# Custom Data Feeds {% hint style="info" %} If you're looking for a data type that isn't currently supported but would like it to be, feel free to [contact us](https://entangle.zendesk.com/hc/en-us/requests/new), and we can discuss implementing it. {% endhint %} Custom data in data feeds refers to user-defined information that is integrated into a data feed to meet the specific needs of a dApp or smart contract. This enables developers to pull tailored data from both on-chain and off-chain sources, facilitating more accurate and relevant decision-making and operations. With UDF, users can easily expand the data available to their applications by incorporating new data types into the Entangle UDF infrastructure. *** ## When Is Custom Data Needed? * **Integrating New Crypto Assets:** Add new cryptocurrency price feeds to ensure decentralized exchanges, lending platforms, or wallets always have the latest market prices. * **Real-World Asset (RWA) Integration:** Introduce real-world assets like commodities, real estate, or physical goods into the decentralized ecosystem, enabling their tokenization and trading. * **Proof of Reserves Integration:** Add external data feeds to verify asset reserves, providing transparency and confidence in the backing of digital assets or financial platforms. *** ## Requesting New Data Types To integrate new data into UDF, [contact us](https://entangle.zendesk.com/hc/en-us/requests/new) and provide the following information: * **Initial Data with Examples**: Share real sample data that will be processed during the integration. * **Data Processing Requirements**: Outline any necessary transformations or formatting for the data to be delivered on-chain. * **Update Frequency Suggestions**: Recommend the desired update frequency to tailor the integration to the protocol’s needs. *** ## Integration Process This section outlines the process of integrating a new data feed into UDF. The default integration flow ensures smooth onboarding of new data sources and utilizes UDF’s capabilities for fetching, parsing, and distributing data on-chain. {% stepper %} {% step %} ### **Define REST URL Template** The Rest URL template defines how data is fetched from external sources. You will need to create a URL template that points to the endpoint of the data provider. The template uses Go text syntax, with placeholders such as `DataKey` and `SourceID`. Example for Binance API: ``` https://api.binance.com/api/v3/avgPrice?symbol={{.DataKey}} ``` This URL template is inserted into the configuration file, allowing Entangle's backend to fetch the necessary data. {% endstep %} {% step %} ### **Set Up Parsing Pipelines** In the configuration file, set up pipelines to parse data from the response JSON. Below is an example JSON response structure: ```json { "asset": { "price": 1000000000000000000, "timestamp": 1721636387, "volume": 10000000000 } } ``` * **Pipeline for Price**: `asset.price` * **Pipeline for Timestamp**: `asset.timestamp` * **Pipeline for Volume**: `asset.volume` These pipelines should be defined using GJSON syntax to extract the required fields. {% endstep %} {% step %} ### **Configure the System** The next step is to implement both the URL template and parsing pipelines in the YAML configuration file. This connects the data feed with Entangle UDF. Example configuration snippet: ```yaml urlTemplate: "https://api.binance.com/api/v3/avgPrice?symbol={{.DataKey}}" pipelines: - value: "asset.price" - timestamp: "asset.timestamp" - volume: "asset.volume" ``` {% endstep %} {% step %} ### **Fetch Data** To retrieve data updates, use the Finalized Data API. For example, to fetch the BTC/USD price feed, execute the following curl command: ```sh curl https://udfsnap.ent-dx.com/last_votes?feedKeys=BTC/USD ``` Below is a sample response containing publisher votes along with their signatures, and data encoded as bytes in the `update_call_data` property which is ready to be used on-chain. ```json { "update_call_data": "0x..", "feeds": [ { "feed_key": "BTC/USD", "votes": [ { "Value": "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAS4fbe+zAAA=", "Timestamp": 1737093395, "Signature": { "R": "0xfb2e89fb52f1d832d5437f4b773c0f67749b914b25c592af9cbc8ffe58e9e928", "S": "0x3c7e717a67b8a0c072f0271f35f3994c865c12b930f20b57149b623cade43d43", "V": 27 } }, { "Value": "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAS4fbe+zAAA=", "Timestamp": 1737093402, "Signature": { "R": "0xe6a1448feac17a219c63a426f978cd395f8be55a74ebc717a88385033c7c5432", "S": "0x1a16ba5138e5293b03c093097c8564c55a0f054537a6c665d3b4bc9cf716d46f", "V": 28 } }, { "Value": "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAS4fbe+zAAA=", "Timestamp": 1737093400, "Signature": { "R": "0x8308dc0d3b5a32a12374fbc8a2852cb14af4e31cc015b4d463e4cfb41d5aa469", "S": "0x12d5746c9499e7dc5edbbc436f696478ab4ad5a96247fb357d3d0c418769778d", "V": 28 } } ] } ] } ``` {% endstep %} {% step %} ### **Finishing** {% hint style="info" %} **Monitor and Update** Ongoing monitoring ensures that the integration functions correctly. Periodically review the configuration and update it as needed to accommodate changes in the data provider's API or Entangle’s system. {% endhint %} Once you have fetched the data, use the `PushMarketplace`or `PullMarketplace` smart contract to verify the updates on-chain. {% endstep %} {% endstepper %} --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.entangle.fi/universal-data-feeds/developer-guides/custom-data-feeds.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.