High Risk →

start_checkout

Automate airline checkout up to the payment page — NEVER submits payment. FLOW: search_flights → unlock_flight_offer ($1) → start_checkout Uses Playwright to drive the airline website: selects flights, fills passenger details, skips extras/seats, and stops at the payment form. Returns a screensho...

Risk signalsHigh parameter count (10 properties)

Part of the BoostedTravel server.

start_checkout can trigger actions in BoostedTravel, with no limits today. PolicyLayer puts allow, deny, and rate-limit rules on every call. Live in minutes.

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AI agents invoke start_checkout to trigger processes or run actions in BoostedTravel. Execute operations can have side effects beyond the immediate call -- triggering builds, sending notifications, or starting workflows. Rate limits and argument validation are essential to prevent runaway execution.

start_checkout can trigger processes with real-world consequences. An uncontrolled agent might start dozens of builds, send mass notifications, or kick off expensive compute jobs. PolicyLayer enforces rate limits and validates arguments to keep execution within safe bounds.

Execute tools trigger processes. Rate-limit and validate arguments to prevent unintended side effects.

policy.json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "start_checkout": {
      "limits": [
        {
          "counter": "start_checkout_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

See the full BoostedTravel policy for all 8 tools.

Get this rule live on your own BoostedTravel server in minutes. PolicyLayer enforces it on every call, before it runs.

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These attack patterns abuse exactly the kind of access start_checkout gives an agent. Each links to the full case and the policy that stops it:

Browse the full MCP Attack Database →

Every attack above starts with a tool call. PolicyLayer checks each one against your policy first, so start_checkout only ever does what you allow.

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Other execute tools across the catalogue. The same approach applies to each: rate-limit and validate the arguments.

What does the start_checkout tool do? +

Automate airline checkout up to the payment page — NEVER submits payment. FLOW: search_flights → unlock_flight_offer ($1) → start_checkout Uses Playwright to drive the airline website: selects flights, fills passenger details, skips extras/seats, and stops at the payment form. Returns a screenshot and booking URL so the user can complete manually in their browser. Supported airlines: Ryanair, Wizz Air, EasyJet. Other airlines return booking URL only. SAFETY: Uses fake test data by default. Never enters payment info. The checkout_token from unlock_flight_offer is required — prevents unauthorized usage. Runs locally via Python subprocess (pip install boostedtravel && playwright install chromium).. It is categorised as a Execute tool in the BoostedTravel MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on start_checkout? +

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

What risk level is start_checkout? +

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

Can I rate-limit start_checkout? +

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

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

start_checkout is provided by the BoostedTravel MCP server (https://api.boostedchat.com/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every BoostedTravel tool call.

Deterministic rules across all 8 BoostedTravel tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.

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4,600+ MCP servers and 31,000+ tools scanned and risk-classified.

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