# Usenami Top-of-Book Orderbook (Single Venue)

> Usenami Top-of-Book Orderbook (Single Venue) is a paid API for AI agents from api.usenami.io, paid per call via x402, $0.001/call, status down (last checked 2026-10-18).

Returns the best bid, best ask, and spread for a single crypto perpetual on a specific CEX or DEX venue in real time.

## Facts

- Endpoint: GET https://api.usenami.io/v1/orderbook/:venue/:symbol/top?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: down
- Last checked: 2026-10-18
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/usenami-top-of-book-orderbook-single-venue-df65dbbc
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_4M_18A2MKia8IYDHwiH-G

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 usenami-top-of-book-orderbook-single-venue-df65dbbc
```

Example prompt: What's the current best bid and ask — and the spread between them — for BTC-PERP on Hyperliquid right now?

## When to prefer this

Use this endpoint when you need a fast, low-cost, single-venue top-of-book snapshot for a specific crypto perpetual — ideal for pre-trade checks, spread monitoring, or real-time price feeds. If you need cross-venue spread comparison or sized-depth slippage at specific notional sizes, use the corresponding Usenami sibling endpoints instead.

## Known failure modes

- Unknown venue name returns an error — must use a supported venue slug (e.g. binance, bybit, hyperliquid, drift)
- Invalid or unsupported symbol returns an error
- Network or exchange connectivity issues may cause stale or missing data
- Payment failure (x402 protocol) blocks the response if USDC is not available

## How this service works

Top-of-book for one crypto perpetual on one venue — best bid, best ask and the spread between them. Covers CEX and DEX perp venues: Binance, Bybit, OKX, Hyperliquid, Paradex, Drift and others.

## Output

Returns the top-of-book for the requested venue and symbol: the best bid price, best ask price, and the spread (ask minus bid) between them, reflecting real-time market conditions.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/usenami-top-of-book-orderbook-single-venue-df65dbbc/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.usenami.io](https://www.zero.xyz/host/api.usenami.io/llms.txt)