# finmath Future Value of Annuity

> finmath Future 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 2026-09-13).

Calculates the future value of an ordinary annuity or annuity-due given a periodic payment, number of periods, and interest rate per period.

## Facts

- Endpoint: POST https://finmath.qzqh5rrbkz.workers.dev/v1/fv_annuity
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/finmath-future-value-of-annuity-c9965998
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_1bkbl47zk6_Sr9RQ9YXXa

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-future-value-of-annuity-c9965998 -d '<json body>'
```

Example prompt: What will my annuity be worth at the end if I make monthly payments of $500 for 10 years (120 periods) at a monthly rate of 0.4167%? Assume it's an ordinary annuity (not due).

## When to prefer this

Use this endpoint when you need exact, deterministic future value of annuity arithmetic — especially when LLM-native math is unreliable for financial calculations. Prefer over manual calculation or LLM approximation when precision matters for financial planning, retirement projections, or structured product analysis. Works for both ordinary annuities and annuities-due via the 'due' flag.

## Known failure modes

- Missing required fields (payment, n_periods, rate_per_period) returns a 400 or validation error
- Non-numeric inputs for numeric fields cause a schema validation failure
- Negative rate_per_period may produce unexpected or mathematically undefined results
- Zero n_periods returns a trivial result or may error
- Payment gateway failure (x402) if USDC payment cannot be processed

## 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 future value of the annuity as a number, plus a 'meta' object with computation metadata such as the formula used and input echo.

## Example request

```json
{
 "due": false,
 "payment": 1000,
 "n_periods": 10,
 "rate_per_period": 0.05
}
```

## 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-future-value-of-annuity-c9965998/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)