diff --git a/core/config/types.ts b/core/config/types.ts
index 6048cf4d30c..0b76419df6d 100644
--- a/core/config/types.ts
+++ b/core/config/types.ts
@@ -1061,6 +1061,7 @@ declare global {
     filepath?: string;
     fileContent?: string;
     originalFileContent?: string;
+    autoFormattingDiff?: string;
   }
   
   export interface RangeInFileWithContents {
diff --git a/core/index.d.ts b/core/index.d.ts
index 6e80bc5d374..5ac6796a1cf 100644
--- a/core/index.d.ts
+++ b/core/index.d.ts
@@ -1387,6 +1387,7 @@ export interface ApplyState {
   fileContent?: string;
   originalFileContent?: string;
   toolCallId?: string;
+  autoFormattingDiff?: string;
 }
 
 export interface StreamDiffLinesPayload {
diff --git a/extensions/vscode/src/diff/processDiff.ts b/extensions/vscode/src/diff/processDiff.ts
index f350e12b4d3..cbff6f4a363 100644
--- a/extensions/vscode/src/diff/processDiff.ts
+++ b/extensions/vscode/src/diff/processDiff.ts
@@ -1,8 +1,11 @@
 import { Core } from "core/core";
 import { DataLogger } from "core/data/log";
+import { myersDiff } from "core/diff/myers";
+
 import { ContinueGUIWebviewViewProvider } from "../ContinueGUIWebviewViewProvider";
 import { editOutcomeTracker } from "../extension/EditOutcomeTracker";
 import { VsCodeIde } from "../VsCodeIde";
+
 import { VerticalDiffManager } from "./vertical/manager";
 
 export async function processDiff(
@@ -42,7 +45,8 @@ export async function processDiff(
   }
 
   if (streamId) {
-    const fileContent = await ide.readFile(newOrCurrentUri);
+    // Capture file content before save to detect autoformatting
+    const preSaveContent = await ide.readFile(newOrCurrentUri);
 
     // Record the edit outcome before updating the apply state
     await editOutcomeTracker.recordEditOutcome(
@@ -51,16 +55,45 @@ export async function processDiff(
       DataLogger.getInstance(),
     );
 
+    // Save the file
+    await ide.saveFile(newOrCurrentUri);
+
+    // Capture file content after save to detect autoformatting
+    const postSaveContent = await ide.readFile(newOrCurrentUri);
+
+    // Detect autoformatting by comparing normalized content
+    let autoFormattingDiff: string | undefined;
+    const normalizedPreSave = preSaveContent.trim();
+    const normalizedPostSave = postSaveContent.trim();
+
+    if (normalizedPreSave !== normalizedPostSave) {
+      // Auto-formatting was applied by the editor
+      const diffLines = myersDiff(preSaveContent, postSaveContent);
+      autoFormattingDiff = diffLines
+        .map((line) => {
+          switch (line.type) {
+            case "old":
+              return `-${line.line}`;
+            case "new":
+              return `+${line.line}`;
+            case "same":
+              return ` ${line.line}`;
+          }
+        })
+        .join("\n");
+    }
+
     await sidebar.webviewProtocol.request("updateApplyState", {
-      fileContent,
+      fileContent: postSaveContent, // Use post-save content
       filepath: newOrCurrentUri,
       streamId,
       status: "closed",
       numDiffs: 0,
       toolCallId,
+      autoFormattingDiff, // Include autoformatting diff
     });
+  } else {
+    // Save the file even if no streamId
+    await ide.saveFile(newOrCurrentUri);
   }
-
-  // Save the file
-  await ide.saveFile(newOrCurrentUri);
 }
diff --git a/gui/src/redux/thunks/handleApplyStateUpdate.ts b/gui/src/redux/thunks/handleApplyStateUpdate.ts
index 25532e75079..8d7c1bec043 100644
--- a/gui/src/redux/thunks/handleApplyStateUpdate.ts
+++ b/gui/src/redux/thunks/handleApplyStateUpdate.ts
@@ -83,6 +83,24 @@ export const handleApplyStateUpdate = createAsyncThunk<
             }
 
             if (accepted) {
+              // Add autoformatting diff to tool output if present
+              if (applyState.autoFormattingDiff) {
+                dispatch(
+                  updateToolCallOutput({
+                    toolCallId: applyState.toolCallId,
+                    contextItems: [
+                      {
+                        icon: "info",
+                        name: "Auto-formatting Applied",
+                        description: "Editor auto-formatting changes",
+                        content: `Along with your edits, the editor applied the following auto-formatting:\n\n${applyState.autoFormattingDiff}\n\n(Note: Pay close attention to changes such as single quotes being converted to double quotes, semicolons being removed or added, long lines being broken into multiple lines, adjusting indentation style, adding/removing trailing commas, etc. This will help you ensure future SEARCH/REPLACE operations to this file are accurate.)`,
+                        hidden: false,
+                      },
+                    ],
+                  }),
+                );
+              }
+
               if (toolCallState.status !== "errored") {
                 dispatch(
                   acceptToolCall({
@@ -98,7 +116,6 @@ export const handleApplyStateUpdate = createAsyncThunk<
               );
             }
           }
-          // TODO return output from edit tools so the model knows the result
         }
       }
     }