diff --git a/app/components/chat/BaseChat.tsx b/app/components/chat/BaseChat.tsx
index 4fb5989e2..eccd80ffc 100644
--- a/app/components/chat/BaseChat.tsx
+++ b/app/components/chat/BaseChat.tsx
@@ -51,6 +51,7 @@ interface BaseChatProps {
   setUploadedFiles?: (files: File[]) => void;
   imageDataList?: string[];
   setImageDataList?: (dataList: string[]) => void;
+  onRewind?: (messageId: string, contents: string) => void;
 }
 
 export const BaseChat = React.forwardRef<HTMLDivElement, BaseChatProps>(
@@ -77,6 +78,7 @@ export const BaseChat = React.forwardRef<HTMLDivElement, BaseChatProps>(
       imageDataList = [],
       setImageDataList,
       messages,
+      onRewind,
     },
     ref,
   ) => {
@@ -241,6 +243,7 @@ export const BaseChat = React.forwardRef<HTMLDivElement, BaseChatProps>(
                       className="flex flex-col w-full flex-1 max-w-chat pb-6 mx-auto z-1"
                       messages={messages}
                       isStreaming={isStreaming}
+                      onRewind={onRewind}
                     />
                   ) : null;
                 }}
diff --git a/app/components/chat/Chat.client.tsx b/app/components/chat/Chat.client.tsx
index 4861094f2..9eb9ffd91 100644
--- a/app/components/chat/Chat.client.tsx
+++ b/app/components/chat/Chat.client.tsx
@@ -49,7 +49,7 @@ export function resetChatFileWritten() {
 }
 
 async function flushSimulationData() {
-  console.log("FlushSimulationData");
+  //console.log("FlushSimulationData");
 
   const iframe = getCurrentIFrame();
   if (!iframe) {
@@ -60,7 +60,7 @@ async function flushSimulationData() {
     return;
   }
 
-  console.log("HaveSimulationData", simulationData.length);
+  //console.log("HaveSimulationData", simulationData.length);
 
   // Add the simulation data to the chat.
   await simulationAddData(simulationData);
@@ -150,24 +150,6 @@ interface ChatProps {
 
 let gNumAborts = 0;
 
-interface InjectedMessage {
-  message: Message;
-  previousId: string;
-}
-
-function handleInjectMessages(baseMessages: Message[], injectedMessages: InjectedMessage[]) {
-  const messages = [];
-  for (const message of baseMessages) {
-    messages.push(message);
-    for (const injectedMessage of injectedMessages) {
-      if (injectedMessage.previousId === message.id) {
-        messages.push(injectedMessage.message);
-      }
-    }
-  }
-  return messages;
-}
-
 function filterFiles(files: FileMap): FileMap {
   const rv: FileMap = {};
   for (const [path, file] of Object.entries(files)) {
@@ -187,7 +169,6 @@ export const ChatImpl = memo(
     const [uploadedFiles, setUploadedFiles] = useState<File[]>([]); // Move here
     const [imageDataList, setImageDataList] = useState<string[]>([]); // Move here
     const [searchParams, setSearchParams] = useSearchParams();
-    const [injectedMessages, setInjectedMessages] = useState<InjectedMessage[]>([]);
     const [simulationLoading, setSimulationLoading] = useState(false);
     const files = useStore(workbenchStore.files);
     const { promptId } = useSettings();
@@ -196,7 +177,7 @@ export const ChatImpl = memo(
 
     const [animationScope, animate] = useAnimate();
 
-    const { messages: baseMessages, isLoading, input, handleInputChange, setInput, stop, append } = useChat({
+    const { messages, isLoading, input, handleInputChange, setInput, stop, append, setMessages } = useChat({
       api: '/api/chat',
       body: {
         files: filterFiles(files),
@@ -213,10 +194,6 @@ export const ChatImpl = memo(
       initialInput: Cookies.get(PROMPT_COOKIE_KEY) || '',
     });
 
-    const messages = useMemo(() => {
-      return handleInjectMessages(baseMessages, injectedMessages);
-    }, [baseMessages, injectedMessages]);
-
     useEffect(() => {
       const prompt = searchParams.get('prompt');
 
@@ -384,7 +361,7 @@ export const ChatImpl = memo(
           }
 
           console.log("RecordingMessage", recordingMessage);
-          setInjectedMessages([...injectedMessages, { message: recordingMessage, previousId: messages[messages.length - 1].id }]);
+          setMessages([...messages, recordingMessage]);
 
           if (recordingId) {
             const info = await enhancedPromptPromise;
@@ -396,7 +373,7 @@ export const ChatImpl = memo(
             simulationEnhancedPrompt = info.enhancedPrompt;
 
             console.log("EnhancedPromptMessage", info.enhancedPromptMessage);
-            setInjectedMessages([...injectedMessages, { message: info.enhancedPromptMessage, previousId: messages[messages.length - 1].id }]);
+            setMessages([...messages, info.enhancedPromptMessage]);
           }
         } finally {
           gLockSimulationData = false;
@@ -451,6 +428,17 @@ export const ChatImpl = memo(
       saveProjectContents(lastMessage.id, { content: contentBase64 });
     };
 
+    const onRewind = async (messageId: string, contents: string) => {
+      console.log("Rewinding", messageId, contents);
+
+      await workbenchStore.restoreProjectContentsBase64(messageId, contents);
+
+      const messageIndex = messages.findIndex((message) => message.id === messageId);
+      if (messageIndex >= 0) {
+        setMessages(messages.slice(0, messageIndex + 1));
+      }
+    };
+
     /**
      * Handles the change event for the textarea and updates the input state.
      * @param event - The change event from the textarea.
@@ -517,6 +505,7 @@ export const ChatImpl = memo(
         setUploadedFiles={setUploadedFiles}
         imageDataList={imageDataList}
         setImageDataList={setImageDataList}
+        onRewind={onRewind}
       />
     );
   },
diff --git a/app/components/chat/LoadProblemButton.tsx b/app/components/chat/LoadProblemButton.tsx
index 3f90e61be..ee50dbe74 100644
--- a/app/components/chat/LoadProblemButton.tsx
+++ b/app/components/chat/LoadProblemButton.tsx
@@ -1,12 +1,11 @@
 import React, { useState } from 'react';
 import type { Message } from 'ai';
 import { toast } from 'react-toastify';
-import { createChatFromFolder, type FileArtifact } from '~/utils/folderImport';
+import { createChatFromFolder } from '~/utils/folderImport';
 import { logStore } from '~/lib/stores/logs'; // Assuming logStore is imported from this location
-import { assert, sendCommandDedicatedClient } from '~/lib/replay/ReplayProtocolClient';
+import { assert } from '~/lib/replay/ReplayProtocolClient';
 import type { BoltProblem } from '~/lib/replay/Problems';
-import { getProblem } from '~/lib/replay/Problems';
-import JSZip from 'jszip';
+import { getProblem, extractFileArtifactsFromRepositoryContents } from '~/lib/replay/Problems';
 
 interface LoadProblemButtonProps {
   className?: string;
@@ -40,17 +39,7 @@ export async function loadProblem(problemId: string, importChat: (description: s
 
   const { repositoryContents, title: problemTitle } = problem;
 
-  const zip = new JSZip();
-  await zip.loadAsync(repositoryContents, { base64: true });
-
-  const fileArtifacts: FileArtifact[] = [];
-  for (const [key, object] of Object.entries(zip.files)) {
-    if (object.dir) continue;
-    fileArtifacts.push({
-      content: await object.async('text'),
-      path: key,
-    });
-  }
+  const fileArtifacts = await extractFileArtifactsFromRepositoryContents(repositoryContents);
 
   try {
     const messages = await createChatFromFolder(fileArtifacts, [], "problem");
diff --git a/app/components/chat/Messages.client.tsx b/app/components/chat/Messages.client.tsx
index b8dcfb554..b98fbf4ac 100644
--- a/app/components/chat/Messages.client.tsx
+++ b/app/components/chat/Messages.client.tsx
@@ -15,6 +15,7 @@ interface MessagesProps {
   className?: string;
   isStreaming?: boolean;
   messages?: Message[];
+  onRewind?: (messageId: string, contents: string) => void;
 }
 
 interface ProjectContents {
@@ -27,11 +28,8 @@ export function saveProjectContents(messageId: string, contents: ProjectContents
   gProjectContentsByMessageId.set(messageId, contents);
 }
 
-// The rewind button is not fully implemented yet.
-const EnableRewindButton = false;
-
 export const Messages = React.forwardRef<HTMLDivElement, MessagesProps>((props: MessagesProps, ref) => {
-  const { id, isStreaming = false, messages = [] } = props;
+  const { id, isStreaming = false, messages = [], onRewind } = props;
 
   const getLastMessageProjectContents = (index: number) => {
     // The message index is for the model response, and the project
@@ -42,7 +40,11 @@ export const Messages = React.forwardRef<HTMLDivElement, MessagesProps>((props:
       return undefined;
     }
     const previousMessage = messages[index - 2];
-    return gProjectContentsByMessageId.get(previousMessage.id);
+    const contents = gProjectContentsByMessageId.get(previousMessage.id);
+    if (!contents) {
+      return undefined;
+    }
+    return { messageId: previousMessage.id, contents };
   };
 
   return (
@@ -82,13 +84,14 @@ export const Messages = React.forwardRef<HTMLDivElement, MessagesProps>((props:
                       <AssistantMessage content={content} annotations={message.annotations} />
                     )}
                   </div>
-                  {!isUserMessage && messageId && getLastMessageProjectContents(index) && EnableRewindButton && (
+                  {!isUserMessage && messageId && onRewind && getLastMessageProjectContents(index) && (
                     <div className="flex gap-2 flex-col lg:flex-row">
-                      <WithTooltip tooltip="Rewind to this message">
+                      <WithTooltip tooltip="Undo changes in this message">
                         <button
                           onClick={() => {
-                            const contents = getLastMessageProjectContents(index);
-                            assert(contents);
+                            const info = getLastMessageProjectContents(index);
+                            assert(info);
+                            onRewind(info.messageId, info.contents.content);
                           }}
                           key="i-ph:arrow-u-up-left"
                           className={classNames(
diff --git a/app/lib/replay/Problems.ts b/app/lib/replay/Problems.ts
index 88b9dd7af..7927d9e25 100644
--- a/app/lib/replay/Problems.ts
+++ b/app/lib/replay/Problems.ts
@@ -4,6 +4,8 @@ import { toast } from "react-toastify";
 import { sendCommandDedicatedClient } from "./ReplayProtocolClient";
 import type { ProtocolMessage } from "./SimulationPrompt";
 import Cookies from 'js-cookie';
+import JSZip from 'jszip';
+import type { FileArtifact } from "~/utils/folderImport";
 
 export interface BoltProblemComment {
   username?: string;
@@ -149,3 +151,18 @@ export function getProblemsUsername(): string | undefined {
 export function setProblemsUsername(username: string) {
   Cookies.set(nutProblemsUsernameCookieName, username);
 }
+
+export async function extractFileArtifactsFromRepositoryContents(repositoryContents: string): Promise<FileArtifact[]> {
+  const zip = new JSZip();
+  await zip.loadAsync(repositoryContents, { base64: true });
+
+  const fileArtifacts: FileArtifact[] = [];
+  for (const [key, object] of Object.entries(zip.files)) {
+    if (object.dir) continue;
+    fileArtifacts.push({
+      content: await object.async('text'),
+      path: key,
+    });
+  }
+  return fileArtifacts;
+}
diff --git a/app/lib/replay/Recording.ts b/app/lib/replay/Recording.ts
index 8564cb4af..3a3e0ab2e 100644
--- a/app/lib/replay/Recording.ts
+++ b/app/lib/replay/Recording.ts
@@ -152,7 +152,7 @@ function addRecordingMessageHandler(messageHandlerId: string) {
   }
 
   async function getSimulationData(): Promise<SimulationData> {
-    console.log("GetSimulationData", simulationData.length, numSimulationPacketsSent);
+    //console.log("GetSimulationData", simulationData.length, numSimulationPacketsSent);
     const data = simulationData.slice(numSimulationPacketsSent);
     numSimulationPacketsSent = simulationData.length;
     return data;
diff --git a/app/lib/replay/ReplayProtocolClient.ts b/app/lib/replay/ReplayProtocolClient.ts
index 7e0c4f66f..a6209880f 100644
--- a/app/lib/replay/ReplayProtocolClient.ts
+++ b/app/lib/replay/ReplayProtocolClient.ts
@@ -35,7 +35,7 @@ export function stringToBase64(inputString: string) {
 }
 
 function logDebug(msg: string, tags: Record<string, any> = {}) {
-  console.log(msg, JSON.stringify(tags));
+  //console.log(msg, JSON.stringify(tags));
 }
 
 class ProtocolError extends Error {
diff --git a/app/lib/stores/workbench.ts b/app/lib/stores/workbench.ts
index b2fccbdd0..4b599c7b2 100644
--- a/app/lib/stores/workbench.ts
+++ b/app/lib/stores/workbench.ts
@@ -19,6 +19,7 @@ import Cookies from 'js-cookie';
 import { createSampler } from '~/utils/sampler';
 import { uint8ArrayToBase64 } from '../replay/ReplayProtocolClient';
 import type { ActionAlert } from '~/types/actions';
+import { extractFileArtifactsFromRepositoryContents } from '../replay/Problems';
 
 export interface ArtifactState {
   id: string;
@@ -326,10 +327,12 @@ export class WorkbenchStore {
       unreachable('Artifact not found');
     }
 
-    const action = artifact.runner.actions.get()[data.actionId];
+    if (data.actionId != 'restore-contents-action-id') {
+      const action = artifact.runner.actions.get()[data.actionId];
 
-    if (!action || action.executed) {
-      return;
+      if (!action || action.executed) {
+        return;
+      }
     }
 
     if (data.action.type === 'file') {
@@ -421,6 +424,62 @@ export class WorkbenchStore {
     return { contentBase64, uniqueProjectName };
   }
 
+  async restoreProjectContentsBase64(messageId: string, contentBase64: string) {
+    const fileArtifacts = await extractFileArtifactsFromRepositoryContents(contentBase64);
+
+    const modifiedFilePaths = new Set<string>();
+
+    // Check if any files we know about have different contents in the artifacts.
+    const files = this.files.get();
+    const fileRelativePaths = new Set<string>();
+    for (const [filePath, dirent] of Object.entries(files)) {
+      if (dirent?.type === 'file' && !dirent.isBinary) {
+        const relativePath = extractRelativePath(filePath);
+        fileRelativePaths.add(relativePath);
+
+        const content = dirent.content;
+
+        const artifact = fileArtifacts.find((artifact) => artifact.path === relativePath);
+        const artifactContent = artifact?.content ?? "";
+
+        if (content != artifactContent) {
+          modifiedFilePaths.add(relativePath);
+        }
+      }
+    }
+
+    // Also create any new files in the artifacts.
+    for (const artifact of fileArtifacts) {
+      if (!fileRelativePaths.has(artifact.path)) {
+        modifiedFilePaths.add(artifact.path);
+      }
+    }
+
+    const actionArtifactId = `restore-contents-artifact-id-${messageId}`;
+
+    for (const filePath of modifiedFilePaths) {
+      console.log("RestoreModifiedFile", filePath);
+
+      const artifact = fileArtifacts.find((artifact) => artifact.path === filePath);
+      const artifactContent = artifact?.content ?? "";
+
+      const actionId = `restore-contents-action-${messageId}-${filePath}`;
+      const data: ActionCallbackData = {
+        actionId,
+        messageId,
+        artifactId: actionArtifactId,
+        action: {
+          type: 'file',
+          filePath: filePath,
+          content: artifactContent,
+        },
+      };
+
+      this.addAction(data);
+      this.runAction(data);
+    }
+  }
+
   async syncFiles(targetHandle: FileSystemDirectoryHandle) {
     const files = this.files.get();
     const syncedFiles = [];