diff --git a/ServerPart/build.gradle b/ServerPart/build.gradle
index 36af0bc4..a9173a3e 100644
--- a/ServerPart/build.gradle
+++ b/ServerPart/build.gradle
@@ -34,6 +34,7 @@ dependencies {
     api "io.ktor:ktor-server:$ktor_version"
     api "io.ktor:ktor-server-core:$ktor_version"
     api "io.ktor:ktor-websockets:$ktor_version"
+    api "io.ktor:ktor-serialization:$ktor_version"
 }
 
 compileKotlin {
diff --git a/ServerPart/src/main/kotlin/com/insanusmokrassar/postssystem/core/server/Installation.kt b/ServerPart/src/main/kotlin/com/insanusmokrassar/postssystem/core/server/Installation.kt
new file mode 100644
index 00000000..d7385168
--- /dev/null
+++ b/ServerPart/src/main/kotlin/com/insanusmokrassar/postssystem/core/server/Installation.kt
@@ -0,0 +1,24 @@
+package com.insanusmokrassar.postssystem.core.server
+
+import io.ktor.application.*
+import io.ktor.features.ContentNegotiation
+import io.ktor.http.ContentType
+import io.ktor.serialization.serialization
+import io.ktor.websocket.WebSockets
+import kotlinx.serialization.json.Json
+
+fun Application.installCorePosts() {
+    featureOrNull(ContentNegotiation) ?: install(ContentNegotiation) {
+        serialization(
+            contentType = ContentType.Application.Json,
+            json = Json.plain
+        )
+    }
+}
+
+fun Application.installCorePostsWrite() {
+    installCorePosts()
+    featureOrNull(WebSockets) ?: install(WebSockets) {
+        maxFrameSize = Long.MAX_VALUE
+    }
+}
diff --git a/ServerPart/src/main/kotlin/com/insanusmokrassar/postssystem/core/server/ReadModules.kt b/ServerPart/src/main/kotlin/com/insanusmokrassar/postssystem/core/server/ReadModules.kt
index 3c8f2b09..326ac614 100644
--- a/ServerPart/src/main/kotlin/com/insanusmokrassar/postssystem/core/server/ReadModules.kt
+++ b/ServerPart/src/main/kotlin/com/insanusmokrassar/postssystem/core/server/ReadModules.kt
@@ -7,7 +7,8 @@ import com.insanusmokrassar.postssystem.core.content.ContentId
 import com.insanusmokrassar.postssystem.core.post.*
 import com.insanusmokrassar.postssystem.core.utils.pagination.PaginationRequest
 import com.insanusmokrassar.postssystem.core.utils.pagination.PaginationResult
-import io.ktor.application.call
+import io.ktor.application.*
+import io.ktor.features.ContentNegotiation
 import io.ktor.http.ContentType
 import io.ktor.http.HttpStatusCode
 import io.ktor.request.receiveOrNull
@@ -15,17 +16,17 @@ import io.ktor.response.respond
 import io.ktor.response.respondText
 import io.ktor.routing.Route
 import io.ktor.routing.post
+import io.ktor.serialization.serialization
+import kotlinx.serialization.InternalSerializationApi
 import kotlinx.serialization.json.Json
 import org.joda.time.DateTime
 
+@InternalSerializationApi
 fun Route.includePostsCoreReadModules(readPostsAPI: ReadPostsAPI) {
     post(getPostByIdAddress) {
         call.receiveOrNull<PostId>() ?.also { id ->
             val post = readPostsAPI.getPostById(id)
-            post ?.let {
-                val simplePost = post.asSimplePost
-                call.answer(SimplePost.serializer(), simplePost)
-            } ?: call.respond(HttpStatusCode.NotFound, "Not found")
+            call.answer(SimplePost.serializer(), post ?.asSimplePost)
         } ?: call.answerBadRequest("Id of post")
     }
     post(getPostsByContentIdAddress) {
diff --git a/ServerPart/src/main/kotlin/com/insanusmokrassar/postssystem/core/server/WriteModules.kt b/ServerPart/src/main/kotlin/com/insanusmokrassar/postssystem/core/server/WriteModules.kt
index d8ee7907..df93f7bf 100644
--- a/ServerPart/src/main/kotlin/com/insanusmokrassar/postssystem/core/server/WriteModules.kt
+++ b/ServerPart/src/main/kotlin/com/insanusmokrassar/postssystem/core/server/WriteModules.kt
@@ -4,11 +4,15 @@ import com.insanusmokrassar.postssystem.core.api.WritePostsAPI
 import com.insanusmokrassar.postssystem.core.clientserver.common.*
 import com.insanusmokrassar.postssystem.core.clientserver.common.models.UpdatePostRequest
 import com.insanusmokrassar.postssystem.core.post.*
-import io.ktor.application.call
+import io.ktor.application.*
+import io.ktor.features.ContentNegotiation
+import io.ktor.http.ContentType
 import io.ktor.http.cio.websocket.Frame
 import io.ktor.request.receiveOrNull
 import io.ktor.routing.Route
 import io.ktor.routing.post
+import io.ktor.serialization.serialization
+import io.ktor.websocket.WebSockets
 import io.ktor.websocket.webSocket
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.collect