> ## Documentation Index > Fetch the complete documentation index at: https://docs.ironflow.sh/llms.txt > Use this file to discover all available pages before exploring further. # Hyperliquid order book (L2) > GET /v1/book returns the live L2 order book of one Hyperliquid market: up to 20 levels a side with size and order count, mid, spread and USD depth. No key needed. ## OpenAPI ````yaml GET /v1/book openapi: 3.1.0 info: title: Ironflow API version: 1.0.0 description: > Hyperliquid market data from Ironflow's own nodes: tick-level fills and trades, candles, funding rates, liquidations, mark prices, open interest, markets and wallet analytics over REST. One schema across native HL perps, HIP-3 builder markets, HIP-4 outcome contracts and HL spot. **Base URL:** `https://api.ironflow.sh` **Authentication:** Read endpoints work without a key (keyless access) or with a Bearer token in the `Authorization` header. Writes always need a key. ``` Authorization: Bearer if_your_api_key ``` Get a free key at https://ironflow.sh/key. **Access levels:** | Access | Requests per minute | History | Max range per request | |---|---|---|---| | No key | 10 per IP | 24 hours | 1 hour | | Free key | 60 | 30 days | 6 hours | | Explorer | 100 | 90 days | 24 hours | | Builder | 1,000 | 1 year | 7 days | | Enterprise | 10,000 | full | unlimited | Without a market filter, high-volume endpoints allow at most 4 hours per request. `/v1/trades` filtered to one perp or spot market allows 24 hours per request without a key and on a free key. A header that is present but malformed returns 401; keyless access applies only when no `Authorization` header is sent. **Data availability:** fills and trades cover a rolling 12 months; other datasets start later (funding 2025-09-27, open interest and mark prices 2026-04-29). **Timestamps:** All timestamps are Unix milliseconds (int64). **Pagination:** Paginated endpoints return a `cursor` in `pagination.next_cursor`. Pass it as the `cursor` query parameter to fetch the next page. When `pagination.has_more` is `false`, you have reached the last page. contact: name: Ironflow Support url: https://ironflow.sh servers: - url: https://api.ironflow.sh description: Production security: - bearerAuth: [] - {} tags: - name: Market Data description: Historical tick-level market data stored in ClickHouse. - name: Analytics description: >- Aggregated analytics. Net flows and funding stats work without a key; the others need a key (a free key works). - name: Cohorts description: Predefined and custom address groups for filtering market data. - name: Alerts description: >- Liquidation alerts that Ironflow posts to your webhook, Discord channel, Slack channel or Telegram chat. - name: Info Proxy description: >- Cached passthrough to the Hyperliquid Info API. No record caps, higher rate limits. - name: Export description: Bulk data export as CSV or Parquet (Builder tier and above). - name: Query description: >- Read-only ClickHouse SQL over curated Hyperliquid tables (hl.*), limited by tier. - name: System description: Health checks and metadata endpoints. - name: TradingApp description: >- Trading app Phase A — wallet auth (SIWE), agent-key provisioning, and kill-switch. paths: /v1/book: get: tags: - Market Data summary: Live L2 order book of one market description: | The live L2 order book of one Hyperliquid market: up to 20 price levels a side with size and order count, best bid and ask, mid, spread in basis points and the USD depth returned on each side. Served from Hyperliquid's l2Book, cached up to one second per market; a book up to 10 s old is returned with `stale: true` when Hyperliquid cannot be reached. Perps, spot, HIP-3 and HIP-4 markets. No key needed. operationId: getOrderBook parameters: - name: market in: query required: true description: >- Market symbol (BTC-PERP, xyz:NVDA-PERP, HYPE/USDC) or Hyperliquid coin name (BTC, @107). schema: type: string - name: depth in: query description: Levels a side, 1 to 20. schema: type: integer minimum: 1 maximum: 20 default: 20 - name: sig_figs in: query description: >- Aggregate prices to 2 to 5 significant figures (coarser levels, deeper book). Leave out for full precision. schema: type: integer minimum: 2 maximum: 5 responses: '200': description: The order book. content: application/json: schema: type: object properties: market: type: string example: BTC-PERP coin: type: string example: BTC time: type: integer format: int64 description: Book time, Unix ms bids: type: array items: type: object properties: price: type: string size: type: string orders: type: integer asks: type: array items: type: object properties: price: type: string size: type: string orders: type: integer best_bid: type: string best_ask: type: string mid: type: number spread_bps: type: number bid_depth_usd: type: number ask_depth_usd: type: number source: type: string stale: type: boolean '400': $ref: '#/components/responses/BadRequest' '404': description: Unknown market. '503': description: Hyperliquid could not be reached; retry after a few seconds. components: responses: BadRequest: description: Invalid request parameters. content: application/json: schema: $ref: '#/components/schemas/Error' example: error: code: BAD_REQUEST message: address is required schemas: Error: type: object required: - error properties: error: type: object required: - code - message properties: code: type: string description: Machine-readable error code. example: RATE_LIMIT_EXCEEDED message: type: string description: Human-readable error description. example: Rate limit exceeded. Retry after 60 seconds. securitySchemes: bearerAuth: type: http scheme: bearer description: >- Ironflow API key, format `if_xxxx`. Free keys at https://ironflow.sh/key. Optional on read endpoints. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.