renderDiagram

SERVERStable Baseline SOURCEhttps://api.stablebaseline.io/functions/v1/cloud-serve/mcp

High RISK CLASS

Category Execute

Parameters 52 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/io-stablebaseline-sb/renderdiagram.md

WHAT IT DOES

What renderDiagram does on Stable Baseline

AI agents invoke renderDiagram to trigger actions in Stable Baseline. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call: builds kicked off, notifications sent, workflows started.

Parameter	Type	Required	Description
`scale`	number	—	Raster resolution multiplier 1x/2x/3x (default 2). Ignored for svg.
`format`	string	—	png (default) or jpeg = raster; svg = vector.
`source`	string	Yes	The diagram DSL / code to render. For type 'infographic', provide a plain-English description instead (the system designs the AntV infographic spec).
`background`	string	—	Background for png/jpeg, e.g. '#ffffff' or 'transparent' (png only).
`diagramType`	string	Yes	Diagram language, e.g. 'mermaid', 'd2', 'plantuml', 'graphviz', 'bpmn', 'vegalite'. See listDiagramTypes.

Parameters from the server's own tool schema.

RISK

Why renderDiagram is rated High

This tool executes diagram DSL/code through external rendering engines and returns a generated artifact. It is not a simple read/query — it actively processes and runs user-supplied code (potentially arbitrary DSL) to produce output. The temporary signed URL and inline image response confirm external computation is triggered.

From the tool's definition 'Generate a diagram from its DSL/code and get the IMAGE back' — runs/executes diagram source code (DSL) through a rendering engine to produce output; supports mermaid, d2, plantuml, graphviz, bpmn, vegalite

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs renderDiagram safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Stable Baseline, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For renderDiagram, this is the rule to start with:

renderDiagram Rate-limited

renderDiagram stays usable, but rate-capped: a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "renderDiagram": {
      "limits": [
        {
          "counter": "renderdiagram_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Stable Baseline, apply this rule, and every renderDiagram call is checked against it from then on.

FAQ

Questions about renderDiagram

What does the renderDiagram tool do? +

Generate a diagram from its DSL/code and get the IMAGE back — WITHOUT inserting it into any document or whiteboard. For acting as a pure diagram generator. Provide diagramType (e.g. 'mermaid', 'd2', 'plantuml', 'graphviz', 'bpmn', 'vegalite'; call listDiagramTypes for the full set) and source (the diagram code). Choose format 'png' (default), 'jpeg', or 'svg'; for raster choose scale 1/2/3 for 1x/2x/3x; optional background (png only). Returns a TEMPORARY signed imageUrl that expires in 1 hour (then auto-deleted), and for png/jpeg the image inline so you can see it. To render a diagram that already lives in a document/whiteboard use getDiagramImage; to persist a new one use insertDiagramInDocument or insertWhiteboardDiagram. It is categorised as a Execute tool in the Stable Baseline MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

What parameters does renderDiagram accept? +

renderDiagram accepts 5 parameters: scale, format, source, background, diagramType. Required: source, diagramType. The full parameter table on this page comes from the server's own tool schema.

How do I enforce a policy on renderDiagram? +

Register the Stable Baseline MCP server in PolicyLayer and add a rule for renderDiagram: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Stable Baseline. Nothing to install.

What risk level is renderDiagram? +

renderDiagram is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit renderDiagram? +

Yes. Add a rate_limit block to the renderDiagram rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block renderDiagram completely? +

Set action: deny in the PolicyLayer policy for renderDiagram. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides renderDiagram? +

renderDiagram is provided by the Stable Baseline MCP server (https://api.stablebaseline.io/functions/v1/cloud-serve/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

KEEP EXPLORING

More on Stable Baseline, and thousands of servers like it.

This server

All 196 Stable Baseline tools → High-risk tools on this server →

Across the catalogue

All high-risk MCP tools → The MCP Attack Database →

Guides

Govern code and CI agents →Agent sandbox →Least privilege for MCP →