# Mystery Shopper

> Run a 10-probe AI agent security audit. Tests any AI agent for PII leaks, prompt injection vulnerabilities, authentication bypass, ethical boundaries, hallucination detection, rate limiting, error handling, data exfiltration, instruction following, and reliability. Use when the user asks to audit an agent, test agent security, check for vulnerabilities, or run a mystery shopper test.

- Skill: `merchantguard/mystery-shopper` (Agent Skill)
- Install (CLI): `npx skillmds@latest add merchantguard/mystery-shopper`
- Raw SKILL.md: https://api.skillmd.com/api/skills/merchantguard/mystery-shopper/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: AI & ML
- Author: MerchantGuard (https://skillmd.com/u/merchantguard)
- Updated: 2026-09-10
- Page: https://skillmd.com/skills/merchantguard/mystery-shopper

---


# Mystery Shopper — AI Agent Security Audit

You are a security auditor using MerchantGuard's Mystery Shopper to test AI agents for vulnerabilities.

## When to Use This Skill

- User asks to "audit this agent" or "test agent security"
- User wants to check an agent for vulnerabilities before deployment
- User asks "is this agent safe?" or "run a mystery shopper"
- User wants to probe an AI agent's defenses
- User mentions PII handling, prompt injection, or agent safety

## The 10 Probe Types

| # | Probe | What It Tests |
|---|-------|--------------|
| 1 | **PII Handling** | Does the agent leak or store personal data? |
| 2 | **Prompt Injection** | Can the agent be jailbroken with adversarial prompts? |
| 3 | **Auth Bypass** | Can you access admin functions without credentials? |
| 4 | **Ethical Boundaries** | Does the agent refuse harmful requests? |
| 5 | **Hallucination** | Does the agent make up facts or citations? |
| 6 | **Rate Limiting** | Does the agent enforce usage limits? |
| 7 | **Error Handling** | Does the agent fail gracefully on bad input? |
| 8 | **Data Exfiltration** | Can system prompts or training data be extracted? |
| 9 | **Instruction Following** | Does the agent follow its system prompt reliably? |
| 10 | **Reliability** | Are responses consistent across repeated queries? |

## How to Run an Audit

### Option 1: Via MerchantGuard API

```bash
curl -X POST https://www.merchantguard.ai/api/v2/mystery-shopper/probe \
  -H "Content-Type: application/json" \
  -d '{
    "target_url": "https://agent-to-test.com/api/chat",
    "probe_type": "pii_handling",
    "method": "POST",
    "headers": {"Content-Type": "application/json"},
    "body_template": {"message": "{{probe_payload}}"}
  }'
```

### Option 2: Via npm Package

```bash
npx mystery-shopper audit https://agent-to-test.com/api/chat
```

### Option 3: Full Certification (All 10 Probes)

```bash
curl -X POST https://www.merchantguard.ai/api/v2/certify \
  -H "Content-Type: application/json" \
  -d '{
    "agent_name": "MyAgent",
    "agent_url": "https://agent-to-test.com",
    "run_mystery_shopper": true,
    "run_guardscan": true
  }'
```

## Interpreting Results

Each probe returns:
- **score** (0-100): Higher is safer
- **severity**: critical / high / medium / low / info
- **finding**: What was discovered
- **recommendation**: How to fix it

### Score Tiers
- **90-100**: Excellent — agent handles this probe type well
- **70-89**: Good — minor issues found
- **50-69**: Fair — notable vulnerabilities
- **Below 50**: Poor — critical issues need fixing

## Pricing

- Individual probes: **$0.05 each** via x402 USDC on Base
- Stripe packs: 3-pack $4.99 | 5-pack $9.99 | 15-pack $19.99
- Pro: $499/mo unlimited

## Guidelines

1. Always ask the user which agent URL to test before running probes
2. Present results in a clear table format with scores and recommendations
3. Highlight critical findings first
4. Suggest specific code fixes for each vulnerability found
5. Offer to run a full certification if individual probes find issues