image-gen-event/client_processing (#13512)

enabling client-side to process with image-generation capabilities
(setting app-server)

codex-rs/protocol/src/protocol.rs

@@ -1086,6 +1086,10 @@ pub enum EventMsg {
 
     WebSearchEnd(WebSearchEndEvent),
 
+    ImageGenerationBegin(ImageGenerationBeginEvent),
+
+    ImageGenerationEnd(ImageGenerationEndEvent),
+
     /// Notification that the server is about to execute a command.
     ExecCommandBegin(ExecCommandBeginEvent),
 
@@ -1367,6 +1371,11 @@ impl HasLegacyEvent for ItemStartedEvent {
             TurnItem::WebSearch(item) => vec![EventMsg::WebSearchBegin(WebSearchBeginEvent {
                 call_id: item.id.clone(),
             })],
+            TurnItem::ImageGeneration(item) => {
+                vec![EventMsg::ImageGenerationBegin(ImageGenerationBeginEvent {
+                    call_id: item.id.clone(),
+                })]
+            }
             _ => Vec::new(),
         }
     }
@@ -1876,6 +1885,21 @@ pub struct WebSearchEndEvent {
     pub action: WebSearchAction,
 }
 
+#[derive(Debug, Clone, Deserialize, Serialize, JsonSchema, TS)]
+pub struct ImageGenerationBeginEvent {
+    pub call_id: String,
+}
+
+#[derive(Debug, Clone, Deserialize, Serialize, JsonSchema, TS)]
+pub struct ImageGenerationEndEvent {
+    pub call_id: String,
+    pub status: String,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    #[ts(optional)]
+    pub revised_prompt: Option<String>,
+    pub result: String,
+}
+
 // Conversation kept for backward compatibility.
 /// Response payload for `Op::GetHistory` containing the current session's
 /// in-memory transcript.
@@ -3115,6 +3139,7 @@ pub struct CollabResumeEndEvent {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::items::ImageGenerationItem;
     use crate::items::UserMessageItem;
     use crate::items::WebSearchItem;
     use anyhow::Result;
@@ -3235,6 +3260,53 @@ mod tests {
         assert!(event.as_legacy_events(false).is_empty());
     }
 
+    #[test]
+    fn item_started_event_from_image_generation_emits_begin_event() {
+        let event = ItemStartedEvent {
+            thread_id: ThreadId::new(),
+            turn_id: "turn-1".into(),
+            item: TurnItem::ImageGeneration(ImageGenerationItem {
+                id: "ig-1".into(),
+                status: "in_progress".into(),
+                revised_prompt: None,
+                result: String::new(),
+            }),
+        };
+
+        let legacy_events = event.as_legacy_events(false);
+        assert_eq!(legacy_events.len(), 1);
+        match &legacy_events[0] {
+            EventMsg::ImageGenerationBegin(event) => assert_eq!(event.call_id, "ig-1"),
+            _ => panic!("expected ImageGenerationBegin event"),
+        }
+    }
+
+    #[test]
+    fn item_completed_event_from_image_generation_emits_end_event() {
+        let event = ItemCompletedEvent {
+            thread_id: ThreadId::new(),
+            turn_id: "turn-1".into(),
+            item: TurnItem::ImageGeneration(ImageGenerationItem {
+                id: "ig-1".into(),
+                status: "completed".into(),
+                revised_prompt: Some("A tiny blue square".into()),
+                result: "Zm9v".into(),
+            }),
+        };
+
+        let legacy_events = event.as_legacy_events(false);
+        assert_eq!(legacy_events.len(), 1);
+        match &legacy_events[0] {
+            EventMsg::ImageGenerationEnd(event) => {
+                assert_eq!(event.call_id, "ig-1");
+                assert_eq!(event.status, "completed");
+                assert_eq!(event.revised_prompt.as_deref(), Some("A tiny blue square"));
+                assert_eq!(event.result, "Zm9v");
+            }
+            _ => panic!("expected ImageGenerationEnd event"),
+        }
+    }
+
     #[test]
     fn rollback_failed_error_does_not_affect_turn_status() {
         let event = ErrorEvent {