create_mock · Postman MCP: Risk & Policy

WHAT IT DOES

What create_mock does on Postman

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

WHY IT NEEDS A POLICY

Why create_mock needs a policy

This tool creates a new mock server within Postman, which is a reversible write operation. It does not retrieve data (Read), execute arbitrary code (Execute), delete resources irreversibly (Destructive), nor involve financial transactions (Financial).

From the tool's definition Tool name 'create_mock' and description 'Create a new mock server' indicate creation of a new resource. The action is reversible (mock servers can be deleted), and creates infrastructure/configuration rather than modifying existing data or executing arbitrary…

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_mock Rate-limited

create_mock 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": {
    "create_mock": {
      "limits": [
        {
          "counter": "create_mock_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 Postman, so you can run agents against it safely.

FAQ

Questions about create_mock

What does the create_mock tool do? +

Create a new mock server. Creates in Personal workspace if workspace not specified. It is categorised as a Write tool in the Postman MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on create_mock? +

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

What risk level is create_mock? +

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

Can I rate-limit create_mock? +

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

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

create_mock is provided by the Postman MCP server (postmanv3/postman-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.