diff --git a/router/src/lib.rs b/router/src/lib.rs
index e62d3a93..5120ad88 100644
--- a/router/src/lib.rs
+++ b/router/src/lib.rs
@@ -11,6 +11,7 @@ use queue::{Entry, Queue};
 use serde::{Deserialize, Serialize};
 use tokio::sync::OwnedSemaphorePermit;
 use tokio_stream::wrappers::UnboundedReceiverStream;
+use tracing::warn;
 use utoipa::ToSchema;
 use validation::Validation;
 
@@ -539,9 +540,25 @@ impl ChatCompletion {
                 content: vec![MessageChunk::Text(Text { text: output })],
                 name: None,
             }),
-            (None, Some(tool_calls)) => OutputMessage::ToolCall(ToolCallMessage { tool_calls }),
-            _ => {
-                todo!("Implement error for invalid tool vs chat");
+            (None, Some(tool_calls)) => OutputMessage::ToolCall(ToolCallMessage {
+                role: "assistant".to_string(),
+                tool_calls,
+            }),
+            (Some(output), Some(_)) => {
+                warn!("Received both chat and tool call");
+                OutputMessage::ChatMessage(Message {
+                    role: "assistant".into(),
+                    content: vec![MessageChunk::Text(Text { text: output })],
+                    name: None,
+                })
+            }
+            (None, None) => {
+                warn!("Didn't receive an answer");
+                OutputMessage::ChatMessage(Message {
+                    role: "assistant".into(),
+                    content: vec![],
+                    name: None,
+                })
             }
         };
         Self {
@@ -574,6 +591,7 @@ pub(crate) struct CompletionCompleteChunk {
     pub model: String,
     pub system_fingerprint: String,
 }
+
 #[derive(Clone, Deserialize, Serialize, ToSchema)]
 pub(crate) struct ChatCompletionChunk {
     pub id: String,
@@ -594,21 +612,20 @@ pub(crate) struct ChatCompletionChoice {
     pub finish_reason: Option<String>,
 }
 
-#[derive(Clone, Debug, Deserialize, Serialize, ToSchema)]
-pub(crate) struct ChatCompletionDelta {
-    #[schema(example = "user")]
-    // TODO Modify this to a true enum.
-    #[serde(default, skip_serializing_if = "Option::is_none")]
-    pub role: Option<String>,
-    #[serde(default, skip_serializing_if = "Option::is_none")]
-    #[schema(example = "What is Deep Learning?")]
-    pub content: Option<String>,
-    // default to None
-    #[serde(default, skip_serializing_if = "Option::is_none")]
-    pub tool_calls: Option<DeltaToolCall>,
+#[derive(Clone, Deserialize, ToSchema, Serialize, Debug, PartialEq)]
+pub struct ToolCallDelta {
+    #[schema(example = "assistant")]
+    role: String,
+    tool_calls: DeltaToolCall,
 }
 
-#[derive(Clone, Deserialize, Serialize, ToSchema, Debug)]
+#[derive(Clone, Debug, Deserialize, Serialize, ToSchema)]
+enum ChatCompletionDelta {
+    Chat(TextMessage),
+    Tool(ToolCallDelta),
+}
+
+#[derive(Clone, Deserialize, Serialize, ToSchema, Debug, PartialEq)]
 pub(crate) struct DeltaToolCall {
     pub index: u32,
     pub id: String,
@@ -616,7 +633,7 @@ pub(crate) struct DeltaToolCall {
     pub function: Function,
 }
 
-#[derive(Clone, Deserialize, Serialize, ToSchema, Debug)]
+#[derive(Clone, Deserialize, Serialize, ToSchema, Debug, PartialEq)]
 pub(crate) struct Function {
     pub name: Option<String>,
     pub arguments: String,
@@ -634,15 +651,13 @@ impl ChatCompletionChunk {
         finish_reason: Option<String>,
     ) -> Self {
         let delta = match (delta, tool_calls) {
-            (Some(delta), _) => ChatCompletionDelta {
-                role: Some("assistant".to_string()),
-                content: Some(delta),
-                tool_calls: None,
-            },
-            (None, Some(tool_calls)) => ChatCompletionDelta {
-                role: Some("assistant".to_string()),
-                content: None,
-                tool_calls: Some(DeltaToolCall {
+            (Some(delta), _) => ChatCompletionDelta::Chat(TextMessage {
+                role: "assistant".to_string(),
+                content: delta,
+            }),
+            (None, Some(tool_calls)) => ChatCompletionDelta::Tool(ToolCallDelta {
+                role: "assistant".to_string(),
+                tool_calls: DeltaToolCall {
                     index: 0,
                     id: String::new(),
                     r#type: "function".to_string(),
@@ -650,13 +665,12 @@ impl ChatCompletionChunk {
                         name: None,
                         arguments: tool_calls[0].to_string(),
                     },
-                }),
-            },
-            (None, None) => ChatCompletionDelta {
-                role: None,
-                content: None,
-                tool_calls: None,
-            },
+                },
+            }),
+            (None, None) => ChatCompletionDelta::Chat(TextMessage {
+                role: "assistant".to_string(),
+                content: "".to_string(),
+            }),
         };
         Self {
             id: String::new(),
@@ -982,6 +996,8 @@ impl From<Message> for TextMessage {
 
 #[derive(Clone, Deserialize, ToSchema, Serialize, Debug, PartialEq)]
 pub struct ToolCallMessage {
+    #[schema(example = "assistant")]
+    role: String,
     tool_calls: Vec<ToolCall>,
     tool_call_id: String,
 }
@@ -1265,6 +1281,7 @@ mod tests {
                 },
             },
                 ]
+
                 }
         ]
         });