# Usenami Cross-Venue Aggregate BBO for Crypto Perpetuals

> Usenami Cross-Venue Aggregate BBO for Crypto Perpetuals is a paid API for AI agents from api.usenami.io, paid per call via x402, $0.002/call, status down (last checked 2026-10-18).

Returns the consolidated best bid and offer (BBO) across all tracked CEX and DEX perpetual venues for a given crypto symbol, identifying which venue holds each side.

## Facts

- Endpoint: GET https://api.usenami.io/v1/orderbook/aggregate/:symbol?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: down
- Last checked: 2026-10-18
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/usenami-cross-venue-aggregate-bbo-for-crypto-perpetuals-992f6d87
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_fq7aWocNuadlAj0hW-mlh

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-cross-venue-aggregate-bbo-for-crypto-perpetuals-992f6d87
```

Example prompt: What's the best bid and ask for BTC-PERP right now across all tracked CEX and DEX venues, and which exchange is holding each side?

## When to prefer this

Choose this endpoint when you need a single, authoritative cross-venue best bid/offer for a crypto perpetual without manually querying each exchange. It is ideal when comparing CEX and DEX liquidity simultaneously, detecting arbitrage opportunities between venues, or routing an order to the best available price. Prefer over single-venue top-of-book endpoints (also available on Usenami) when the goal is market-wide price discovery rather than venue-specific depth.

## Known failure modes

- Unknown or unsupported symbol returns a 404 or error response
- Symbol format mismatch (e.g. wrong delimiter) causes no data returned
- Temporary venue connectivity issues may result in partial BBO with fewer venues covered
- Rate limiting or payment failure returns 402 or 429 error
- Stale data if a venue feed is lagging, resulting in outdated bid/ask prices

## How this service works

Consolidated best bid and ask for one crypto perpetual across every tracked venue — the cross-venue BBO, and which venue holds each side. CEX and DEX perp venues in one quote.

## Output

A snapshot of the consolidated best bid price and best ask price for the requested perpetual symbol, along with the name of the venue holding the best bid and the venue holding the best ask, drawn from both CEX and DEX perpetual markets tracked by Usenami.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/usenami-cross-venue-aggregate-bbo-for-crypto-perpetuals-992f6d87/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)