Execute custom Playwright JS code against the current page
AI agents invoke execute-code to trigger actions in Playwright MCP. 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.
This tool allows running arbitrary JavaScript code within a browser context with full DOM access and side-effect capabilities (navigating pages, submitting forms, clicking elements, modifying state).
From the tool's definition Tool name 'execute-code' and description 'Execute custom Playwright JS code against the current page' explicitly indicate execution of arbitrary code with browser context access.
Documented attack patterns abuse exactly the kind of access execute-code gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Playwright MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for execute-code:
{
"version": "1",
"default": "deny",
"tools": {
"execute-code": {
"limits": [
{
"counter": "execute-code_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}execute-code 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.
Free to start. No card required.
Execute custom Playwright JS code against the current page. It is categorised as a Execute tool in the Playwright MCP MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Playwright MCP server in PolicyLayer and add a rule for execute-code: 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 MCP. Nothing to install.
execute-code is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the execute-code 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 execute-code. 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.
execute-code is provided by the Playwright MCP server (qabyai/playwright-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 5 Playwright MCP tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
5 Playwright MCP tools catalogued and risk-classified — across an index of 42,500+ MCP servers.