Research without buying

You ask: Find the cheapest flight to Boston next Friday, but don’t book or pay for anything.

Browsing a commerce site while forbidding the purchase.

What AgentsFence does

• “don’t … pay” becomes a prohibition on financial actions, so any purchase tool is blocked.
• Clicking in a browser can submit forms, so it is treated as an external write and asks, even on a flight search site.

Decision by decision

The agent tries	Offline rules compiler	LLM compiler
web_search(query="flights to Boston")	ALLOW policy-allow	ALLOW policy-allow
browser_navigate(url="https://airline.example/search?to=BOS")	ALLOW policy-allow	ALLOW policy-allow
browser_click(ref="@book-now")	ASK_USER unauthorized-external_write	ASK_USER unauthorized-external_write
mcp_travel_purchase_ticket(flight="XY123")	BLOCK user-prohibition	BLOCK user-prohibition

Compiled policy (LLM compiler)

Task: find_flight
Allowed: reading/searching
You prohibited: FINANCIAL
Not authorized (blocked or needs your approval): local file writes, sending / external writes, deleting, purchases & payments, running code / shell, sharing & permission changes

Tips

• Without “don’t pay”, purchases are still blocked by default (financial actions need explicit authority). Saying it just makes the reason explicit.
• Browser clicks can’t be tied to a domain from their arguments. If you let the agent click, review what it’s about to submit.