Start a UCP checkout session for a product. Discovers the merchant's UCP capabilities, creates a checkout session, and attaches content attribution data from the current session's search and comparison activity. Returns the checkout status and any information the merchant still needs (email, ship...
Part of the Forage Shopping server.
Free to start. No card required.
AI agents invoke start_checkout to trigger processes or run actions in Forage Shopping. 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.
{
"version": "1",
"default": "deny",
"tools": {
"start_checkout": {
"limits": [
{
"counter": "start_checkout_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}See the full Forage Shopping policy for all 7 tools.
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:
Other execute tools across the catalogue. The same approach applies to each: rate-limit and validate the arguments.
Start a UCP checkout session for a product. Discovers the merchant's UCP capabilities, creates a checkout session, and attaches content attribution data from the current session's search and comparison activity. Returns the checkout status and any information the merchant still needs (email, shipping address, etc).. It is categorised as a Execute tool in the Forage Shopping MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Forage Shopping 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 Forage Shopping. Nothing to install.
start_checkout 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 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.
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.
start_checkout is provided by the Forage Shopping MCP server (https://forageshopping.com/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 7 Forage Shopping tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
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