diff --git a/briar-headless/src/main/java/org/briarproject/bramble/identity/OutputAuthor.kt b/briar-headless/src/main/java/org/briarproject/bramble/identity/OutputAuthor.kt
index 2b498c712..7c0790ba1 100644
--- a/briar-headless/src/main/java/org/briarproject/bramble/identity/OutputAuthor.kt
+++ b/briar-headless/src/main/java/org/briarproject/bramble/identity/OutputAuthor.kt
@@ -1,21 +1,13 @@
 package org.briarproject.bramble.identity
 
 import org.briarproject.bramble.api.identity.Author
-import javax.annotation.concurrent.Immutable
 
-@Immutable
-data class OutputAuthor(
-    val id: ByteArray,
-    val name: String,
-    val publicKey: ByteArray
-) {
-    constructor(author: Author) : this(
-        id = author.id.bytes,
-        name = author.name,
-        publicKey = author.publicKey
-    )
-}
-
-fun Author.output() = OutputAuthor(this)
+fun Author.output() = mapOf(
+    "formatVersion" to formatVersion,
+    "id" to id.bytes,
+    "name" to name,
+    "publicKey" to publicKey
+)
 
 fun Author.Status.output() = name.toLowerCase()
+
diff --git a/briar-headless/src/main/java/org/briarproject/briar/headless/blogs/BlogControllerImpl.kt b/briar-headless/src/main/java/org/briarproject/briar/headless/blogs/BlogControllerImpl.kt
index 21f8a719d..4125dfba1 100644
--- a/briar-headless/src/main/java/org/briarproject/briar/headless/blogs/BlogControllerImpl.kt
+++ b/briar-headless/src/main/java/org/briarproject/briar/headless/blogs/BlogControllerImpl.kt
@@ -23,12 +23,10 @@ internal class BlogControllerImpl
 ) : BlogController {
 
     override fun listPosts(ctx: Context): Context {
-        val posts = blogManager.blogs.flatMap { blog ->
-            blogManager.getPostHeaders(blog.id).map { header ->
-                val body = blogManager.getPostBody(header.id)
-                header.output(body)
-            }
-        }.sortedBy { it.timestampReceived }
+        val posts = blogManager.blogs
+            .flatMap { blog -> blogManager.getPostHeaders(blog.id) }
+            .sortedBy { it.timeReceived }
+            .map { header -> header.output(blogManager.getPostBody(header.id)) }
         return ctx.json(posts)
     }
 
diff --git a/briar-headless/src/main/java/org/briarproject/briar/headless/blogs/OutputBlogPost.kt b/briar-headless/src/main/java/org/briarproject/briar/headless/blogs/OutputBlogPost.kt
index 5ac53ea42..b744c9401 100644
--- a/briar-headless/src/main/java/org/briarproject/briar/headless/blogs/OutputBlogPost.kt
+++ b/briar-headless/src/main/java/org/briarproject/briar/headless/blogs/OutputBlogPost.kt
@@ -1,38 +1,20 @@
 package org.briarproject.briar.headless.blogs
 
-import org.briarproject.bramble.identity.OutputAuthor
 import org.briarproject.bramble.identity.output
 import org.briarproject.briar.api.blog.BlogPostHeader
 import org.briarproject.briar.api.blog.MessageType
-import javax.annotation.concurrent.Immutable
 
-@Immutable
-internal data class OutputBlogPost(
-    val body: String,
-    val author: OutputAuthor,
-    val authorStatus: String,
-    val type: String,
-    val id: ByteArray,
-    val parentId: ByteArray?,
-    val read: Boolean,
-    val rssFeed: Boolean,
-    val timestamp: Long,
-    val timestampReceived: Long
-) {
-    internal constructor(header: BlogPostHeader, body: String) : this(
-        body = body,
-        author = OutputAuthor(header.author),
-        authorStatus = header.authorStatus.output(),
-        type = header.type.output(),
-        id = header.id.bytes,
-        parentId = header.parentId?.bytes,
-        read = header.isRead,
-        rssFeed = header.isRssFeed,
-        timestamp = header.timestamp,
-        timestampReceived = header.timeReceived
-    )
-}
-
-internal fun BlogPostHeader.output(body: String) = OutputBlogPost(this, body)
+internal fun BlogPostHeader.output(body: String) = mapOf(
+    "body" to body,
+    "author" to author.output(),
+    "authorStatus" to authorStatus.output(),
+    "type" to type.output(),
+    "id" to id.bytes,
+    "parentId" to parentId?.bytes,
+    "read" to isRead,
+    "rssFeed" to isRssFeed,
+    "timestamp" to timestamp,
+    "timestampReceived" to timeReceived
+)
 
 internal fun MessageType.output() = name.toLowerCase()
diff --git a/briar-headless/src/main/java/org/briarproject/briar/headless/contact/OutputContact.kt b/briar-headless/src/main/java/org/briarproject/briar/headless/contact/OutputContact.kt
index 823d5d9de..397a1fdc5 100644
--- a/briar-headless/src/main/java/org/briarproject/briar/headless/contact/OutputContact.kt
+++ b/briar-headless/src/main/java/org/briarproject/briar/headless/contact/OutputContact.kt
@@ -1,21 +1,10 @@
 package org.briarproject.briar.headless.contact
 
 import org.briarproject.bramble.api.contact.Contact
-import org.briarproject.bramble.identity.OutputAuthor
 import org.briarproject.bramble.identity.output
-import javax.annotation.concurrent.Immutable
 
-@Immutable
-internal data class OutputContact(
-    val contactId: Int,
-    val author: OutputAuthor,
-    val verified: Boolean
-) {
-    internal constructor(c: Contact) : this(
-        contactId = c.id.int,
-        author = c.author.output(),
-        verified = c.isVerified
-    )
-}
-
-internal fun Contact.output() = OutputContact(this)
+internal fun Contact.output() = mapOf(
+    "contactId" to id.int,
+    "author" to author.output(),
+    "verified" to isVerified
+)
\ No newline at end of file
diff --git a/briar-headless/src/main/java/org/briarproject/briar/headless/forums/OutputForum.kt b/briar-headless/src/main/java/org/briarproject/briar/headless/forums/OutputForum.kt
index d06d26c11..1def6f959 100644
--- a/briar-headless/src/main/java/org/briarproject/briar/headless/forums/OutputForum.kt
+++ b/briar-headless/src/main/java/org/briarproject/briar/headless/forums/OutputForum.kt
@@ -1,19 +1,10 @@
 package org.briarproject.briar.headless.forums
 
 import org.briarproject.briar.api.forum.Forum
-import javax.annotation.concurrent.Immutable
 
-@Immutable
-internal data class OutputForum(
-    val name: String,
-    val id: ByteArray
-) {
-    constructor(forum: Forum) : this(
-        name = forum.name,
-        id = forum.id.bytes
-    )
-}
-
-internal fun Forum.output() = OutputForum(this)
+internal fun Forum.output() = mapOf(
+    "name" to name,
+    "id" to id.bytes
+)
 
 internal fun Collection<Forum>.output() = map { it.output() }
diff --git a/briar-headless/src/main/java/org/briarproject/briar/headless/messaging/MessagingControllerImpl.kt b/briar-headless/src/main/java/org/briarproject/briar/headless/messaging/MessagingControllerImpl.kt
index 8a6091ce1..ce22dc649 100644
--- a/briar-headless/src/main/java/org/briarproject/briar/headless/messaging/MessagingControllerImpl.kt
+++ b/briar-headless/src/main/java/org/briarproject/briar/headless/messaging/MessagingControllerImpl.kt
@@ -40,16 +40,18 @@ internal class MessagingControllerImpl
 
     override fun list(ctx: Context): Context {
         val contact = getContact(ctx)
-        val messages = conversationManager.getMessageHeaders(contact.id).map { header ->
-            when (header) {
-                is PrivateRequest<*> -> header.output(contact.id)
-                is PrivateResponse -> header.output(contact.id)
-                else -> {
-                    val body = messagingManager.getMessageBody(header.id)
-                    header.output(contact.id, body)
+        val messages = conversationManager.getMessageHeaders(contact.id)
+            .sortedBy { it.timestamp }
+            .map { header ->
+                when (header) {
+                    is PrivateRequest<*> -> header.output(contact.id)
+                    is PrivateResponse -> header.output(contact.id)
+                    else -> {
+                        val body = messagingManager.getMessageBody(header.id)
+                        header.output(contact.id, body)
+                    }
                 }
             }
-        }.sortedBy { it.timestamp }
         return ctx.json(messages)
     }
 
diff --git a/briar-headless/src/main/java/org/briarproject/briar/headless/messaging/OutputPrivateMessage.kt b/briar-headless/src/main/java/org/briarproject/briar/headless/messaging/OutputPrivateMessage.kt
index b26c53b73..ff858c6b2 100644
--- a/briar-headless/src/main/java/org/briarproject/briar/headless/messaging/OutputPrivateMessage.kt
+++ b/briar-headless/src/main/java/org/briarproject/briar/headless/messaging/OutputPrivateMessage.kt
@@ -3,56 +3,32 @@ package org.briarproject.briar.headless.messaging
 import org.briarproject.bramble.api.contact.ContactId
 import org.briarproject.briar.api.messaging.PrivateMessage
 import org.briarproject.briar.api.messaging.PrivateMessageHeader
-import javax.annotation.concurrent.Immutable
 
-@Immutable
-internal abstract class OutputPrivateMessage(
-    protected open val iHeader: PrivateMessageHeader,
-    protected open val iContactId: ContactId,
-    open val body: String?
-) {
-
-    abstract val type: String
-    val contactId: Int get() = iContactId.int
-    val timestamp: Long get() = iHeader.timestamp
-    val read: Boolean get() = iHeader.isRead
-    val seen: Boolean get() = iHeader.isSeen
-    val sent: Boolean get() = iHeader.isSent
-    val local: Boolean get() = iHeader.isLocal
-    val id: ByteArray get() = iHeader.id.bytes
-    val groupId: ByteArray get() = iHeader.groupId.bytes
-
-}
-
-@Immutable
-internal data class OutputPrivateMessageHeader(
-    override val iHeader: PrivateMessageHeader,
-    override val iContactId: ContactId,
-    override val body: String?
-) : OutputPrivateMessage(iHeader, iContactId, body) {
-
-    override val type = "org.briarproject.briar.api.messaging.PrivateMessageHeader"
-
-    /**
-     * Only meant for own [PrivateMessage]s directly after creation.
-     */
-    internal constructor(m: PrivateMessage, contactId: ContactId, body: String) : this(
-        PrivateMessageHeader(
-            m.message.id,
-            m.message.groupId,
-            m.message.timestamp,
-            true,
-            true,
-            true,
-            true
-        ), contactId, body
+internal fun PrivateMessageHeader.output(contactId: ContactId, body: String?): Map<String, Any> {
+    val map: HashMap<String, Any> = hashMapOf(
+        "type" to "org.briarproject.briar.api.messaging.PrivateMessageHeader",
+        "contactId" to contactId.int,
+        "timestamp" to timestamp,
+        "read" to isRead,
+        "seen" to isSeen,
+        "sent" to isSent,
+        "local" to isLocal,
+        "id" to id.bytes,
+        "groupId" to groupId.bytes
     )
+    if (body != null) map.put("body", body)
+    return map
 }
 
-internal fun PrivateMessageHeader.output(
-    contactId: ContactId,
-    body: String?
-) = OutputPrivateMessageHeader(this, contactId, body)
-
-internal fun PrivateMessage.output(contactId: ContactId, body: String) =
-    OutputPrivateMessageHeader(this, contactId, body)
+internal fun PrivateMessage.output(contactId: ContactId, body: String) = mapOf(
+    "type" to "org.briarproject.briar.api.messaging.PrivateMessageHeader",
+    "contactId" to contactId.int,
+    "timestamp" to message.timestamp,
+    "read" to true,
+    "seen" to true,
+    "sent" to true,
+    "local" to true,
+    "id" to message.id.bytes,
+    "groupId" to message.groupId.bytes,
+    "body" to body
+)
\ No newline at end of file
diff --git a/briar-headless/src/main/java/org/briarproject/briar/headless/messaging/OutputPrivateRequest.kt b/briar-headless/src/main/java/org/briarproject/briar/headless/messaging/OutputPrivateRequest.kt
index b197b499b..5d40f9c7b 100644
--- a/briar-headless/src/main/java/org/briarproject/briar/headless/messaging/OutputPrivateRequest.kt
+++ b/briar-headless/src/main/java/org/briarproject/briar/headless/messaging/OutputPrivateRequest.kt
@@ -6,54 +6,56 @@ import org.briarproject.bramble.api.contact.ContactId
 import org.briarproject.briar.api.blog.BlogInvitationRequest
 import org.briarproject.briar.api.forum.ForumInvitationRequest
 import org.briarproject.briar.api.introduction.IntroductionRequest
+import org.briarproject.briar.api.messaging.PrivateMessageHeader
 import org.briarproject.briar.api.messaging.PrivateRequest
 import org.briarproject.briar.api.privategroup.invitation.GroupInvitationRequest
 import org.briarproject.briar.api.sharing.InvitationRequest
-import javax.annotation.concurrent.Immutable
 
-@Immutable
-internal abstract class OutputPrivateRequest(header: PrivateRequest<*>, contactId: ContactId) :
-    OutputPrivateMessage(header, contactId, header.message) {
-
-    val sessionId: ByteArray = header.sessionId.bytes
-    val name: String = header.name
-    val answered = header.wasAnswered()
+internal fun PrivateRequest<*>.output(contactId: ContactId): Map<String, Any> {
+    val map: HashMap<String, Any> = hashMapOf(
+        "sessionId" to sessionId.bytes,
+        "name" to name,
+        "answered" to wasAnswered()
+    )
+    map.putAll((this as PrivateMessageHeader).output(contactId, null))
+    return map
 }
 
-@Immutable
-internal data class OutputIntroductionRequest(
-    override val iHeader: IntroductionRequest,
-    override val iContactId: ContactId
-) : OutputPrivateRequest(iHeader, iContactId) {
-
-    override val type = "org.briarproject.briar.api.introduction.IntroductionRequest"
-    val alreadyContact get() = iHeader.isContact
-
+internal fun IntroductionRequest.output(contactId: ContactId): Map<String, Any> {
+    val map: HashMap<String, Any> = hashMapOf(
+        "type" to "org.briarproject.briar.api.introduction.IntroductionRequest",
+        "alreadyContact" to isContact
+    )
+    map.putAll((this as PrivateRequest<*>).output(contactId))
+    return map
 }
 
-@Immutable
-internal data class OutputInvitationRequest(
-    override val iHeader: InvitationRequest<*>,
-    override val iContactId: ContactId
-) : OutputPrivateRequest(iHeader, iContactId) {
-
-    override val type = when (iHeader) {
-        is ForumInvitationRequest -> "org.briarproject.briar.api.forum.ForumInvitationRequest"
-        is BlogInvitationRequest -> "org.briarproject.briar.api.blog.BlogInvitationRequest"
-        is GroupInvitationRequest -> "org.briarproject.briar.api.privategroup.invitation.GroupInvitationRequest"
-        else -> throw AssertionError("Unknown InvitationRequest")
-    }
-    val canBeOpened get() = iHeader.canBeOpened()
-
+internal fun InvitationRequest<*>.output(contactId : ContactId): Map<String, Any> {
+    val map: HashMap<String, Any> = hashMapOf("canBeOpened" to canBeOpened())
+    map.putAll((this as PrivateRequest<*>).output(contactId))
+    return map
 }
 
-internal fun PrivateRequest<*>.output(contactId: ContactId): OutputPrivateMessage {
-    return when (this) {
-        is IntroductionRequest -> OutputIntroductionRequest(this, contactId)
-        is InvitationRequest -> OutputInvitationRequest(this, contactId)
-        else -> throw AssertionError("Unknown PrivateRequest")
-    }
+internal fun BlogInvitationRequest.output(contactId : ContactId): Map<String, Any> {
+    val map: HashMap<String, Any> = hashMapOf(
+        "type" to "org.briarproject.briar.api.blog.BlogInvitationRequest"
+    )
+    map.putAll((this as InvitationRequest<*>).output(contactId))
+    return map
 }
 
-internal fun IntroductionRequest.output(contactId: ContactId) =
-    OutputIntroductionRequest(this, contactId)
+internal fun ForumInvitationRequest.output(contactId: ContactId): Map<String, Any> {
+    val map: HashMap<String, Any> = hashMapOf(
+        "type" to "org.briarproject.briar.api.forum.ForumInvitationRequest"
+    )
+    map.putAll((this as InvitationRequest<*>).output(contactId))
+    return map
+}
+
+internal fun GroupInvitationRequest.output(contactId : ContactId): Map<String, Any> {
+    val map: HashMap<String, Any> = hashMapOf(
+        "type" to "org.briarproject.briar.api.privategroup.invitation.GroupInvitationRequest"
+    )
+    map.putAll((this as InvitationRequest<*>).output(contactId))
+    return map
+}
\ No newline at end of file
diff --git a/briar-headless/src/main/java/org/briarproject/briar/headless/messaging/OutputPrivateResponse.kt b/briar-headless/src/main/java/org/briarproject/briar/headless/messaging/OutputPrivateResponse.kt
index ded18502d..158a9a761 100644
--- a/briar-headless/src/main/java/org/briarproject/briar/headless/messaging/OutputPrivateResponse.kt
+++ b/briar-headless/src/main/java/org/briarproject/briar/headless/messaging/OutputPrivateResponse.kt
@@ -7,49 +7,56 @@ import org.briarproject.bramble.identity.output
 import org.briarproject.briar.api.blog.BlogInvitationResponse
 import org.briarproject.briar.api.forum.ForumInvitationResponse
 import org.briarproject.briar.api.introduction.IntroductionResponse
+import org.briarproject.briar.api.messaging.PrivateMessageHeader
 import org.briarproject.briar.api.messaging.PrivateResponse
 import org.briarproject.briar.api.privategroup.invitation.GroupInvitationResponse
 import org.briarproject.briar.api.sharing.InvitationResponse
-import javax.annotation.concurrent.Immutable
 
-@Immutable
-internal abstract class OutputPrivateResponse(header: PrivateResponse, contactId: ContactId) :
-    OutputPrivateMessage(header, contactId, null) {
-
-    val sessionId: ByteArray = header.sessionId.bytes
-    val accepted = header.wasAccepted()
+internal fun PrivateResponse.output(contactId: ContactId): Map<String, Any> {
+    val map: HashMap<String, Any> = hashMapOf(
+        "sessionId" to sessionId.bytes,
+        "accepted" to wasAccepted()
+    )
+    map.putAll((this as PrivateMessageHeader).output(contactId, null))
+    return map
 }
 
-@Immutable
-internal data class OutputIntroductionResponse(
-    override val iHeader: IntroductionResponse,
-    override val iContactId: ContactId
-) : OutputPrivateResponse(iHeader, iContactId) {
-
-    override val type = "org.briarproject.briar.api.introduction.IntroductionResponse"
-    val introducedAuthor get() = iHeader.introducedAuthor.output()
-    val introducer get() = iHeader.isIntroducer
+internal fun IntroductionResponse.output(contactId: ContactId): Map<String, Any> {
+    val map: HashMap<String, Any> = hashMapOf(
+        "type" to "org.briarproject.briar.api.introduction.IntroductionResponse",
+        "introducedAuthor" to introducedAuthor.output(),
+        "introducer" to isIntroducer
+    )
+    map.putAll((this as PrivateResponse).output(contactId))
+    return map
 }
 
-@Immutable
-internal data class OutputInvitationResponse(
-    override val iHeader: InvitationResponse,
-    override val iContactId: ContactId
-) : OutputPrivateResponse(iHeader, iContactId) {
-
-    override val type = when (iHeader) {
-        is ForumInvitationResponse -> "org.briarproject.briar.api.forum.ForumInvitationResponse"
-        is BlogInvitationResponse -> "org.briarproject.briar.api.blog.BlogInvitationResponse"
-        is GroupInvitationResponse -> "org.briarproject.briar.api.privategroup.invitation.GroupInvitationResponse"
-        else -> throw AssertionError("Unknown InvitationResponse")
-    }
-    val shareableId: ByteArray get() = iHeader.shareableId.bytes
+internal fun InvitationResponse.output(contactId: ContactId): Map<String, Any> {
+    val map: HashMap<String, Any> = hashMapOf("shareableId" to shareableId.bytes)
+    map.putAll((this as PrivateResponse).output(contactId))
+    return map
 }
 
-internal fun PrivateResponse.output(contactId: ContactId): OutputPrivateMessage {
-    return when (this) {
-        is IntroductionResponse -> OutputIntroductionResponse(this, contactId)
-        is InvitationResponse -> OutputInvitationResponse(this, contactId)
-        else -> throw AssertionError("Unknown PrivateResponse")
-    }
+internal fun BlogInvitationResponse.output(contactId: ContactId): Map<String, Any> {
+    val map: HashMap<String, Any> = hashMapOf(
+        "type" to "org.briarproject.briar.api.blog.BlogInvitationResponse"
+    )
+    map.putAll((this as InvitationResponse).output(contactId))
+    return map
 }
+
+internal fun ForumInvitationResponse.output(contactId: ContactId): Map<String, Any> {
+    val map: HashMap<String, Any> = hashMapOf(
+        "type" to "org.briarproject.briar.api.blog.BlogInvitationResponse"
+    )
+    map.putAll((this as InvitationResponse).output(contactId))
+    return map
+}
+
+internal fun GroupInvitationResponse.output(contactId: ContactId): Map<String, Any> {
+    val map: HashMap<String, Any> = hashMapOf(
+        "type" to "org.briarproject.briar.api.privategroup.invitation.GroupInvitationResponse"
+    )
+    map.putAll((this as InvitationResponse).output(contactId))
+    return map
+}
\ No newline at end of file
diff --git a/briar-headless/src/test/java/org/briarproject/briar/headless/blogs/BlogControllerTest.kt b/briar-headless/src/test/java/org/briarproject/briar/headless/blogs/BlogControllerTest.kt
index fa242b882..55abc28c4 100644
--- a/briar-headless/src/test/java/org/briarproject/briar/headless/blogs/BlogControllerTest.kt
+++ b/briar-headless/src/test/java/org/briarproject/briar/headless/blogs/BlogControllerTest.kt
@@ -101,7 +101,7 @@ internal class BlogControllerTest : ControllerTest() {
     fun testEmptyList() {
         every { blogManager.blogs } returns listOf(blog)
         every { blogManager.getPostHeaders(group.id) } returns emptyList()
-        every { ctx.json(emptyList<OutputBlogPost>()) } returns ctx
+        every { ctx.json(emptyList<Any>()) } returns ctx
 
         controller.listPosts(ctx)
     }
diff --git a/briar-headless/src/test/java/org/briarproject/briar/headless/contact/ContactControllerTest.kt b/briar-headless/src/test/java/org/briarproject/briar/headless/contact/ContactControllerTest.kt
index c4ffb9531..8c339d31e 100644
--- a/briar-headless/src/test/java/org/briarproject/briar/headless/contact/ContactControllerTest.kt
+++ b/briar-headless/src/test/java/org/briarproject/briar/headless/contact/ContactControllerTest.kt
@@ -14,7 +14,7 @@ internal class ContactControllerTest : ControllerTest() {
     @Test
     fun testEmptyContactList() {
         every { contactManager.activeContacts } returns emptyList<Contact>()
-        every { ctx.json(emptyList<OutputContact>()) } returns ctx
+        every { ctx.json(emptyList<Any>()) } returns ctx
         controller.list(ctx)
     }
 
diff --git a/briar-headless/src/test/java/org/briarproject/briar/headless/messaging/MessagingControllerImplTest.kt b/briar-headless/src/test/java/org/briarproject/briar/headless/messaging/MessagingControllerImplTest.kt
index 2dc197b6d..c1a4d62d5 100644
--- a/briar-headless/src/test/java/org/briarproject/briar/headless/messaging/MessagingControllerImplTest.kt
+++ b/briar-headless/src/test/java/org/briarproject/briar/headless/messaging/MessagingControllerImplTest.kt
@@ -55,7 +55,7 @@ internal class MessagingControllerImplTest : ControllerTest() {
         every { ctx.pathParam("contactId") } returns contact.id.int.toString()
         every { contactManager.getContact(contact.id) } returns contact
         every { conversationManager.getMessageHeaders(contact.id) } returns emptyList<PrivateMessageHeader>()
-        every { ctx.json(emptyList<OutputPrivateMessageHeader>()) } returns ctx
+        every { ctx.json(emptyList<Any>()) } returns ctx
 
         controller.list(ctx)
     }
@@ -73,7 +73,7 @@ internal class MessagingControllerImplTest : ControllerTest() {
     @Test
     fun write() {
         val privateMessage = PrivateMessage(message)
-        val slot = CapturingSlot<OutputPrivateMessageHeader>()
+        val slot = CapturingSlot<Map<String, Any>>()
 
         expectGetContact()
         every { ctx.formParam("text") } returns body
@@ -92,9 +92,9 @@ internal class MessagingControllerImplTest : ControllerTest() {
         controller.write(ctx)
 
         val output = slot.captured
-        assertEquals(contact.id.int, output.contactId)
-        assertEquals(body, output.body)
-        assertEquals(message.id.bytes, output.id)
+        assertEquals(contact.id.int, output.get("contactId"))
+        assertEquals(body, output.get("body"))
+        assertEquals(message.id.bytes, output.get("id"))
     }
 
     @Test