# Agent402 Perpetuals Open Interest

> Agent402 Perpetuals Open Interest is a paid API for AI agents from agent402.tools, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Fetches live perpetual futures open interest data across markets from Hyperliquid, optionally filtered to a single coin, ranked by size

## Facts

- Endpoint: POST https://agent402.tools/api/perp-open-interest
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agent402-perpetuals-open-interest-6fca4199
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_eToeoXEMY4-3CWoN23yYH

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 agent402-perpetuals-open-interest-6fca4199 -d '<json body>'
```

Example prompt: Show me the top 10 perpetual futures markets ranked by open interest right now — I want to see the mark price, open interest in USD, and each market's share of total OI.

## When to prefer this

Choose this endpoint when you need real-time perpetual futures open interest data sourced from Hyperliquid, especially for ranking markets by size or checking a specific coin's OI. Prefer this over CEX-based alternatives when you need on-chain/DeFi perp data without API key setup, and when you want normalized USD-denominated OI with volume and market-share metrics in a single call.

## Known failure modes

- Invalid coin ticker returns empty markets array or 404-equivalent error
- limit exceeding 500 returns validation error
- Hyperliquid data feed temporarily unavailable returns upstream error
- Malformed request body returns 400 with schema validation message

## How this service works

Open interest for one perpetual in coins and USD notional with its share of the venue total, or the top N contracts ranked by open interest plus the venue total. Use it when an agent needs positioning size for a market or a leaderboard of where leverage is concentrated right now.

## Output

A JSON object with the data source ('hyperliquid'), a timestamp, total open interest in USD across all markets, and an array of market objects each containing the coin ticker, mark price, open interest in contracts and USD, 24h volume in USD, and that market's percentage share of total open interest. Results are ranked by open interest when no specific coin is requested.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "coin": {
   "type": "string",
   "description": "Optional perp ticker for a single market (e.g. BTC)."
  },
  "limit": {
   "type": "number",
   "description": "Rows when ranking (default 20, max 500)."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "source": "hyperliquid",
  "markets": [
   {
    "coin": "BTC",
    "markPx": 77267,
    "openInterest": 35935.67,
    "volume24hUsd": 4679441788.67,
    "openInterestUsd": 2776803000,
    "shareOfTotalPct": 29.2
   }
  ],
  "fetchedAt": "2026-08-22T12:00:00.000Z",
  "totalOpenInterestUsd": 9500000000
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agent402-perpetuals-open-interest-6fca4199/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agent402.tools](https://www.zero.xyz/host/agent402.tools/llms.txt)