> ## Documentation Index
> Fetch the complete documentation index at: https://docs.backquant.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Cross-venue book
> Consolidated best bid and offer across every venue we collect, with the venue named on each side, plus how far apart venues are quoting the same contract.
Best bid and best offer for each contract across **every venue we collect**,
with the venue named on each side, plus how far apart those venues are quoting
the same contract.
This is not what [`/options/chain`](/api/v2/options/chain) returns. The chain's
`bid` and `ask` come from the aggregated row, which is based on a single venue.
This endpoint is the genuine best-of, and by construction its spread is never
wider than any individual venue's.
Read this as **execution quality**, not as a dislocation scanner. Across the
liquid band, cross-venue implied-vol dispersion sits *inside* the tightest
single venue's own spread roughly 70% of the time, so for the typical contract
there is nothing to capture. What the endpoint answers well is where to execute
and what it costs.
## Scope
Computed only for contracts inside the liquid band: **0.85 to 1.15 moneyness,
2 or more days to expiry**.
Outside that band implied vol stops carrying information. Deep-ITM contracts
have almost no vega, so a trivial price difference reads as tens of vol points.
Before the band was applied, the widest apparent "dislocation" in a live run was
52 vol points on a 60,000 strike with spot at 77,600, which is an artefact
rather than a signal.
Contracts quoted by a single venue are omitted, since every field here is a
comparison. A symbol with no multi-venue coverage returns `404` rather than an
empty list, because an empty list reads as "spreads are zero".
## Units
All prices are **coin-denominated**, and the response states this in
`price_unit`.
Most venues publish option premium in USD or USDT; those are converted at
ingest. Deribit quotes its linear (USDC-settled) assets in USD and is converted
the same way, while its BTC and ETH options are inverse and already coin-
denominated. Do not infer the unit from magnitude: comparing an unconverted USD
premium against a coin premium is exactly how a spread of -195% gets published.
## Reading the fields
`true` only when **two different venues** make the top of book. When `false`,
one venue is best on both sides, so the spread shown is that venue's own and
there is no consolidation benefit to report.
`true` when both sides come from a deep venue (Deribit, Bybit, OKX, Binance).
When `false` the best price is coming from a thinner venue. Still worth
seeing, but not a number to lean on.
A negative spread: one venue bidding above another's offer. Reported, never
hidden, but excluded from `median_spread_pct` so the headline is not dragged
below what trading actually costs.
The same idea on the implied-vol axis: best bid vol above best ask vol,
evaluated only between deep venues.
The comparison spans both settlement conventions. Deribit's BTC and ETH
options are inverse (coin-settled); the USDC venues are linear. Implied vol
is comparable across the two to first order, but part of any gap flagged this
way is numeraire rather than volatility.
**A crossed market is an observation, not an opportunity.** Venue quote
timestamps are collection times rather than exchange quote times, so a stale
quote on the thinner venue cannot be ruled out. Measured crossings are small,
short-dated and consistently one-directional, which points at structural causes
(settlement, index, funding) rather than anything capturable. Treat `crossed`
and `book_crossed` as venue-quality signals.
## Coverage
Venue coverage is not uniform, and the response tells you which venues actually
contributed via `venues` per contract and `coverage.venues` overall.
| | |
| -------------- | ------------------------------- |
| Deribit | Prices, no per-side implied vol |
| OKX | Per-side implied vol, no prices |
| Bybit, Binance | Both |
| Thalex, Delta | Prices, single mark vol |
A venue takes part in whichever comparison it actually supplied inputs for.
Venues missing an input are omitted rather than zero-filled, since a zero would
read as a dislocation.
BTC and ETH have the deepest coverage. SOL is thinner. Single-venue markets
return no rows at all.
## See also
## OpenAPI
````yaml GET /options/venue-book
openapi: 3.1.0
info:
title: BackQuant API v2
description: >-
# BackQuant API v2
Options + gamma-exposure focused public API. Built on the same data the
BackQuant Pro Terminal renders - pre-computed every 30s, served from cache.
## What's in v2
* **Discovery**: `/v2/symbols` (universe + per-symbol freshness + supported
endpoint list), `/v2/expiries` (active expiry tokens with DTE), `/v2/status`
(per-symbol-per-category health with thresholds + overall classification).
* **GEX**: composable levels (HVL / call wall / put support / max-pain /
expected move / gamma-flip zones), strike profile with typed expiry
filter, expiry profile, strike × expiry heatmap with downsampling,
greek time-heatmap with DTE/OI/IV filters, history (cursor-paginated),
Postgres-backed stress history, **per-expiry max-pain with pain curve**.
* **Options**: filtered options chain with two-layer projection (top-level
`?fields=` and per-contract `?include=oi,iv,greeks,bid_ask,volume,gex`)
plus moneyness filter (`?moneyness_min=0.9&moneyness_max=1.1`), expiry
summary table, full IV suite (surface / term structure / 25Δ-10Δ skew /
curves / **single-expiry smile** / IV-RV history / VRP), expected move,
**Breeden-Litzenberger probability density and surface**, typed greek
profiles (delta / theta / vanna / charm / vega), strike × time charm/vega
surfaces, strike × expiry 3D greek surface, OI by expiry + history,
put/call ratio (intraday or daily), 0DTE & weekly premium tide,
dated-futures term structure.
* **Liquidation**: heatmap + leverage-tiered distribution.
* **Multi**: `/v2/multi/gex/levels` - bundled multi-symbol read across the
universe in one round-trip, with the same `?include=` model as the
single-symbol endpoint.
## Authentication
Every v2 route (except `/v2/openapi.json`, `/v2/docs`, `/v2/redoc`, and
`/v2/health`) requires the `X-API-Key` header.
```
X-API-Key: bq_live_your_api_key_here
```
**Get your API key at
[backquant.com/api-access](https://backquant.com/api-access).**
The same key works across v1 and v2 - if you already have a v1 key, no
re-issuance is needed.
## Rate limits
Two budgets, both derived from your subscription tier: a **monthly request
allowance** per account, and a **per-minute burst** per key. Size your
integration against the monthly figure - sustained polling at the burst rate
exhausts the month early.
| Plan | Monthly allowance | Burst | Sustained |
|---------------------------|-------------------|----------|-------------|
| Starter (Terminal Yearly) | 10,000 req/month | 10/min | ~333/day |
| Standard (Crypto API) | 250,000 req/month | 60/min | ~8,300/day |
| Pro (Terminal + API) | 1,000,000/month | 120/min | ~33,000/day |
| Enterprise | custom | 600/min | custom |
Headers `X-RateLimit-Limit / -Remaining / -Reset` (burst) and
`X-Quota-Limit / -Used / -Remaining / -Period` (monthly) are included in
every response; the rate-limit triple is echoed inside `meta.rate_limit`
when populated by middleware. Exceeding either budget returns `429`.
The live ladder is served at `GET /v2/meta` under `rate_limits`.
## Response envelope
```json
{
"success": true,
"data": { ... },
"meta": {
"version": "2.0",
"timestamp": "2026-04-29T12:00:00.000Z",
"request_id": "req_…",
"symbol": "BTCUSDT",
"spot_price": 67213.5,
"computed_at": "2026-04-29T11:59:48.000Z",
"freshness_seconds": 12.0,
"source": ["deribit","bybit","okx","binance","derive","thalex","delta_india","delta"],
"exchanges_filtered": ["deribit","bybit"]
}
}
```
## Errors
```json
{
"success": false,
"error": {
"code": "NOT_FOUND",
"message": "No data for BTCUSDT"
},
"meta": { "version": "2.0", "timestamp": "..." }
}
```
| Code | When |
|-----------------------|------|
| `UNAUTHORIZED` | Missing or invalid API key |
| `FORBIDDEN` | Subscription doesn't allow API access |
| `NOT_FOUND` | Symbol/expiry/etc. not present in cache |
| `VALIDATION_ERROR` | Bad query parameters |
| `RATE_LIMIT_EXCEEDED` | Per-tier limit hit |
| `UPSTREAM_ERROR` | Cache or DB temporarily unreachable |
| `INTERNAL_ERROR` | Anything else |
version: '2.6'
servers: []
security: []
tags:
- name: Meta
description: Unauthenticated metadata + endpoint catalog (planning your integration)
- name: Discovery
description: Symbol catalog, active expiries, and service status
- name: GEX
description: Gamma exposure analytics
- name: Options
description: Options chain, IV, greeks, probability, premium tide
- name: Liquidation
description: Liquidation heatmap and distribution
- name: Multi
description: Bundled multi-symbol endpoints (single round-trip across the universe)
paths:
/options/venue-book:
get:
tags:
- Options
summary: Consolidated cross-venue book and quote dispersion
description: >-
Best bid and best offer for each contract **across every venue we
collect**, with the venue named on each side, plus how far apart those
venues are quoting the same contract.
This is not what `/options/chain` returns. The chain's `bid`/`ask` come
from the aggregated row, which is based on a single venue; this endpoint
is the genuine best-of, and by construction its spread is never wider
than any individual venue's.
**Scope.** Computed only for liquid contracts (0.85-1.15 moneyness, 2+
DTE). Outside that band implied vol stops carrying information: deep-ITM
contracts have almost no vega, so a trivial price difference reads as
tens of vol points. Contracts quoted by a single venue are omitted,
since every field here is a comparison.
**On `crossed`.** A crossed market (best bid vol above best ask vol) is
reported as an observation, not an opportunity. Venue quote timestamps
are collection times rather than exchange quote times, so a stale quote
on the thinner venue cannot be ruled out, and measured crossings are
small, short-dated and consistently one-directional - which points at
structural causes (settlement, index, funding) rather than anything
capturable.
**On `mixed_settlement`.** Deribit's BTC/ETH options are inverse
(coin-settled); the USDC venues are linear. Implied vol is comparable
across the two to first order, but part of any gap flagged this way is
numeraire rather than volatility.
operationId: get_venue_book_options_venue_book_get
parameters:
- name: symbol
in: query
required: false
schema:
enum:
- BTCUSDT
- ETHUSDT
- SOLUSDT
- HYPEUSDT
type: string
description: 'Trading symbol: BTCUSDT, ETHUSDT, SOLUSDT, or HYPEUSDT.'
default: BTCUSDT
title: Symbol
description: 'Trading symbol: BTCUSDT, ETHUSDT, SOLUSDT, or HYPEUSDT.'
- name: expiries
in: query
required: false
schema:
anyOf:
- type: string
- type: 'null'
description: Comma-separated expiry tokens, e.g. `26DEC25,27MAR26`.
title: Expiries
description: Comma-separated expiry tokens, e.g. `26DEC25,27MAR26`.
- name: option_type
in: query
required: false
schema:
anyOf:
- type: string
enum:
- call
- put
- type: 'null'
description: Restrict to calls or puts.
title: Option Type
description: Restrict to calls or puts.
- name: crossed_only
in: query
required: false
schema:
type: boolean
description: >-
Return only contracts where best bid vol exceeds best ask vol.
Read the note on `crossed` above before acting on this.
default: false
title: Crossed Only
description: >-
Return only contracts where best bid vol exceeds best ask vol. Read
the note on `crossed` above before acting on this.
- name: sort
in: query
required: false
schema:
enum:
- spread
- spread_pct
- dispersion
- strike
type: string
description: Ordering for the returned contracts.
default: spread_pct
title: Sort
description: Ordering for the returned contracts.
- name: limit
in: query
required: false
schema:
type: integer
maximum: 1000
minimum: 1
description: Max contracts returned.
default: 200
title: Limit
description: Max contracts returned.
- name: X-API-Key
in: header
required: false
schema:
anyOf:
- type: string
- type: 'null'
title: X-Api-Key
responses:
'200':
description: Successful Response
content:
application/json:
schema: {}
'401':
description: Invalid or missing API key
content:
application/json:
example:
success: false
error:
code: UNAUTHORIZED
message: Invalid API key
meta:
version: '2.0'
timestamp: '2026-04-29T12:00:00Z'
'404':
description: No data available for the requested resource
content:
application/json:
example:
success: false
error:
code: NOT_FOUND
message: No data for BTCUSDT
meta:
version: '2.0'
timestamp: '2026-04-29T12:00:00Z'
'422':
description: Validation error on query parameters
content:
application/json:
example:
success: false
error:
code: VALIDATION_ERROR
message: Invalid request parameters
details:
errors: []
meta:
version: '2.0'
timestamp: '2026-04-29T12:00:00Z'
'429':
description: Rate limit exceeded
content:
application/json:
example:
success: false
error:
code: RATE_LIMIT_EXCEEDED
message: Rate limit exceeded. Try again later.
meta:
version: '2.0'
timestamp: '2026-04-29T12:00:00Z'
security:
- ApiKeyAuth: []
components:
securitySchemes:
ApiKeyAuth:
type: apiKey
in: header
name: X-API-Key
description: Your BackQuant API key (same key as v1)
````