Investment Fee Impact Calculator

How much an expense ratio costs over time — ending balance with vs without fees, and total fee drag.

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

Parameters

Parameter	Type	Required	Description
`initial_investment`	number	required	Starting investment in USD
`years`	number	required	Investment horizon in years
`annual_contribution`	number	optional	Amount added each year in USD
`gross_return`	number	optional	Gross annual return before fees as a PERCENT (default 7)
`expense_ratio`	number	optional	Annual fee/expense ratio as a PERCENT (default 0.5)

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": "investment_fee", "arguments": {"initial_investment": 100, "years": 30}}}'

Or plain HTTP

curl -s https://wingmanprotocol.com/tools/investment_fee \
  -H 'Content-Type: application/json' \
  -d '{"initial_investment": 100, "years": 30}'

Try it live

Edit the JSON and run it — this POSTs to https://wingmanprotocol.com/tools/investment_fee 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).