Close a browser session and terminate its backend process
AI agents call close_session to permanently remove resources in Playwright Parallel — typically in cleanup and lifecycle workflows. It does its job in a single call, and there is no undo.
This tool irreversibly terminates a browser session and its backend process. Once closed, any unsaved state, in-progress operations, or session context is permanently lost. This cannot be undone, matching the Destructive category. Severity is high because an AI agent misusing this tool could terminate active sessions mid-task, causing data loss or interrupting critical automation workflows.
From the tool's definition 'Close a browser session and terminate its backend process' — closing and terminating are irreversible actions that destroy the session and its associated process
Documented attack patterns abuse exactly the kind of access close_session gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Playwright Parallel, and nothing reaches the server without passing your rules. This is the rule we recommend for close_session:
{
"version": "1",
"default": "deny",
"hide": [
"close_session"
]
}close_session disappears from the agent's tool list entirely, and any attempt to call it is denied. The rest of the server keeps working.
Free to start. No card required.
Close a browser session and terminate its backend process. It is categorised as a Destructive tool in the Playwright Parallel MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.
Register the Playwright Parallel MCP server in PolicyLayer and add a rule for close_session: 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 Playwright Parallel. Nothing to install.
close_session is a Destructive tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.
Yes. Add a rate_limit block to the close_session 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.
Set action: deny in the PolicyLayer policy for close_session. 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.
close_session is provided by the Playwright Parallel MCP server (sumyapp/playwright-parallel-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Playwright Parallel, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
3 Playwright Parallel tools catalogued and risk-classified — across an index of 43,000+ MCP servers.