call_api

通过限流代理发送 HTTP 请求。所有外部 API 调用建议经此工具。参数：url（必填）/ method（可选，默认 GET）/ body（可选，JSON 字符串或对象）/ headers（可选，JSON 字符串或对象）。返回：API 响应内容 + 速率限制用量快照。被限流时返回 RATE_LIMIT_EXCEEDED 及建议等待秒数；单次请求超过每分钟 token 总额时返回 REQUEST_EXCEEDS_WINDOW（等待无效，需减小请求体）。仅允许 http/https。请求 30 秒超时，最多跟随 5 次重定向（跨域时剥离敏感头），响应最多返回 200KB 并以 tr...

SERVER429 Throttle SOURCE429-throttle-mcp

Low RISK CLASS

Category Read

Parameters 00 required

Recommended Allowedsee the rule below

Registry record Grade B, identity unverified Pull the record →

This record as markdown: /tools/429-throttle-mcp/call-api.md

WHAT IT DOES

What call_api does on 429 Throttle

AI agents call call_api to retrieve information from 429 Throttle without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

RISK

Why call_api is rated Low

Even though call_api only reads data, uncontrolled read access leaks sensitive information and racks up API costs: an agent caught in a retry loop can make thousands of calls a minute without anyone noticing.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs call_api safely

PolicyLayer is an MCP gateway: it sits between your AI agents and 429 Throttle, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For call_api, this is the rule to start with:

call_api Allowed

call_api is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "call_api": {}
  }
}

ALLOW ONLY THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect 429 Throttle, apply this rule, and every call_api call is checked against it from then on.

FAQ

Questions about call_api

What does the call_api tool do? +

How do I enforce a policy on call_api? +

Register the 429 Throttle MCP server in PolicyLayer and add a rule for call_api: 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 429 Throttle. Nothing to install.

What risk level is call_api? +

call_api is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit call_api? +

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

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

call_api is provided by the 429 Throttle MCP server (429-throttle-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

KEEP EXPLORING

More on 429 Throttle, and thousands of servers like it.

This server

All 5 429 Throttle tools →

Across the catalogue

The MCP Attack Database →

Guides

Roll out MCP under one policy →Data exfiltration →MCP token cost →