What's new in Mermaid Studio 2026.4.5?

Mermaid Studio 2026.4.5 is a patch release. It removes the plugin’s MCP Tools settings page in IDE versions 2026.1 and later since you can already manage enabled tools in the JetBrains MCP Server’s Exposed Tools settings page. It also sharpens highlighting for agentflow and use case diagrams and fixes node completion after pipe-labeled flowchart edges.

For the latest features, including Mermaid.js 12 support and the new use case and agentflow diagrams, see what’s new in 2026.4.2.

Highlights

MCP tool toggles

In IDE versions 2026.1 and later, you turn Mermaid Studio’s MCP tools on or off in Settings > Tools > MCP Server > Exposed Tools like any other tool exposed via the IDE’s MCP Server. The Mermaid Studio > MCP Tools settings page remains in IDE version 2025.3 where the MCP Server plugin doesn’t offer fine-grained control over enabled tools.

See configuring MCP tools for both IDE versions.

Changelog

Changed

• MCP tools: in IDE versions 2026.1 and later, turn tools on or off in Settings > Tools > MCP Server > Exposed Tools; the Mermaid Studio > MCP Tools page remains in IDE version 2025.3
• Agentflow and use case diagrams: node labels, metadata keys, and metadata values each get their own highlighting, and words inside labels are no longer highlighted as keywords

Fixed

• Flowchart: node completion now works after an edge with a pipe label, such as A -->|Yes| B
• MCP: icon search for flowchart, swimlane, and TreeView diagrams returns icons from every icon set
• Railroad (PEG): # comments are highlighted as comments
• Agentflow, use case, and railroad diagrams: title, accTitle, or accDescr inside a node label or mid-line no longer turns the rest of the line into plain text