# Delx Binary Expected Value Calculator

> Delx Binary Expected Value Calculator is a paid API for AI agents from api.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Computes the expected value (EV) of a binary bet given stake, true probability, and market price

## Facts

- Endpoint: POST https://api.delx.ai/api/v1/x402/binary-ev
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/delx-binary-expected-value-calculator-787f4f68
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_I0-UpWWoxleasz7muYuQh

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-expected-value-calculator-787f4f68 -d '<json body>'
```

Example prompt: I want to place a $100 stake on a binary prediction market where I think the true probability is 60% but the market is pricing it at 48% — can you calculate the expected value and how many shares I'd get?

## When to prefer this

Use this endpoint when an AI agent needs to programmatically evaluate the profitability of a binary prediction market position before executing a trade. Prefer this over manual calculation when you need consistent, machine-readable EV outputs (including shares) as part of an automated trading or decision workflow. Best suited for agents operating in prediction market or binary options contexts where true probability estimates differ from market prices.

## Known failure modes

- Missing required fields (stake, true_prob, or market_price) result in validation error
- true_prob outside [0,1] range may produce nonsensical or error results
- market_price of 0 or 1 may cause division-by-zero or extreme share values
- Negative stake values may produce invalid output
- Non-numeric inputs for numeric fields will fail schema validation

## How this service works

Expected value of buying binary YES at market_price under true_prob. Call when deciding whether a YES buy has positive EV before size. Returns EV per $1 notional on YES 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 computed expected value (ev), the original stake, the number of shares received, and a schema identifier. For example: {"ev": 14.58, "stake": 100, "schema": "delx/util-binary-ev/v1", "shares": 208.33}.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "stake": {
   "type": "integer",
   "description": "Input field: stake."
  },
  "true_prob": {
   "type": "number",
   "description": "Input field: true prob."
  },
  "market_price": {
   "type": "number",
   "description": "Input field: market price."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ev": 14.58333333333334,
  "stake": 100,
  "schema": "delx/util-binary-ev/v1",
  "shares": 208.3333333333333
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-binary-expected-value-calculator-787f4f68/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)