diff --git a/frontend/src/state/chat-slice.ts b/frontend/src/state/chat-slice.ts
index fc3da4e77099..9c250aad0ce9 100644
--- a/frontend/src/state/chat-slice.ts
+++ b/frontend/src/state/chat-slice.ts
@@ -5,6 +5,8 @@ import {
   OpenHandsObservation,
   CommandObservation,
   IPythonObservation,
+  WriteObservation,
+  ReadObservation,
 } from "#/types/core/observations";
 import { OpenHandsAction } from "#/types/core/actions";
 import { OpenHandsEventType } from "#/types/core/base";
@@ -142,9 +144,14 @@ export const chatSlice = createSlice({
         // For IPython, we consider it successful if there's no error message
         const ipythonObs = observation.payload as IPythonObservation;
         causeMessage.success = !ipythonObs.message.toLowerCase().includes("error");
-      } else if (observationID === "write" || observationID === "read") {
-        // For file operations, we consider them successful if there's no error message
-        causeMessage.success = !observation.payload.message.toLowerCase().includes("error");
+      } else if (observationID === "write") {
+        // For write operations, we consider them successful if there's no error message
+        const writeObs = observation.payload as WriteObservation;
+        causeMessage.success = !writeObs.message.toLowerCase().includes("error");
+      } else if (observationID === "read") {
+        // For read operations, we consider them successful if there's no error message
+        const readObs = observation.payload as ReadObservation;
+        causeMessage.success = !readObs.message.toLowerCase().includes("error");
       }
 
       if (observationID === "run" || observationID === "run_ipython") {
diff --git a/frontend/src/types/core/observations.ts b/frontend/src/types/core/observations.ts
index 0b95099a8384..7ddc3f05dd94 100644
--- a/frontend/src/types/core/observations.ts
+++ b/frontend/src/types/core/observations.ts
@@ -52,6 +52,21 @@ export interface BrowseObservation extends OpenHandsObservationEvent<"browse"> {
   };
 }
 
+export interface WriteObservation extends OpenHandsObservationEvent<"write"> {
+  source: "agent";
+  extras: {
+    path: string;
+    content: string;
+  };
+}
+
+export interface ReadObservation extends OpenHandsObservationEvent<"read"> {
+  source: "agent";
+  extras: {
+    path: string;
+  };
+}
+
 export interface ErrorObservation extends OpenHandsObservationEvent<"error"> {
   source: "user";
   extras: {
@@ -65,4 +80,6 @@ export type OpenHandsObservation =
   | IPythonObservation
   | DelegateObservation
   | BrowseObservation
+  | WriteObservation
+  | ReadObservation
   | ErrorObservation;