Why Update Prices

Pyth uses a pull oracle model. Unlike traditional push oracles that automatically update prices on-chain at regular intervals, Pyth requires users to explicitly update the on-chain price before reading it.

This design offers several advantages:

• Lower costs: You only pay for price updates when you need them
• Lower latency: You can fetch the latest price update directly from Pyth's low-latency oracle network and submit it on-chain immediately
• Flexibility: Different applications can update prices at different frequencies based on their needs

In the pull integration pattern, your contract must:

1. Accept priceUpdate data from the caller (fetched from Hermes)
2. Call updatePriceFeeds() to submit this data on-chain before reading prices
3. Pay a small fee for each update (calculated via getUpdateFee())

If you don't update the price or if the on-chain price becomes too stale, calls to getPriceNoOlderThan() will revert with a StalePrice error. See how to fetch price updates for more details on obtaining price updates.