# x402toll True APR Calculator (Reg Z / TILA)

> x402toll True APR Calculator (Reg Z / TILA) is a paid API for AI agents from x402toll.com, paid per call via x402, $0.05/call, status unknown (last checked 2026-09-15).

Computes the true Annual Percentage Rate (APR) under Regulation Z / TILA from a note rate plus financed fees, revealing the real cost of borrowing.

## Facts

- Endpoint: POST https://x402toll.com/v1/lending/apr
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402toll-true-apr-calculator-reg-z-tila-536f503f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_0HyHtfPMOP-5h3ZkNtshU

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-true-apr-calculator-reg-z-tila-536f503f -d '<json body>'
```

Example prompt: What's the true Reg Z APR on a $350,000 loan over 360 months at a 6.75% note rate with $8,500 in financed fees?

## When to prefer this

Use this endpoint when you need a precise, regulation-compliant APR figure (Reg Z / TILA) that accounts for financed fees — particularly for mortgage disclosures, loan comparisons, or any scenario where the note rate alone understates the true borrowing cost. Prefer this over generic interest-rate calculators when regulatory accuracy and fee inclusion matter.

## Known failure modes

- Missing required fields (loanAmount, termMonths, noteRatePct) returns a 400 error
- Negative or zero loan amount or term returns a validation error
- Extremely high fee ratios relative to loan amount may produce edge-case APR values
- Network or payment failure returns a 402 or 5xx error

## How this service works

True APR (Reg Z / TILA) from the note rate plus financed fees — the real cost of borrowing.

## Output

Returns the true APR as a percentage, calculated per Regulation Z / TILA methodology, reflecting the effective annual cost of the loan after accounting for the note rate and all financed fees rolled into the loan.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "loanAmount": {
   "type": "number"
  },
  "termMonths": {
   "type": "number"
  },
  "noteRatePct": {
   "type": "number"
  },
  "feesFinanced": {
   "type": "number",
   "default": 0
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402toll-true-apr-calculator-reg-z-tila-536f503f/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)