Upload one or more files to a file chooser. The file chooser must be visible first (triggered by clicking a file input). Use absolute file paths.
AI agents invoke browser_file_upload to trigger actions in Playwright Autopilot. 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 uploads files from the local filesystem to a browser file input. It triggers an external operation (file upload) that depends on the arguments provided (file paths and target chooser). Misuse could lead to sensitive local files being uploaded to arbitrary web destinations, making it high severity.
From the tool's definition 'Upload one or more files to a file chooser' and 'Use absolute file paths'
Documented attack patterns abuse exactly the kind of access browser_file_upload gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Playwright Autopilot, and nothing reaches the server without passing your rules. This is the rule we recommend for browser_file_upload:
{
"version": "1",
"default": "deny",
"tools": {
"browser_file_upload": {
"limits": [
{
"counter": "browser_file_upload_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}browser_file_upload 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.
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Upload one or more files to a file chooser. The file chooser must be visible first (triggered by clicking a file input). Use absolute file paths. It is categorised as a Execute tool in the Playwright Autopilot MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Playwright Autopilot MCP server in PolicyLayer and add a rule for browser_file_upload: 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 Autopilot. Nothing to install.
browser_file_upload 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 browser_file_upload 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 browser_file_upload. 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.
browser_file_upload is provided by the Playwright Autopilot MCP server (kaizen-yutani/playwright-autopilot). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Playwright Autopilot, 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.
51 Playwright Autopilot tools catalogued and risk-classified — across an index of 43,000+ MCP servers.