Mermaid Styles and Options¶

The Mermaid backend supports several layout and styling options that control diagram direction, legend visibility, and overall visual appearance.

See the Mermaid documentation for additional information.

Layout Options¶

Layout behavior is configured via the MermaidRenderOptionsBuilder builder:

from c4.renderers import MermaidRenderOptionsBuilder

render_options = (
    MermaidRenderOptionsBuilder()
    .update_layout_config(
        c4_shape_in_row=4,
        c4_boundary_in_row=2
    )
    .update_element_style(
        "customer",
        font_color="red",
        bg_color="grey",
        border_color="red",
    )
    .build()
)

You can pass render_options to MermaidRenderer.

See the MermaidRenderOptionsBuilder reference section for the complete list of available methods and configuration options.

Layout configuration can also be set via RenderOptions.