X402 Attack Surface Gate

    2

    Automated launch-readiness auditor for x402 and agent-payment API surfaces.

    $19

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    0 installsSecurity scanned

    Works with the AI tools you already use

    Claude CodeClaude CodeCursorCursorCodex CLICodex CLIGitHub CopilotGitHub CopilotGemini CLIGemini CLI+20 more

    x402-attack-surface-gate

    Example session with this skill installed

    Run a launch-readiness audit on my new x402-enabled generation API at https://api.example.com/v1/generate using the public manifest.

    • Read your context and instructions
    • Compiled the x402-attack-surface-gate

    Verdict: hold_for_patch
    Spend Map: POST /v1/generate | 0.05 USDC | Resource Binding: FAILED
    Findings: [High] Paid-but-denied risk: Route returns 200 OK before 402 challenge on large payloads.
    Patch: Move payment validation middleware before the body parser to prevent unpaid resource exhaustion.

    Connects securely to your tools. The creator never sees your data.

    What you get

    Map paid API routes and price points from public manifests and docs.Identify payment bypass risks where work executes before a 402 challenge.Verify idempotency and replay protection to prevent double-charging.Audit CORS and cache headers for agent-client compatibility.Generate a prioritized patch order for payment-layer vulnerabilities.

    About this skill

    What it does

    The x402 Attack Surface Gate is a security and reliability auditor for AI agent payment layers. It performs automated, no-payment probes of x402, MPP, and Pay.sh implementations to identify launch-blocking risks like payment bypass, replay vulnerabilities, and browser-related CORS or cache leaks.

    Why use this skill

    Testing paid API surfaces is notoriously difficult because you often have to spend real funds or mock complex wallet signatures. This skill solves that by using standardized, non-destructive probing techniques. It ensures your 402 payment challenges are correctly bound to resources, idempotent, and compatible with agent-centric browser environments before you go live.

    Supported tools

    • x402 protocol manifests
    • OpenAPI / Swagger specifications
    • MPP and Pay.sh agent payment standards
    • Agent wallet registries and marketplace listings

    The output provides a structured "Spend Map" and a prioritized "Patch Order," giving developers a clear checklist to move from 'hold_for_patch' to 'launch_ready'.

    How to install

    Works the same in every agent - Claude, Cursor, Codex, Copilot and 20+ more.

    ~30 seconds
    1. 1

      Download the ZIP

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    2. 2

      Unzip into your skills folder

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    3. 3

      Ask your agent to use it

      Restart the agent if it was already running. It picks the skill up automatically - no config needed.

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    Recently published to Agensi

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    Trust & safety

    Security scanned

    Verified clean 4 months ago

    • Passed all security checks, Safe to install

    Listed4 months ago

    What's inside

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