# x402toll DTI Calculator

> x402toll DTI Calculator is a paid API for AI agents from x402toll.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-15).

Calculates front-end and back-end debt-to-income ratios and returns a pass/fail verdict against conventional 28/36 or custom limits.

## Facts

- Endpoint: POST https://x402toll.com/v1/lending/dti
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402toll-dti-calculator-3e990730
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_waeNXt-mkwB5vWz585isw

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability x402toll-dti-calculator-3e990730 -d '<json body>'
```

Example prompt: My gross monthly income is $7,500, my proposed mortgage payment including taxes and insurance would be $1,800, and I have $400/month in other debts like a car loan — can you calculate my front-end and back-end DTI ratios and tell me if I pass the standard 28/36 rule?

## When to prefer this

Use this endpoint when you need an instant, deterministic DTI calculation with pass/fail logic against configurable or standard 28/36 lending thresholds — ideal for mortgage pre-qualification checks, loan affordability screening, or financial planning workflows where you need both front-end and back-end ratios in a single call without implementing the math yourself.

## Known failure modes

- Missing grossMonthlyIncome — required field, returns validation error
- Missing proposedHousingPayment — required field, returns validation error
- grossMonthlyIncome is zero or negative — division by zero or invalid result
- Non-numeric values for any field — schema validation error
- Custom limit percentages outside reasonable range may produce unexpected pass/fail results

## How this service works

Debt-to-income ratio — front-end and back-end — with pass/fail against your (or the conventional 28/36) limits.

## Output

Returns the computed front-end DTI (housing payment / gross income) and back-end DTI ((housing + other debts) / gross income) as percentages, along with pass/fail verdicts compared against either the user-supplied limits or the conventional 28% front-end and 36% back-end thresholds.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "backLimitPct": {
   "type": "number",
   "default": 36
  },
  "frontLimitPct": {
   "type": "number",
   "default": 28
  },
  "otherMonthlyDebts": {
   "type": "number",
   "default": 0
  },
  "grossMonthlyIncome": {
   "type": "number"
  },
  "proposedHousingPayment": {
   "type": "number"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402toll-dti-calculator-3e990730/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402toll.com](https://www.zero.xyz/host/x402toll.com/llms.txt)