[Bug]: New remote streaming web previews remove DevTools & Annotation functionality

[DarthNerdus]

Before submitting

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

Area

apps/desktop

Steps to reproduce

1. Update to nightly 0.0.46-nightly.20261006.2735 or later
2. Start a thread on a remote Connection
3. Open a web preview
4. Attempt to visit any URL
5. Observe DevTools and Annotation features are missing
6. Attempt to visit a URL that is available outside of localhost (i.e., a public URL or Tailscale URL local app can access without tunneling)
7. Observe the URL still streams through the remote and all DevTools & Annotation features are missing

Expected behavior

Beyond sharpness and lag issues documented in #16578, annotation features should not be suppressed by the new streaming functionality. There is no explanation or ability to restore these features, which are suddenly available if you open a different threat that runs locally. The way this applies to ALL URLs further confounds the issue.

I want to be clear that the server-side tabs and agent interaction make a ton of sense, I would not expect this to be fully on-or-off.

I would expect:

• The ability to open tabs in a remote-originated thread that do not stream.
• Even when streaming, I would expect to have access to Annotation features.
• Distinguish "agent preview tabs" from "human review" or "manual" tabs.
• Capability to assess whether a URL requires streaming (localhost) or is available externally (google.com, xyz.tailscale.net) -- this may be a good option for 'Default to open in X type of Preview' config

Actual behavior

Using a thread on a remote always-on machine introduces lag and loss of expected functionality with no explanation or workaround.

Impact

Major degradation or frequent failure

Version or commit

PR #15328 / nightly 0.0.46-nightly.20261006.2735 and beyond

Environment

macOS T3 Code connected to Arch T3 Code instance

Logs or stack traces

Screenshots, recordings, or supporting files

file-6618fbcd3df8b223eecf8c1eb87a1f4b.png

Workaround

No response

[DarthNerdus]

Playing with my clanker on some ideas/alterations that balance this functionality with legacy / local performance. The language still isn't clear, unless you understand what these options meant before, but something to noodle on.

[MatthewLopez1990]

+1. Preview annotations are the feature I use most in T3 Code, and since the server browser landed in #15328 the Annotate button is gone for me (0.0.46-nightly.20261008.2833, macOS).

My workflow: open my locally hosted site in the preview, click Annotate preview, select elements, write the change I want for each one, and let several annotations collect in the composer. Then I send them all to the agent in one message. Batching design tweaks against the live page is what makes T3 Code work for front-end work. Without it I'm back to screenshots and describing elements in words.

From reading the source at that nightly tag, the button isn't broken. It's no longer rendered for streamed tabs:

// apps/web/src/components/preview/PreviewView.tsx
const isServerTab = snapshot?.runtime === "server" && !nativeServerTab;
// ...
onPickElement={previewBridge && tabId && !isServerTab ? handlePickElement : undefined}

nativeServerTab is only true in the desktop app, for tabs of the server that app launched (rendersServerTabNatively in apps/web/src/browser/previewRuntime.ts). In every other case the Annotate button (and Capture screenshot, line 905) just disappears, with no message saying why, and there's no setting to get the local preview back.

What would fix it for me:

• Annotations in streamed tabs, or a way to open a preview tab in the local desktop browser so annotations work again (the opt-out requested in [Bug]: Server-side browser makes previews blurry, with no way to opt out #16578).
• Until then, a disabled button with a tooltip explaining why annotations are unavailable, instead of the button vanishing.

Posted with help from Claude Opus 5.5 in T3 Code.

[juliusmarminge]

Note

Grok responding on behalf of Julius.

Closing as fixed by merged #17316 — desktop now opens remote-environment tabs locally for user-opened pages, which restores native DevTools/annotation on those tabs. Agent-opened streamed tabs are unchanged.