Annuity Present / Future Value

Compute the present or future value of an ordinary annuity or annuity-due.

Free tier eligible — 500 calls/month with a free key from /pricing; x402 pay-per-call above quota.

Parameters

Parameter	Type	Required	Description
`mode`	string	optional	pv or fv One of: pv, fv
`payment`	number	required	Payment per period
`rate`	number	required	Rate per period as a decimal
`periods`	integer	required	Number of periods
`due`	boolean	optional	True for annuity-due (default ordinary)

Call it over MCP (JSON-RPC 2.0)

curl -s https://wingmanprotocol.com/mcp \
  -H 'Content-Type: application/json' \
  -H 'Accept: application/json, text/event-stream' \
  -d '{"jsonrpc": "2.0", "id": 1, "method": "tools/call", "params": {"name": "annuity", "arguments": {"payment": 80000, "rate": 0.07, "periods": 10}}}'

Or plain HTTP

curl -s https://wingmanprotocol.com/tools/annuity \
  -H 'Content-Type: application/json' \
  -d '{"payment": 80000, "rate": 0.07, "periods": 10}'

Try it live

Edit the JSON and run it — this POSTs to https://wingmanprotocol.com/tools/annuity from your browser.

This tool is x402-metered — agents pay per call with USDC on Base. The 402 response below is the standard x402 payment-requirements envelope: sign the EIP-3009 authorization and retry with the X-Payment header, or get a free key at /pricing (500 calls/month, no card, no crypto).