refi derived

{
  "input": {
    "type": "http",
    "method": "GET",
    "queryParams": {
      "country": "US",
      "loan_type": "federal",
      "credit_tier": "good"
    }
  },
  "output": {
    "type": "json",
    "errors": {
      "400": {
        "example": {
          "error": "invalid request"
        },
        "description": "Invalid or missing parameter(s). Returned before the payment gate on paid requests, so a malformed call is never charged. JSON body: { error: <what is wrong and how to fix it> } plus usage hints."
      },
      "402": {
        "description": "Payment required — x402 v2 challenge; the accepts array lists scheme, network, and amount. Retry the same request with a PAYMENT-SIGNATURE (v2) or X-PAYMENT (v1) header. Verification is free."
      },
      "500": {
        "example": {
          "error": "upstream_failed"
        },
        "description": "Unexpected server error. If a payment settled without a usable result, contact info@theaslangroupllc.com with the settlement tx hash for a re-run or credit."
      }
    },
    "example": {
      "lender_categories": [
        {
          "best_for": "comparison shopping across multiple lenders",
          "category": "rate marketplace"
        }
      ],
      "refi_recommendation": {
        "worth_it": false,
        "rationale": "Federal loan — refinancing would forfeit SAVE/IBR access and PSLF eligibility",
        "benefits_forfeited_if_federal_to_private": [
          "income-driven repayment",
          "PSLF",
          "forbearance"
        ]
      }
    }
  }
}