# Hyperliquid Perps Open Interest Lookup

> Hyperliquid Perps Open Interest Lookup is a paid API for AI agents from x402-services-production.up.railway.app, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-14).

Returns open interest (with USD notional) for a specific perpetuals coin on Hyperliquid, or lists the top perp markets ranked by open interest.

## Facts

- Endpoint: POST https://x402-services-production.up.railway.app/api/perps/oi
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/hyperliquid-perps-open-interest-lookup-0fc58aa4
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_2NWYCvAY8xqvOUrblnCFa

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 hyperliquid-perps-open-interest-lookup-0fc58aa4 -d '<json body>'
```

Example prompt: What's the current open interest for BTC perps on Hyperliquid, including the USD notional value? Also show me the top 15 markets ranked by OI.

## When to prefer this

Use this endpoint when you need open interest data specifically from Hyperliquid perpetuals — either for a single coin's positioning depth or to rank top perp markets by OI. Prefer this over generic market data APIs when the user explicitly needs Hyperliquid-specific derivatives positioning or liquidity context.

## Known failure modes

- Unknown or unsupported coin symbol returns an error or empty result
- Limit exceeding 50 is clamped or rejected
- Hyperliquid data feed unavailable causes service error
- Malformed request body (wrong types) returns 400-level error

## How this service works

Open interest for a coin (with USD notional) or the top perps by open interest across Hyperliquid. Send { coin } or { limit }. Positioning & liquidity depth for derivatives agents.

## Output

Returns open interest figures for the queried coin (including USD notional value), or a ranked list of up to 50 perp markets by open interest, with per-market OI and USD notional figures — useful for assessing positioning and liquidity depth in Hyperliquid derivatives markets.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "coin": {
   "type": "string",
   "description": "Perp symbol; omit to list top markets by OI"
  },
  "limit": {
   "type": "number",
   "description": "Max markets when listing, default 15 (max 50)"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/hyperliquid-perps-open-interest-lookup-0fc58aa4/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-services-production.up.railway.app](https://www.zero.xyz/host/x402-services-production.up.railway.app/llms.txt)