# QuantOracle FX Interest Rate Parity

> QuantOracle FX Interest Rate Parity is a paid API for AI agents from api.quantoracle.dev, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-14).

Calculates covered or uncovered interest rate parity, detects FX mispricing, and identifies arbitrage opportunities between forward and theoretical forward rates.

## Facts

- Endpoint: POST https://api.quantoracle.dev/v1/fx/interest-rate-parity
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/api-quantoracle-dev-05e23a58
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_erlpg0J00WtXoFTBzR43y

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-quantoracle-dev-05e23a58 -d '<json body>'
```

Example prompt: Check covered interest rate parity for a EUR/USD spot rate of 1.085, domestic rate 5.25%, foreign rate 3.75%, over 1 year — the actual forward rate on offer is 1.07, and I want to know if it's mispriced and what the arbitrage profit would be.

## When to prefer this

Use this endpoint when you need a fast, programmatic check of interest rate parity conditions for a specific currency pair — particularly when you have a concrete forward rate to benchmark against the theoretical value and want to detect arbitrage or carry trade opportunities. Prefer this over manual spreadsheet calculations or generic financial data APIs that don't perform the full covered/uncovered parity analysis with arbitrage profit quantification.

## Known failure modes

- Missing required fields (spot_rate, domestic_rate, foreign_rate, time_years) returns a 400 error
- Invalid parity_type value (not 'covered' or 'uncovered') causes a validation error
- Negative or zero time_years may produce nonsensical results or an error
- actual_forward is optional for uncovered parity but required for mispricing detection — omitting it may result in null arbitrage fields
- Payment failure via x402 protocol returns a 402 Payment Required response

## How this service works

QuantOracle: fx/interest-rate-parity

## Output

Returns the theoretical forward rate, whether the market rate is mispriced, the arbitrage profit in absolute and percentage terms, the forward premium percentage, the recommended carry direction (e.g. BORROW_FOREIGN), and the annualized carry yield. Response time is typically under 10ms.

## Example request

```json
{
 "spot_rate": 1.085,
 "time_years": 1,
 "parity_type": "covered",
 "foreign_rate": 0.0375,
 "domestic_rate": 0.0525,
 "actual_forward": 1.07
}
```

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "spot_rate": {
   "type": "number",
   "title": "Spot Rate",
   "description": "Current spot exchange rate"
  },
  "time_years": {
   "type": "number",
   "title": "Time Years",
   "default": 1,
   "description": "Time horizon in years"
  },
  "parity_type": {
   "enum": [
    "covered",
    "uncovered"
   ],
   "type": "string",
   "title": "Parity Type",
   "default": "covered",
   "description": "Parity type: covered or uncovered"
  },
  "foreign_rate": {
   "type": "number",
   "title": "Foreign Rate",
   "description": "Foreign interest rate (annualized)"
  },
  "domestic_rate": {
   "type": "number",
   "title": "Domestic Rate",
   "description": "Domestic interest rate (annualized)"
  },
  "actual_forward": {
   "anyOf": [
    {
     "type": "number"
    },
    {
     "type": "null"
    }
   ],
   "title": "Actual Forward",
   "description": "Actual forward rate for arbitrage detection"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/api-quantoracle-dev-05e23a58/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
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