local_session_start · Squidlerio MCP: Risk & Policy

WHAT IT DOES

What local_session_start does on Squidlerio

AI agents invoke local_session_start to trigger actions in Squidlerio. 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 local_session_start needs a policy

This tool triggers the launch of a Chrome browser process and initiates a connection to a Chrome DevTools Protocol proxy. These are external operations with side effects (process creation, network connections, resource allocation) that cannot be trivially undone without calling local_session_stop.

From the tool's definition The tool "Start a local Chrome session" and "Launches Chrome and connects it to the CDP proxy" indicate it executes a browser process and establishes external connections whose behavior depends on the test cases subsequently run through it.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

local_session_start Rate-limited

local_session_start 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": {
    "local_session_start": {
      "limits": [
        {
          "counter": "local_session_start_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 Squidlerio, so you can run agents against it safely.

FAQ

Questions about local_session_start

What does the local_session_start tool do? +

Start a local Chrome session for testing localhost URLs. Launches Chrome and connects it to the CDP proxy so cloud tests can control it. It is categorised as a Execute tool in the Squidlerio MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on local_session_start? +

Register the Squidlerio MCP server in PolicyLayer and add a rule for local_session_start: 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 Squidlerio. Nothing to install.

What risk level is local_session_start? +

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

Can I rate-limit local_session_start? +

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

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

local_session_start is provided by the Squidlerio MCP server (squidlerio/squidler-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.