Blackwall X402 Guardrail MCP server
{
"mcpServers": {
"blackwalltier-blackwall-x402-guardrail": {
"type": "http",
"url": "https://mcp.blackwalltier.com"
}
}
}{
"mcpServers": {
"blackwalltier-blackwall-x402-guardrail": {
"type": "http",
"url": "https://mcp.blackwalltier.com"
}
}
}{
"mcpServers": {
"blackwalltier-blackwall-x402-guardrail": {
"type": "http",
"url": "https://mcp.blackwalltier.com"
}
}
}{
"servers": {
"blackwalltier-blackwall-x402-guardrail": {
"type": "http",
"url": "https://mcp.blackwalltier.com"
}
}
}{
"mcpServers": {
"blackwalltier-blackwall-x402-guardrail": {
"type": "http",
"url": "https://mcp.blackwalltier.com"
}
}
}file .mcp.json (in your project root)file claude_desktop_config.jsonfile ~/.cursor/mcp.jsonfile .vscode/mcp.jsonfile ~/.codeium/windsurf/mcp_config.jsonversion 0.1.2
What it does
A hosted MCP server that evaluates payment risk before x402 transactions are signed, returning GO/HOLD/STOP verdicts based on counterparty reputation, price anomalies, and sanctions checks. It is for MCP-capable agents that need to assess payment safety without local installation.
- Check whether to proceed with a payment to a given counterparty before signing the transaction.
- Detect price anomalies by comparing a quoted amount against the payee's historical median price.
- Retrieve a verifiable Ed25519-signed receipt that proves a payment verdict was issued and can be validated independently.
Tools this server exposes
| Tool | Does |
|---|---|
| forecast_payment | Takes counterparty wallet, amount, asset, and chain; returns a verdict (GO/HOLD/STOP) with reasoning and a signed receipt. Amounts under $10 at risk are free; h |
Before you enable it
An MCP server runs with whatever access you give it. Start with a development account rather than production, and check which tools the server exposes before you let an agent call them unattended.