# Using Data Feeds on Stellar Source: https://docs.chain.link/data-feeds/stellar > For the complete documentation index, see [llms.txt](/llms.txt). [Stellar](https://stellar.org/) is a Layer 1 blockchain that uses [Soroban](https://soroban.stellar.org/) smart contracts written in [Rust](https://www.rust-lang.org/). Chainlink Data Feeds on Stellar are delivered through [Chainlink Runtime Environment (CRE)](/cre), which publishes data onchain using a decentralized oracle network. Chainlink Data Feeds on Stellar follow the same pattern as [Data Feeds on Aptos](/data-feeds/aptos): a single cache contract serves every feed, and consumers select a feed by its 32-byte `data_id` rather than by a per-feed contract address. This contrasts with Chainlink's integration on EVM blockchains, where each price feed has a separate contract address. A `data_id` is a 32-byte identifier for a feed, similar to how a contract address identifies a feed on EVM chains. It is the same value as the **Feed ID** shown in the [Price Feed Contract Addresses](/data-feeds/price-feeds/addresses?network=stellar) table. You pass the `data_id` to the cache contract to read that feed's data. ## How Stellar Data Feeds work Data Feeds on Stellar use a cache contract that the Chainlink oracle network writes into. Consumers read feeds directly from the cache by passing a 32-byte `data_id`: - **Cache contract**: A single cache contract serves every feed. The Chainlink oracle network writes round data into the cache, and consumers read it by passing the `data_id` for the feed they need. The cache address stays stable across upgrades. - **Fallback proxy**: A separate fallback proxy exists for the DF1 data feed, but it is not customer-facing and is not documented here. Consumers select a feed by passing its 32-byte `data_id` to the cache. You can find the `data_id` for each feed on the [Price Feed Contract Addresses](/data-feeds/price-feeds/addresses?network=stellar) page with Stellar selected. ## Supported networks Chainlink Data Feeds are available on the following Stellar networks: - [Stellar Testnet](https://stellar.org/developers/guides/concepts/networks#testnet) - [Stellar Mainnet (Pubnet)](https://stellar.org/developers/guides/concepts/networks#public-network) ## Cache contract addresses The cache contract address is the same for every feed on a given network. You only ever interact with the cache. - **Stellar Testnet**: CAVLZXJDRGOS6UZ7BHYTYW7STQMZIOCUJIVRMT7JE7T5F6JIA3LPAOVW - **Stellar Mainnet (Pubnet)**: CAAFKBE6AMTERARISMMT4TCC4UGNO35XCKQNC5XVLL5WY5GRWXH6AMIO ## Reader interface Consumers call the following functions on the cache contract. The interface is defined in the [chainlink-stellar](https://github.com/smartcontractkit/chainlink-stellar/tree/main/contracts/common/interfaces/src/data_feeds_cache.rs) repository. | Function | Returns | | ------------------------------ | ----------------------------------------------------- | | `latest_round(data_ids)` | The most recent round for each requested `data_id` | | `get_round(data_id, round_id)` | A specific historical round | | `decimals(data_ids)` | Decimal places for each requested `data_id` | | `description(data_ids)` | Human-readable pair name for each requested `data_id` | ### Round structure A round returned by the cache carries the following fields: | Field | Description | | ------------ | ------------------------------------------------------------- | | `round_id` | The unique identifier of the round | | `answer` | The answer for the feed, represented as an `I256` | | `timestamp` | The Unix timestamp in seconds when the round was recorded | | `ledger_seq` | The Stellar ledger sequence at which the round was recorded | | `primary` | Indicates whether the round is the primary round for the feed | ## Error handling When you call the cache, the contract can return a `CacheError`. The following cases describe what each error means for a consumer: | Error | Meaning | | ------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `FeedNotConfigured` | The `data_id` you passed does not correspond to a configured feed. Check that you are using the correct `data_id` from the [Price Feed Contract Addresses](/data-feeds/price-feeds/addresses?network=stellar) page with Stellar selected. | | `InvalidDataId` | The `data_id` you passed is invalid. | | `FeedFrozen` | The feed is frozen and cannot be read. | ## How long a round is available A round is stored in the cache contract's temporary storage with a retention period of `3,110,400` ledgers. After this period, a round can no longer be read from the cache. ## Getting started You can read Chainlink Data Feeds on Stellar either onchain or offchain: - **Onchain**: Deploy a [Soroban contract in Rust](/data-feeds/stellar/using-data-feeds-on-chain) that calls the cache and reads a price, deployed with `stellar-cli` to the Stellar Testnet. - **Offchain**: Read a feed via [Soroban RPC simulation](/data-feeds/stellar/using-data-feeds-off-chain) using `stellar-cli` and the [Stellar JavaScript SDK](https://github.com/stellar/js-stellar-sdk). ## Answer precision The cache stores every answer at a fixed `18` decimal places (`DECIMALS`). Feeds sourced at a lower precision, such as `8` decimals, are scaled up to `18` on write, so the stored value is always `18`-decimal regardless of the feed's native precision. When you read a round, the `answer` is returned at `18` decimal places. > **DANGER: Select quality data feeds** > > Be aware of the quality of the data that you use. [Learn more about making responsible data quality decisions](/data-feeds/selecting-data-feeds).