Excalidraw Architect MCP

What BV-Venky/excalidraw-architect-mcp MCP server does

BV-Venky/excalidraw-architect-mcp MCP server creates Excalidraw files from structured nodes and connections, or from a supported subset of Mermaid flowchart syntax. The server owns positioning and visual treatment, so callers provide relationships and labels instead of drawing coordinates. Labels can trigger architecture-aware styling; for example, a node mentioning PostgreSQL can receive database styling.

The project supports a broad set of diagram forms, including architecture diagrams, flowcharts, sequence diagrams, state machines, entity-relationship models, swimlanes, timelines, Gantt charts, quadrants, funnels, trees, organizational charts, and several chart types. It can also export an existing diagram as SVG or PNG without requiring the Excalidraw application or a browser.

How it works

For direct diagram creation, an agent sends component and connection data to create_diagram. The layout engine determines placement and renders a real .excalidraw file. mermaid_to_excalidraw accepts directions such as top-down, left-to-right, bottom-to-top, and right-to-left, along with several node shapes, edge styles, labels, and subgraphs.

Existing diagrams can be changed incrementally. The recommended sequence is to call get_diagram_info, inspect the returned node IDs, labels, types, and connections, and then call modify_diagram. This supports adding components, deleting nodes, changing labels, and rewiring relationships without rebuilding the complete file.

The optional knowledge graph uses a markdown file as its persistent architecture model. Services, domains, and directed dependencies can be added, removed, linked, queried, rendered, and exported. Focused views can show a selected service neighborhood, a domain, or an induced subgraph. The graph also supports dependency paths, failure-impact analysis, architecture linting, Git-based diffs, onboarding documentation, and best-effort comparison with Python imports.

Tools and capabilities

The MCP tool set includes:

• Create diagrams from structured node and connection data.
• Convert supported Mermaid flowcharts into Excalidraw files.
• Inspect and modify diagrams iteratively.
• Export diagrams to SVG and PNG.
• Initialize and maintain a markdown architecture knowledge graph.
• Render complete, domain-specific, or service-focused graph views.
• Analyze dependency paths, upstream impact, cycles, orphans, and single points of failure.
• Compare the graph with a Git reference or Python import structure.
• Generate an onboarding guide from the recorded architecture.

Limitations and notes

Mermaid conversion is limited to the documented flowchart subset: four graph directions, four node-shape forms, the listed arrow styles and labels, and subgraph ... end blocks. Knowledge-graph drift analysis is best effort: it treats top-level Python packages as services and infers relationships from imports, so its findings may require review.

The project is described as running offline and requiring no API keys. The supplied material names Cursor, Claude Code, and Windsurf as supported usage environments; it does not provide a Claude Desktop configuration or a complete installation command. Before changing a diagram or mutating the knowledge graph, inspect its current state with get_diagram_info or kg_info respectively. BV-Venky/excalidraw-architect-mcp MCP server is therefore most suitable when the source structure can be represented as nodes, edges, services, domains, or supported diagram data.