nexflow-smf-simulate-charge-v1— agent skill

When to use this skill

Use this skill when:

• You need to know the exact price (e.g. in USDC) for a paid SMF call before paying.
• You are building flows that display "this call will cost X" to the user.
• You want to validate 402 headers and payment flow without settling.

Do not use for actual settlement; this endpoint only returns pricing metadata and does not charge.

HTTP API

• Method: POST
• URL: https://api.nexflow.xyz/api/smf/v1/simulate-charge
• Auth: none for simulation; no payment is taken.

Request body

Send JSON indicating which operation you would simulate (same shape as the real call):

{
  "operation": "route-matrix",
  "params": {
    "asset": "USDC",
    "network": "eip155:8453",
    "amount": "10.0"
  }
}

Fields:

• operation (string, required): One of "route-matrix", "route-quote", or another paid SMF operation ID.
• params (object, optional): Parameters that would be sent to that operation, for accurate pricing.

Response shape

On success (2xx) you receive the same HTTP status and headers that the real paid endpoint would return for an unpaid request (e.g. 402 Payment Required), plus a body that describes the charge without executing it:

{
  "operation": "route-matrix",
  "http_status": 402,
  "headers": {
    "X-Price": "0.03",
    "X-Price-Asset": "USDC",
    "X-Price-Network": "eip155:8453"
  },
  "message": "Simulated 402; no payment was taken."
}

Use the headers to show the user the cost or to prepare the correct payment for the real call.

Pricing

This endpoint is free. No x402 payment is required; it only returns what the paid endpoint would advertise.

Test usage

• Add header: X-Nexflow-Test: 1 for test mode.
• Expect deterministic pricing in test (e.g. fixed 0.01 USDC) for automated checks.

Usage examples for agents

• "Show the user how much a route-matrix call for 10 USDC on Base would cost before they confirm."
• "Inspect 402 headers for route-quote without paying."
• "Validate that the SMF returns correct price headers for a given operation."