publish_mock · Postman MCP: Risk & Policy

WHAT IT DOES

What publish_mock does on Postman

AI agents use publish_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 publish_mock needs a policy

This tool modifies configuration state (Access Control settings) in a reversible manner. Publishing can be unpublished, so it is a Write action rather than Destructive. The blast radius is medium because misconfiguration could inadvertently expose mock API endpoints or test data to the public internet, but the action itself is not irreversible.

From the tool's definition Tool description: 'Publish mock server (sets Access Control to public)' — modifies the access control configuration of a mock server, making it publicly accessible.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

publish_mock Rate-limited

publish_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": {
    "publish_mock": {
      "limits": [
        {
          "counter": "publish_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 publish_mock

What does the publish_mock tool do? +

Publish mock server (sets Access Control to public). 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 publish_mock? +

Register the Postman MCP server in PolicyLayer and add a rule for publish_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 publish_mock? +

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

Can I rate-limit publish_mock? +

Yes. Add a rate_limit block to the publish_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 publish_mock completely? +

Set action: deny in the PolicyLayer policy for publish_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 publish_mock? +

publish_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.