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Mermaid MCP Integration for LangChain
Connect Mermaid to LangChain through the local KosmoKrator MCP gateway with scoped tools, credentials, and write policy.
Connect Mermaid to LangChain
Bridge LangChain agents to local KosmoKrator integration tools through MCP or headless CLI calls.
Use the MCP gateway when the agent should discover tools, or wrap kosmo integrations:call for fixed chains. The gateway is local, scoped to this integration, and starts with
--write=deny so LangChain can inspect read-capable tools without receiving write access by default.
Mermaid MCP Config for LangChain
Keep the gateway scoped to the integration and operation class needed by the chain.
{
"mcpServers": {
"kosmokrator-mermaid": {
"type": "stdio",
"command": "kosmo",
"args": [
"mcp:serve",
"--integration=mermaid",
"--write=deny"
]
}
}
}Run the Gateway Manually
kosmokrator mcp:serve --integration=mermaid --write=denyWhy Use KosmoKrator Here
Expose only Mermaid instead of a broad multi-service tool list.
Reuse credentials already configured for the KosmoKrator CLI and Lua runtime.
Start read-only, then opt into ask or allow for trusted workspaces.
Mermaid Tools Visible to LangChain
LangChain sees stable MCP tool names generated from the Mermaid integration catalog.
| MCP tool | Source function | Type | Description |
|---|---|---|---|
integration__mermaid__render_mermaid | mermaid.render_mermaid | Write | Render a Mermaid diagram to a PNG image. Pass valid Mermaid syntax and get back a markdown image embed. Supported diagram types: flowchart, sequence, class, state, ER, Gantt, pie, quadrant, requirement, git graph, C4, mindmap, timeline, sankey, XY chart, block. Example syntax: ``` graph TD A[Start] --> B{Decision} B -->|Yes| C[Action] B -->|No| D[End] ``` Tips: - Use `graph TD` for top-down flowcharts, `graph LR` for left-to-right - Use `sequenceDiagram` for sequence diagrams - Use `erDiagram` for entity-relationship diagrams - Use `classDiagram` for class diagrams - Use `stateDiagram-v2` for state diagrams - Use `gantt` for Gantt charts - Use `pie` for pie charts - Use `gitgraph` for git graphs - Use `mindmap` for mind maps |