Markdown Chart Skill Integration

Status: accepted

Integration contract

Qwen Code WebShell owns the rendering side of the contract:

• @qwen-code/web-shell includes the markdown-chart renderer and ECharts runtime.
• Hosts install the canonical markdown-chart skill so the model emits renderable chart blocks.
• Qwen Code core does not bundle or inject the skill. A project can install it at .qwen/skills/markdown-chart/SKILL.md; user-level skill installation is also supported.

For the normal data.kind="inline" output produced by the skill, the WebShell host needs no chart-specific code:

import { WebShellWithProviders } from '@qwen-code/web-shell';

<WebShellWithProviders
  baseUrl="http://127.0.0.1:4170"
  token={token}
  sessionId={sessionId}
/>;

Referenced data

If the host exposes real controlled datasets to the skill and allows data.kind="ref", it provides resolveDataRef through a custom registry:

import {
  createMarkdownChartRegistry,
  WebShellWithProviders,
} from '@qwen-code/web-shell';

const chartRegistry = createMarkdownChartRegistry({
  resolveDataRef: async (ref, context) =>
    loadControlledChartDataset(ref, context),
});
const markdown = { chart: { registry: chartRegistry } };

<WebShellWithProviders
  baseUrl="http://127.0.0.1:4170"
  token={token}
  sessionId={sessionId}
  markdown={markdown}
/>;

The renderer never fetches a ref or reads a local path by itself. resolveDataRef is the host-owned boundary from a model-visible reference to a trusted dataset. The default registry accepts normalized artifact:// and session-file:// refs, parses the block as JSON, validates the option, and then passes the normalized ref plus declared format and dimensions to the resolver. Resolver waits are bounded to 30 seconds. Keep markdown, chart, and labels overrides referentially stable while charts are mounted.

Streaming behavior

The shared React adapter distinguishes a closed chart fence from the active unterminated tail fence:

• A closed markdown-chart block renders immediately and remains mounted while later answer text streams, including when the fence is inside a blockquote.
• Only the active unterminated chart fence displays the loading state.

Scope

• The skill defines the model output contract; it does not load the renderer.
• WebShell defines the rendering contract; it does not automatically install the skill.
• No daemon, ACP, or client-capability negotiation change is required.
• No automatic network or filesystem access is introduced.