# Take out a loan ### Prerequisites * An account that has been whitelisted as a borrower on the target inventory pool * A sufficient amount of collateral deposited ### Process Overview 1. Request a borrow digest from the API 2. Sign the digest with your private key 3. Submit the borrow request with your signature 4. Execute the resulting transaction on-chain ### Step 1: Request Borrow Digest This step authenticates your request, preventing any other address from requesting a borrow on your behalf. Make a GET request to `https://api.nomial.io/borrow/digest` with the following query parameters: | Name | Description | | ----------- | -------------------------------------------------------------------------- | | `chain_id` | The chain ID (e.g., `1` for Ethereum mainnet) | | `pool` | The inventory pool address | | `borrower` | Your borrower address | | `amount` | The amount of ERC20 to borrow (in base units) | | `recipient` | The address that will receive the borrowed funds (can be same as borrower) | | `expiry` | Unix timestamp when the request expires (e.g., 1 hour in the future) | | `salt` | Arbitrary 32-byte hex string to ensure request uniqueness | **Example** ``` curl "https://api.nomial.io/borrow/digest?\ chain_id=1&\ pool=0xabc123...&\ borrower=0xdef456...&\ amount=1000000&\ recipient=0xdef456...&\ expiry=1234567890&\ salt=0xabcdefabcdefabcdefabcdefabcdefabcdefabcdefabcdefabcdefabcdef" ``` The API will return a digest that needs to be signed by your borrower address ```json { "digest": "0x..." // The digest to sign } ``` ### Step 2: Sign the Digest Sign the provided hex digest directly with the private key of your borrower address. The resulting signature must use the standard 65-byte Ethereum format (r, s, v). Be sure to sign the raw digest, without including an ERC-191 (“Ethereum Signed Message”) prefix. #### Using Foundry cast to sign manually You can use the [cast](https://getfoundry.sh/cast/overview) CLI tool to sign the digest manually with the [cast wallet sign](https://getfoundry.sh/cast/reference/cast-wallet-sign) command ``` cast wallet sign --private-key --no-hash ``` ### Step 3: Submit Borrow Request Make a POST request to `https://api.nomial.io/borrow`. This should include identical parameters and values to your digest request, with the addition of `signature` (your signature of the request digest). ```json { "chain_id": "1", // The chain ID "pool": "0x...", // The inventory pool address "borrower": "0x...", // Your borrower address "amount": "1000000", // The amount to borrow in base units "recipient": "0x...", // The address that will receive the borrowed funds "expiry": "1234567890", // Unix timestamp when the request expires "salt": "0x...", // The same salt used for the request digest "signature": "0x..." // Your signature of the request digest } ``` If your borrow request is valid, the API will return a transaction with validator signatures that can be executed to the inventory pool's owner (access manager): ```json { "call": { "chain": { "id": "1", "name": "ethereum" }, "contract": { "name": "InventoryPoolDefaultAccessManager01", "address": "0x..." }, "function": "borrow(address pool, uint256 amount, address recipient, uint256 expiry, bytes32 salt, bytes[] signatures)", "selector": "0x...", "calldata": "0x...", "params": [ { "name": "pool", "value": "0x..." }, { "name": "amount", "value": "1000000" }, { "name": "recipient", "value": "0x..." }, { "name": "expiry", "value": "1234567890" }, { "name": "salt", "value": "0x..." }, { "name": "signatures", "value": ["0x...", "0x..."] } ] }, "tx": { "to": "0x...", // The access manager contract address "data": "0x...", // The encoded function call data "value": "0", // The amount of native token to send "chain_id": "1" // The chain ID }, "signed_digest": "0x...", // The digest that was signed "validator_signatures": [ // Array of validator signatures { "validator": "validator1", "signature": "0x..." } ] } ``` ### Step 4: Execute the Transaction You can submit your signed transaction to the chain it was intended for. Here's an example using ethers.js: 
const provider = new ethers.providers.JsonRpcProvider(rpcUrl);

const tx = {
  to: response.tx.to,
  data: response.tx.data,
  value: response.tx.value
};

// Send the transaction
const result = await wallet.connect(provider).sendTransaction(tx);
await result.wait();
Alternatively, you can construct the transaction yourself using the `call` object: ```javascript // Import the contract ABI const accessManagerABI = [ "function borrow(address pool, uint256 amount, address recipient, uint256 expiry, bytes32 salt, bytes[] signatures)" ]; // Create contract instance const accessManager = new ethers.Contract( response.call.contract.address, accessManagerABI, wallet ); // Execute the borrow function const result = await accessManager.borrow( response.call.params[0].value, // pool response.call.params[1].value, // amount response.call.params[2].value, // recipient response.call.params[3].value, // expiry response.call.params[4].value, // salt response.call.params[5].value // signatures ); await result.wait(); ``` Note that you must execute your transaction on the access manager contract that is `owner` on the inventory pool, and not the inventory pool itself. --- # 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.nomial.io/solvers/take-out-a-loan.md?ask= ``` 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.