# Hyperextend HIP-4 Outcome Open Interest (Per-Minute)

> Hyperextend HIP-4 Outcome Open Interest (Per-Minute) is a paid API for AI agents from api.hyperextend.xyz, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Returns per-minute two-sided open interest (notional) for a specified HIP-4 outcome market on Hyperliquid, queryable over any time window.

## Facts

- Endpoint: GET https://api.hyperextend.xyz/v1/outcome/%7Boutcome%7D/oi
- 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/hyperextend-hip-4-outcome-open-interest-per-minute-484f1632
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_WNQswB5IwZJSioxNuY2KI

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 hyperextend-hip-4-outcome-open-interest-per-minute-484f1632
```

Example prompt: Pull the per-minute open interest history for Hyperliquid HIP-4 outcome market 100 for the last 500 data points so I can see how notional OI has been trending.

## When to prefer this

Use this endpoint when you need granular, per-minute open interest data specifically for HIP-4 outcome (prediction) markets on Hyperliquid. Prefer this over generic perp OI endpoints when dealing with outcome/event markets rather than standard perpetual futures.

## Known failure modes

- Invalid or non-existent outcome market ID returns 404 or empty result
- Missing required path parameter 'outcome' returns 400 bad request
- start/end timestamps out of valid range return empty array
- Rate limiting or payment failure via x402 returns 402 Payment Required
- Requesting a limit that exceeds server maximum may return truncated or error response

## How this service works

Per-minute Hyperliquid market history: open interest, candles, trades, liquidations, HIP-3, spot and outcome markets. Query any window, pay per request over x402.

## Output

Returns a JSON array of per-minute records, each containing: the number of market sides, the minute-level Unix timestamp, and the notional open interest value (e.g. {sides: 2, minute_ts: 1700000000, oi_notional: '12345.6'}).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "pathParams": {
     "type": "object",
     "required": [
      "outcome"
     ],
     "properties": {
      "outcome": {
       "type": "string",
       "description": "HIP-4 outcome market id (integer), e.g. 100"
      }
     }
    },
    "queryParams": {
     "type": "object",
     "required": [],
     "properties": {
      "end": {
       "type": "integer"
      },
      "limit": {
       "type": "integer"
      },
      "start": {
       "type": "integer"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "sides": 2,
  "minute_ts": 1700000000,
  "oi_notional": "12345.6"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/hyperextend-hip-4-outcome-open-interest-per-minute-484f1632/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.hyperextend.xyz](https://www.zero.xyz/host/api.hyperextend.xyz/llms.txt)