diff --git a/crates/zesdex-cms/src/domain/conversation.rs b/crates/zesdex-cms/src/domain/conversation.rs
index 35e430a..fe17286 100644
--- a/crates/zesdex-cms/src/domain/conversation.rs
+++ b/crates/zesdex-cms/src/domain/conversation.rs
@@ -14,77 +14,7 @@
 
 use serde::{Deserialize, Serialize};
 
-/// A single message role / content pair.
-#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
-pub enum Role {
-    #[serde(rename = "user")]
-    User,
-    #[serde(rename = "assistant")]
-    Assistant,
-    #[serde(rename = "system")]
-    System,
-    #[serde(rename = "tool")]
-    Tool,
-}
-
-/// A single message in a conversation.
-#[derive(Debug, Clone, Serialize, Deserialize)]
-pub struct ChatMessage {
-    pub role: Role,
-    pub content: Option<String>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub tool_calls: Option<Vec<serde_json::Value>>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub tool_call_id: Option<String>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub name: Option<String>,
-}
-
-impl ChatMessage {
-    /// Build a user-role message with the given text content.
-    pub fn user(content: impl Into<String>) -> Self {
-        Self {
-            role: Role::User,
-            content: Some(content.into()),
-            tool_calls: None,
-            tool_call_id: None,
-            name: None,
-        }
-    }
-
-    /// Build an assistant-role message with an optional text response.
-    pub fn assistant(content: Option<String>) -> Self {
-        Self {
-            role: Role::Assistant,
-            content,
-            tool_calls: None,
-            tool_call_id: None,
-            name: None,
-        }
-    }
-
-    /// Build a system-role message with the given instruction text.
-    pub fn system(content: impl Into<String>) -> Self {
-        Self {
-            role: Role::System,
-            content: Some(content.into()),
-            tool_calls: None,
-            tool_call_id: None,
-            name: None,
-        }
-    }
-
-    /// Build a tool-role result message referencing a prior tool call.
-    pub fn tool(tool_call_id: String, content: String) -> Self {
-        Self {
-            role: Role::Tool,
-            content: Some(content),
-            tool_calls: None,
-            tool_call_id: Some(tool_call_id),
-            name: None,
-        }
-    }
-}
+pub use zesdex_entities::seaorm::common::message::{ChatMessage, Role};
 
 /// A single conversation's message history and generation settings.
 #[derive(Debug, Clone, Serialize, Deserialize)]
@@ -143,3 +73,15 @@ impl Conversation {
         self.messages.is_empty()
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn chat_message_is_the_canonical_entities_type() {
+        let canonical = zesdex_entities::seaorm::common::message::ChatMessage::user("hi");
+        let via_cms: ChatMessage = canonical;
+        assert_eq!(via_cms.content.as_deref(), Some("hi"));
+    }
+}