diff --git a/src/api/conversations.rs b/src/api/conversations.rs
index 10e81f5d..a0a58a59 100644
--- a/src/api/conversations.rs
+++ b/src/api/conversations.rs
@@ -76,6 +76,10 @@ where
                     ("cursor", req.cursor.as_ref().map(|x| x.value())),
                     ("limit", req.limit.map(|v| v.to_string()).as_ref()),
                     ("inclusive", req.inclusive.map(|v| v.to_string()).as_ref()),
+                    (
+                        "include_all_metadata",
+                        req.include_all_metadata.map(|v| v.to_string()).as_ref(),
+                    ),
                     ("latest", req.latest.as_ref().map(|x| x.value())),
                     ("oldest", req.oldest.as_ref().map(|x| x.value())),
                 ],
@@ -386,6 +390,7 @@ pub struct SlackApiConversationsHistoryRequest {
     pub limit: Option<u16>,
     pub oldest: Option<SlackTs>,
     pub inclusive: Option<bool>,
+    pub include_all_metadata: Option<bool>,
 }
 
 #[skip_serializing_none]
diff --git a/src/models/messages/mod.rs b/src/models/messages/mod.rs
index e86de34e..ab3b42d1 100644
--- a/src/models/messages/mod.rs
+++ b/src/models/messages/mod.rs
@@ -20,6 +20,13 @@ pub struct SlackMessageOrigin {
     pub client_msg_id: Option<SlackClientMessageId>,
 }
 
+#[skip_serializing_none]
+#[derive(Debug, PartialEq, Clone, Serialize, Deserialize, Builder)]
+pub struct SlackMessageMetadata {
+    pub event_type: String,
+    pub event_payload: Option<std::collections::HashMap<String, String>>,
+}
+
 #[skip_serializing_none]
 #[derive(Debug, PartialEq, Clone, Serialize, Deserialize, Builder)]
 pub struct SlackMessageContent {
@@ -29,6 +36,7 @@ pub struct SlackMessageContent {
     pub upload: Option<bool>,
     pub files: Option<Vec<SlackFile>>,
     pub reactions: Option<Vec<SlackReaction>>,
+    pub metadata: Option<SlackMessageMetadata>,
 }
 
 #[skip_serializing_none]