mcpbeat

Blackwall X402 Guardrail MCP Server

com.blackwalltier/blackwall-x402-guardrail
answering

Blackwall X402 Guardrail is answering right now. Last checked 1 min ago. It exposes 1 tools. Last commit 8 Jul 2026.

Pre-signature x402 payment verdict (GO/HOLD/STOP) for AI agents, with a verifiable signed receipt.

Uptime history 43 hours of history
43 hours agonow
100.0%
Uptime 24h
92 of 92 checks
1
Tools
read from the server
84 ms
Response time
average over 24h
0
Stars
last commit 8 Jul 2026

Connect this server

Endpoint below is the one we actually reach during checks — not the one copied from a README. Last verified 1 min ago.

run in your terminal
claude mcp add blackwall-x402-guardrail --transport http https://mcp.blackwalltier.com
~/Library/Application Support/Claude/claude_desktop_config.json
{
  "mcpServers": {
    "blackwall-x402-guardrail": {
      "url": "https://mcp.blackwalltier.com"
    }
  }
}
~/.codex/config.toml
[mcp_servers.blackwall-x402-guardrail]
url = "https://mcp.blackwalltier.com"
.cursor/mcp.json
{
  "mcpServers": {
    "blackwall-x402-guardrail": {
      "url": "https://mcp.blackwalltier.com"
    }
  }
}
.vscode/mcp.json
{
  "mcpServers": {
    "blackwall-x402-guardrail": {
      "url": "https://mcp.blackwalltier.com"
    }
  }
}

Available tools 1

Read directly from the server with tools/list, grouped by what they act on. If a tool disappears, we record the date.

forecast
forecast_payment
Pre-signature x402 payment verdict: GO / HOLD / STOP for paying a counterparty, from settlement reputation, price-anomaly (quoted vs the payee's own median), and OFAC sanctions — with a third-party-verifiable Ed25519 signed receipt. Verdict only; never takes custody. Free under $10 at risk; over that, returns an x402 payment challenge.

Endpoints

URLTransportStateLatencyChecked
https://mcp.blackwalltier.com streamable-http answering 90 ms 1 min ago

Blackwall X402 Guardrail — questions

Answers built from our own checks of this server.

What can Blackwall X402 Guardrail do?
It exposes 1 tools, read directly from the server on our last check. Among them: forecast_payment. The full list with descriptions is on this page — we take it from the server itself via tools/list, not from a README. How MCP servers expose tools in the first place →
Is Blackwall X402 Guardrail working right now?
We send a real MCP handshake every 15 minutes. Over the last 24 hours 92 of 92 checks got a reply (100.0%), average response time 84 ms. The bar chart above shows every period we have measured.
How do I connect Blackwall X402 Guardrail?
Copy the ready config from this page — we generate it for Claude Code, Claude Desktop, Codex, Cursor and VS Code, each with the file path that client actually reads. It is a remote server, so there is nothing to install — the client connects to the address.
Does Blackwall X402 Guardrail need an API key?
No. Blackwall X402 Guardrail completed a full MCP handshake with us as an anonymous client and listed its tools without asking for anything. All 1 of them are readable on this page. This is what we observed, not what the docs claim.
How fast is Blackwall X402 Guardrail?
It answers our handshake in 84 ms on average, which is faster than 89% of all working MCP servers we measure. That puts it in the quick quarter of the ecosystem. The comparison comes from our own checks across the whole registry, every 15 minutes.
Is Blackwall X402 Guardrail open source?
Yes — written in JavaScript and 0 stars on GitHub. The source link is on this page, so you can read exactly what it does with your data before you connect it.