# finmath Present Value of Annuity

> finmath Present Value of Annuity is a paid API for AI agents from finmath.qzqh5rrbkz.workers.dev, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Computes the present value (PV) of an ordinary or due annuity given a fixed periodic payment, number of periods, and interest rate per period.

## Facts

- Endpoint: POST https://finmath.qzqh5rrbkz.workers.dev/v1/pv_annuity
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/finmath-present-value-of-annuity-0e86a26c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_xgRe2u8640ejvHLyPj_xI

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 finmath-present-value-of-annuity-0e86a26c -d '<json body>'
```

Example prompt: What's the present value of an annuity that pays $1,200 per month for 60 months at a monthly interest rate of 0.4%? It's an ordinary annuity (payments at end of period).

## When to prefer this

Use this endpoint when you need exact, deterministic annuity present value calculations — especially in agentic workflows where LLM arithmetic is unreliable. Ideal for loan valuation, lease pricing, pension lump-sum equivalence, or bond coupon discounting when you already know the periodic payment, number of periods, and rate per period.

## Known failure modes

- Missing required fields (payment, n_periods, rate_per_period) returns a 4xx validation error
- Zero or negative rate_per_period may produce mathematically degenerate results
- Non-positive n_periods returns an error or zero
- Payment request without USDC authorization returns HTTP 402 Payment Required
- Very large n_periods or extreme rates may cause floating-point edge cases

## How this service works

Deterministic finance and crypto math for AI agents: TradFi (NPV, IRR, XIRR, Black-Scholes + Greeks, bonds, VaR, Sharpe) and DeFi (impermanent loss, perp liquidation, funding, Uniswap v3, health factor, cost basis). Exact, model-free arithmetic that LLMs get wrong — priced per call in USDC.

## Output

Returns a JSON object with a 'result' field containing the computed present value of the annuity (a single numeric value), and a 'meta' field with supporting metadata about the calculation.

## Example request

```json
{
 "due": false,
 "payment": 1200,
 "n_periods": 60,
 "rate_per_period": 0.004
}
```

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "payment",
  "n_periods",
  "rate_per_period"
 ],
 "properties": {
  "due": {
   "type": "boolean",
   "description": "due"
  },
  "payment": {
   "type": "number",
   "description": "payment"
  },
  "n_periods": {
   "type": "number",
   "description": "n_periods"
  },
  "rate_per_period": {
   "type": "number",
   "description": "rate_per_period"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "result",
  "meta"
 ],
 "properties": {
  "meta": {
   "type": "object"
  },
  "result": {}
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/finmath-present-value-of-annuity-0e86a26c/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from finmath.qzqh5rrbkz.workers.dev](https://www.zero.xyz/host/finmath.qzqh5rrbkz.workers.dev/llms.txt)