add_web_layer · QGIS MCP: Risk & Policy

WHAT IT DOES

What add_web_layer does on QGIS MCP

AI agents use add_web_layer to create or update resources in QGIS MCP — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your QGIS MCP environment.

WHY IT NEEDS A POLICY

Why add_web_layer needs a policy

This tool adds (creates) a web layer to a QGIS project, modifying the project's data layers. This is a Write operation because it creates a new resource in the project that can be removed or modified later. While it doesn't delete or execute arbitrary code, it does persist a change to the GIS project structure.

From the tool's definition add_web_layer: Add a web layer (XYZ, WMS, WFS) to the project — creates and adds a new layer resource to a GIS project, which is a reversible modification of project state.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

add_web_layer Rate-limited

add_web_layer stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "add_web_layer": {
      "limits": [
        {
          "counter": "add_web_layer_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches QGIS MCP, so you can run agents against it safely.

FAQ

Questions about add_web_layer

What does the add_web_layer tool do? +

Add a web layer (XYZ, WMS, WFS) to the project. service:. It is categorised as a Write tool in the QGIS MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on add_web_layer? +

Register the QGIS MCP server in PolicyLayer and add a rule for add_web_layer: 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 QGIS MCP. Nothing to install.

What risk level is add_web_layer? +

add_web_layer is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit add_web_layer? +

Yes. Add a rate_limit block to the add_web_layer 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 add_web_layer completely? +

Set action: deny in the PolicyLayer policy for add_web_layer. 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 add_web_layer? +

add_web_layer is provided by the QGIS MCP server (nkarasiak/qgis-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.