post_request · API Tester MCP Server MCP: Risk & Policy

WHAT IT DOES

What post_request does on API Tester MCP Server

AI agents invoke post_request to trigger actions in API Tester MCP Server. 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.

WHY IT NEEDS A POLICY

Why post_request needs a policy

POST requests trigger external operations with side effects that depend entirely on the target URL and body — they can create resources, trigger workflows, send messages, or invoke any remote action. Since the tool makes arbitrary POST requests to any URL, the blast radius is high: a misused call could submit forms, create accounts, send emails, or trigger financial/destructive operations on third-party systems.

From the tool's definition Make a POST request with a JSON body to the specified URL

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

post_request Rate-limited

post_request 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": {
    "post_request": {
      "limits": [
        {
          "counter": "post_request_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

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

FAQ

Questions about post_request

What does the post_request tool do? +

Make a POST request with a JSON body to the specified URL. It is categorised as a Execute tool in the API Tester MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on post_request? +

Register the API Tester MCP Server MCP server in PolicyLayer and add a rule for post_request: 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 API Tester MCP Server. Nothing to install.

What risk level is post_request? +

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

Can I rate-limit post_request? +

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

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

post_request is provided by the API Tester MCP Server MCP server (vikrant-khedkar/api-tester-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.