> For the complete documentation index, see [llms.txt](https://docs.yo.xyz/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.yo.xyz/integrations/integration-guides/sdk/core/overview.md).

# Overview

The framework-agnostic TypeScript SDK for the Yo yield protocol. Use it in any environment — Node.js, serverless functions, scripts, or the browser.

## What's Inside

| Module          | Purpose                                                                        |
| --------------- | ------------------------------------------------------------------------------ |
| **YoClient**    | Main entry point — wraps reads, actions, and API calls in a single interface   |
| **Vault reads** | On-chain state queries: vault state, balances, allowances, conversion previews |
| **Actions**     | Transaction builders: deposit via gateway, request withdrawal, redeem, approve |
| **API client**  | REST client for off-chain data: snapshots, APY/TVL timeseries, user history    |
| **Constants**   | Vault addresses, chain configs, contract ABIs                                  |

## Architecture

```
YoClient (entry point)
├── publicClient (viem) — On-chain reads
├── walletClient (viem) — Transaction signing
└── apiClient (fetch) — REST API calls
```

The client is initialized with a `chainId` and optional viem clients. If no `publicClient` is provided, one is created automatically via `http()` transport.

## Quick Example

```ts
import { createYoClient, VAULTS } from '@yo-protocol/core'

// 1 — Create a client targeting Base
const client = createYoClient({ chainId: 8453 })

// 2 — Read on-chain vault state
const state = await client.getVaultState(VAULTS.yoETH.address)
console.log(state.name, state.totalAssets)

// 3 — Fetch off-chain snapshot (TVL, APY, pools)
const snapshot = await client.getVaultSnapshot(VAULTS.yoETH.address)
console.log(`APY: ${snapshot.apy}%`, `TVL: $${snapshot.tvl}`)
```

{% hint style="info" %}
**No framework required**

`@yo-protocol/core` has zero React or DOM dependencies. It works anywhere that supports `fetch` and `BigInt` — backend services, CLI tools, scripts, or browsers.
{% endhint %}

## Chains

| Chain    | Chain ID | Status    |
| -------- | -------- | --------- |
| Ethereum | `1`      | Supported |
| Base     | `8453`   | Supported |

## Next Steps

* [Client](broken://pages/9d7260e75dd75f06619208e7e14336dbf6509033) — Creating and configuring YoClient
* [Vault Reads](broken://pages/d68e3d414b4e85e74716da059762a410642e5b70) — Querying on-chain vault state
* [Actions](broken://pages/c0d48baa517ce45149c5d9a002ad6e0e80295eb2) — Building deposit, withdraw, and approve transactions
* [API Client](broken://pages/5ca6b1a45df09b8899f1089e56c0b4869ca537e3) — Fetching snapshots, timeseries, and user history
* [Constants](broken://pages/316177dbbaa039279d32a4e39dff04638fd16ee6) — Vault addresses and chain configs
* [Types](broken://pages/058f9022a1a38cb759535b76991f8cc6fb77704b) — Full type reference


---

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