# Future Value Calculator (finance.openverbs.com)

> Future Value Calculator (finance.openverbs.com) is a paid API for AI agents from finance.openverbs.com, paid per call via x402, $0.004/call, status unknown (last checked 2026-09-15).

Calculates the future value of a present lump sum and/or a level periodic payment (annuity), given a per-period interest rate and number of periods, with support for annuity-due timing.

## Facts

- Endpoint: POST https://finance.openverbs.com/v1/future-value
- Price: $0.004/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/future-value-calculator-finance-openverbs-com-c2a1bcc1
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_HLwbFehM3qUS6apgHWpIo

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 future-value-calculator-finance-openverbs-com-c2a1bcc1 -d '<json body>'
```

Example prompt: If I invest $5,000 today and add $200 every month for 15 years at a 6% annual rate (so 0.5% per period), what will my investment be worth at the end?

## When to prefer this

Choose this endpoint when you need a standard time-value-of-money future value calculation for a lump sum, a level annuity, or a combination of both. It handles both ordinary annuity and annuity-due conventions via the dueAtBeginning flag. Prefer it over general compound interest endpoints when periodic payments are involved, and over NPV/IRR endpoints when you are projecting forward rather than discounting cash flows.

## Known failure modes

- Missing required fields (ratePercent or periods) returns a validation error
- periods exceeding 100,000 or ratePercent outside -99 to 1000 range returns a 400 bad request
- Negative interest rates near -99% may produce near-zero or unexpected results
- Non-integer periods value is rejected by the schema
- Incorrect bodyType (not json/form-data/text) causes a request format error
- Payment/presentValue not provided defaults to 0, which may produce a trivial result if the caller forgets to include them

## How this service works

Future value of a present sum and/or a level annuity, given a per-period rate and number of periods. Set dueAtBeginning=true for an annuity-due (payments at the start of each period).

## Output

A computed future value figure representing how much a present sum and/or a series of level periodic payments will be worth after a given number of compounding periods at the specified per-period interest rate. The response reflects ordinary annuity (end-of-period payments) or annuity-due (beginning-of-period payments) depending on the dueAtBeginning flag.

## 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",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object",
     "required": [
      "ratePercent",
      "periods"
     ],
     "properties": {
      "payment": {
       "type": "number",
       "description": "Level payment per period (annuity). Default 0."
      },
      "periods": {
       "type": "integer",
       "maximum": 100000,
       "minimum": 0,
       "description": "Number of periods."
      },
      "ratePercent": {
       "type": "number",
       "maximum": 1000,
       "minimum": -99,
       "description": "Interest rate per period, as a percentage."
      },
      "presentValue": {
       "type": "number",
       "description": "Present lump sum. Default 0."
      },
      "dueAtBeginning": {
       "type": "boolean",
       "description": "Annuity-due (payments at period start). Default false."
      }
     },
     "additionalProperties": false
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/future-value-calculator-finance-openverbs-com-c2a1bcc1/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from finance.openverbs.com](https://www.zero.xyz/host/finance.openverbs.com/llms.txt)