[Bug]: Files panel keeps showing old file contents after the file changes on the server

[nekohasekai]

Before submitting

• I searched existing issues and did not find a duplicate.
• I included enough detail to reproduce or investigate the problem.

Area

apps/web

Steps to reproduce

Use a project with a text file (docs/release-notes.md), an image (assets/hero.png) and a README.md that embeds the image (![Hero banner](assets/hero.png)).

A. File changed outside the thread

1. Open a thread, then open docs/release-notes.md in the Files panel. Open assets/hero.png in another tab.
2. Overwrite both files on the server without going through this thread, for example from a terminal, an editor, or another thread in the same checkout.
3. Look at each tab, then switch to another file tab and back. Click Refresh workspace files.

B. Image embedded in a Markdown preview

1. Open README.md in the Files panel and switch it to the rendered view.
2. Ask the agent in this thread to overwrite the image, for example cp hero-v2.png assets/hero.png.
3. When the turn finishes, compare the rendered README with the hero.png tab.

Expected behavior

A file preview shows the file as it is on the server. At the latest, opening the file again or clicking Refresh workspace files shows the current version.

Actual behavior

• A, text: While the file is open, it keeps the old text and does not update by itself. Clicking Refresh workspace files or opening the file again shows the new text.
• A, image: The preview keeps the old image while it is open, after switching tabs and opening it again, and after Refresh workspace files. Only reloading the page shows the new image.
• B: The rendered README keeps the old image even though the agent in this thread changed it. The hero.png tab shows the new image.

A change made by the agent in this thread does refresh an open text file and the image tab. Only changes from anywhere else stay stale.

Mobile very likely has the same problem, also for changes the agent makes in the thread. I did not test it, but in the code the Files screen never refreshes an open file after it changes: open text stays old, and the image loads with cache: "force-cache" and only gets a new URL from the Refresh menu.

Why (source at 4ee6bfd)

The Files panel re-reads an open file only when workspaceMutationId changes, and that is the thread's latest completed command or file change (ChatView.tsx#L4003). Text is re-read on that signal (FilePreviewPanel.tsx#L1040-L1052), and the image preview appends it to its URL (FilePreviewPanel.tsx#L142). A change from outside the thread does not move it, so an open file does not update by itself.

Images also stay old after reopening, because both the client and the browser reuse the signed asset URL by path:

• The client keeps the URL it got for a thread and path. A newly opened preview reuses it for 5 minutes, an open one gets a new URL every 30 minutes, and an unused entry lives for an hour (assets.ts#L28-L30).
• The server lets the browser cache the response for an hour (http.ts#L100). Only audio and video get no-store (http.ts#L178).
• Refresh workspace files re-reads an open text file but skips images and PDFs (FilePreviewPanel.tsx#L1310-L1312), so an open image keeps its URL.

B: the Markdown preview renders images with the chat image component, which asks for a media-file URL without the revision (ChatMarkdown.tsx#L3385-L3390).

Mobile: WorkspaceFileImagePreview.tsx#L21 (force-cache), ThreadFilesRouteScreen.tsx#L647 (new image URL only after Refresh), ThreadFilesRouteScreen.tsx#L660 (the text query has no refresh on change).

Related reports

• [Bug]: Image previews don't update when file updates #13138 and [Bug]: Re-embedding an overwritten local image shows the old cached version #15676 report the same URL reuse for images in chat. Open PR fix(clients): chat images show the new file after an agent rewrites it #14943 fixes those by giving each chat message its own URL. It does not change the Files panel, the Markdown preview in Files (it does not pass the new assetScope), mobile Files, or the server headers, so A, B and mobile stay as they are.
• [Bug]: Files panel stays stale after external file creation, F5, and Refresh files #6452: the Files tree does not list files created outside T3. That is the server's file index, not file contents. One comment there also describes an open file tab showing an old version.

Not affected in my tests: an HTML preview picks up a CSS file the agent changed, because Chrome gives the sandboxed frame a fresh cache on every load.

Impact

Minor bug or occasional failure

Version or commit

main @ 4ee6bfd (server reports 0.0.45); unmodified server and web.

Environment

Web in Chrome 154 against a local isolated dev server; macOS 27.0.1 (26A434), Apple Silicon; Node 26.9.0; Codex 0.160.0 / GPT-6-Astra for the agent turns. The same code path is used for local and remote environments; I first noticed it on a remote one. Mobile not tested.

Logs or stack traces

No response

Screenshots, recordings, or supporting files

Step B, isolated demo project. The agent overwrote assets/hero.png with v2 in this thread:

Workaround

Text: click Refresh workspace files or open the file again. Images: reload the page. On mobile, use Refresh in the file's menu.

[juliusmarminge]

Note

Grok responding on behalf of Julius.

Triage

Thanks for the thorough write-up, @nekohasekai! The repro, the screenshot, and splitting out the outside edit from the Markdown embed made this easy to confirm.

What I found

Confirmed on main at 4ee6bfd50e. This is separate from the chat image reports.

• The image tab only refreshes when this thread changes the workspace. WorkspaceImagePreview appends workspace-revision from workspaceMutationId (apps/web/src/components/files/FilePreviewPanel.tsx). That id is this thread's latest completed command, file change, or checkpoint (ChatView.tsx). The new query string is what makes the browser fetch again.
• An outside edit never moves that id. The client reuses the signed URL: for 5 minutes on reopen, with a refresh every 30 minutes while open, and for up to an hour when unused (packages/client-runtime/src/state/assets.ts). Image responses are Cache-Control: private, max-age=3600 (assetResponseHeaders in apps/server/src/http.ts); only audio and video get no-store. Since the URL stays the same, the browser keeps the first bytes until a page reload signs a new token.
• Refresh workspace files skips open images. It reloads the tree and re-reads the open file, but not when that file is media or a PDF.
• Images in the rendered README skip the revision. FileMarkdownPreview renders through ChatMarkdown, which loads images as a media-file URL without workspace-revision (ChatMarkdown.tsx). The README text is re-read, but the image src never changes.
• Mobile looks the same in code, though I haven't run it on a device.
  • Images are drawn with cache: "force-cache" (WorkspaceFileImagePreview.tsx).
  • The URL only gets a new revision from the file menu's Refresh (ThreadFilesRouteScreen.tsx).
  • Nothing in apps/mobile watches workspaceMutationId.

Related, not duplicates:

• [Bug]: Image previews don't update when file updates #13138 and [Bug]: Re-embedding an overwritten local image shows the old cached version #15676 cover chat images.
• Open fix(clients): chat images show the new file after an agent rewrites it #14943 gives each chat message its own URL. It doesn't change the Files panel, FileMarkdownPreview, mobile Files, or the image cache headers.
• [Bug]: Files panel stays stale after external file creation, F5, and Refresh files #6452 is the file tree index, not file contents.

Likely fix area

Some options:

• Web Files image tab: have Refresh workspace files (and maybe reopening an image) get a fresh asset URL or revision for the open image.
• Markdown preview in Files: pass a revision or scope through FileMarkdownPreview into ChatMarkdown images.
• Mobile Files: tie the image URL and the text query to workspaceMutationId, and/or drop force-cache for workspace files.
• Server headers: use shorter caching or revalidation for workspace-file images only. Chat can keep its current behavior; that question stays with [Bug]: Re-embedding an overwritten local image shows the old cached version #15676.

A maintainer will decide on the fix direction.