }
+
+    fun removeValidator(contract: Contract.Checkpoint) {
+        val identifier = contractTracker[contract] ?: return
+        val contractsToRemove = contractTracker.entries
+            .filter { it.value == identifier }
+            .map { it.key }
+        contractsToRemove.forEach {
+            contractTracker.remove(it)
+        }
+        tracker[identifier]?.removeFirstOrNull()
+    }
+}
diff --git a/transmission/src/main/java/com/trendyol/transmission/transformer/checkpoint/CheckpointValidator.kt b/transmission/src/main/java/com/trendyol/transmission/transformer/checkpoint/CheckpointValidator.kt
new file mode 100644
index 0000000..ccf5d23
--- /dev/null
+++ b/transmission/src/main/java/com/trendyol/transmission/transformer/checkpoint/CheckpointValidator.kt
@@ -0,0 +1,9 @@
+package com.trendyol.transmission.transformer.checkpoint
+
+import com.trendyol.transmission.InternalTransmissionApi
+import com.trendyol.transmission.transformer.request.Contract
+
+@InternalTransmissionApi
+interface CheckpointValidator<C : Contract.Checkpoint, A : Any> {
+    suspend fun validate(contract: C, args: A): Boolean
+}
\ No newline at end of file
diff --git a/transmission/src/main/java/com/trendyol/transmission/transformer/dataholder/TransmissionDataHolder.kt b/transmission/src/main/java/com/trendyol/transmission/transformer/dataholder/TransmissionDataHolder.kt
index 965563b..f852813 100644
--- a/transmission/src/main/java/com/trendyol/transmission/transformer/dataholder/TransmissionDataHolder.kt
+++ b/transmission/src/main/java/com/trendyol/transmission/transformer/dataholder/TransmissionDataHolder.kt
@@ -16,7 +16,6 @@ interface TransmissionDataHolder<T : Transmission.Data?> {
     suspend fun updateAndGet(updater: (T) -> @UnsafeVariance T): T
 }
 
-@PublishedApi
 internal class TransmissionDataHolderImpl<T : Transmission.Data?>(
     initialValue: T,
     publishUpdates: Boolean,
diff --git a/transmission/src/main/java/com/trendyol/transmission/transformer/handler/CommunicationScope.kt b/transmission/src/main/java/com/trendyol/transmission/transformer/handler/CommunicationScope.kt
index 9f9971e..53de3be 100644
--- a/transmission/src/main/java/com/trendyol/transmission/transformer/handler/CommunicationScope.kt
+++ b/transmission/src/main/java/com/trendyol/transmission/transformer/handler/CommunicationScope.kt
@@ -3,10 +3,11 @@ package com.trendyol.transmission.transformer.handler
 import com.trendyol.transmission.Transmission
 import com.trendyol.transmission.router.TransmissionRouter
 import com.trendyol.transmission.transformer.Transformer
+import com.trendyol.transmission.transformer.checkpoint.CheckpointHandler
 import com.trendyol.transmission.transformer.request.Contract
 import com.trendyol.transmission.transformer.request.RequestHandler
 
-interface CommunicationScope : RequestHandler {
+interface CommunicationScope : RequestHandler, CheckpointHandler {
     /**
      * Sends data to [TransmissionRouter]
      * @param data of type [Transmission.Data]
diff --git a/transmission/src/main/java/com/trendyol/transmission/transformer/request/Contract.kt b/transmission/src/main/java/com/trendyol/transmission/transformer/request/Contract.kt
index 4a20b4f..bbddd8b 100644
--- a/transmission/src/main/java/com/trendyol/transmission/transformer/request/Contract.kt
+++ b/transmission/src/main/java/com/trendyol/transmission/transformer/request/Contract.kt
@@ -20,9 +20,22 @@ sealed interface Contract {
         internal val useCache: Boolean = false
     ) : Contract
 
-    class Execution internal constructor(internal val key: String) : Contract
+    @JvmInline
+    value class Execution internal constructor(internal val key: String) : Contract
 
     class ExecutionWithArgs<A : Any> internal constructor(
         internal val key: String
     ) : Contract
+
+    sealed class Checkpoint(
+        internal open val key: String,
+    ) : Contract {
+        class Default internal constructor(
+            internal override val key: String,
+        ) : Checkpoint(key)
+
+        class WithArgs<A : Any> internal constructor(
+            internal override val key: String,
+        ) : Checkpoint(key)
+    }
 }
diff --git a/transmission/src/main/java/com/trendyol/transmission/transformer/request/ContractExt.kt b/transmission/src/main/java/com/trendyol/transmission/transformer/request/ContractExt.kt
index 4b9c02e..594a09c 100644
--- a/transmission/src/main/java/com/trendyol/transmission/transformer/request/ContractExt.kt
+++ b/transmission/src/main/java/com/trendyol/transmission/transformer/request/ContractExt.kt
@@ -1,5 +1,6 @@
 package com.trendyol.transmission.transformer.request
 
+import com.trendyol.transmission.ExperimentalTransmissionApi
 import com.trendyol.transmission.Transmission
 import com.trendyol.transmission.identifier.IdentifierGenerator
 
@@ -38,3 +39,17 @@ fun Contracts.execution(): Contract.Execution {
 fun <A : Any> Contracts.executionWithArgs(): Contract.ExecutionWithArgs<A> {
     return Contract.ExecutionWithArgs<A>(key = IdentifierGenerator.generateIdentifier())
 }
+
+@ExperimentalTransmissionApi
+fun Contracts.checkpoint(): Contract.Checkpoint.Default {
+    return Contract.Checkpoint.Default(
+        key = IdentifierGenerator.generateIdentifier(),
+    )
+}
+
+@ExperimentalTransmissionApi
+fun <A : Any> Contracts.checkpointWithArgs(): Contract.Checkpoint.WithArgs<A> {
+    return Contract.Checkpoint.WithArgs(
+        key = IdentifierGenerator.generateIdentifier(),
+    )
+}
diff --git a/transmission/src/main/java/com/trendyol/transmission/transformer/request/Query.kt b/transmission/src/main/java/com/trendyol/transmission/transformer/request/Query.kt
index 14818a0..2d2a8b5 100644
--- a/transmission/src/main/java/com/trendyol/transmission/transformer/request/Query.kt
+++ b/transmission/src/main/java/com/trendyol/transmission/transformer/request/Query.kt
@@ -31,4 +31,5 @@ internal sealed interface Query {
         val key: String,
         val args: A,
     ) : Query
+
 }
diff --git a/transmission/src/main/java/com/trendyol/transmission/transformer/request/QueryResult.kt b/transmission/src/main/java/com/trendyol/transmission/transformer/request/QueryResult.kt
index 579ebbe..aa6a85b 100644
--- a/transmission/src/main/java/com/trendyol/transmission/transformer/request/QueryResult.kt
+++ b/transmission/src/main/java/com/trendyol/transmission/transformer/request/QueryResult.kt
@@ -2,7 +2,7 @@ package com.trendyol.transmission.transformer.request
 
 import com.trendyol.transmission.Transmission
 
-sealed class QueryResult(
+internal sealed class QueryResult(
     open val owner: String,
     open val key: String,
 ) {
@@ -19,4 +19,12 @@ sealed class QueryResult(
         val data: D?,
         val resultIdentifier: String,
     ) : QueryResult(owner, key)
+
+    class Checkpoint<D : Any>(
+        override val owner: String,
+        override val key: String,
+        val data: D,
+        val resultIdentifier: String,
+    ) : QueryResult(owner, key)
+
 }
diff --git a/transmission/src/main/java/com/trendyol/transmission/transformer/request/RequestHandler.kt b/transmission/src/main/java/com/trendyol/transmission/transformer/request/RequestHandler.kt
index c0d4ce9..c608bff 100644
--- a/transmission/src/main/java/com/trendyol/transmission/transformer/request/RequestHandler.kt
+++ b/transmission/src/main/java/com/trendyol/transmission/transformer/request/RequestHandler.kt
@@ -1,23 +1,50 @@
 package com.trendyol.transmission.transformer.request
 
 import com.trendyol.transmission.Transmission
+import com.trendyol.transmission.transformer.Transformer
 
 interface RequestHandler {
 
+    /**
+     * Gets the data using the provided [Contract.DataHolder]
+     * @param contract DataHolder Contract to be sent
+     */
     suspend fun <C : Contract.DataHolder<D>, D : Transmission.Data> getData(contract: C): D?
 
+    /**
+     * Starts computation in the target [Transformer] and returns the result data.
+     * @param contract Computation Contract to be sent
+     * @param invalidate if the Computation is cached, this invalidates the result make it compute
+     * again. If it is not cached, it doesn't have any effect.
+     */
     suspend fun <C : Contract.Computation<D>, D : Any> compute(
         contract: C,
         invalidate: Boolean = false,
     ): D?
 
+    /**
+     * Starts computation in the target [Transformer] and returns the result data.
+     * @param contract Computation Contract to be sent
+     * @param args data required by Computation
+     * @param invalidate if the Computation is cached, this invalidates the result make it compute
+     * again. If it is not cached, it doesn't have any effect.
+     */
     suspend fun <C : Contract.ComputationWithArgs<A, D>, A : Any, D : Any> compute(
         contract: C,
         args: A,
         invalidate: Boolean = false,
     ): D?
 
+    /**
+     * Starts Execution in the target [Transformer]
+     * @param contract Execution Contract to be sent
+     */
     suspend fun execute(contract: Contract.Execution)
 
+    /**
+     * Starts Execution in the target [Transformer]
+     * @param contract Execution Contract to be sent
+     * @param args data required by Execution
+     */
     suspend fun <C : Contract.ExecutionWithArgs<A>, A : Any> execute(contract: C, args: A)
 }
diff --git a/transmission/src/main/java/com/trendyol/transmission/transformer/request/TransformerRequestDelegate.kt b/transmission/src/main/java/com/trendyol/transmission/transformer/request/TransformerRequestDelegate.kt
index 3ce398b..d50924f 100644
--- a/transmission/src/main/java/com/trendyol/transmission/transformer/request/TransformerRequestDelegate.kt
+++ b/transmission/src/main/java/com/trendyol/transmission/transformer/request/TransformerRequestDelegate.kt
@@ -1,20 +1,142 @@
 package com.trendyol.transmission.transformer.request
 
+import com.trendyol.transmission.ExperimentalTransmissionApi
+import com.trendyol.transmission.InternalTransmissionApi
 import com.trendyol.transmission.Transmission
 import com.trendyol.transmission.identifier.IdentifierGenerator
 import com.trendyol.transmission.router.createBroadcast
+import com.trendyol.transmission.transformer.checkpoint.CheckpointHandler
+import com.trendyol.transmission.transformer.checkpoint.CheckpointTracker
+import com.trendyol.transmission.transformer.checkpoint.CheckpointValidator
+import com.trendyol.transmission.transformer.handler.CommunicationScope
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.channels.Channel
 import kotlinx.coroutines.flow.filter
 import kotlinx.coroutines.flow.filterIsInstance
 import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.suspendCancellableCoroutine
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
+import java.util.concurrent.ConcurrentHashMap
+import kotlin.coroutines.resume
 
-internal class TransformerRequestDelegate(scope: CoroutineScope, identity: Contract.Identity) {
+@OptIn(InternalTransmissionApi::class)
+@ExperimentalTransmissionApi
+internal class TransformerRequestDelegate(
+    scope: CoroutineScope,
+    checkpointTrackerProvider: () -> CheckpointTracker?,
+    identity: Contract.Identity
+) {
 
     val outGoingQuery: Channel<Query> = Channel(capacity = Channel.BUFFERED)
     val resultBroadcast = scope.createBroadcast<QueryResult>()
 
-    val interactor: RequestHandler = object : RequestHandler {
+    val checkpointHandler: CheckpointHandler by lazy {
+        object : CheckpointHandler {
+
+            @ExperimentalTransmissionApi
+            override suspend fun CommunicationScope.pauseOn(contract: Contract.Checkpoint.Default) {
+                val queryIdentifier = IdentifierGenerator.generateIdentifier()
+                suspendCancellableCoroutine<Unit> { continuation ->
+                    val validator =
+                        object : CheckpointValidator<Contract.Checkpoint.Default, Unit> {
+
+                            override suspend fun validate(
+                                contract: Contract.Checkpoint.Default,
+                                args: Unit
+                            ): Boolean {
+                                continuation.resume(Unit)
+                                return true
+                            }
+                        }
+                    checkpointTrackerProvider()?.run {
+                        registerContract(contract, queryIdentifier)
+                        putOrCreate(queryIdentifier, validator)
+                    }
+                }
+            }
+
+            @ExperimentalTransmissionApi
+            override suspend fun CommunicationScope.pauseOn(
+                vararg contract: Contract.Checkpoint.Default
+            ) {
+                val contractList = contract.toList()
+                check(contractList.isNotEmpty()) {
+                    "At least one checkpoint should be provided"
+                }
+                check(contractList.toSet().size == contractList.size) {
+                    "All Checkpoint Contracts should be unique"
+                }
+                val queryIdentifier = IdentifierGenerator.generateIdentifier()
+                suspendCancellableCoroutine<Unit> { continuation ->
+                    val validator =
+                        object : CheckpointValidator<Contract.Checkpoint.Default, Unit> {
+                            private val lock = Mutex()
+                            private val contractMap =
+                                ConcurrentHashMap<Contract.Checkpoint.Default, Boolean>()
+                                    .apply { putAll(contractList.map { it to false }) }
+
+                            override suspend fun validate(
+                                contract: Contract.Checkpoint.Default,
+                                args: Unit
+                            ): Boolean {
+                                lock.withLock { contractMap.put(contract, true) }
+                                if (contractMap.values.all { it }) {
+                                    continuation.resume(Unit)
+                                    return true
+                                } else return false
+                            }
+                        }
+                    checkpointTrackerProvider()?.run {
+                        contractList.forEach { registerContract(it, queryIdentifier) }
+                        putOrCreate(queryIdentifier, validator)
+                    }
+                }
+            }
+
+            @ExperimentalTransmissionApi
+            override suspend fun <C : Contract.Checkpoint.WithArgs<A>, A : Any> CommunicationScope.pauseOn(
+                contract: C
+            ): A {
+                val queryIdentifier = IdentifierGenerator.generateIdentifier()
+                return suspendCancellableCoroutine<A> { continuation ->
+                    val validator = object : CheckpointValidator<C, A> {
+                        override suspend fun validate(contract: C, args: A): Boolean {
+                            continuation.resume(args)
+                            return true
+                        }
+                    }
+                    checkpointTrackerProvider()?.run {
+                        registerContract(contract, queryIdentifier)
+                        putOrCreate(queryIdentifier, validator)
+                    }
+                }
+            }
+
+            override suspend fun validate(contract: Contract.Checkpoint.Default) {
+                val validator = checkpointTrackerProvider()
+                    ?.useValidator<Contract.Checkpoint.Default, Unit>(contract)
+                if (validator?.validate(contract, Unit) == true) {
+                    checkpointTrackerProvider()
+                        ?.removeValidator(contract)
+                }
+            }
+
+            override suspend fun <C : Contract.Checkpoint.WithArgs<A>, A : Any> validate(
+                contract: C,
+                args: A
+            ) {
+                val validator = checkpointTrackerProvider()
+                    ?.useValidator<C, A>(contract)
+                if (validator?.validate(contract, args) == true) {
+                    checkpointTrackerProvider()
+                        ?.removeValidator(contract)
+                }
+            }
+        }
+    }
+
+    val requestHandler: RequestHandler = object : RequestHandler {
 
         override suspend fun <C : Contract.DataHolder<D>, D : Transmission.Data> getData(contract: C): D? {
             val queryIdentifier = IdentifierGenerator.generateIdentifier()
diff --git a/transmission/src/main/java/com/trendyol/transmission/transformer/request/execution/ExecutionExt.kt b/transmission/src/main/java/com/trendyol/transmission/transformer/request/execution/ExecutionExt.kt
index 3ff1d0a..3b0e2e9 100644
--- a/transmission/src/main/java/com/trendyol/transmission/transformer/request/execution/ExecutionExt.kt
+++ b/transmission/src/main/java/com/trendyol/transmission/transformer/request/execution/ExecutionExt.kt
@@ -13,8 +13,8 @@ import com.trendyol.transmission.transformer.request.RequestHandler
  * Can be queried using [RequestHandler.execute]
  * @param execution execution to get the result [Transmission.Data]
  */
-fun <C : Contract.Execution> ExecutionScope.register(
-    contract: C,
+fun ExecutionScope.register(
+    contract: Contract.Execution,
     execution: suspend RequestHandler.() -> Unit,
 ) {
     this.executionRegistry.buildWith(contract.key, execution)