> 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/constants.md).

# Constants

Exported contract addresses, vault configs, and chain information. All constants are fully typed and tree-shakeable.

## Contract Addresses

```ts
import {
  YO_GATEWAY_ADDRESS,
  VAULT_REGISTRY_ADDRESS,
  YO_ORACLE_ADDRESS,
  REDEEMER_ADDRESS,
} from '@yo-protocol/core'
```

| Constant                 | Description               | Address        |
| ------------------------ | ------------------------- | -------------- |
| `YO_GATEWAY_ADDRESS`     | Deposit gateway router    | `0xF1EeE…69FA` |
| `VAULT_REGISTRY_ADDRESS` | On-chain vault registry   | `0x56c31…2232` |
| `YO_ORACLE_ADDRESS`      | Price oracle              | `0x6E879…96B0` |
| `REDEEMER_ADDRESS`       | Async withdrawal redeemer | `0x0439e…2162` |

{% hint style="info" %}
**Checksummed**

All address constants are checksummed `0x${string}` literals — they work directly with viem without additional formatting.
{% endhint %}

## Vault Registry

The `VAULTS` object exposes every supported vault with its address, underlying token, and available chains.

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

VAULTS.yoETH.address            // '0x3a43aec...'
VAULTS.yoETH.underlying.symbol  // 'WETH'
VAULTS.yoETH.chains             // [1, 8453]
VAULTS.yoUSD.chains             // [8453]
```

### Available Vaults

| ID       | Underlying | Chains         |
| -------- | ---------- | -------------- |
| `yoETH`  | WETH       | Ethereum, Base |
| `yoBTC`  | cbBTC      | Base           |
| `yoUSD`  | USDC       | Base           |
| `yoEUR`  | EURC       | Base           |
| `yoGOLD` | XAUt       | Ethereum       |
| `yoUSDT` | USDT       | Ethereum       |

Each vault entry includes:

| Property              | Type       | Description                     |
| --------------------- | ---------- | ------------------------------- |
| `address`             | `Address`  | Vault contract address          |
| `underlying.address`  | `Address`  | Underlying ERC-20 token address |
| `underlying.symbol`   | `string`   | Token symbol                    |
| `underlying.decimals` | `number`   | Token decimals                  |
| `chains`              | `number[]` | Supported chain IDs             |

## Chain Helpers

```ts
import {
  SUPPORTED_CHAINS,
  SUPPORTED_CHAIN_IDS,
  isSupportedChain,
  getChain,
} from '@yo-protocol/core'

SUPPORTED_CHAIN_IDS  // [1, 8453]

isSupportedChain(8453) // true
isSupportedChain(137)  // false

const chain = getChain(8453)  // viem Chain object for Base
```

| Export                 | Type                      | Description                      |
| ---------------------- | ------------------------- | -------------------------------- |
| `SUPPORTED_CHAINS`     | `Chain[]`                 | Array of viem chain objects      |
| `SUPPORTED_CHAIN_IDS`  | `number[]`                | `[1, 8453]`                      |
| `isSupportedChain(id)` | `(id: number) => boolean` | Check if a chain ID is supported |
| `getChain(id)`         | `(id: number) => Chain`   | Get viem chain object by ID      |


---

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