> ## Documentation Index
> Fetch the complete documentation index at: https://docs.mandate.md/llms.txt
> Use this file to discover all available pages before exploring further.

# Chain Reference

> Supported chains, chain IDs, USDC contract addresses, and runtime key prefixes for Mandate.

## Supported chains

Mandate supports 4 EVM chains: 2 mainnets and 2 testnets. Your runtime key prefix determines which chains you can use.

| Chain            | Chain ID   | USDC Address                                 | Decimals | Key Prefix    |
| ---------------- | ---------- | -------------------------------------------- | -------- | ------------- |
| Ethereum Mainnet | `1`        | `0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48` | 6        | `mndt_live_*` |
| Ethereum Sepolia | `11155111` | `0x1c7D4B196Cb0C7B01d743Fbc6116a902379C7238` | 6        | `mndt_test_*` |
| Base Mainnet     | `8453`     | `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913` | 6        | `mndt_live_*` |
| Base Sepolia     | `84532`    | `0x036CbD53842c5426634e7929541eC2318f3dCF7e` | 6        | `mndt_test_*` |

## Test vs live keys

Runtime keys use prefixes to enforce environment separation:

* **`mndt_test_*`** keys work with testnet chains (Sepolia, Base Sepolia). Use these for development and testing. Testnet usage is free.
* **`mndt_live_*`** keys work with mainnet chains (Ethereum, Base). Use these for production deployments.

A test key cannot validate transactions on mainnet. A live key cannot validate transactions on testnet. This prevents accidental production transactions during development.

## SDK constants

The SDK exports chain and token constants so you avoid hardcoding addresses:

```typescript theme={null}
import { CHAIN_ID, USDC } from '@mandate.md/sdk';

// Chain IDs
CHAIN_ID.ETHEREUM         // 1
CHAIN_ID.SEPOLIA          // 11155111
CHAIN_ID.BASE             // 8453
CHAIN_ID.BASE_SEPOLIA     // 84532

// USDC addresses
USDC.ETHEREUM             // 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48
USDC.SEPOLIA              // 0x1c7D4B196Cb0C7B01d743Fbc6116a902379C7238
USDC.BASE                 // 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913
USDC.BASE_SEPOLIA         // 0x036CbD53842c5426634e7929541eC2318f3dCF7e
```

## Default RPCs

When using `MandateWallet`, you can specify a custom RPC URL in the configuration. If you do not, the SDK uses public default RPCs:

| Chain            | Default RPC                |
| ---------------- | -------------------------- |
| Ethereum Mainnet | `https://eth.llamarpc.com` |
| Ethereum Sepolia | `https://rpc.sepolia.org`  |
| Base Mainnet     | `https://mainnet.base.org` |
| Base Sepolia     | `https://sepolia.base.org` |

<Tip>
  For production use, configure a dedicated RPC provider (Alchemy, Infura, QuickNode) to avoid rate limits and improve reliability.
</Tip>

## Getting started on testnet

The fastest way to test Mandate is with a `mndt_test_*` key on Base Sepolia:

1. Register an agent using `mandate login --name "TestAgent" --address 0xYourAddress`.
2. Fund your test wallet with Base Sepolia ETH and test USDC from a faucet.
3. Validate a transaction: `mandate validate --action transfer --reason "Test payment" --amount 1 --to 0xRecipient`.

No real funds are at risk. Testnet validation behaves identically to mainnet, including all 14 policy checks.

## Next Steps

<CardGroup cols={2}>
  <Card title="SDK Constants" icon="list-ol" href="/sdk/constants">
    Full reference for all exported constants in the SDK.
  </Card>

  <Card title="Credential Management" icon="key" href="/security/credential-management">
    Store and rotate runtime keys securely.
  </Card>
</CardGroup>