> ## Documentation Index
> Fetch the complete documentation index at: https://docs.0xarchive.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Get current HIP-4 open interest JSON Schema

> Get current HIP-4 open interest JSON Schema contract. Includes parameters, response shapes, examples, and implementation notes from the 0xArchive contract.

Source OpenAPI: 0xArchive API 1.5.0; 140 paths; 119 component schemas.

Get the latest per-side open interest value for a HIP-4 outcome side. Mirrors HIP-3 OI shape plus `outcome_id` and `side` fields. Note: `mark_price` for HIP-4 outcomes is an implied probability in \[0,1], not a USD price; same field name as perps because Hyperliquid upstream uses `markPx` for both.

## Route Metadata

| Field                | Value                                                |
| -------------------- | ---------------------------------------------------- |
| Method               | `GET`                                                |
| Path                 | `/v1/hyperliquid/hip4/openinterest/{symbol}/current` |
| operationId          | `getCurrentHip4OpenInterest`                         |
| Tag                  | HIP-4 Outcomes - Open Interest                       |
| Family               | HIP-4                                                |
| Deprecated or legacy | no                                                   |

## Request Parameters

### Path Parameters

```json theme={"theme":"github-dark"}
{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "getCurrentHip4OpenInterest path parameters",
  "type": "object",
  "required": [
    "symbol"
  ],
  "properties": {
    "symbol": {
      "description": "HIP-4 coin id (e.g., `0` for outcome 0 Yes side, `1` for No side). The `#`-prefixed form (`#0`, `#1`) is also accepted.",
      "type": "string",
      "example": "0",
      "x-parameter-location": "path"
    }
  }
}
```

## Response Contracts

### Status 200

Current open interest

#### application/json

```json theme={"theme":"github-dark"}
{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "getCurrentHip4OpenInterest response 200",
  "description": "API response wrapping a single HIP-4 per-side open-interest record",
  "type": "object",
  "properties": {
    "data": {
      "description": "HIP-4 per-side open-interest record. Mirrors the HIP-3 OI shape and adds `outcome_id` and `side`. `oracle_price` is omitted for HIP-4 (outcomes have no oracle feed). Note: `mark_price` is an implied probability in [0,1], not a USD price; same field name as perps because Hyperliquid upstream uses `markPx` for both.",
      "type": "object",
      "required": [
        "coin",
        "open_interest",
        "outcome_id",
        "side",
        "symbol",
        "timestamp"
      ],
      "properties": {
        "coin": {
          "description": "`#`-prefixed per-side coin identifier",
          "type": "string",
          "example": "#0"
        },
        "mark_price": {
          "description": "Implied probability in [0,1], NOT a USD price. Same field name as perps because Hyperliquid upstream uses `markPx` for both.",
          "type": "string",
          "nullable": true,
          "example": "0.6502"
        },
        "mid_price": {
          "description": "Mid price (probability in [0,1])",
          "type": "string",
          "nullable": true,
          "example": "0.65038"
        },
        "open_interest": {
          "description": "Open interest in contracts (notional currency: USDH)",
          "type": "string",
          "example": "568048"
        },
        "outcome_id": {
          "description": "Numeric outcome identifier",
          "type": "integer",
          "format": "int64",
          "example": 0
        },
        "side": {
          "description": "Side index: 0 = Yes, 1 = No",
          "type": "integer",
          "enum": [
            0,
            1
          ],
          "example": 0
        },
        "symbol": {
          "description": "Same value as `coin`. Provided for consistency with other venues.",
          "type": "string",
          "example": "#0"
        },
        "timestamp": {
          "description": "Snapshot timestamp (UTC)",
          "type": "string",
          "format": "date-time",
          "example": "2026-05-02T20:27:21Z"
        }
      }
    },
    "meta": {
      "description": "Response metadata",
      "type": "object",
      "properties": {
        "count": {
          "description": "Number of records returned",
          "type": "integer"
        },
        "next_cursor": {
          "description": "Cursor for pagination (timestamp). Use this value as the `cursor` parameter to fetch the next page of results.",
          "type": "string",
          "nullable": true
        },
        "request_id": {
          "description": "Unique request ID for support",
          "type": "string",
          "format": "uuid"
        }
      }
    },
    "success": {
      "type": "boolean",
      "example": true
    }
  }
}
```

### Status 400

Invalid request

#### application/json

```json theme={"theme":"github-dark"}
{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "getCurrentHip4OpenInterest response 400",
  "description": "Error response",
  "type": "object",
  "properties": {
    "code": {
      "description": "HTTP status code",
      "type": "integer"
    },
    "error": {
      "description": "Error message",
      "type": "string"
    }
  }
}
```

##### OpenAPI example

```json theme={"theme":"github-dark"}
{
  "code": 400,
  "error": "Invalid request parameters"
}
```

### Status 401

Authentication required

#### application/json

```json theme={"theme":"github-dark"}
{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "getCurrentHip4OpenInterest response 401",
  "description": "Error response",
  "type": "object",
  "properties": {
    "code": {
      "description": "HTTP status code",
      "type": "integer"
    },
    "error": {
      "description": "Error message",
      "type": "string"
    }
  }
}
```

##### OpenAPI example

```json theme={"theme":"github-dark"}
{
  "code": 401,
  "error": "Missing or invalid API key. Provide X-API-Key header."
}
```

### Status 404

Resource not found

#### application/json

```json theme={"theme":"github-dark"}
{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "getCurrentHip4OpenInterest response 404",
  "description": "Error response",
  "type": "object",
  "properties": {
    "code": {
      "description": "HTTP status code",
      "type": "integer"
    },
    "error": {
      "description": "Error message",
      "type": "string"
    }
  }
}
```

##### OpenAPI example

```json theme={"theme":"github-dark"}
{
  "code": 404,
  "error": "Resource not found"
}
```

### Status 429

Rate limit exceeded

#### application/json

```json theme={"theme":"github-dark"}
{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "getCurrentHip4OpenInterest response 429",
  "description": "Error response",
  "type": "object",
  "properties": {
    "code": {
      "description": "HTTP status code",
      "type": "integer"
    },
    "error": {
      "description": "Error message",
      "type": "string"
    }
  }
}
```

##### OpenAPI example

```json theme={"theme":"github-dark"}
{
  "code": 429,
  "error": "Rate limit exceeded"
}
```