Nanobot drafts one preview pane for files and websites without a full browser

Nanobot is proposing a conversation-side preview workspace rather than another stream of file links. Its draft combines file actions and website previews in one resizable pane, with tabs belonging to the current session. Returning to a conversation can restore its preview choices while that in-memory state remains available. This is a product-direction story: the small agent interface is becoming a place to inspect the work without pretending it is a general browser.

That qualification is central. The proposed website pane does not forward credentials, evade frame restrictions or retain a third-party page's DOM and forms across navigation. When a site cannot be embedded under those rules, the fallback is an external-open link, not a covert proxy.

The facts

- PR 5847 is still a draft and unmerged; its interface is not established as part of the current release. - The preview pane combines session-owned file and website tabs and is resizable. - PNG, JPEG, GIF and WebP receive image previews; HTML and SVG remain source views. - Raster responses are signature-checked and limited to 8 MiB, while workspace and owner checks remain authoritative. - Website embedding requires credentialless support and an opaque scripts-only sandbox; blocked sites retain external navigation. - Preview state is memory-only and cleared on deletion or disconnect, with no new durable store or agent-tool permission.

Why it matters

The interface problem is practical: users need to inspect a generated file, compare it with a referenced page and return to the conversation without losing their place. A shared preview surface can reduce that friction, but only if it does not silently become a privileged web session. Nanobot's stated boundaries keep the pane closer to a controlled viewer. Those limits are a feature for administrators even when they mean that some pages simply will not work inside it.

Current

Checked September 24, 2026. The inspected release baseline is v0.3.5. The primary source is open proposal. Package availability and development-source state are separate: a tag does not establish that an open proposal is usable, and a merge does not establish that every installation has received it.

Evidence

Primary: HKUDS/nanobot PR #5847 (https://github.com/HKUDS/nanobot/pull/5847). Supporting context: HKUDS/nanobot — webui.md at e403511a (https://github.com/HKUDS/nanobot/blob/e403511a08bcca542a02f889d71217764d7f9e92/docs%2Fwebui.md); HKUDS/nanobot PR #5847 — implementation diff (https://github.com/HKUDS/nanobot/pull/5847/files). Source pages and available diffs were inspected; test and live-account results remain attributed to their authors, not independently repeated measurements.

Operator take

Judge the proposal on ordinary review tasks: opening a file from a reply, switching conversations, renewing credentials, returning to a tab, copying a reference and handling a blocked website. The authors report actual-browser tests with production components and synthetic conversations, including a real cross-origin page and a deliberately frame-blocked page. That is stronger than a static mockup, but it does not establish all device interactions or a complete external-browser handoff.

Caveat

The reported 1,877 WebUI and 234 focused Python tests were not rerun for this story. Physical iOS/Android gestures were not hardware-tested, and a one-click external-open handoff was not observed end to end in the embedded test browser. This draft adds neither a native editor/terminal launcher nor general authenticated browsing.