com.blackwalltier/blackwall-x402-guardrail
Keyless hosted MCP: pre-signature x402 payment verdict (GO/HOLD/STOP) with a signed receipt.
Installation
Ajoutez ceci à la configuration MCP de votre client (Claude Desktop : claude_desktop_config.json ; Cursor : .cursor/mcp.json ; VS Code et les autres utilisent la même forme « mcpServers »).
claude mcp add --transport http blackwall-x402-guardrail 'https://mcp.blackwalltier.com'{
"mcpServers": {
"blackwall-x402-guardrail": {
"type": "http",
"url": "https://mcp.blackwalltier.com"
}
}
}Documentation
Tirée du README du projet sur GitHub, actualisée chaque semaine. Les liens ouvrent GitHub.
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.comTransport: 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 | ||
|---|---|---|
counterparty | string, required | recipient wallet from the 402 |
amount | string, required | decimal string, e.g. "0.09" |
asset | string, required | e.g. USDC |
chain | string, required | e.g. base |
payer / resource / agent_id / context | optional | binds 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
node test.mjs # unit tests (mocked oracle)
npx wrangler dev # run locally
npx wrangler deploy # deploy (Cloudflare Workers)By BlueTier. Verdict only — never takes custody, never in the settlement path. No evidence is not trust.
Questions fréquentes
Qu'est-ce que com.blackwalltier/blackwall-x402-guardrail ?
Keyless hosted MCP: pre-signature x402 payment verdict (GO/HOLD/STOP) with a signed receipt.
Comment installer com.blackwalltier/blackwall-x402-guardrail ?
Il fonctionne comme serveur distant. Dans Claude Code : claude mcp add --transport http blackwall-x402-guardrail 'https://mcp.blackwalltier.com'. Pour les autres clients, collez la configuration JSON de cette page dans leurs réglages MCP.
Faut-il une clé API pour com.blackwalltier/blackwall-x402-guardrail ?
Son entrée au registre n'indique aucune clé ni secret obligatoire. Certaines fonctions peuvent tout de même demander un compte auprès du service auquel il se connecte.
com.blackwalltier/blackwall-x402-guardrail est-il open source ?
Son code est public sur GitHub, mais le dépôt ne déclare pas de licence standard.
Qui maintient com.blackwalltier/blackwall-x402-guardrail ?
Il est publié par bluetieroperations-create. AI.tn le référence sans le maintenir ni le recommander.
Issu du registre MCP officiel. Être listé n'est pas une recommandation : vérifiez le code et les permissions d'un serveur avant de lui donner accès à vos données.