Supported Diagram Types

Kroki-rs supports a wide variety of diagram types by leveraging existing CLI tools and a high-performance Native Browser Engine.

ID	Name	Primary Format	Backend
`graphviz`	Graphviz	SVG	`dot` (CLI)
`mermaid`	Mermaid	SVG	Native Engine (Headless Chromium)
`bpmn`	BPMN	SVG	Native Engine (Headless Chromium)
`d2`	D2	SVG	`d2` (CLI)
`ditaa`	Ditaa	PNG	`ditaa` (CLI)
`excalidraw`	Excalidraw	SVG	`excalidraw-to-svg` (CLI)
`vega`	Vega	SVG	`vg2svg` (CLI)
`vegalite`	Vega-Lite	SVG	`vl2vg` & `vg2svg` (CLI)
`wavedrom`	WaveDrom	SVG	`wavedrom-cli` (CLI)

Native Browser Engine (Mermaid & BPMN)¶

Starting from v0.0.8, Mermaid and BPMN are rendered using a native headless Chromium instance. This ensures:

Accuracy: Perfect rendering using official JS libraries.
Performance: Managed tab pooling and concurrency control.
Serverless Architecture: Uses a local file:// based harness, eliminating the need for internal HTTP servers or loopback networking.
Zero-Dependency Core: No local Node.js or Playwright installation required (all assets are embedded).

High-Performance Font Support¶

Our Native Engine features a robust font-management system:

Google Fonts: Supported out-of-the-box via internet access in headless mode.
Dynamic Injection: You can inject custom CSS (e.g., @font-face or @import) into the rendering harness at runtime via the window.krokiFontCss configuration.
Consistency: Automatically uses --font-render-hinting=none to ensure pixel-perfect SVG generation across different operating systems.

Installation of Tools¶

Most tools can be installed via your system package manager.

macOS (Homebrew)¶

brew install graphviz d2 ditaa
# For Mermaid/BPMN rendering, kroki-rs uses its native engine;
# however, an external browser is recommended for local development:
brew install --cask chromium

Note on Format¶

While Kroki-rs supports SVG, PNG, and PDF, SVG is the recommended format for most web-based documentation as it provides the best clarity and scalability.