How to Use Real-Time Data in Aptos Contracts
This guide explains how to use real-time Pyth data in Aptos applications.
Configuring the Move.toml
file
Add the Pyth Contract to your project dependencies in the Move.toml
file:
[dependencies]
Pyth = { git = "https://github.com/pyth-network/pyth-crosschain.git", subdir = "target_chains/aptos/contracts", rev = "main" }
The named addresses of pyth
, wormhole
, and deployers
must be defined at compile time. These addresses are used to interact with the Pyth contract on Aptos.
[addresses]
pyth = "0x7e783b349d3e89cf5931af376ebeadbfab855b3fa239b7ada8f5a92fbea6b387"
deployer = "0xb31e712b26fd295357355f6845e77c888298636609e93bc9b05f0f604049f434"
wormhole = "0x5bc11445584a763c1fa7ed39081f1b920954da14e04b32440cba863d03e19625"
Consult Aptos Contract Addresses for the complete list of contract addresses on different Aptos networks.
Write Contract Code
The code snippet below provides an example module fetching the BTC/USD price from Pyth price feeds:
module example::example {
use pyth::pyth;
use pyth::price::Price;
use pyth::price_identifier;
use aptos_framework::coin;
// Add the pyth_price_update argument to any method on your contract that needs to read the Pyth price.
// See https://docs.pyth.network/price-feeds/fetch-price-updates for more information on how to fetch the pyth_price_update.
public fun get_btc_usd_price(user: &signer, pyth_price_update: vector<vector<u8>>): Price {
// First update the Pyth price feeds
let coins = coin::withdraw(user, pyth::get_update_fee(&pyth_price_update));
pyth::update_price_feeds(pyth_price_update, coins);
// Read the current price from a price feed.
// Each price feed (e.g., BTC/USD) is identified by a price feed ID.
// The complete list of feed IDs is available at https://pyth.network/developers/price-feed-ids
// Note: Aptos uses the Pyth price feed ID without the `0x` prefix.
let btc_price_identifier = x"e62df6c8b4a85fe1a67db44dc12de5db330f7ac66b72dc658afedf0f4a415b43";
let btc_usd_price_id = price_identifier::from_byte_vec(btc_price_identifier);
pyth::get_price(btc_usd_price_id)
}
}
The pyth_price_update
argument contains verified prices from Pyth. Calling
pyth::update_price_feeds
with this value updates the on-chain Pyth price and
ensures your application has recent price data. The pyth_price_update can be
fetched from Hermes; Consult Fetch Price Updates for
more information on how to fetch the pyth_price_update
.
The code snippet above does the following things:
- Call
pyth::get_update_fee
to get the fee required to update the Pyth price feeds. - Call
pyth::update_price_feeds
and passpyth_price_update
to update the Pyth price feeds. - Call
pyth::get_price
to read the current price, providing the price feed ID (opens in a new tab) you wish to read.
Additional Resources
You may find these additional resources helpful for developing your Aptos application.
API Reference
The Aptos API reference lets you interactively explore the complete API of the Pyth contract.
Example Applications
- Minimal on-chain contract (opens in a new tab), which updates and returns the BTC/USD price from Pyth price feeds.
- Mint NFT (opens in a new tab) that use Pyth price feeds to mint an NFT.