diff --git a/android/src/main/java/expo/modules/xmtpreactnativesdk/XMTPModule.kt b/android/src/main/java/expo/modules/xmtpreactnativesdk/XMTPModule.kt
index d41863b3..a707c428 100644
--- a/android/src/main/java/expo/modules/xmtpreactnativesdk/XMTPModule.kt
+++ b/android/src/main/java/expo/modules/xmtpreactnativesdk/XMTPModule.kt
@@ -713,6 +713,26 @@ class XMTPModule : Module() {
             }
         }
 
+        AsyncFunction("prepareEncodedMessage") Coroutine { installationId: String, conversationId: String, encodedContentData: List<Int> ->
+            withContext(Dispatchers.IO) {
+                logV("prepareEncodedMessage")
+                val client = clients[installationId] ?: throw XMTPException("No client")
+                val conversation = client.findConversation(conversationId)
+                    ?: throw XMTPException("no conversation found for $conversationId")
+                val encodedContentDataBytes =
+                    encodedContentData.foldIndexed(ByteArray(encodedContentData.size)) { i, a, v ->
+                        a.apply {
+                            set(
+                                i,
+                                v.toByte()
+                            )
+                        }
+                    }
+                val encodedContent = EncodedContent.parseFrom(encodedContentDataBytes)
+                conversation.prepareMessage(encodedContent = encodedContent)
+            }
+        }
+
         AsyncFunction("findOrCreateDm") Coroutine { installationId: String, peerAddress: String ->
             withContext(Dispatchers.IO) {
                 logV("findOrCreateDm")
diff --git a/src/index.ts b/src/index.ts
index 8ce6af61..29e87b54 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -596,6 +596,25 @@ export async function prepareMessage(
   )
 }
 
+export async function prepareMessageWithContentType<T>(
+  installationId: InstallationId,
+  conversationId: ConversationId,
+  content: any,
+  codec: ContentCodec<T>
+): Promise<MessageId> {
+  if ('contentKey' in codec) {
+    return prepareMessage(installationId, conversationId, content)
+  }
+  const encodedContent = codec.encode(content)
+  encodedContent.fallback = codec.fallback(content)
+  const encodedContentData = EncodedContent.encode(encodedContent).finish()
+  return await XMTPModule.prepareEncodedMessage(
+    installationId,
+    conversationId,
+    Array.from(encodedContentData)
+  )
+}
+
 export async function findOrCreateDm<
   ContentTypes extends DefaultContentTypes = DefaultContentTypes,
 >(
diff --git a/src/lib/Conversation.ts b/src/lib/Conversation.ts
index a230d673..a801079e 100644
--- a/src/lib/Conversation.ts
+++ b/src/lib/Conversation.ts
@@ -28,6 +28,10 @@ export interface ConversationBase<ContentTypes extends DefaultContentTypes> {
     content: ConversationSendPayload<SendContentTypes>,
     opts?: SendOptions
   ): Promise<MessageId>
+  prepareMessage<SendContentTypes extends DefaultContentTypes = ContentTypes>(
+    content: ConversationSendPayload<SendContentTypes>,
+    opts?: SendOptions
+  ): Promise<MessageId>
   sync()
   messages(opts?: MessagesOptions): Promise<DecodedMessageUnion<ContentTypes>[]>
   streamMessages(
diff --git a/src/lib/Dm.ts b/src/lib/Dm.ts
index 6b1bfaf9..9619642d 100644
--- a/src/lib/Dm.ts
+++ b/src/lib/Dm.ts
@@ -113,11 +113,13 @@ export class Dm<ContentTypes extends DefaultContentTypes = DefaultContentTypes>
    */
   async prepareMessage<
     SendContentTypes extends DefaultContentTypes = ContentTypes,
-  >(content: ConversationSendPayload<SendContentTypes>): Promise<string> {
-    // TODO: Enable other content types
-    // if (opts && opts.contentType) {
-    // return await this._sendWithJSCodec(content, opts.contentType)
-    // }
+  >(
+    content: ConversationSendPayload<SendContentTypes>,
+    opts?: SendOptions
+  ): Promise<MessageId> {
+    if (opts && opts.contentType) {
+      return await this._prepareWithJSCodec(content, opts.contentType)
+    }
 
     try {
       if (typeof content === 'string') {
@@ -135,6 +137,27 @@ export class Dm<ContentTypes extends DefaultContentTypes = DefaultContentTypes>
     }
   }
 
+  private async _prepareWithJSCodec<T>(
+    content: T,
+    contentType: XMTP.ContentTypeId
+  ): Promise<MessageId> {
+    const codec =
+      this.client.codecRegistry[
+        `${contentType.authorityId}/${contentType.typeId}:${contentType.versionMajor}.${contentType.versionMinor}`
+      ]
+
+    if (!codec) {
+      throw new Error(`no codec found for: ${contentType}`)
+    }
+
+    return await XMTP.prepareMessageWithContentType(
+      this.client.installationId,
+      this.id,
+      content,
+      codec
+    )
+  }
+
   /**
    * Publish all prepared messages.
    *
diff --git a/src/lib/Group.ts b/src/lib/Group.ts
index 08445f9b..82e6d017 100644
--- a/src/lib/Group.ts
+++ b/src/lib/Group.ts
@@ -84,7 +84,7 @@ export class Group<
    * Sends a message to the current group.
    *
    * @param {string | MessageContent} content - The content of the message. It can be either a string or a structured MessageContent object.
-   * @returns {Promise<string>} A Promise that resolves to a string identifier for the sent message.
+   * @returns {Promise<MessageId>} A Promise that resolves to a string identifier for the sent message.
    * @throws {Error} Throws an error if there is an issue with sending the message.
    */
   async send<SendContentTypes extends DefaultContentTypes = ContentTypes>(
@@ -136,16 +136,18 @@ export class Group<
    * Prepare a group message to be sent.
    *
    * @param {string | MessageContent} content - The content of the message. It can be either a string or a structured MessageContent object.
-   * @returns {Promise<string>} A Promise that resolves to a string identifier for the prepared message to be sent.
+   * @returns {Promise<MessageId>} A Promise that resolves to a string identifier for the prepared message to be sent.
    * @throws {Error} Throws an error if there is an issue with sending the message.
    */
   async prepareMessage<
     SendContentTypes extends DefaultContentTypes = ContentTypes,
-  >(content: ConversationSendPayload<SendContentTypes>): Promise<string> {
-    // TODO: Enable other content types
-    // if (opts && opts.contentType) {
-    // return await this._sendWithJSCodec(content, opts.contentType)
-    // }
+  >(
+    content: ConversationSendPayload<SendContentTypes>,
+    opts?: SendOptions
+  ): Promise<MessageId> {
+    if (opts && opts.contentType) {
+      return await this._prepareWithJSCodec(content, opts.contentType)
+    }
 
     try {
       if (typeof content === 'string') {
@@ -163,6 +165,27 @@ export class Group<
     }
   }
 
+  private async _prepareWithJSCodec<T>(
+    content: T,
+    contentType: XMTP.ContentTypeId
+  ): Promise<MessageId> {
+    const codec =
+      this.client.codecRegistry[
+        `${contentType.authorityId}/${contentType.typeId}:${contentType.versionMajor}.${contentType.versionMinor}`
+      ]
+
+    if (!codec) {
+      throw new Error(`no codec found for: ${contentType}`)
+    }
+
+    return await XMTP.prepareMessageWithContentType(
+      this.client.installationId,
+      this.id,
+      content,
+      codec
+    )
+  }
+
   /**
    * Publish all prepared messages.
    *