> ## Content Index > Fetch the complete content index at: https://blog.vaults.fyi/llms.txt > Use this file to discover other available public pages before exploring further. # Case Study: Etherscan Cards – Bringing DeFi Yield Insights to the World’s Most Trusted Block Explorer - URL: https://blog.vaults.fyi/case-study-etherscan-cards-bringing-defi-yield-insights-to-the-worlds-most-trusted-block-explorer/ - Published: 2025-04-22T18:14:00.000Z - Updated: 2025-04-22T19:10:08.000Z - Author: vaults.fyi - Tags: #Featured, Product The **vaults.fyi API suite** powers real-time, onchain analytics for DeFi yield opportunities and transactional capabilities across leading protocols. In this case study, we explore how [**Etherscan**](https://etherscan.io/?ref=blog.vaults.fyi)—Ethereum’s go-to block explorer—leveraged both our **Insights API** and **Earn API** to enhance the user experience with the **Etherscan Cards** integration. --- ## **The Idea: Contextual Yield Insights for Wallet Viewers** When users explore an Ethereum address on Etherscan, they’re often looking to understand what that wallet holds and how it’s being used. But what if they could also see what those idle assets *could* be doing? That’s where the [**vaults.fyi Insights API** and **Earn API**](https://docs.vaults.fyi/api/vaults.fyi-api-overview?ref=blog.vaults.fyi) come in. By surfacing real-time DeFi yield opportunities and enabling user interaction with vaults, they provide helpful, actionable context directly within the Etherscan interface. ![](https://storage.ghost.io/c/80/1e/801e59ba-aea3-41d2-aff6-47dda0ee853e/content/images/2025/04/image.png) > "The idea behind Etherscan Cards was driven by two key goals. First, to empower users by surfacing insights about an address from domain specialists. Second, to give back to projects across the ecosystem by providing them exposure through Etherscan’s distribution. The Yield Opportunity Card was a natural fit: it helps users discover potential earning opportunities for their tokens that they might have otherwise missed." - Harith Kamarul, Product Manager --- ## **How It Works** Here’s how the integration functions behind the scenes: ### **1\. Balance Detection** When a user views an Ethereum wallet address on Etherscan, the [**Insights API**](https://docs.vaults.fyi/api/vaults.fyi-api-overview/insights-api?ref=blog.vaults.fyi) checks for idle balances in: - ETH - Stablecoins: USDC, USDT, and DAI ### **2\. Opportunity Matching** Etherscan queries the **Insights API** to identify the top DeFi yield opportunities that match those assets, filtered by clear and trusted criteria (see below). ### **3\. In-Interface Display** The **Yield Opportunity card** is shown in the **Etherscan** **Cards** tab of the wallet page (for example: vitalik.eth), highlighting: - Token type (ETH or stablecoin) - Estimated 7-day APY - Protocol offering the yield ### **4\. User Action** Interested users can click the card to visit **vaults.fyi**, where they can explore more detailed analytics via the **Insights API**, and use the [**Earn API**](https://docs.vaults.fyi/api/vaults.fyi-api-overview/earn-api?ref=blog.vaults.fyi) to: - Supply or withdraw funds - Manage DeFi positions - Take direct onchain actions in a user-friendly interface --- ## **Criteria for Yield Opportunities** To ensure only high-quality, high-confidence opportunities are shown, the following criteria are used: - **ETH Vaults**: Must have a Total Value Locked (TVL) over $100 million. The vault with the highest 7-day APY is selected. - **Stablecoin Vaults**: Same rules apply for USDC, USDT, and DAI—only vaults with >$100 million TVL are considered, and the top APY is surfaced. This ensures that users are presented with yield options that are not just enticing, but also backed by substantial liquidity and protocol maturity. --- ## **The Bigger Picture: API-Powered UX** > When evaluating Etherscan Cards applications, we look for interesting use cases and strong technical reliability. vaults.fyi delivered on both fronts. Their API was straightforward to integrate and has proven robust enough to handle Etherscan’s scale seamlessly. - Harith Kamarul, Product Manager Etherscan’s Cards integration is just one example of what’s possible with the **vaults.fyi Insights API** and **Earn API**: - The [**Insights API**](https://docs.vaults.fyi/api/vaults.fyi-api-overview/insights-api?ref=blog.vaults.fyi) delivers real-time, structured data on user wallet balances and corresponding yield opportunities. - The [**Earn API**](https://docs.vaults.fyi/api/vaults.fyi-api-overview/earn-api?ref=blog.vaults.fyi) enables frictionless DeFi interactions—allowing users to supply, withdraw, or manage funds directly within integrated apps or platforms. Together, these APIs create a seamless, informed experience that empowers users to get more out of their onchain assets—right from the tools they already trust. --- ## **Build With vaults.fyi** Whether you’re building a wallet, dashboard, portfolio tracker, or DeFi application, **vaults.fyi is your backend for yield discovery and execution**. With the **Insights API** and **Earn API**, you can: ✅ Deliver actionable yield insights✅ Connect users to trusted opportunities✅ Enable native onchain transactions from inside your product Want to integrate DeFi insights into your product? Visit[ vaults.fyi](https://vaults.fyi/?ref=blog.vaults.fyi) or explore [our API docs](https://vaults.fyi/api?ref=blog.vaults.fyi) to get started.