x402check MCP Server
by caiovicentinoio.github.caiovicentino/x402checkv0.3.0
Risk-check counterparties before an AI agent pays; pay x402 resources only after a verified allow
context tax
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security
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cold start
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freshness
Active3d ago
Install x402check MCP server
Install in Claude Code
claude mcp add caiovicentino -e X402CHECK_CREDIT_TOKEN='<x402check-credit-token>' -e X402CHECK_PAYER_KEY='<x402check-payer-key>' -- npx -y @x402check/mcpInstall in Cursor
{
"mcpServers": {
"caiovicentino": {
"command": "npx",
"args": [
"-y",
"@x402check/mcp"
],
"env": {
"X402CHECK_CREDIT_TOKEN": "<x402check-credit-token>",
"X402CHECK_PAYER_KEY": "<x402check-payer-key>"
}
}
}
}Add to ~/.cursor/mcp.json (global) or .cursor/mcp.json (project).
Install in Claude Desktop
{
"mcpServers": {
"caiovicentino": {
"command": "npx",
"args": [
"-y",
"@x402check/mcp"
],
"env": {
"X402CHECK_CREDIT_TOKEN": "<x402check-credit-token>",
"X402CHECK_PAYER_KEY": "<x402check-payer-key>"
}
}
}
}Settings → Developer → Edit Config (claude_desktop_config.json), then restart.
Install in VS Code
{
"servers": {
"caiovicentino": {
"type": "stdio",
"command": "npx",
"args": [
"-y",
"@x402check/mcp"
],
"env": {
"X402CHECK_CREDIT_TOKEN": "<x402check-credit-token>",
"X402CHECK_PAYER_KEY": "<x402check-payer-key>"
}
}
}
}Add to .vscode/mcp.json in your workspace.
Install in Windsurf
{
"mcpServers": {
"caiovicentino": {
"command": "npx",
"args": [
"-y",
"@x402check/mcp"
],
"env": {
"X402CHECK_CREDIT_TOKEN": "<x402check-credit-token>",
"X402CHECK_PAYER_KEY": "<x402check-payer-key>"
}
}
}
}Add to ~/.codeium/windsurf/mcp_config.json.
Configuration
| Variable | Required | Secret | Description |
|---|---|---|---|
| X402CHECK_CREDIT_TOKEN | — | yes | Prepaid credit token (x402c_…, from POST https://x402check.xyz/v1/credits): $0.001 a check |
| X402CHECK_PAYER_KEY | — | yes | Private key of a dedicated low-balance wallet: pays the x402 resources x402check_pay clears, and per-call checks without credits |
| X402CHECK_BUDGET_USD | — | — | Spend cap for this server process: the payer's spend (checks and resources), and separately what checks spend from prepaid credits |
| X402CHECK_PINNED_KEYS | — | — | Comma-separated RFC 7638 thumbprints of the attestation keys accepted (default: x402check's own keys, for its own issuer) |
| X402CHECK_MAX_PAYMENT_USD | — | — | The most a single payment may cost (a check or a resource) |
Freshness
Active — last maintenance signal 3d ago. The newest of the signals below sets the band.
Last commit (default branch)
2026-10-07 · 3d ago · GitHub
Latest release
2026-10-03 · 6d ago · GitHub · v0.6.4
Package published
no data · npm/PyPI
Registry entry updated
2026-09-30 · 9d ago · official registry · v0.3.0
FAQ
›How do I install the x402check MCP server in Claude Code?
Run: claude mcp add caiovicentino -e X402CHECK_CREDIT_TOKEN='<x402check-credit-token>' -e X402CHECK_PAYER_KEY='<x402check-payer-key>' -- npx -y @x402check/mcp. For Cursor, VS Code, Claude Desktop and Windsurf, use the install tabs above.
›Does x402check require an API key?
Yes. It expects X402CHECK_CREDIT_TOKEN, X402CHECK_PAYER_KEY, of which 2 are secrets.
›Can I use x402check as a remote (hosted) MCP server?
No hosted endpoint is published; it runs locally over stdio.
›Is x402check in the official MCP registry?
Yes, as io.github.caiovicentino/x402check.