# Interest & Loan Payment Calculator

> Interest & Loan Payment Calculator is a paid API for AI agents from api.x402node.dev, paid per call via x402, $0.008/call, status unknown (last checked 2026-09-14).

Computes simple interest, compound interest, annuity loan payments, and related financial metrics (APR/APY, future/present value) with configurable compounding frequency

## Facts

- Endpoint: GET https://api.x402node.dev/math/interest
- Price: $0.008/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/api-x402node-dev-32c874d2
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_r233Z4m53Lq1wIxrhB-HC

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 api-x402node-dev-32c874d2
```

Example prompt: Calculate the monthly payment for a $250,000 mortgage at 6.5% annual interest compounded monthly over 30 years using compound annuity mode.

## When to prefer this

Use this endpoint when you need reliable server-side financial math for compound/simple interest, loan or mortgage payments, annuity calculations, APR/APY conversions, or future/present value projections — especially in agentic pipelines where reproducibility and a standardized API response matter more than building custom formulas

## Known failure modes

- Missing required fields (principal, rate, or period) returns 400 validation error
- Invalid compounding frequency value returns 400
- Negative principal or rate may return 422 or unexpected results
- Request times out if server is overloaded — retry recommended
- Payment failure returns 402 if x402 wallet balance is insufficient

## How this service works

Interest calculator, compound interest, simple interest, loan payment, mortgage calculator, annuity, APR APY, future value, present value, investment return. Compute simple/compound interest or annuity loan payments with configurable compounding frequency. Accepts payment on Base or Solana — either network works.

## Output

Returns computed financial values including interest amount, total payment or balance, future or present value, APR, APY, and periodic payment amount depending on the calculation type requested

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "n": {
       "type": "string",
       "description": "N (optional)"
      },
      "rate": {
       "type": "string",
       "description": "Rate (optional)"
      },
      "type": {
       "type": "string",
       "description": "Type (optional)"
      },
      "years": {
       "type": "string",
       "description": "Years (optional)"
      },
      "principal": {
       "type": "string",
       "description": "Principal (optional)"
      }
     }
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/api-x402node-dev-32c874d2/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.x402node.dev](https://www.zero.xyz/host/api.x402node.dev/llms.txt)