This tool is no longer present in the server's latest manifest. Showing the last observed version (server version 1.28.0).
onyx_x402_simulate
InactiveTool of onyx-paid-mcp
declared in 1.28.0
Simulate an x402 v2 payment flow against any paid endpoint. Fetches the 402 challenge (or introspection card), parses paymentRequirements, generates a template X-PAYMENT payload with the exact fields an agent would need to sign (EIP-3009 authorization shape, validBefore window, asset address, recipient), and returns next-step guidance. Pure simulation — no keys, no signing, no payment. SSRF-hardened. (price: $0 USDC, tier: free)
Parameters schema
{
"type": "object",
"required": [
"endpoint_url"
],
"properties": {
"method": {
"enum": [
"GET",
"POST"
],
"type": "string",
"default": "GET",
"description": "GET hits the introspection card (works even on unpaid endpoints); POST hits the live 402 challenge (works on every paid endpoint)."
},
"endpoint_url": {
"type": "string",
"description": "Full URL of the paid endpoint to simulate against (e.g. https://onyx-actions.onrender.com/v1/onyx_aml_screen)."
},
"signer_address": {
"type": "string",
"description": "Address that would sign the EIP-3009 authorization. Used to fill the 'from' field in the template payment payload. Optional — defaults to 0x0...01."
}
}
}Parent server
onyx-paid-mcp
https://github.com/dimitrilaouanis-tech/onyx-mcp
2/7 registries