winget install --id=TrellisLab.Trellis -e Trellis is a Mermaid-compatible diagram renderer that uses custom routing to produce overlap-free orthogonal SVG layouts. Supports flowchart, class, ER, C4 and architecture diagram types.
Mermaid diagrams that actually look good.
> Early access — join the discussion
Trellis is a drop-in replacement for the default Mermaid renderer. It produces clean, overlap-free diagrams — no tangled edges, no manual layout tweaking, no post-processing in a drawing tool.
→ trellislab.net — live comparison and interactive editor
Standard Mermaid uses an aging layout engine that frequently produces diagrams with overlapping and crossing edges. The result is diagrams that are hard to read and not presentation-ready without significant manual effort.
Trellis replaces that engine. Every edge finds its own clear corridor. Diagrams come out clean the first time.
Standard Mermaid syntax. Zero migration. Existing .mmd files work without changes.
architecture-beta) — with icon support (AWS and other Iconify sets)Install from the marketplace:
ext install trellislab.trellis-mermaid
Or search "Trellis" in the VS Code Extensions panel. Live preview updates as you type.
Download the pre-built binary for your platform from the releases page:
| Platform | File |
|---|---|
| macOS (Apple Silicon) | trellis-vX.Y.Z-aarch64-apple-darwin.tar.gz |
| macOS (Intel) | trellis-vX.Y.Z-x86_64-apple-darwin.tar.gz |
| Linux x86_64 | trellis-vX.Y.Z-x86_64-unknown-linux-gnu.tar.gz |
| Windows x86_64 | trellis-vX.Y.Z-x86_64-pc-windows-gnu.zip |
Extract and add the binary to your PATH.
docker pull ghcr.io/trellis-lab/trellis:latest
docker run --rm -v "$(pwd):/data" ghcr.io/trellis-lab/trellis:latest input.mmd -o output.svg
# Render to SVG (default)
trellis render diagram.mmd -o diagram.svg
# Render to PNG
trellis render diagram.mmd -o diagram.png
# Render to interactive HTML
trellis render diagram.mmd -o diagram.html -f html
# Render to editable Draw.io
trellis render diagram.mmd -o diagram.drawio -f drawio
# Render from stdin
echo "flowchart LR
A --> B --> C" | trellis render - -o diagram.svg
# Render all diagrams in a directory (commercial feature — requires a license)
trellis render-batch ./diagrams -o ./output
# Validate syntax only (no render)
trellis validate diagram.mmd
# Render with custom config
trellis render diagram.mmd -o diagram.svg --config trellis.toml
Full CLI reference: docs/cli.md
| Format | Description |
|---|---|
svg | Scalable, embeddable, publication-ready |
png | Rasterized for presentations and documentation |
html | Self-contained interactive file — click nodes and edges to explore |
ascii | UTF-8 box-drawing for terminal preview and AI-agent workflows |
drawio | Editable .mxfile for draw.io, Confluence, and the VS Code draw.io extension |
Full format details and purpose: docs/cli.md
default, paper, blueprint, dark, midnight, forest
Set via --config trellis.toml:
theme = "paper"
Trellis includes a Pandoc Docker image for rendering Markdown documents with embedded Mermaid diagrams directly to PDF or HTML — no pre-processing step, no local Trellis install required.
docker pull ghcr.io/trellis-lab/trellis-pandoc:latest
docker run --rm -v "$(pwd):/data" ghcr.io/trellis-lab/trellis-pandoc:latest document.md -o document.pdf
Full Pandoc guide: docs/pandoc.md
Trellis ships an MCP server for use with Claude Desktop and other MCP-compatible clients. The server exposes a render tool backed by the CLI binary.
Setup guide: docs/mcp.md
Two separate licenses apply, covering different things:
render-batch and MCP SVG/HTML/Draw.io output are commercial features that require a license key.Bundled open-source dependencies of the binary are attributed in THIRD-PARTY-LICENSES.md.
Commercial terms and key activation: docs/licensing.md
Try Trellis in the browser without installing anything:
→ github.com/trellis-lab/trellis/releases