browserbase_session_create · Browserbase MCP Server MCP

WHAT IT DOES

What browserbase_session_create does on Browserbase MCP Server

AI agents invoke browserbase_session_create to trigger actions in Browserbase MCP Server. 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 browserbase_session_create needs a policy

Creating a cloud browser session initiates an external execution environment that can be used to run arbitrary browser-based operations (navigation, form submission, scraping, clicks). This is an Execute-category action with high severity because a miscreated or misused session could trigger unintended web interactions, authentication attempts, or data exfiltration at scale.

From the tool's definition "Create or reuse a single cloud browser session using Browserbase with fully initialized Stagehand" — launches a live cloud browser session capable of web automation, form interactions, and arbitrary browser actions

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

browserbase_session_create Rate-limited

browserbase_session_create 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": {
    "browserbase_session_create": {
      "limits": [
        {
          "counter": "browserbase_session_create_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 Browserbase MCP Server, so you can run agents against it safely.

FAQ

Questions about browserbase_session_create

What does the browserbase_session_create tool do? +

Create or reuse a single cloud browser session using Browserbase with fully initialized Stagehand. WARNING: This tool is for SINGLE browser workflows only. If you need multiple browser sessions running simultaneously (parallel scraping, A/B testing, multiple accounts), use. It is categorised as a Execute tool in the Browserbase MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on browserbase_session_create? +

Register the Browserbase MCP Server MCP server in PolicyLayer and add a rule for browserbase_session_create: 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 Browserbase MCP Server. Nothing to install.

What risk level is browserbase_session_create? +

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

Can I rate-limit browserbase_session_create? +

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

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

browserbase_session_create is provided by the Browserbase MCP Server MCP server (vaibhavatlys/mcp-server-browserbase). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.