dsh-surface

Live pages in the conversation. Preview, report, or ask.

dsh-surface is a DeepSeekRuntime plugin that renders a complete HTML page inside the conversation. Use it for UI previews, data reports, mockups, calculators — or for forms and approvals where the page can send a structured answer back to the agent through the same tool call.

Why

Most chat UIs can show text or a fixed component tree. A page is different: it can lay out a real report, run a chart, look exactly like the UI you are building, and collect an answer without making the user translate their choice into prose.

dsh-surface gives the model one tool:

• render a page — a self-contained HTML document, sandboxed, themed with the host's tokens, auto-sized;
• optionally wait for it — the tool call blocks until the user submits, cancels, or the timeout expires;
• return data, not prose — the page calls dshSurface.submit(data, summary) and the agent receives { answered, summary, data } in the same turn.

It is not a component library, and it is not an artifact manager. It is the page surface between the model and the user.

Features

• Any self-contained HTML — inline CSS/JS, SVG, canvas; no external requests.
• Sandboxed by default — opaque origin, no allow-same-origin, CSP blocks network, forms, nested frames, and top-level navigation.
• Follows the host theme — --dsw-* tokens are bridged to --background, --foreground, --chart-*, --radius, and friends.
• Auto height — the frame reports its content height and the card sizes itself.
• Blocking answers — awaitAnswer-style semantics without a separate question panel.
• OpenChamber-compatible pages — window.openchamber.submit(data, summary) is an alias of window.dshSurface.
• Small and auditable — one host file, one client bundle, a 12-case test suite.

Install

Requires DeepSeekRuntime with the Web UI (dsh web) and Node.js ^22.19.0 || >=24.

dsh plugin --profile web add dsh-surface

Restart dsh web, then refresh the browser. The plugin activates on the next session.

The package is published as dsh-surface. If you are installing from a checkout instead, use dsh plugin --profile web add link:/path/to/dsh-surface and run npm install && npm run build first.

Use it

Ask for a page, or point the model at one:

Render a one-page Q3 revenue report with a bar chart and a table. Use the render tool; make the page self-contained.

Here is our release checklist. Render it as a page with an approve / reject choice and a note field. On submit call dshSurface.submit({ decision, note }, summary).

The model calls the render tool with a complete HTML document. The page appears in the tool card. If it calls dshSurface.submit, the call stays open until the answer arrives.

Tool reference

Field	Type	Required	Meaning
html	string	yes	A complete, self-contained HTML document (max 200,000 bytes).
title	string	no	Card title; the page's own <title> still names the frame.
timeoutSeconds	number	no	How long to wait for a submission. Default 600, max 3600.

The tool returns one JSON string:

{ "answered": true, "summary": "Approved with a note", "data": { "decision": "approve", "note": "ship it" } }

On timeout it returns { "answered": false, "reason": "timeout" }. On cancellation the call fails with the host's cancellation error.

Page API

Inside the page:

<button onclick="dshSurface.submit({ decision: 'approve' }, 'Approved')">Approve</button>

API	Meaning
dshSurface.submit(data, summary)	Send the answer. data must be JSON-serializable (≤ 16 KB); summary is a short human-readable line (≤ 500 chars). Returns a Promise. Must be called from a user gesture.
dshSurface.answered	Whether an answer has been accepted.
dshSurface.answer	The accepted answer, when available.
dshRender / openchamber	Aliases kept for pages written before the rename.

The page may also listen for dsh-surface:result on window to react to the host's acknowledgement.

Security model

• The page runs in an iframe with sandbox="allow-scripts allow-forms" and no allow-same-origin. It has an opaque origin and cannot read the host page, cookies, or storage.
• A document-level CSP allows inline scripts/styles and data: images, and blocks connect-src, nested frames, forms, and navigation.
• The submission route is registered on the host's authenticated /api channel (ctx.connection.fetch). Only the owner peer reaches it; the host checks Host/Origin and browser authentication before the handler runs.
• Payload limits: 500-character summary, 16 KB JSON data, 200 KB HTML.
• Pages should not ask for secrets. Treat any page content as untrusted.

See docs/architecture.md for the full lifecycle.

Compatibility

Surface	Status
dsh web (0.2.1-rc.2)	Tested end to end
dsh headless / TUI	No page surface; the tool waits until its timeout and returns answered: false
Desktop (Electron)	Not yet verified; custom fetch over the desktop IPC bridge needs a real run

Known limitations

1. The page folds when the turn ends. The card lives inside the tool-call group; after the turn settles, that group collapses. The answer remains visible in the transcript, and expanding the group brings the page back. A conversation.chat.turnTail card is the planned fix.
2. No local images yet. Only data: / inline images render; reading workspace files and enforcing a budget is not implemented.
3. HTML lives in the tool arguments. A large page is part of the session log and may be resent with later turns. An artifact-backed page (short id + file) is the planned improvement.
4. No waiting notification. If you switch sessions, nothing tells you that a page is waiting; the tool does not appear in a global inbox.
5. A host restart loses the wait. The pending map is in memory; after a restart the call is interrupted and the page becomes read-only.
6. No persistence or versions. The plugin stores nothing of its own; every render is a new call.

Development

npm install
npm run check      # lint + typecheck + tests + build + format check
npm test           # node:test
npm run build      # lib/index.js + lib/client.js

Project layout:

src/index.js              host: render tool, wait registry, answer route
src/wait.js               pending calls (first answer wins, cancel, timeout)
src/answer.js             POST body validation and responses
src/client/index.tsx      client plugin: tool.call.toolview registration
src/client/RenderCard.tsx iframe card, theme, height, submit bridge
src/client/shell.ts       frame document, CSP, height script, bridge
src/client/theme.ts       --dsw-* → page variables
tests/                    wait/answer unit tests
examples/approval.html    a ready-to-use approval page

See CONTRIBUTING.md before opening a pull request.

License

MIT © 2026 woolsen