DeepSeek Harness Flowchart
An installable DeepSeek Harness profile bundle that adds a render_flowchart tool. The tool turns Mermaid flowchart source into a polished, themed, self-contained SVG and delegates file creation to Harness's existing write tool.
中文说明
Install
Requires DeepSeek Harness 0.1.0-rc.6 or later and GitHub CLI access to this private repository.
gh repo clone lizhecome/deepseek-harness-flowchart
cd deepseek-harness-flowchart
dsh plugin --profile web add --ignore-workspace-root-check .
Use headless instead of web for one-shot tasks. DeepSeek Harness anchors add . to the invoking checkout before pnpm switches to the profile directory. The package manifest declares a dsh.bundle patch, so installation mounts the tool and its invariant companion automatically.
To remove it:
dsh plugin --profile web remove --ignore-workspace-root-check @lizhecome/dsh-flowchart
Use
Ask the agent for a flowchart and name the SVG destination, for example:
Create a left-to-right flowchart of the checkout process and save it as docs/checkout.svg. Use the catppuccin-mocha theme.
The model calls render_flowchart with Mermaid source similar to:
flowchart LR
cart([Cart]) --> payment{Payment valid?}
payment -->|Yes| success([Order placed])
payment -->|No| retry[Retry payment]
retry --> payment
The tool accepts only Mermaid flowchart/graph documents with an explicit TD, TB, BT, LR, or RL direction. The destination must end in .svg.
Tool arguments
| Argument | Required | Meaning |
|---|
source | yes | Complete Mermaid flowchart source. |
file_path | yes | SVG destination resolved by the installed write tool. |
theme | no | One of the 15 themes below; defaults to the deployment setting. |
transparent | no | Remove the theme background; default false. |
padding | no | Canvas padding, 0–200; default 40. |
node_spacing | no | Horizontal sibling spacing, 8–160; default 24. |
layer_spacing | no | Vertical layer spacing, 8–240; default 40. |
Themes: zinc-light, zinc-dark, tokyo-night, tokyo-night-storm, tokyo-night-light, catppuccin-mocha, catppuccin-latte, nord, nord-light, dracula, github-light, github-dark, solarized-light, solarized-dark, and one-dark.
Configuration
Later profile patches replace a row's complete config, so restate every field you want to keep:
- id: flowchart
config:
defaultTheme: github-light
maxSourceChars: 50000
maxSvgBytes: 2000000
| Field | Default | Meaning |
|---|
defaultTheme | tokyo-night | Theme used when a tool call omits theme. |
maxSourceChars | 50000 | Positive integer limit on complete Mermaid input. |
maxSvgBytes | 2000000 | Positive integer limit on the complete UTF-8 SVG. |
Invalid bounds or an unavailable configured theme fail at plugin load.
Filesystem and SVG safety
The plugin never writes through Node's ambient filesystem. It dispatches the generated content to the registered Harness write tool as a nested call, so tool restrictions, approval, sandbox policy, read-before-overwrite rules, cancellation, and final result normalization remain authoritative. If write is unavailable or denied, render_flowchart fails without claiming success.
Before dispatching the SVG, the plugin removes renderer-owned external font imports, rejects scripts, event handlers, embedded browser documents, JavaScript URLs, and external href values, and applies maxSvgBytes to the complete self-contained result.
Model and token effects
The model sees one tool schema. A successful call returns only the output path, theme, and byte count; the SVG body is passed to the nested write tool but is not copied into the parent model result. Changing package configuration or tool availability changes the request's tool-schema prefix.
Rendering is local and deterministic; it makes no LLM or network request. The implementation uses beautiful-mermaid 1.1.3 for Mermaid parsing, layout, theming, and SVG generation.
Known limitations
- Only flowcharts are accepted; sequence, class, state, ER, XY, and other Mermaid diagrams are rejected.
- Output is SVG only. PNG/PDF conversion is not included.
- Existing-file replacement follows the installed
write tool policy and may require the agent to read the file first.
- The removed web-font import means viewers use their local
Inter or system sans-serif font.
Development
pnpm install
pnpm run check
Tests boot the published Harness tool runtime, filesystem provider, and real write tool. They verify themed SVG creation, concise result/file agreement, limits, unsupported input, missing-write failure, presentation metadata, and registration disposal.
