# finmath Bond Convexity Calculator

> finmath Bond Convexity Calculator is a paid API for AI agents from finmath.qzqh5rrbkz.workers.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-13).

Computes the convexity of a bond given face value, coupon rate, yield, maturity, and payment frequency

## Facts

- Endpoint: POST https://finmath.qzqh5rrbkz.workers.dev/v1/bond_convexity
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/finmath-bond-convexity-calculator-195b8fd0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_a5i1nRkGXxQjlllVCqhBK

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-bond-convexity-calculator-195b8fd0 -d '<json body>'
```

Example prompt: Calculate the convexity of a $1,000 face value bond with a 5% annual coupon rate, 4% annual yield, 10 years to maturity, and semi-annual payments (freq=2).

## When to prefer this

Use this endpoint when you need exact, deterministic bond convexity arithmetic rather than relying on LLM estimation. Ideal for interest rate risk management, duration-convexity hedging strategies, bond pricing analytics, or any fixed income workflow where numerical precision is critical.

## Known failure modes

- Missing required fields (face, coupon_rate, or annual_yield) returns a validation error
- Negative yield or coupon values may produce unexpected results or errors
- Zero years to maturity or zero frequency may cause division-by-zero
- Payment is required in USDC via x402 protocol; missing payment returns 402 Payment Required

## 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 result object containing the computed bond convexity value (a dimensionless measure of the curvature of the price-yield relationship), plus a meta object with calculation details such as inputs echoed back and any auxiliary values.

## Example request

```json
{
 "face": 1000,
 "freq": 2,
 "years": 10,
 "coupon_rate": 0.05,
 "annual_yield": 0.04
}
```

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "face",
  "coupon_rate",
  "annual_yield"
 ],
 "properties": {
  "face": {
   "type": "number",
   "description": "face"
  },
  "freq": {
   "type": "number",
   "description": "freq"
  },
  "years": {
   "type": "number",
   "description": "years"
  },
  "coupon_rate": {
   "type": "number",
   "description": "coupon_rate"
  },
  "annual_yield": {
   "type": "number",
   "description": "annual_yield"
  }
 }
}
```

## 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-bond-convexity-calculator-195b8fd0/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)