Worked Example — 7-Year ARM Purchase

A 7-year Adjustable Rate Mortgage (7/6 ARM) purchase for a $500,000 home in Miami, FL. ARM loans offer a fixed introductory rate for the initial term, then adjust periodically — attractive for borrowers who plan to sell or refinance before the adjustment period.

What is a 7/6 ARM?
Fixed for the first 7 years, then adjusts every 6 months based on SOFR + a margin. Amortized over 30 years. Caps: initial (max increase at first adjustment), periodic (max per subsequent adjustment), lifetime (max total increase). At 80% LTV with a 780 score, no PMI applies.

Scenario Parameters

Parameter	Value
Loan Purpose	Purchase
Loan Type	ARM
ARM Term	7 years (7/6 ARM — fixed 7yr, adjusts every 6 months)
List Price	$500,000
Loan Amount	$400,000
Down Payment	$100,000 (20%)
LTV	80%
Credit Score	780
State / City / ZIP	FL / Miami / 33130
Monthly Income	$17,500
Lock Period	30 days
Loan Term	30 years (amortization)
loid	44
Loan Officer ID (loid)	6309

Request Payload

loan_type: "ARM" and arm_term: "7" are both required. loan_term: 30 is the full amortization period. Other ARM terms: "3", "5", "10".

POST https://api.bankingbridge.com/rateflow
Content-Type: application/json
x-api-key: uL6aLuwfcq1dUvEZTq3Gv2O0KgorNbYXXXXXXXX

{
  "lock_period": 30,
  "first_time_homebuyer": false,
  "loan_type": "ARM",
  "list_price": 500000,
  "loan_purpose": "purchase",
  "loan_amount": 400000,
  "credit_score": 780,
  "state": "FL",
  "city": "Miami",
  "zipcode": "33130",
  "coords": { "lat": 0, "lng": 0 },
  "residency_type": "primary_home",
  "property_type": "single_family_home",
  "cash_out": 0,
  "down_payment": 100000,
  "waive_escrows": false,
  "monthly_income": 17500,
  "arm_term": "7",
  "loid": 6309,
  "id": 44,
  "withCredentials": false,
  "min_credit": 780,
  "loan_term": 30,
  "aus": "NotSpecified"
}

cURL Example

curl -X POST "https://api.bankingbridge.com/rateflow" \
  -H "x-api-key: uL6aLuwfcq1dUvEZTq3Gv2O0KgorNbYXXXXXXXX" \
  -H "Content-Type: application/json" \
  -d '{
    "lock_period": 30,
    "first_time_homebuyer": false,
    "loan_type": "ARM",
    "list_price": 500000,
    "loan_purpose": "purchase",
    "loan_amount": 400000,
    "credit_score": 780,
    "state": "FL",
    "city": "Miami",
    "zipcode": "33130",
    "residency_type": "primary_home",
    "property_type": "single_family_home",
    "cash_out": 0,
    "down_payment": 100000,
    "monthly_income": 17500,
    "arm_term": "7",
    "loid": 6309,
    "id": 44,
    "min_credit": 780,
    "loan_term": 30,
    "aus": "NotSpecified"
  }'

JavaScript (fetch) Example

const response = await fetch("https://api.bankingbridge.com/rateflow", {
  method: "POST",
  headers: {
    "Content-Type": "application/json",
    "x-api-key": "uL6aLuwfcq1dUvEZTq3Gv2O0KgorNbYXXXXXXXX"
  },
  body: JSON.stringify({
    lock_period: 30,
    first_time_homebuyer: false,
    loan_type: "ARM",
    list_price: 500000,
    loan_purpose: "purchase",
    loan_amount: 400000,
    credit_score: 780,
    state: "FL",
    city: "Miami",
    zipcode: "33130",
    residency_type: "primary_home",
    property_type: "single_family_home",
    cash_out: 0,
    down_payment: 100000,
    monthly_income: 17500,
    arm_term: "7",
    loid: 6309,
    id: 44,
    min_credit: 780,
    loan_term: 30,
    aus: "NotSpecified"
  })
});
const data = await response.json();
console.log(data.pricing_results);

Python (requests) Example

import requests

headers = {
  "Content-Type": "application/json",
  "x-api-key": "uL6aLuwfcq1dUvEZTq3Gv2O0KgorNbYXXXXXXXX"
}

payload = {
  "lock_period": 30,
  "first_time_homebuyer": False,
  "loan_type": "ARM",
  "list_price": 500000,
  "loan_purpose": "purchase",
  "loan_amount": 400000,
  "credit_score": 780,
  "state": "FL",
  "city": "Miami",
  "zipcode": "33130",
  "residency_type": "primary_home",
  "property_type": "single_family_home",
  "cash_out": 0,
  "down_payment": 100000,
  "monthly_income": 17500,
  "arm_term": "7",
  "loid": 6309,
  "id": 44,
  "min_credit": 780,
  "loan_term": 30,
  "aus": "NotSpecified"
}

response = requests.post(
  "https://api.bankingbridge.com/rateflow",
  json=payload,
  headers=headers
)
data = response.json()

Sample Response Structure

ARM responses include arm_caps, index, margin, and fully_indexed_rate in each result.

{
  "returncode": 0,
  "status": "success",
  "loid": 44,
  "pricing_results": [
    {
      "lender_name": "Example Lender A",
      "program_name": "7/6 ARM",
      "rate": 6.125,
      "apr": 6.892,
      "points": 0.00,
      "monthly_payment": 2430.11,
      "pmi_monthly": 0,
      "arm_caps": "5/1/5",
      "index": "SOFR",
      "margin": 2.75,
      "fully_indexed_rate": 7.89,
      "lock_period": 30
    },
    {
      "lender_name": "Example Lender B",
      "program_name": "7/6 ARM",
      "rate": 6.000,
      "apr": 6.801,
      "points": 0.50,
      "monthly_payment": 2398.20,
      "pmi_monthly": 0,
      "arm_caps": "2/1/5",
      "index": "SOFR",
      "margin": 2.625,
      "fully_indexed_rate": 7.76,
      "lock_period": 30
    }
  ]
}

ARM Response Fields Explained:

• arm_caps: "initial/periodic/lifetime". Example "5/1/5": +5% max at first adjustment, +1% per subsequent adjustment, +5% max lifetime.
• index: Benchmark rate for adjustments. Most lenders use SOFR (replaced LIBOR in 2023).
• margin: Fixed spread added to index at each adjustment. New rate = index + margin (subject to caps).
• fully_indexed_rate: Current index + margin. Useful for TRID worst-case payment disclosure.
• Available arm_term values: "3" (3/6 ARM), "5" (5/6 ARM), "7" (7/6 ARM), "10" (10/6 ARM).