# Index Price Sources

Accurate and reliable index prices are crucial for our platform. We source index price data from multiple reputable sources via APIs to ensure robustness and reduce the risk of price manipulation and sustain availability.  Accurate and up-to-date index prices are essential for Rails core services such as [funding](https://help.rails.xyz/trading/funding) and [trading metrics](https://help.rails.xyz/getting-started/trading-metrics-guide) calculations. 

To ensure reliability and availability, our system uses a multi-sourced cascading fallback approach for index pricing, detailed below:

|                                                                     Primary Source                                                                    |
| :---------------------------------------------------------------------------------------------------------------------------------------------------: |
| [Coindesk Aggregate Index API - CCIX](https://developers.coindesk.com/documentation/data-streamer/index_cc_v1_latest_tick_direct_trading_methodology) |
|                                                            Our main source of index prices.                                                           |

<table><thead><tr><th align="center">Backup Source 1</th><th align="center" valign="middle">Backup Source 2</th><th align="center">Backup Source 3</th></tr></thead><tbody><tr><td align="center"><a href="https://developers.coindesk.com/documentation/legacy-websockets/AggregateIndex">CoinDesk Aggregate Index API - CCCAGG</a></td><td align="center" valign="middle"><a href="https://hyperliquid.gitbook.io/hyperliquid-docs/for-developers/api/websocket/subscriptions">Hyperliquid Subscriptions API - Hyperliquid</a></td><td align="center"><a href="https://docs.kraken.com/api/docs/websocket-v2/ticker/">Kraken's Ticker (Level 1) AP</a>I</td></tr><tr><td align="center">Used if the primary source becomes unavailable.</td><td align="center" valign="middle">Acts as a secondary fallback to maintain price availability.</td><td align="center">Acts as the last fallback to maintain price availability.</td></tr></tbody></table>


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