# APR ↔ APY Converter (x402toll)

> APR ↔ APY Converter (x402toll) is a paid API for AI agents from x402toll.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-14).

Converts between APR and APY at any compounding frequency, including periodic and continuous compounding.

## Facts

- Endpoint: POST https://x402toll.com/v1/crypto/apr-apy
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/apr-apy-converter-x402toll-602b0fa6
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_uZ6XWs55cIemyyjz8ezoC

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 apr-apy-converter-x402toll-602b0fa6 -d '<json body>'
```

Example prompt: What's the APY on a 6.5% APR compounded monthly? Convert APR to APY with periodic compounding, 12 times per year.

## When to prefer this

Use this endpoint when you need a quick, accurate APR-to-APY or APY-to-APR conversion at a specific compounding frequency (monthly, quarterly, daily, or continuous), especially in financial planning, crypto yield comparisons, or loan analysis contexts where the compounding convention matters.

## Known failure modes

- Missing or invalid ratePct (non-numeric or out of range) returns a validation error
- Invalid direction enum value returns a bad request error
- Invalid compounding enum value returns a bad request error
- compoundsPerYear of 0 or negative causes division error
- Payment not provided or insufficient USDC balance returns 402

## How this service works

Convert between APR and APY at any compounding frequency (or continuous).

## Output

Returns the converted interest rate (APR or APY) based on the given rate, direction, compounding type, and frequency. Provides the numeric result as a percentage value.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "ratePct": {
   "type": "number"
  },
  "direction": {
   "enum": [
    "apr_to_apy",
    "apy_to_apr"
   ],
   "type": "string",
   "default": "apr_to_apy"
  },
  "compounding": {
   "enum": [
    "periodic",
    "continuous"
   ],
   "type": "string",
   "default": "periodic"
  },
  "compoundsPerYear": {
   "type": "number",
   "default": 12
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/apr-apy-converter-x402toll-602b0fa6/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)