# Delx Expected Log Growth

> Delx Expected Log Growth 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 expected logarithmic growth (Kelly criterion growth rate) given a bet fraction, true probability, and market price

## Facts

- Endpoint: POST https://api.delx.ai/api/v1/x402/expected-log-growth
- 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-expected-log-growth-28baf8c7
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_hmA_-wjfoozoNcSLUVWA3

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-expected-log-growth-28baf8c7 -d '<json body>'
```

Example prompt: What's the expected log growth if I bet a fraction of 0.1 with a true probability of 0.6 and a market price of 0.55?

## When to prefer this

Use this endpoint when you need to compute the Kelly-criterion-style expected log growth for a binary bet or prediction market position given a specific fraction, true probability estimate, and market price. Prefer this over manual calculation when operating in an agent pipeline that needs a fast, governed, API-accessible computation of log-utility growth. Ideal for position-sizing workflows, portfolio optimization agents, or prediction market arbitrage bots that need to evaluate the value of an edge before committing capital.

## Known failure modes

- Missing required fields (fraction, true_prob, or market_price) return a validation error
- Probabilities outside [0,1] or fractions outside valid range may produce undefined or error responses
- Market price of 0 or 1 may cause division errors or infinite log values
- Negative fraction values may return nonsensical results or errors

## How this service works

Approx expected log bankroll growth for a binary bet fraction. Call when comparing bet sizes by growth rate under true_prob (advisory). Returns expected log growth 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 conforming to schema 'delx/util-expected-log-growth/v1', containing the input fraction and the computed expected_log_growth value (a float representing the expected logarithmic portfolio growth from taking that bet at the given fraction, true probability, and market price).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "fraction": {
   "type": "number",
   "description": "Input field: fraction."
  },
  "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": {
  "schema": "delx/util-expected-log-growth/v1",
  "fraction": 0.1,
  "expected_log_growth": 0.02704230164346613
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-expected-log-growth-28baf8c7/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)