aahilafraz123

Agentguard Merchant — Security skill for Claude Code

Security community

Policy checkpoint between AI agents and PayPal refunds: MCP security proxy, LangGraph risk pipeline with human-in-the-loop approval, adversarial evals.

How to install Agentguard Merchant

This entry records only its repository, not the path inside it, so there is no exact command to give. Open aahilafraz123/agentguard-merchant and copy the folder into ~/.claude/skills/, or the file into ~/.claude/agents/.

What Agentguard Merchant does

Policy checkpoint between AI agents and PayPal refunds: MCP security proxy, LangGraph risk pipeline with human-in-the-loop approval, adversarial evals.

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README

AgentGuard

**Your AI support agent can issue refunds. AgentGuard makes sure nobody can talk it into one.**

[![CI](https://github.com/aahilafraz123/agentguard-merchant/actions/workflows/ci.yml/badge.svg)](https://github.com/aahilafraz123/agentguard-merchant/actions/workflows/ci.yml) ![License: MIT](https://img.shields.io/badge/license-MIT-green) ![Python 3.12](https://img.shields.io/badge/python-3.12-blue) ![PayPal Sandbox](https://img.shields.io/badge/PayPal-Sandbox-003087)

AgentGuard is a policy checkpoint between AI agents and PayPal. Every refund an agent asks for is checked against **PayPal's own records**: who placed the order, what was captured and already refunded, and whether tracking shows it shipped. It is also checked against the merchant's refund policy, the customer's refund history and a Claude risk agent. Each request is then **allowed** (the refund executes on PayPal), **escalated** (the owner approves or denies it in a review queue) or **blocked** (logged as an incident).

It plugs in two ways:

Inside an AI support agent. The demo shop's Claude support bot calls AgentGuard instead of PayPal.
As an MCP security proxy (agentguard-mcp) in front of PayPal's official MCP server, which is built on the PayPal Agent Toolkit. Any MCP client gets PayPal's 28 tools, but create_refund is policy-checked first and irreversible actions need a human.

Built for the [PayPal AI Hackathon](https://paypalaihackathon.devpost.com/) (2026).

![Live demo: an attacker claiming to be the store owner is stopped; the merchant view shows the PayPal evidence](docs/live-demo.png)

*Left: the shop's Claude support agent. Alex claims to be the owner and asks for a refund on Marcus's order; AgentGuard hides the order and the ownership check blocks the refund. Right: the owner's live view, with every check and the PayPal evidence behind the decision.*