lambda_invoke

What lambda_invoke does on Ncp

AI agents invoke lambda_invoke to trigger actions in Ncp. 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 lambda_invoke is rated High

Invoking Lambda functions is a code execution operation where the blast radius depends entirely on what the invoked Lambda does (could read data, modify systems, call external services, delete resources, etc.). This is classified as Execute rather than a more severe category because the actual destructive capability depends on the specific Lambda being invoked, not the tool itself.

From the tool's definition Tool name 'lambda_invoke' and description 'Invoke a Lambda function' directly indicate execution of arbitrary AWS Lambda functions. Lambda functions can run arbitrary code with effects determined by function arguments and configuration.

The rule that runs lambda_invoke safely

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

{
  "version": "1",
  "default": "deny",
  "tools": {
    "lambda_invoke": {
      "limits": [
        {
          "counter": "lambda_invoke_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

Questions about lambda_invoke