> ## Documentation Index > Fetch the complete documentation index at: https://docs.li.fi/llms.txt > Use this file to discover all available pages before exploring further. # How Earn Works > How the Earn Data API aggregates and normalizes vault data: the NormalizedVault schema, transactional capabilities, and data freshness. This page explains how the Earn Data API aggregates vault data across protocols, normalizes it into a consistent schema, and keeps it fresh. *** ## Architecture Overview The Earn Data API is a **data aggregation layer** that sits between protocol data and your application. It handles: 1. **Ingestion.** Fetching vault data from multiple data sources across supported protocols. 2. **Normalization.** Transforming protocol-specific formats into a unified `NormalizedVault` schema. 3. **Capability Resolution.** Determining which vaults support deposits and withdrawals via Composer. 4. **Serving.** Exposing the normalized data through a REST API with filtering, sorting, and pagination. *** ## Data Freshness The Earn Data API runs a background sync pipeline that keeps vault data current: | Data | Refresh Frequency | | ----------------------------------------------------- | ----------------- | | Vault metadata, APY, and TVL | Every 15 minutes | | Transactional capabilities (deposit/withdraw support) | Every 2 minutes | This means APY and TVL data is at most 15 minutes stale, and transactional capability data is at most 2 minutes stale. *** ## The NormalizedVault Schema Every vault in the Earn API follows the same schema, regardless of which protocol or data provider it comes from. This is the core data structure: ```json theme={"system"} { "address": "0x7BfA7C4f149E7415b73bdeDfe609237e29CBF34A", "network": "base", "chainId": 8453, "slug": "morpho-base-usdc-0x7bfa", "name": "Morpho USDC Vault", "description": "Optimized USDC lending vault on Morpho", // optional, may be absent "protocol": { "name": "Morpho", "logoUri": "https://example.com/morpho-logo.png", "url": "https://morpho.org" }, "underlyingTokens": [ { "address": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913", "symbol": "USDC", "decimals": 6, "weight": 1.0 } ], "lpTokens": [], // typically empty; use vault `address` as toToken for Composer "rewardTokens": [], // optional, may be absent "tags": ["stablecoin", "lending"], "analytics": { "apy": { "base": 0.0534, // nullable, can be null "reward": null, // nullable, can be null "total": 0.0534 }, "apy1d": 0.0521, // nullable, can be null "apy7d": 0.0538, // nullable, can be null "apy30d": 0.0545, "tvl": { "usd": "12500000.00", "native": "12500000000000" // optional, may be absent }, "updatedAt": "2026-03-31T14:30:00.000Z" }, "caps": { // optional, may be absent "totalCap": "50000000000000", "maxCap": "100000000000000" }, "timeLock": 0, // optional, may be absent "kyc": false, // optional, may be absent "isTransactional": true, "isRedeemable": true, "depositPacks": [ { "name": "morpho-deposit", "stepsType": "instant" } ], "redeemPacks": [ { "name": "morpho-redeem", "stepsType": "instant" } ], "syncedAt": "2026-03-31T14:30:00.000Z" } ``` ### Key Fields | Field | Type | Description | | -------------------------------------- | ---------------- | ---------------------------------------------------------------------------------------------------------------------------- | | `address` | `string` | Vault contract address | | `network` | `string` | Network name (e.g., `"base"`, `"ethereum"`) | | `chainId` | `number` | EVM chain ID | | `slug` | `string` | Unique vault identifier across providers | | `protocol` | `object` | Protocol metadata (name, logo, URL) | | `underlyingTokens` | `array` | Tokens the vault accepts for deposit (with optional weight for multi-asset vaults) | | `lpTokens` | `array` | Tokens representing the vault position. Typically empty; use the vault's `address` field as `toToken` for Composer deposits. | | `rewardTokens` | `array?` | Additional reward tokens (e.g., governance tokens). Optional, may be absent. | | `analytics.apy` | `object` | Current APY breakdown: `base` (nullable), `reward` (nullable), `total` | | `analytics.apy1d` / `apy7d` / `apy30d` | `number \| null` | Rolling average APY over 1 day, 7 days, and 30 days. Nullable, may be `null` for new vaults. | | `analytics.tvl` | `object` | Total value locked. `usd` is always present; `native` is optional. | | `isTransactional` | `boolean` | Whether deposits are available via Composer | | `isRedeemable` | `boolean` | Whether withdrawals are available via Composer | | `depositPacks` / `redeemPacks` | `array` | Composer zap-pack entries describing available deposit/redeem methods | | `description` | `string?` | Vault description. Optional, may be absent. | | `caps` | `object?` | Deposit caps (`totalCap`, `maxCap`). Optional, may be absent. | | `timeLock` | `number?` | Lock period in seconds (0 = no lock). Optional, may be absent. | | `kyc` | `boolean?` | Whether the vault requires KYC. Optional, may be absent. | ### Transactional Capabilities The `isTransactional` and `isRedeemable` flags are derived from Composer's zap-pack data, not from the vault itself. This tells you whether the LI.FI infrastructure can execute deposits and withdrawals for this vault: * **`isTransactional: true`** means you can use [Composer's quote endpoint](/composer/guides/api-integration) with this vault's contract address as `toToken` to deposit. * **`isRedeemable: true`** means you can use Composer with this vault's contract address as `fromToken` to withdraw. Use these flags to control your UI. For example, hide the "Deposit" button for vaults where `isTransactional` is `false`. *** ## Supported Protocols and Chains The Earn Data API aggregates vaults from 20+ protocols across 20 chains. Use the discovery endpoints to see what is currently indexed: * `GET /v1/chains` — returns all chains with at least one active vault * `GET /v1/protocols` — returns all protocols with at least one active vault These endpoints reflect live data from the sync pipeline and will grow as new protocols and chains are onboarded. *** ## Next Steps Make your first Earn API calls in under 5 minutes Full endpoint reference with all parameters and response shapes