---
title: "Net present value and internal rate of return for a cash-flow series (index 0 = today, usually a negative outlay), plus the profitability index and an accept/reject call."
method: POST
path: "/v1/investing/npv-irr"
tags: ["Investing"]
---

# Net present value and internal rate of return for a cash-flow series (index 0 = today, usually a negative outlay), plus the profitability index and an accept/reject call.

`POST /v1/investing/npv-irr`

## Request

- Base URL: `` (relative, and it does not resolve against the document’s source URL)
- URL: `/v1/investing/npv-irr`
- Auth: none declared

Net present value and internal rate of return for a cash-flow series (index 0 = today, usually a negative outlay), plus the profitability index and an accept/reject call.

Payment: x402 ($0.05 USDC on eip155:8453). Call unpaid to receive an HTTP 402 with requirements, then retry with the PAYMENT-SIGNATURE header. Method: NPV = Σ CFₜ/(1+r)ᵗ at your discount rate; IRR = the rate where NPV = 0 (bisection); profitability index = (NPV - CF₀)/-CF₀

## Request body

- object
  - `cashFlows` number[], required
  - `discountRatePct` number

## Response `200`

Verified result + provenance (formula, sources, reproducible SHA-256 hash).

## Other responses

- `400`: Invalid input (no charge) — body echoes the JSON Schema.
- `402`: Payment required — PAYMENT-REQUIRED header carries the x402 accepts[] quote.

---

[API](https://skmtc.dev/x402toll/apis/tollbooth-verified-calculators-for-ai-agents.md) · [All operations](https://skmtc.dev/x402toll/apis/tollbooth-verified-calculators-for-ai-agents/llms.txt) · [OpenAPI document](https://skmtc.dev/x402toll/apis/tollbooth-verified-calculators-for-ai-agents/revisions/60cb70a3e1a5?raw)