http_post · Http Client MCP: Risk & Policy

WHAT IT DOES

What http_post does on Http Client

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

WHY IT NEEDS A POLICY

Why http_post needs a policy

HTTP POST is fundamentally a Write operation—it sends data to a server to create or update resources. The lack of a description lowers confidence slightly, but the tool name and server context make the classification clear. Severity is high because an AI agent could use this to modify data on arbitrary external systems, though without visibility into target endpoints, the blast radius is partially bounded.

From the tool's definition Tool name 'http_post' combined with server description stating support for 'full HTTP methods' and 'request bodies' indicates POST request capability, which creates or modifies data on remote servers.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

http_post Rate-limited

http_post 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": {
    "http_post": {
      "limits": [
        {
          "counter": "http_post_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 Http Client, so you can run agents against it safely.

FAQ

Questions about http_post

What does the http_post tool do? +

http_post. It is categorised as a Write tool in the Http Client MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on http_post? +

Register the Http Client MCP server in PolicyLayer and add a rule for http_post: 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 Http Client. Nothing to install.

What risk level is http_post? +

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

Can I rate-limit http_post? +

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

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

http_post is provided by the Http Client MCP server (keijeizei/http-client-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.