# Delx ETH Up/Down 30-Minute Probability

> Delx ETH Up/Down 30-Minute Probability is a paid API for AI agents from api.delx.ai, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-15).

Estimates the probability that Ethereum's price will be up or down in a 30-minute window using caller-supplied historical observations and optional market share pricing context.

## Facts

- Endpoint: POST https://api.delx.ai/api/v1/x402/ethereum-up-down-30m
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/delx-eth-up-down-30-minute-probability-200a28d7
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_BNOvo3dx3O32HnyuswPtK

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-eth-up-down-30-minute-probability-200a28d7 -d '<json body>'
```

Example prompt: I have 12 recent ETH price observations from the last hour — can you estimate the probability that ETH will be up or down in the next 30 minutes, with the window opening at $3,250.00 and closing at timestamp 1720000000? Also include UP share price of 0.55 and DOWN share price of 0.45 with a 100 bps fee so I can see the model edge.

## When to prefer this

Choose this endpoint when you need a wide-context ETH directional probability estimate using your own historical price series (8–240 observations) rather than relying on live market data. It is ideal for prediction market edge analysis when you can supply UP/DOWN share prices and entry fees. Prefer it over shorter-context siblings in the Delx family when you have rich historical data and want the most informed conservative estimate. Use it when you need a deterministic, reproducible result for the same input — useful for backtesting or auditing prediction logic.

## Known failure modes

- Fewer than 8 observations provided — request rejected with validation error
- Observations array exceeds 240 items — schema validation failure
- window_open_price or window_close_timestamp missing — may degrade or reject estimate
- Payment not provided or insufficient USDC via x402 — 402 Payment Required response
- market_up_price + market_down_price do not sum to ~1 — edge comparison may be skewed
- Timestamps not ordered or not Unix integers — input quality score degraded, warnings returned
- Price values outside allowed range (below 1e-12 or above 1e15) — rejected by schema validation

## How this service works

Ethereum Up or Down 30-Minute Probability estimates p_up and p_down for half-hour windows using the widest caller-supplied context in this family. Send 8-240 ordered caller-supplied ETH price observations, the target venue's opening price, and its close timestamp; optionally include UP/DOWN share prices and entry fees for a descriptive model-edge comparison. Returns a conservative probability pair, lean, input-quality score, model contract, and warnings for $0.003 USDC via x402 on Base or Solan…

## Output

Returns a JSON object containing: asset identifier (ETH), probability pair (p_up, p_down) as floats summing to 1, a directional lean ('up' or 'down'), a data quality score and label, number of observations used, model contract metadata (version, calibration status, determinism flags), horizon in minutes (30), input provenance label, and an array of warnings (e.g. uncalibrated probability, not trading advice).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "fee_bps": {
   "type": "integer",
   "maximum": 1000,
   "minimum": 0
  },
  "observations": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "timestamp",
     "price"
    ],
    "properties": {
     "price": {
      "type": "number",
      "maximum": 1000000000000000,
      "minimum": 1e-12
     },
     "timestamp": {
      "type": "integer",
      "minimum": 1
     }
    },
    "additionalProperties": false
   },
   "maxItems": 240,
   "minItems": 8
  },
  "market_up_price": {
   "type": "number",
   "maximum": 1,
   "minimum": 0
  },
  "market_down_price": {
   "type": "number",
   "maximum": 1,
   "minimum": 0
  },
  "window_open_price": {
   "type": "number",
   "maximum": 1000000000000000,
   "minimum": 1e-12
  },
  "window_close_timestamp": {
   "type": "integer",
   "minimum": 1
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "asset": "ETH",
  "model": {
   "version": "delx-local-updown-v1",
   "no_live_market_data": true,
   "probability_is_uncalibrated": true,
   "deterministic_for_same_input": true
  },
  "schema": "delx/prediction-updown-estimate/v1",
  "status": "estimate",
  "estimate": {
   "lean": "up",
   "p_up": 0.800833,
   "p_down": 0.199167
  },
  "warnings": [
   "caller_supplied_prices_not_verified",
   "probability_is_uncalibrated",
   "not_trading_advice"
  ],
  "data_quality": {
   "label": "adequate_input_coverage",
   "score": 0.758333,
   "observations_used": 8
  },
  "horizon_minutes": 30,
  "input_provenance": "caller_supplied"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-eth-up-down-30-minute-probability-200a28d7/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)