GateCheck by LarryBuildsAI

One-cent x402 and MCP readiness checks plus fixed-price marketplace launch packs.

CommunityOnlineAPI key requiredGlobalFreeRead-only

What it can do

    What data it sees

    Do you need an account

    An API key from the service settings is required

    One-cent x402 and MCP readiness checks plus fixed-price marketplace launch packs.

    How to connect

    How to connect GateCheck by LarryBuildsAI to Claude

    The server address to paste into Claude settings:

    https://proofbeforepay.vercel.app/gatecheck/mcp

    1. Open Claude (claude.ai or the desktop app).
    2. Go to Settings → Connectors.
    3. Click Add custom connector.
    4. Paste the server address copied below into Remote MCP server URL and click Add.
    5. In a chat, click + → Connectors and switch the new connector on.

    Custom connectors are available on Free, Pro, Max, Team and Enterprise plans (Free is limited to one). On Team and Enterprise an organization Owner adds the connector first under Organization settings → Connectors.

    Authorization

    After you click Add, a sign-in window for the service opens. Sign in with your own account and approve access. Claude never sees your password.

    How to connect GateCheck by LarryBuildsAI to ChatGPT

    The server address to paste into ChatGPT settings:

    https://proofbeforepay.vercel.app/gatecheck/mcp

    1. Open ChatGPT in a browser (chatgpt.com). A Plus, Pro, Business, Enterprise or Edu plan is required.
    2. Turn on developer mode once: Settings → Apps → Advanced settings → Developer mode.
    3. Open Settings → Connectors and click Create.
    4. Fill in the form: Name (anything), Description (one line about what the service does), MCP server URL (copy it below).
    5. Under Authentication choose OAuth if the service requires sign-in, otherwise None. Click Create.
    6. In a new chat open + → Apps/Connectors and enable the connector.

    OpenAI has renamed this section before (Connectors → Apps/Plugins). If the label differs, search settings for "developer mode". On Business/Enterprise workspaces an admin must allow custom connectors first.

    Authorization

    On first use ChatGPT opens the service's sign-in window. Sign in and approve access.

    How to connect GateCheck by LarryBuildsAI to Cursor

    The server address to paste into Cursor settings:

    https://proofbeforepay.vercel.app/gatecheck/mcp

    Fastest: click Open in Cursor below and confirm the prompt.

    Manually:

    1. In Cursor open Settings → Cursor Settings → MCP and click Add new global MCP server.
    2. Paste the JSON copied below into ~/.cursor/mcp.json (per project: .cursor/mcp.json in the repo root).
    3. Save the file. The server appears in the MCP list; authorize it there if asked.

    Authorization

    If the service needs sign-in, an authorize button appears next to the server in the MCP list.

    Server tool list (6)

    Raw names from tools/list. Only developers need these.

    boundary_guard_checkCreate a deterministic, read-only pre-action receipt from request, policy, and optional result evidence. Use before an agent posts, spends, lists, or writes so the decision can be audited; no external action is executed.
    scan_x402_resourceRead-only scan of a public API/provider URL for x402, OpenAPI, pricing, and agent-discovery metadata. Pass url, and optionally marketplace_url plus expected_resources, to get a readiness score, issues, and fixes; no private endpoints are called.
    probe_x402_paid_pathProbe a public x402 paid endpoint without signing or paying, then parse the HTTP 402 challenge. Pass target plus optional expected network/asset/price to verify payment metadata and receive a deterministic health receipt.
    check_agent_tool_readinessGateCheck readiness: check whether an x402/agent-facing tool is ready for agent routing, marketplace listing, and paid-path monitoring, including public agent discovery surfaces (/llms.txt, /agents.txt, /.well-known/mcp.json, /mcp). Pass target plus optional tier, marketplace_url, expected_resources, and paid_path; deep/report tiers add unpaid 402 probing when paid_path is supplied. Tiers: quick $1, deep $5, report $10.
    generate_x402_launch_packGenerate marketplace-safe launch assets for an x402/MCP seller: listing copy, buyer FAQ, checklist, approval packet, and claim boundaries. Pass target plus optional product_name, audience, primary_use_case, marketplace_url, and paid_path; service/premium tiers include readiness evidence. Tiers: single $9, service $29, premium $49.
    generate_trust_receiptGenerate a deterministic trust receipt from sanitized request/policy/result/payment summaries. Do not submit raw auth headers, cookies, API keys, private keys, payment signatures, payment response headers, customer prompts, customer documents, or payer-identifying evidence.