Read Data from Data Feeds on Starknet using Starknet Foundry
In this example, you'll read from a Chainlink price feed on Starknet using the Starknet Foundry toolkit. You'll call the latest_round_data function on the ETH / USD aggregator proxy contract to read the latest round of data.
Requirements
Make sure you have the Starknet Foundry toolkit installed. You can check your current version by running snforge --version or sncast --version in your terminal. Follow the installation guide if necessary.
Tutorial
Run the following command to read data from the ETH / USD data feed proxy contract:
sncast \
--url https://starknet-sepolia.public.blastapi.io/rpc/v0_7 \
call \
--contract-address <ETH_USD_PROXY_ADD> \
--function "latest_round_data" \
Expect an output similar to the following:
command: call
response: [0x10000000000000000000000000000320c, 0x5293770eb1, 0xd44d, 0x6606b8cc, 0x6606b8a2]
The example output contains an array with the hex encoded latest round of data for the ETH / USD price feed. The array contains the following values:
| Value name | Hex-encoded value | Decoded value | Description |
|---|---|---|---|
round_id | 0x10000000000000000000000000000320c | 340282366920938463463374607431768224268 | The unique identifier of the data round |
answer | 0x5293770eb1 | 354661371569 | The actual data provided by the data feed, representing the latest price of an asset in the case of a price feed |
block_num | 0xd44d | 54349 | The block number at which the data was recorded on the blockchain |
started_at | 0x6606b8cc | 1711716556 | The Unix timestamp indicating when the data round started |
updated_at | 0x6606b8a2 | 1711716514 | The Unix timestamp indicating when the data was last updated |
For a complete list of Chainlink Price Feeds available on Starknet, see the Price Feed Contract Addresses page.
Note: This example utilizes a Blast API RPC endpoint. You can interact with the network using any other Starknet Sepolia RPC provider, such as Alchemy or Infura.