
Diagrams MCP
Generate cloud architecture diagrams, flowcharts, and sequence diagrams.
What it can do
What data it sees
Do you need an account
No: the server works without sign-in
Generate cloud architecture diagrams, flowcharts, and sequence diagrams.
How to connect
How to connect Diagrams MCP to Claude
The server address to paste into Claude settings:
https://diagrams-mcp-production.up.railway.app/mcp
- Open Claude (claude.ai or the desktop app).
- Go to Settings → Connectors.
- Click Add custom connector.
- Paste the server address copied below into Remote MCP server URL and click Add.
- In a chat, click + → Connectors and switch the new connector on.
Custom connectors are available on Free, Pro, Max, Team and Enterprise plans (Free is limited to one). On Team and Enterprise an organization Owner adds the connector first under Organization settings → Connectors.
Authorization
After you click Add, a sign-in window for the service opens. Sign in with your own account and approve access. Claude never sees your password.
How to connect Diagrams MCP to ChatGPT
The server address to paste into ChatGPT settings:
https://diagrams-mcp-production.up.railway.app/mcp
- Open ChatGPT in a browser (chatgpt.com). A Plus, Pro, Business, Enterprise or Edu plan is required.
- Turn on developer mode once: Settings → Apps → Advanced settings → Developer mode.
- Open Settings → Connectors and click Create.
- Fill in the form: Name (anything), Description (one line about what the service does), MCP server URL (copy it below).
- Under Authentication choose OAuth if the service requires sign-in, otherwise None. Click Create.
- In a new chat open + → Apps/Connectors and enable the connector.
OpenAI has renamed this section before (Connectors → Apps/Plugins). If the label differs, search settings for "developer mode". On Business/Enterprise workspaces an admin must allow custom connectors first.
Authorization
On first use ChatGPT opens the service's sign-in window. Sign in and approve access.
How to connect Diagrams MCP to Cursor
The server address to paste into Cursor settings:
https://diagrams-mcp-production.up.railway.app/mcp
Fastest: click Open in Cursor below and confirm the prompt.
Manually:
- In Cursor open Settings → Cursor Settings → MCP and click Add new global MCP server.
- Paste the JSON copied below into
~/.cursor/mcp.json(per project:.cursor/mcp.jsonin the repo root). - Save the file. The server appears in the MCP list; authorize it there if asked.
Authorization
If the service needs sign-in, an authorize button appears next to the server in the MCP list.
Server tool list (9)
Raw names from tools/list. Only developers need these.
| render_diagram | Render a mingrammer/diagrams Python snippet to PNG and return the image. The code must be a complete Python script using `from diagrams import ...` imports and a `with Diagram(...)` context manager block. Use search_nodes to verify node names and get correct import paths before writing code. Read the diagrams://reference/diagram, diagrams://reference/edge, and diagrams://reference/cluster resources for constructor options and usage examples. Args: code: Full Python code using the diagrams library. filename: Output filename without extension. format: Output format — ``"png"`` (default), ``"svg"``, or ``"pdf"``. download_link: If True, return a temporary download URL path (/images/{token}) that expires after 15 minutes; if False, return inline image bytes. Defaults to True (URL) — set ``DIAGRAMS_INLINE_DEFAULT=true`` on the server to flip the default. SVG/PDF and PNGs larger than the inline limit always use a download link. |
| list_providers | List all available diagram providers (aws, gcp, azure, k8s, onprem, etc.). Use list_providers -> list_services -> list_nodes to browse available node types for a specific provider. |
| list_services | List service categories for a provider (e.g. 'aws' -> ['compute', 'database', ...]). Args: provider: Provider name from list_providers (e.g. 'aws', 'gcp', 'k8s'). |
| list_nodes | List available node classes for a provider.service combo. Args: provider: Provider name (e.g. 'aws', 'gcp', 'k8s'). service: Service category (e.g. 'compute', 'database', 'network'). Returns: List of nodes with keys: name, import, alias_of (optional). |
| search_nodes | Search for diagram nodes by keyword across all providers and services. For targeted browsing when you know the provider, use list_providers -> list_services -> list_nodes instead. Args: query: Search term (case-insensitive substring match). Returns: List of matching nodes with keys: node, provider, service, import, alias_of (optional). Sorted by relevance: exact match first, then prefix, then substring. |
| render_mermaid | Render a Mermaid diagram definition and return the image with metadata. The definition should be valid Mermaid syntax (e.g. flowchart, sequence, class, ER, state, or Gantt diagram). Returns a list of content blocks: the rendered image plus a JSON text block with metadata including a mermaid.live edit link for opening the diagram in a browser editor. Args: definition: Mermaid diagram definition text. filename: Output filename without extension. format: Output format — ``"png"`` (default), ``"svg"``, or ``"pdf"``. download_link: If True, return a temporary download URL path (/images/{token}) that expires after 15 minutes; if False, return inline image bytes. Defaults to True (URL) — set ``DIAGRAMS_INLINE_DEFAULT=true`` on the server to flip the default. SVG/PDF and PNGs larger than the inline limit always use a download link. |
| render_plantuml | Render a PlantUML diagram definition and return the image. The definition should be valid PlantUML syntax wrapped in @startuml/@enduml (sequence, class, component, activity, state, deployment, etc.). Args: definition: PlantUML diagram definition text. filename: Output filename without extension. format: Output format — ``"png"`` (default) or ``"svg"``. PDF is not supported (requires Batik/FOP). download_link: If True, return a temporary download URL path (/images/{token}) that expires after 15 minutes; if False, return inline image bytes. Defaults to True (URL) — set ``DIAGRAMS_INLINE_DEFAULT=true`` on the server to flip the default. SVG and PNGs larger than the inline limit always use a download link. |
| find_equivalent | Find cross-provider equivalents for a diagram node by infrastructure role. Given a node name (e.g. 'EC2', 'Lambda', 'ComputeEngine'), returns the infrastructure role category it belongs to and the equivalent nodes from other providers. If a node name is ambiguous, use list_categories to see all mapped roles and pick a provider-specific node name. Args: node: Node class name to look up (case-insensitive, e.g. 'EC2', 'lambda'). target_provider: Optional provider to filter equivalents to (e.g. 'gcp', 'azure', 'aws'). If omitted, all equivalents across all other providers are returned. Returns: A dict with keys: category (str): Infrastructure role category name. description (str): Human-readable description of the category. source (dict): The matched node with keys node, provider, service, import. equivalents (list[dict]): Equivalent nodes, each with keys node, provider, service, import. |
| list_categories | List all infrastructure role categories with their mapped nodes. Use this to browse all available equivalence mappings, or to disambiguate node names when find_equivalent reports ambiguity. Returns a list of category dicts, each with: category (str): Category identifier (e.g. 'virtual_machine'). description (str): Human-readable description. providers (list[str]): Providers covered by this category. nodes (dict): Mapping of provider → list of node names in that category. |