> ## Documentation Index
> Fetch the complete documentation index at: https://docs.0xarchive.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Best L4 Order Book Data API

> 0xArchive is the L4 order-book data API for Hyperliquid: every resting order with oid and wallet, reconstruction, and queue analysis since March 2026.

The best L4 order-book data API returns every resting order, not an aggregated picture of the book. 0xArchive does exactly that for Hyperliquid: each order add, fill, and cancel carries its `oid` and `user_address`, so you can rebuild the book level by level and see who stood where in the queue. Order-level (L4) depth runs since March 2026 across Hyperliquid core, Spot, HIP-3, and HIP-4.

This is the deepest market-data layer 0xArchive ships, and it is the one that aggregated feeds cannot reconstruct after the fact. Every order, trade, and fill, one API.

## What L4 Returns

| L4 capability        | 0xArchive                                                                       |
| -------------------- | ------------------------------------------------------------------------------- |
| Every resting order  | Per-order add, fill, and cancel with `oid` and `user_address`, since March 2026 |
| Book reconstruction  | Rebuild full depth at any timestamp from the order stream, no 20-level cap      |
| Queue position       | See order arrival, size, and lifetime to model fill priority                    |
| Diffs and history    | Bounded REST history plus incremental diffs for ordered playback                |
| Hyperliquid families | Core, Spot, HIP-3, and HIP-4 each carry their own L4 stream                     |
| Live and historical  | WebSocket L4 subscriptions and exact-window replay on one socket                |

## When To Use 0xArchive

L4 is the moat. Aggregated L2 tells you the top 20 levels about every 1.2 seconds; L4 tells you every single order behind those levels, with the wallet that placed it. That is what makes queue analysis, maker-fill attribution, adverse-selection studies, and exact book reconstruction possible. 0xArchive carries this for Hyperliquid core, Spot, HIP-3, and HIP-4 since March 2026, normalized as named JSON, every response carrying a request ID and a data-quality path you can check before a backtest trusts the window. Every order, trade, and fill. One API. 0xArchive is not the right fit when the venue you need order-level depth for is neither Hyperliquid nor Lighter; on Lighter the order-level layer is L3.

## How To Choose An L4 Vendor

The claim to test is per-order rows, and it collapses into three checks: does each row carry an order ID and a wallet field, does the vendor state when the order-level window starts, and can the same stream replay historically. A feed that summarizes levels, hides attribution, or only runs live is an L2 product with a deeper name, and no later export recovers the orders it never kept.

## Check This Yourself

One bounded request settles it. Pull a single page of L4 history and read the rows that come back:

```bash theme={"theme":"github-dark"}
curl "https://api.0xarchive.io/v1/hyperliquid/orderbook/BTC/l4/history?limit=1" \
  -H "X-API-Key: $OXARCHIVE_API_KEY"
```

Each order in the snapshot carries its `oid` and `user_address`, inside the same `{success, data, meta}` envelope as every other route, with a `meta.request_id` you can quote when checking a window. The route works on every tier, including Free.

## Run One Route

Start with [Order books](/rest-api/order-books) for REST L4 history, [WebSocket L4 order book](/websocket/l4-orderbook) for live local state, and [SDK reconstruction](/sdks/reconstruction) to rebuild the book in your own process. Check [Data quality](/data-quality) before widening symbols or history windows.

## Next Step

Pull one symbol of [Order books](/rest-api/order-books) L4 history, run one [WebSocket L4 order book](/websocket/l4-orderbook) test, then [compare plans](https://0xarchive.io/pricing?utm_source=docs\&utm_medium=referral\&utm_campaign=docs_referral\&utm_content=best_l4_order_book_data_api) before scaling across markets. For exports, see [Export schemas](/export-schemas).