> ## 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.

# HIP-4 Data Provider: Historical Outcome-Market Data API

> HIP-4 outcome-market data under /v1/hyperliquid/hip4/*: probability-priced order books, trades, candles, outcome metadata, and open interest.

HIP-4 outcome markets use side identifiers and probability-priced fields. `mark_price` and `mid_price` represent implied probability in `[0, 1]`, not USD.

Stored HIP-4 market-data coverage for native order books, trades, open interest, and L4 begins May 2, 2026 across current symbol rows. Outcome discovery and settlement metadata are separate route contracts: the outcomes response exposes `is_settled`. The candles route provides a probability-history series without a per-schema floor in the current coverage response. Use the selected outcome side's coverage metadata for the exact window rather than inferring a venue-wide history.

```bash theme={"theme":"github-dark"}
curl "https://api.0xarchive.io/v1/hyperliquid/hip4/orderbook/%230" \
  -H "X-API-Key: $OXARCHIVE_API_KEY"
```

<CardGroup cols={2}>
  <Card title="HIP-4 REST" icon="binary" href="/rest-api/hip4">
    Outcome-market route family.
  </Card>

  <Card title="Response schemas" icon="braces" href="/schemas">
    Shared field rules and envelope behavior.
  </Card>
</CardGroup>

## Route Scope

The current contract keeps outcome-market routes under `/v1/hyperliquid/hip4/*`:

| Workload | Route family |
| - | - |
| Discover outcomes and settlement state | `/v1/hyperliquid/hip4/outcomes`, `/v1/hyperliquid/hip4/questions` |
| Resolve an outcome | `/v1/hyperliquid/hip4/outcomes/{outcome_id}`, `/v1/hyperliquid/hip4/outcomes/by-slug/{slug}`, `/v1/hyperliquid/hip4/questions/{question_id}` |
| Read market data | `/v1/hyperliquid/hip4/orderbook/{symbol}`, `/v1/hyperliquid/hip4/trades/{symbol}`, `/v1/hyperliquid/hip4/candles/{symbol}`, `/v1/hyperliquid/hip4/openinterest/{symbol}` |
| Read order-level depth | `/v1/hyperliquid/hip4/orderbook/{symbol}/l4`, `/v1/hyperliquid/hip4/orderbook/{symbol}/l4/history`, `/v1/hyperliquid/hip4/orderbook/{symbol}/l4/diffs` |

There is no HIP-4 funding or liquidation route. A listed route does not establish non-empty coverage for every outcome; use coverage and freshness for the selected identifier before relying on its window.

## Implementation Pattern

For probability-history analysis, an outcome-liquidity monitor, or an outcome-market dashboard, start by discovering the question or outcome side, then pull one small order-book, trade, or candle request. If the output feeds a model, alert, or backtest, check [data quality and freshness](/data-quality) routes and label price fields as probabilities. Preserve the `#` identifier or URL-encoded form in requests and storage.

See the [Hyperliquid market data API](https://0xarchive.io/hyperliquid) for other data types.

Read [Understanding HIP-4 probability-priced data](https://0xarchive.io/resources/market-data-guides/hip4-outcome-markets-data) to interpret outcome prices.

## Next Step

Open [HIP-4 REST](/rest-api/hip4), then pair it with [Schemas](/schemas) and [Data quality](/data-quality).

## Workload Boundary

Use this family when the application needs outcome-market state rather than a normal perp or Spot market. The relevant workloads are probability-history analysis, outcome-liquidity monitoring, and outcome-market dashboards. Keep HIP-4 output separate from dollar-priced series in storage and analytics, and add data-quality checks before a model or alert acts on the result.


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