Compatible with Cursor, Claude Code, Cline, Roo Code, Antigravity

API Endpoint Adversarial Fuzzing & Boundary Matrix

Generate adversarial fuzzing test cases, SQL injection payloads, and schema violation matrices for REST endpoints.

SecurityTestingFuzzingRESTQA

v1.0.0 · Updated 2026-08

Skill Objective

Generate adversarial payload matrices and automated fuzzing tests to ensure endpoints reject malformed data, payload explosions, and injection attacks with 4xx errors.

Execution Workflow Procedure

Ordered steps the coding agent executes when performing this skill.

Construct Type Coercion & Overflow Payloads

Generate oversized arrays, 10MB strings, deeply nested JSON trees, and type-coercion values.

Generate Injection & Character Vector Matrix

Assemble SQLi, XSS, path traversal, UTF-8 multibyte, and null-byte test vectors.

Generate Automated Fuzzing Test Code

Write automated tests that execute the matrix and assert consistent 400/422 status codes without 500 crashes.

Agent Safety Guardrails & Anti-Hallucination Rules

DO NOT allow endpoints to throw unhandled 500 Internal Server Errors on malformed client input.
DO NOT expose internal database exception traces in error responses.

Expected Output Format

Markdown test matrix and automated execution code.

📋 Fuzzing Matrix Table: Case ID, Payload, Expected Status, Error Code.

🧪 Automated Fuzzing Test Code: Executable test runner.

Domain Verification Checks

Payload Size Guard: Enforces max request body size limits.

Injection Resistance: Validates input sanitization.

Deterministic 4xx Status: Returns consistent validation errors.

Example Agent Invocations

"Generate an adversarial fuzzing test matrix for our workspace invitation endpoint."

"Test this user profile update route for JSON payload explosion vulnerabilities."

Install / Configure This Skill

# Place in .cursorrules or create .cursor/rules/api-adversarial-fuzzing-matrix.mdc
# Trigger: Whenever you perform api endpoint adversarial fuzzing & boundary matrix

---
name: api-adversarial-fuzzing-matrix
description: Create adversarial test matrices and automated fuzzing suites for REST API endpoints.
version: 1.0.0
compatibility: [Cursor, Claude Code, Cline, Roo Code, Antigravity]
---

# API Endpoint Adversarial Fuzzing & Boundary Matrix

## Objective
Harden API endpoints against payload explosions, injection attacks, and type coercion bugs by generating comprehensive fuzzing test suites.

## Workflow
1. **Payload Generation**: Create oversized arrays, deep JSON objects, and injection strings.
2. **Matrix Construction**: Map expected HTTP status codes and RFC 7807 error codes.
3. **Automated Verification**: Deliver automated tests validating that all malformed payloads return 400/422.

Complementary Agent Prompt

Need a quick one-time prompt for chat?

Try the API Endpoint Fuzzing & Boundary Value Test Matrix — a lightweight version designed for 1-click copying directly into Claude, ChatGPT, or Cursor chat.

View Prompt