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

# perpsAtOpenInterestCap | Hyperliquid Info API

> Hyperliquid perpsAtOpenInterestCap: list the perp assets currently at their open-interest cap.

> [card] Credit Cost
>
> 1 per call

> [card] Processing
>
> Realtime

The Hyperliquid info endpoint with `type: "perpsAtOpenInterestCap"` is used to list the perp assets currently at their open-interest cap.

> [!TIP]
>
> Estimate your monthly cost for this API using the [Pricing Calculator](https://goldrush.dev/docs/pricing-calculator.md?endpoint=%2Fapi-reference%2Fhyperliquid-info%2Fperps-at-open-interest-cap).

> [!NOTE]
>
> * Wire-equal to `POST api.hyperliquid.xyz/info` with `{"type": "perpsAtOpenInterestCap"}`.
> * While an asset is in this list it has reached its open-interest cap; orders that would increase aggregate open interest are rejected (see the `openInterestCap*` order-rejection reasons) until open interest falls back below the cap.
> * This is a global, non-user-keyed type refreshed continuously from upstream Hyperliquid.

Returns the list of perpetual assets that are currently at their open-interest cap, as an array of coin symbol strings. Use it to detect which markets are constrained before placing orders that would add open interest.

## Endpoint

```
POST https://hypercore.goldrushdata.com/info
Authorization: Bearer <GOLDRUSH_API_KEY>
Content-Type: application/json
```

## Request

**type** `string` *required*

Always `"perpsAtOpenInterestCap"`.

### Example

```bash cURL theme={null}
curl -X POST https://hypercore.goldrushdata.com/info \
  -H "Authorization: Bearer $GOLDRUSH_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "type": "perpsAtOpenInterestCap"
  }'
```

```typescript TypeScript theme={null}
const response = await fetch("https://hypercore.goldrushdata.com/info", {
  method: "POST",
  headers: {
    "Authorization": `Bearer ${process.env.GOLDRUSH_API_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    type: "perpsAtOpenInterestCap",
  }),
});

const cappedPerps = await response.json();
```

```python Python theme={null}
import os, requests

response = requests.post(
    "https://hypercore.goldrushdata.com/info",
    headers={"Authorization": f"Bearer {os.environ['GOLDRUSH_API_KEY']}"},
    json={"type": "perpsAtOpenInterestCap"},
)

capped_perps = response.json()
```

## Response

An array of coin symbol strings for the perp assets currently at their open-interest cap. Empty when no market is capped.

```json theme={null}
["CANTO", "FTM", "JELLY", "LOOM", "RLB", "ZEREBRO"]
```

### Field descriptions

**\[n]** `string`

Coin symbol of a perp asset currently at its open-interest cap.

## Related endpoints

> [card] [allPerpMetas](https://goldrush.dev/docs/api-reference/hyperliquid-info/all-perp-metas.md)
>
> fetch the perpetuals metadata — universe definitions and margin tables — for every perp DEX in a single request.

> [card] [perpDeployAuctionStatus](https://goldrush.dev/docs/api-reference/hyperliquid-info/perp-deploy-auction-status.md)
>
> fetch the current perp-deploy Dutch-auction status.

> [card] [perpDexLimits](https://goldrush.dev/docs/api-reference/hyperliquid-info/perp-dex-limits.md)
>
> fetch the open-interest, position-size, and transfer limits for a HIP-3 perp DEX.

> [card] [perpDexs](https://goldrush.dev/docs/api-reference/hyperliquid-info/perp-dexs.md)
>
> enumerate every HIP-3 builder-deployed perpetual DEX on HyperCore.

See all Hyperliquid endpoints: [Overview hub](https://goldrush.dev/docs/goldrush-hyperliquid/overview.md) · [Info API reference](https://goldrush.dev/docs/goldrush-hyperliquid/info-api/overview.md)

*Last reviewed: 2026-08-17*


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