DeepSeek Harness Plugin

lokih1028/dsh-plugin-canvas-pro

Stars ★ 0 Category UI Enhancements Added 2026-09-07

Adds a Canvas drawer and eight model tools to create, patch, version, and export HTML, Markdown, Mermaid, SVG, and React artifacts.

Install

# from GitHub (first run asks for allowBuilds approval — follow the hint, retry)

dsh plugin --profile web add github:lokih1028/dsh-plugin-canvas-pro

Any plugin you install runs third-party code with your own permissions — it can read your files, use your credentials, and reach the network, and tool approvals don’t sandbox it. GitHub-sourced plugins also run build scripts at install time — pnpm blocks those until you allow them, so an install can stop with ERR_PNPM_GIT_DEP_PREPARE_NOT_ALLOWED or ERR_PNPM_IGNORED_BUILDS; dsh prints the exact key to add under allowBuilds in your profile’s pnpm-workspace.yaml, and the install works on the next run. Allowing a build is a trust decision: only install sources you trust, and pin a commit (github:owner/repo#sha).

README

Canvas-Pro for DeepSeek Harness: a Web drawer plus eight model tools for creating, patching, versioning, and exporting canvas artifacts.

What it does

After install, the Web session header gets a Canvas button. The agent can create HTML, Markdown, Mermaid, SVG, or React artifacts; the drawer previews them in a sandboxed iframe.

Model tools:

Tool Purpose
create_canvas_artifact Create an artifact
update_canvas_artifact Patch by selection, line range, or overwrite
get_canvas_selection Read the latest preview selection
get_canvas_artifact Read current content
list_canvas_versions List snapshots
revert_canvas_artifact Restore a previous snapshot as a new version
diff_canvas_artifact Unified or split diff between versions
export_canvas_artifact Export markdown, html, svg, png data URL, or json

Selecting text in the preview opens Explain / Refactor / Fix / custom prompt actions and submits them into the current chat.

Compared with open-source DSH plugins

Sources are the plugins' own listings on awesome-dsh-plugin. This table only covers claims that those listings make and that this repo implements.

dsh-live-canvas dsh-canvas-preview dsh-generative-ui Canvas-Pro
What it is Live sandbox for HTML / React / Vue / SVG / Mermaid / Markdown Conversation tab that previews workspace HTML Streaming TSX UI inline or in a side canvas Artifact workspace: drawer + eight model tools
Agent tools Preview-oriented canvas_preview-style HTML preview Agent writes TSX; cards can run bash / curl / model / files create / update / get / get_selection / list_versions / revert / diff / export
Partial edit Not the product focus Typically whole HTML New TSX frames replace_selection, replace_range, full_overwrite
Selection → next turn DOM click inspector Not listed Click on a card drives the next chat turn Explain / Refactor / Fix / custom prompt from a text selection
Versions Side-by-side visual diff Not listed State kept across stream frames Snapshot history, revert as a new version, unified and split line diff
Export Vite ZIP Local PNG / JPG / SVG Not listed Markdown, standalone HTML, SVG, PNG rasterization (SVG fallback), JSON archive
Persistence Session / HMR Workspace HTML files In-memory UI state $DSH_HOME/storages/canvas-pro/artifacts.json
Drawer Preview surface Conversation tab Inline + side canvas Resizable overlay; chat turns do not force it open

Same-name plugins that are not competitors here:

Where the others are stronger:

  • live-canvas: real React / Vue / Mermaid runtimes, SSE hot reload, device matrix, Vite ZIP.
  • canvas-preview: first-class PNG / JPG export from workspace HTML.
  • generative-ui: streaming TSX compile, no extra tool schema, clicks inside a card start the next turn.

Where Canvas-Pro is stronger for DSH artifact work:

  1. Patch instead of regenerate. The agent can replace a selected span or a line range. Preview plugins usually take a new full document.
  2. Text selection is a first-class agent input. The drawer posts the span into the current composer; the host can also read it via get_canvas_selection.
  3. Version time machine. Each patch is a snapshot; the agent can list, diff, and revert without rewriting the file from scratch.
  4. Export is a model tool, not only a UI button: markdown / html / svg / png / json from export_canvas_artifact.
  5. Local artifact store survives Web restarts under $DSH_HOME.

Not claimed: richer live React/Mermaid than live-canvas; streaming TSX than generative-ui; raster PNG/JPG reliability than canvas-preview.

Install

dsh plugin --profile web add github:lokih1028/dsh-plugin-canvas-pro

Restart the Web profile, then refresh the GUI.

Config

- id: canvas-pro
  name: dsh-plugin-canvas-pro
  config:
    maxHistoryPerArtifact: 50
    enableReactPreview: true

Artifacts are stored under $DSH_HOME/storages/canvas-pro/artifacts.json when DSH_HOME is set.

Limits

  • React artifacts currently show source in the preview sandbox; they are not executed as a live React tree.
  • Mermaid artifacts show source unless you convert them to HTML.
  • PNG export tries a browser rasterization of the SVG preview; if that fails it falls back to SVG.
  • Selection line numbers come from the rendered preview, not always from source lines. Prefer replace_selection over replace_range when the two disagree.

License

MIT

Content from the project README on GitHub ↗

Links

More in this category

View the whole category →

Community comments

Comments are public GitHub Discussions. Loading them connects to GitHub and Giscus; a GitHub account is required to post.