# Delx Binary Fair Price

> Delx Binary Fair Price is a paid API for AI agents from api.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Computes the fair (breakeven) price for a binary outcome given its probability, suitable for pricing binary options or bets.

## Facts

- Endpoint: POST https://api.delx.ai/api/v1/x402/binary-fair-price
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/delx-binary-fair-price-ed2e6718
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_NXv9XeOwMWSTeqwCTpwpS

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 delx-binary-fair-price-ed2e6718 -d '<json body>'
```

Example prompt: What's the fair price for a binary outcome that has a 37% chance of happening?

## When to prefer this

Use this endpoint when you need to quickly compute the theoretical fair (expected-value) price for a binary outcome from a raw probability — especially useful in prediction markets, binary options pricing, or any agent workflow that must translate a probability estimate into a fair-value monetary amount without implementing the math locally.

## Known failure modes

- Probability value outside [0,1] range may return a validation error or unexpected result
- Missing 'prob' field in request body returns an error
- Non-numeric value for 'prob' causes a schema validation failure
- Network or service unavailability returns a 5xx error

## How this service works

Map a true probability into a binary contract fair price in [0,1]. Call when pricing yes/no markets from your probability model. Returns fair price in [0,1] as deterministic JSON for $0.001 USDC via x402 on Base. First-party local math only—no RPC, live market feed, API keys, storage, or mediagen. Advisory only; the caller owns capital, risk, and production controls.

## Output

Returns a JSON object containing the echoed input probability, the computed fair price (numerically equal to the probability for a binary contract, i.e. expected value), and a schema identifier string ('delx/util-binary-fair-price/v1') confirming the calculation schema used.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "prob": {
   "type": "number",
   "description": "Input field: prob."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "prob": 0.37,
  "schema": "delx/util-binary-fair-price/v1",
  "fair_price": 0.37
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-binary-fair-price-ed2e6718/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.delx.ai](https://www.zero.xyz/host/api.delx.ai/llms.txt)