# Loans & Collateral

This guide demonstrates how to integrate with Curvance Protocol using JavaScript and ethers.js v5.7, with specific examples using the shMON for collateral and USDC for lending.

{% hint style="info" %}
The MarketManager coordinates all cTokens, for a deep dive check out this article: [Market Manager](/app/developer-docs/lending-protocol/market-manager.md)
{% endhint %}

#### Setting Up Your Integration

First, install ethers.js, for the examples in these docs, we use ethers 5.7.x.

```bash
npm install ethers@5.7.3
```

You'll need to define your contract addresses and ABIs. Here's a simplified example for the most important ones:

```javascript
const ADDRESSES = {
  SHMON: "0x21E27a5E5513D6e65C4f830167390997aA84843a",
  USDC: "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48",
  SHMON_CTOKEN: "0x..." // Replace with actual cToken address
  USDC_CTOKEN: "0x..." // Replace with actual cToken address
};
```

## Important Considerations Before Depositing

Before sending any transactions, check these important protocol values by calling `mintPaused()` in the MarketManager contract.

1. **Protocol Status:** Verify if minting of the cToken is not paused:

Call [`actionsPaused()`](/app/developer-docs/lending-protocol/market-manager.md#actionspaused) with the following arguments. Returning a tuple of booleans, indicating if minting, collateralization, and borrowing is paused.

<table><thead><tr><th width="109.20001220703125">Type</th><th width="469.98333740234375">Description</th></tr></thead><tbody><tr><td>address</td><td>Address of the cToken to check the minting status of.</td></tr></tbody></table>

Implementation:

```javascript
const marketManager = new ethers.Contract(MARKET_MANAGER_ADDRESS, MARKET_MANAGER_ABI, provider);
const actionsPaused = await marketManager.mintPaused(SHMON_CTOKEN);
```

2. **Collateral Caps:** If depositing as collateral, check if the asset has reached its collateral cap by calling `collateralCaps()`, and `marketCollateralPosted()` in the MarketManager contract:

Calling `collateralCaps()` using these function arguments, returning uint256 indicating the maximum amounts of cTokens that can be posted as collateral:

<table><thead><tr><th width="109.20001220703125">Type</th><th width="469.98333740234375">Description</th></tr></thead><tbody><tr><td>address</td><td>Address of the cToken to check the max amount of shares that can be posted as collateral.</td></tr></tbody></table>

Call `marketCollateralPosted()`  which returns a uint256 indicating the current amount of cTokens currently posted as collateral:

<table><thead><tr><th width="109.20001220703125">Type</th><th width="469.98333740234375">Description</th></tr></thead><tbody><tr><td>address</td><td>Address of the cToken to check the amount of collateral posted.</td></tr></tbody></table>

Implementation:

```javascript
const cap = await marketManager.collateralCaps(SHMON_CTOKEN);
const posted = await marketManager.marketCollateralPosted(SHMON_CTOKEN)
const capReached = posted.gte(cap) && !cap.isZero();
```

3. **Minimum Hold Period:** Be aware that Curvance implements a 20-minute minimum hold period for collateralized deposits to mitigate flash loan attacks.
4. **Non Rebasing:** Understand that your share value increases over time rather than the number of shares.

#### Best Practices for Production Implementations

1. **Error Handling:** Implement proper error handling for all transactions.
2. **Gas Estimation:** Use estimateGas before sending transactions to ensure proper gas limits.
3. **Approval Checking:** Check existing allowances before sending approval transactions.
4. **Transaction Monitoring:** Implement logic to track transaction status after submission.
5. **Read-Only Checks:** Use read-only calls to validate operations before sending transactions.

By following this guide, you'll be able to integrate with Curvance's deposit functionality for both yield-optimized collateral positions and lending positions using JavaScript and ethers.js v5.7.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.curvance.com/app/developer-docs/quick-start-guides/loans-and-collateral.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.