Blackwall X402 Guardrail

com.blackwalltier由 blackwalltier.com 發布官方發布者v0.1.2更新於 Oct 24, 2026

Keyless hosted MCP: pre-signature x402 payment verdict (GO/HOLD/STOP) with a signed receipt.

已驗證Streamable HTTP可網頁執行金融安全與監控

概覽

AI 產生的概覽

託管型遠端 MCP，在代理簽署 x402 付款前給出 GO/HOLD/STOP 風險判定，並附可驗證的簽章回執。

可以做什麼
  • 依交易對手錢包、金額、資產與鏈請求付款判定，可選填付款方、資源、代理 ID 與情境。
  • 取得 GO、HOLD 或 STOP 以及原因與訊號，依據結算信譽、報價相對收款方自身中位數的價格異常，以及 OFAC 制裁名單。
  • 取得 Ed25519 簽章回執，第三方可依公開金鑰獨立驗證。
適用情境
當代理即將簽署 x402 付款、需要先判斷交易對手與價格是否安全時使用。適合需要可稽核審計紀錄的自動化付款流程，它不託管資金也不介入結算。
執行需求
遠端 Streamable HTTP 端點，無需安裝、註冊或 API 金鑰。呼叫需提供 counterparty、amount、asset 與 chain。風險金額低於 10 美元時判定免費；達到或超過該金額時，工具會回傳 x402 付款挑戰，代理須以自身錢包付款並以 X-PAYMENT 標頭回傳後重試。
安裝前請注意
超過免費額度時，代理需以自身錢包付款才能取得判定，涉及實際支出。工具只提供判定、不託管資金，但 GO 並非保證。呼叫會轉送至獨立的 oracle 服務，回執公鑰發布於另一主機，兩者可用性都會影響結果；失敗時回傳錯誤而非 GO。

安裝

在 SourceWeft 中

  1. 開啟 儀表板中的 Blackwall X402 Guardrail，將其新增到工作區。
  2. 為需要使用其工具的對話啟用該服務。

Web executable，透過 Streamable HTTP。 遠端服務在工作區中設定後即可從網頁執行環境執行。

交給代理程式安裝

把這段提示詞貼上到 Claude Code、Codex、Cursor 等代理程式，或 SourceWeft 對話中。代理程式會讀取該伺服器的安裝指南，先向你展示發布者、端點和登入方式，經你同意後再把它新增到你的客戶端。金鑰不會寫進任何命令。

閱讀 https://sourceweft.com/mcp/com.blackwalltier%2Fblackwall-x402-guardrail/install.md，並按其中說明把這個 MCP 伺服器接入我的客戶端。修改任何設定之前，先告訴我它的發布者、端點和登入方式，等我確認。不要把 API 金鑰寫進命令或我會提交的檔案；問我金鑰應從哪裡取得。

檢視代理程式所依據的安裝指南

其他 MCP 客戶端

把它新增到你客戶端的 mcpServers 設定中。

{
  "mcpServers": {
    "blackwall-x402-guardrail": {
      "type": "http",
      "url": "https://mcp.blackwalltier.com/"
    }
  }
}

README

Black_Wall remote MCP

A hosted remote MCP (Model Context Protocol over HTTP) that gives any MCP-capable agent a pre-signature payment-risk verdict — with no install and no signup. Add one URL and your agent can ask, before it signs an x402 payment, "should I pay this?" and get GO / HOLD / STOP — from counterparty settlement reputation, price-anomaly (quoted vs the payee's own median), and OFAC sanctions — plus a third-party-verifiable Ed25519 signed receipt.

Add it

Point your MCP client at:

https://mcp.blackwalltier.com

Transport: Streamable HTTP. No API key. Verdicts for amounts under $10 at risk are free; at or above that, the tool returns an x402 payment challenge your agent settles from its own wallet (pass the settled payment back as an X-PAYMENT header, then retry).

The tool: forecast_payment

field
counterpartystring, requiredrecipient wallet from the 402
amountstring, requireddecimal string, e.g. "0.09"
assetstring, requirede.g. USDC
chainstring, requirede.g. base
payer / resource / agent_id / contextoptionalbinds settlement / context

Returns a verdict (GO/HOLD/STOP) + reasons + signals, and a signed_receipt anyone can verify against the published key at https://agent-egress-proxy.onrender.com/.well-known/blackwall-receipt-key.json (any RFC 8032 Ed25519 library) — Black_Wall never has to be in the loop.

How it works

This Worker is a thin transport + proxy: it speaks minimal MCP JSON-RPC (initialize / tools/list / tools/call / ping) and forwards forecast_payment calls to the Black_Wall x402 oracle. All decision logic and the receipt come from the oracle unchanged.

Fail-closed by design: if the oracle errors, is unreachable, or returns a non-verdict, the tool returns an error — never a phantom GO. A payment guardrail that can't reach its backend must not imply "safe to pay."

Registry

Published to the official MCP Registry as com.blackwalltier/blackwall-x402-guardrail.

Develop

sh
node test.mjs        # unit tests (mocked oracle)npx wrangler dev     # run locallynpx wrangler deploy  # deploy (Cloudflare Workers)

By BlueTier. Verdict only — never takes custody, never in the settlement path. No evidence is not trust.

來源：README.md，提交 4a69626

工具

1

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.

輸入參數asset必填chain必填payeramount必填contextagent_idresourcecounterparty必填

版本歷史

1
  1. v0.1.2最新Sep 16, 2026

評分

已滿足適用檢查項的 90%

該評分衡量此收錄條目的完整程度，依據註冊中心條目、端點與公開來源計算得出。它不是對伺服器本身的評價，也不表示伺服器安全或目前可用：可連通性是帶日期的檢查結果，評分也不包含安裝量或使用者評價。

  • 近 30 天內可連通必需25 分
  • 已宣告認證方式必需10 分
  • 已列出工具必需15 分
  • 描述必需15 分
  • 圖示10 分
  • 文件15 分
  • 授權條款10 分

    請在儲存庫或註冊中心條目中宣告授權條款。

其他 Blackwalltier 整合

Blackwall

com.blackwalltier

本機 MCP 護欄，在代理執行動作前先評分，並回傳 GO、CAUTION 或 STOP 結論與風險標記。

STDIO僅桌面
開發者工具尚未驗證Oct 24, 2026