Overview
This series explains how Mermaid JS turns editable diagram text into SVG through detection, parsing, semantic state, layout, styling, security, accessibility, and host integration. Its central value is a shorter, reviewable path between changing a system and updating its visual explanation—not automatic truth. The series shows how APIs, tests, configuration, and extension contracts make that path reusable while leaving semantic ownership, trust decisions, host behavior, and readable output with the team.
Learning outcomes
- Mermaid JS makes diagrams easier to revise, compare, and regenerate, but editable source does not guarantee semantic correctness.
- Its pipeline separates language detection, semantic state, layout, SVG policy, and host behavior, giving each failure a clearer owner.
- Security and accessibility depend on deployment policy and author effort; sanitization or metadata alone is not a complete guarantee.
- Reliable adoption requires representative rendering tests, explicit trust and version choices, and domain owners who review what diagrams mean.
Keywords
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PlansFAQ
What problem does Mermaid JS solve?
Mermaid JS reduces the distance between a changing system and its visual documentation by keeping diagram definitions as editable text that can be reviewed and rendered again.
Does Mermaid JS keep diagrams automatically up to date?
No. Mermaid JS makes updates easier to review and regenerate, but it cannot know whether the source still describes the real system; domain review remains necessary.
What happens between Mermaid text and an SVG?
Mermaid JS normalizes and detects the definition, parses it into diagram-specific state, lays out and styles that model, then serializes it under security and accessibility rules before the host embeds the SVG.
Is Mermaid JS secure and accessible by default?
Not universally across deployments. Mermaid JS offers security levels, sanitization or sandboxing, and SVG accessibility metadata, but hosts must choose a trust model and authors must supply meaningful descriptions.