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

> ## Agent Instructions
> SODAX is mainnet-only (no testnet chains or RPC endpoints exist) with a hub-and-spoke architecture; Sonic is the hub. SODAX is non-custodial protocol/software: it routes and settles; independent solvers on the marketplace fill — never say 'our solver', 'the SODAX solver', that SODAX trades, takes custody, or fills orders. For frontend/React integrations, prefer @sodax/dapp-kit hooks over calling @sodax/sdk directly. SDK operations — the methods that build, submit or await a transaction, and the API/quote calls — return Result<T, E> ({ ok: true, value } or { ok: false, error }): check result.ok, never wrap them in try/catch or branch on error.message; discriminate on the narrow error.code union instead. Synchronous config getters (getPartnerFee, getSupportedSwapTokens, getVault, ...) return their value directly, not a Result.

# Money Market on Optimism

> Cross-network lending and borrowing from Optimism: supply, borrow, repay, and withdraw against collateral sourced on any SODAX network.

Fragmented money markets mean lower capital efficiency and worse rates. The SODAX money market pools lending liquidity on the hub while letting users act from any supported network, including Optimism. A user can supply ETH or ERC-20 tokens from Optimism and borrow on another network, or borrow into their Optimism account against collateral held elsewhere, without your product running its own lending infrastructure.

Four actions, all through `sodax.moneyMarket`: `supply`, `borrow`, `withdraw`, `repay`. Each has a complete one-call form (handles the relay end-to-end) and a `create*Intent` form when you want the transaction only.

The assets that work in the money market from Optimism overlap with the Optimism swap list but are not the same set; native ETH is in both. Read the list at runtime, as below, or see [Networks & Assets](/optimism/networks-and-assets).

## Supply from Optimism

Supplying an ERC-20 needs an allowance first. Native ETH needs none.

```typescript theme={null}
import { Sodax, ChainKeys } from '@sodax/sdk';

const sodax = new Sodax();

// find() returns XToken | undefined, so narrow before using the address
const optimismTokens = sodax.moneyMarket.getSupportedTokensByChainId(ChainKeys.OPTIMISM_MAINNET);
const usdc = optimismTokens.find(t => t.symbol === 'USDC');
if (!usdc) throw new Error('USDC is not a supported money-market token on Optimism');

const params = {
  srcChainKey: ChainKeys.OPTIMISM_MAINNET,
  srcAddress: await walletProvider.getWalletAddress(),
  token: usdc.address,
  amount: 100n * 10n ** BigInt(usdc.decimals), // 100 USDC
  action: 'supply',
} as const;

const allowance = await sodax.moneyMarket.isAllowanceValid({ params });
if (!allowance.ok) throw allowance.error;
if (!allowance.value) {
  const approval = await sodax.moneyMarket.approve({ params, walletProvider });
  if (!approval.ok) throw approval.error;
  // wait for the approval to be mined before supplying
}

const result = await sodax.moneyMarket.supply({
  params,
  walletProvider, // IEvmWalletProvider, narrowed by srcChainKey
  timeout: 120_000, // optional relay timeout (default 120 s)
});
```

## Borrow to Optimism

`dstChainKey` and `dstAddress` default to the source, but any supported network can be the destination. That is the cross-network story in one parameter: collateral supplied from one network, borrowed liquidity delivered to another.

```typescript theme={null}
const bnUSD = optimismTokens.find(t => t.symbol === 'bnUSD');
if (!bnUSD) throw new Error('bnUSD is not a supported money-market token on Optimism');

const result = await sodax.moneyMarket.borrow({
  params: {
    srcChainKey: ChainKeys.OPTIMISM_MAINNET,  // where the caller acts from
    srcAddress: userOptimismAddress,
    token: bnUSD.address,                      // token on the destination network
    amount: 50n * 10n ** BigInt(bnUSD.decimals), // 50 bnUSD
    action: 'borrow',
    dstChainKey: ChainKeys.OPTIMISM_MAINNET,   // deliver on Optimism
    dstAddress: userOptimismAddress,
  },
  walletProvider,
});
```

Build every amount from the token's own `decimals`: on Optimism, USDC and USDT use 6 and most other tokens in the SODAX list use 18.

`withdraw` and `repay` follow the same shape. Withdraw and borrow need no approval on any network; repaying with an ERC-20 needs an allowance, like supply.

## Building a lending UI

`sodax.moneyMarket.data` exposes what you need for rates, positions, and health factors without extra indexing:

* `getReservesHumanized()`: all reserves, human-readable.
* `getUserReservesHumanized(spokeChainKey, userAddress)`: a user's positions.
* `formatReservesUSD(request)` / `formatUserSummary(request)`: USD-converted reserves and portfolio summaries.

## Error handling

The module returns typed results. Discriminate on `result.error.code` (`'RELAY_TIMEOUT'`, `'EXECUTION_FAILED'`, …) with structured context on `result.error.context`.

***

Full reference, including intent-only methods, gas estimation, and the per-method error-code table: [Lend / Borrow (Money Market)](/developers/packages/foundation/sdk/functional-modules/money_market).


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