diff --git a/xmtp_content_types/src/lib.rs b/xmtp_content_types/src/lib.rs
index 3bafb2a03..c0fe8fb42 100644
--- a/xmtp_content_types/src/lib.rs
+++ b/xmtp_content_types/src/lib.rs
@@ -1,6 +1,11 @@
 pub mod group_updated;
 pub mod membership_change;
+pub mod reaction;
+pub mod reply;
+pub mod read_receipt;
+pub mod remote_attachment;
 pub mod text;
+pub mod transaction_reference;
 
 use thiserror::Error;
 use xmtp_proto::xmtp::mls::message_contents::{ContentTypeId, EncodedContent};
diff --git a/xmtp_content_types/src/reaction.rs b/xmtp_content_types/src/reaction.rs
new file mode 100644
index 000000000..50a89ebce
--- /dev/null
+++ b/xmtp_content_types/src/reaction.rs
@@ -0,0 +1,6 @@
+pub struct ReactionCodec {}
+
+impl ReactionCodec {
+    const AUTHORITY_ID: &'static str = "xmtp.org";
+    pub const TYPE_ID: &'static str = "reaction";
+}
diff --git a/xmtp_content_types/src/read_receipt.rs b/xmtp_content_types/src/read_receipt.rs
new file mode 100644
index 000000000..a81a2b7ad
--- /dev/null
+++ b/xmtp_content_types/src/read_receipt.rs
@@ -0,0 +1,6 @@
+pub struct ReadReceiptCodec {}
+
+impl ReadReceiptCodec {
+    const AUTHORITY_ID: &'static str = "xmtp.org";
+    pub const TYPE_ID: &'static str = "read_receipt";
+}
diff --git a/xmtp_content_types/src/remote_attachment.rs b/xmtp_content_types/src/remote_attachment.rs
new file mode 100644
index 000000000..77680aefe
--- /dev/null
+++ b/xmtp_content_types/src/remote_attachment.rs
@@ -0,0 +1,6 @@
+pub struct RemoteAttachmentCodec {}
+
+impl RemoteAttachmentCodec {
+    const AUTHORITY_ID: &'static str = "xmtp.org";
+    pub const TYPE_ID: &'static str = "remote_attachment";
+}
diff --git a/xmtp_content_types/src/reply.rs b/xmtp_content_types/src/reply.rs
new file mode 100644
index 000000000..6f8ba32f3
--- /dev/null
+++ b/xmtp_content_types/src/reply.rs
@@ -0,0 +1,6 @@
+pub struct ReplyCodec {}
+
+impl ReplyCodec {
+    const AUTHORITY_ID: &'static str = "xmtp.org";
+    pub const TYPE_ID: &'static str = "reply";
+}
diff --git a/xmtp_content_types/src/transaction_reference.rs b/xmtp_content_types/src/transaction_reference.rs
new file mode 100644
index 000000000..c7060dc88
--- /dev/null
+++ b/xmtp_content_types/src/transaction_reference.rs
@@ -0,0 +1,6 @@
+pub struct TransactionReferenceCodec {}
+
+impl TransactionReferenceCodec {
+    const AUTHORITY_ID: &'static str = "xmtp.org";
+    pub const TYPE_ID: &'static str = "transaction_reference";
+}