# 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 use a single proxy contract that serves every feed. Instead of a per-feed contract address, you select a feed by its 32-byte `data_id`. 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 proxy contract to read that feed's data. ## How Stellar Data Feeds work Data Feeds on Stellar use a proxy contract that sits in front of a cache contract. Consumers read feeds from the proxy by passing a 32-byte `data_id`: - **Proxy contract**: A single proxy contract serves every feed. Consumers read feed data from the proxy by passing the `data_id` for the feed they need. The proxy address stays stable, which lets the underlying cache be replaced without changing the address consumers use. Consumers select a feed by passing its 32-byte `data_id` to the proxy. 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) ## Available data feeds on Stellar The following table shows all available data feeds on Stellar. Each feed is identified by its `data_id` (the Feed ID), which you pass to the proxy contract to read that feed's data. ## Proxy contract addresses The proxy contract address is the same for every feed on a given network. You only ever interact with the proxy. - **Stellar Testnet**: CBUF6IADAWPWIDWRTHJNINKXHG2UTIQ6TU2F2HRAXWAI7OT3KJPKK6O4 - **Stellar Mainnet (Pubnet)**: CDQBHEUGLDHMSUHG4IH33RJBUTMNCZOT4JIAQR4WZFRDZW6DR6S32ZLZ ## Reader interface Consumers call the following functions on the proxy contract. The interface is defined in the [chainlink-stellar](https://github.com/smartcontractkit/chainlink-stellar/tree/main/contracts/common/interfaces/src/data_feeds_proxy.rs) repository. | Function | Returns | | ---------------------------------------- | ---------------------------------------------------------------- | | `latest_round(data_id, decimals)` | The most recent round for that feed, at the requested `decimals` | | `get_round(data_id, round_id, decimals)` | A specific historical round, at the requested `decimals` | | `decimals(data_id)` | Decimal places for the answer | | `description(data_id)` | Human-readable pair name | ### Round structure A round returned by the proxy 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 | ## Error handling When you call the proxy, the contract can return a `ProxyReadError`. The following cases describe what each error means for a consumer: | Error | Meaning | | ----------------- | ----------------------------------------------------------------------------------------------------------------------------------------------- | | `NoDataPresent` | No round is available for the requested `data_id` or `round_id`. This can happen if the feed has not been written yet or the round has expired. | | `InvalidDecimals` | The `decimals` you requested is outside the supported range for the feed. | | `RoundsToZero` | A non-zero answer would truncate to zero at the requested `decimals`. Request fewer decimal places. | ## 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 proxy. ## Getting started You can read Chainlink Data Feeds on Stellar either offchain or onchain. Both methods read the same data from the proxy contract, differing only in where the read happens. - **[Using Data Feeds Offchain](/data-feeds/stellar/using-data-feeds-off-chain)**: Read a feed via Soroban RPC simulation using `stellar-cli` and the Stellar JavaScript SDK. This method is for applications that need to read feed data without deploying a contract. - **[Using Data Feeds Onchain](/data-feeds/stellar/using-data-feeds-on-chain)**: Deploy a Soroban contract in Rust that calls the proxy and reads a price. This method is for applications that need to read feed data directly within a smart contract. Each guide lists the tools and requirements you need to complete it. ## Answer precision All feeds are stored at `18` decimal places and are typically returned at `18` decimal places. In some instances, Chainlink approves the serving of a reduced precision for certain feeds. In this case, you can pass the precision as a parameter when requesting a feed from the proxy. The precision is truncated, so if an `18`-decimal feed is requested at `8` decimal places, the answer is truncated (rounded down). Factor this into your calculations. If you need to control the precision yourself, request the feed at `18` decimal places and override the precision in your application. > **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).