Cloudviz API vs Mermaid Chart MCP

Cloudviz API

Diagrams come from the live AWS account through a read-only cross-account role with a per-customer external ID. AWS only, and API access starts at the $49 a month Team plan.

Mermaid Chart MCP

Validation and rendering work with no account or key. Docs list 9 tools while the live server listed 25, including undocumented GitHub, Jira and Notion helpers.

Cloudviz API

1. Call GET /aws/accounts/ first to get the Cloudviz account ID, then request /aws/accounts/{account-id}/{region}/{format}
2. On a 202, wait and repeat the same GET until the diagram is ready
3. Ask for jsonSnapshot or jsonDiagram (there is no plain json format) when the agent has to reason over resources
4. Use a read-only key unless the agent has to add, change or delete AWS accounts

Mermaid Chart MCP

1. Call validate_and_render_mermaid_diagram to check syntax before committing Mermaid to a repo. It needs no token
2. Only add the token if you need to save into Mermaid Chart projects. It reaches every project on the account
3. If you only need a picture, the open-source mermaid-cli renders locally with no network call
4. Use mcp.mermaid.ai. The registry still lists the older mcp.mermaidchart.com host