Requires checkout:write scope. Add a product variant to an existing cart. Use the variant_id from search_products results. Returns full cart state including item_ids you can use with update_cart_item. Max quantity per item and max cart total are enforced — call get_platform_limits to check the cu...
Part of the Kifly — Agentic Commerce & Payments server.
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AI agents use add_to_cart to create or modify resources in Kifly — Agentic Commerce & Payments. Write operations carry medium risk because an autonomous agent could trigger bulk unintended modifications. Rate limits prevent a single agent session from making hundreds of changes in rapid succession. Argument validation ensures the agent passes expected values.
Without a policy, an AI agent could call add_to_cart repeatedly, creating or modifying resources faster than any human could review. PolicyLayer's rate limiting ensures write operations happen at a controlled pace, and argument validation catches malformed or unexpected inputs before they reach Kifly — Agentic Commerce & Payments.
Write tools can modify data. A rate limit prevents runaway bulk operations from AI agents.
{
"version": "1",
"default": "deny",
"tools": {
"add_to_cart": {
"limits": [
{
"counter": "add_to_cart_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}See the full Kifly — Agentic Commerce & Payments policy for all 18 tools.
These attack patterns abuse exactly the kind of access add_to_cart gives an agent. Each links to the full case and the policy that stops it:
Other write tools across the catalogue. The same approach applies to each: rate-limit and validate the arguments.
Requires checkout:write scope. Add a product variant to an existing cart. Use the variant_id from search_products results. Returns full cart state including item_ids you can use with update_cart_item. Max quantity per item and max cart total are enforced — call get_platform_limits to check the current limits before building a large cart. Exceeding the per-item limit returns 400 QUANTITY_EXCEEDS_LIMIT; exceeding the cart total returns 400 CART_TOTAL_EXCEEDS_LIMIT at checkout.. It is categorised as a Write tool in the Kifly — Agentic Commerce & Payments MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Kifly — Agentic Commerce & Payments MCP server in PolicyLayer and add a rule for add_to_cart: 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 Kifly — Agentic Commerce & Payments. Nothing to install.
add_to_cart is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the add_to_cart 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 add_to_cart. 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.
add_to_cart is provided by the Kifly — Agentic Commerce & Payments MCP server (https://kifly.io/api/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 18 Kifly — Agentic Commerce & Payments tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
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