> For the complete documentation index, see [llms.txt](https://docs.bsc.lista.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.bsc.lista.org/for-developer/lista-lending/sdk.md).

# Moolah Lending SDK

The Moolah Lending SDK is the TypeScript integration path for Lista Lending (Moolah) on BNB Chain and Ethereum, published on public npm under the `@lista-dao` scope.

It is **wallet-agnostic**: read methods call the chain (via [viem](https://viem.sh)) or the public Lista API, and write methods return an array of plain transaction-step descriptors that you execute with your own wallet client. The SDK never holds keys, never signs, and never broadcasts on your behalf.

> **Check the published version before you pin.** The two packages release independently of the protocol, so the npm release can trail the contracts — run `npm view @lista-dao/moolah-lending-sdk version` and compare against the [Smart Contract](/for-developer/lista-lending/smart-contract.md) tables. Where the SDK is behind, the contract reference is authoritative and you can call Moolah directly; see [Contract & Interface Reference](/for-developer/lista-lending/contract-reference.md).

## Packages

| Package                                                                                        | Description                                                                                |
| ---------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------ |
| [`@lista-dao/moolah-lending-sdk`](https://www.npmjs.com/package/@lista-dao/moolah-lending-sdk) | The `MoolahSDK` builder — reads chain/API data, returns transaction steps.                 |
| [`@lista-dao/moolah-sdk-core`](https://www.npmjs.com/package/@lista-dao/moolah-sdk-core)       | Types, pure simulation functions, contract ABIs, the `Decimal` utility, `MoolahApiClient`. |

Installing the lending SDK pulls the core package in and re-exports a convenience subset of it. The pure **simulate functions**, interest-rate helpers, and contract **ABIs** are *not* re-exported — import those from `@lista-dao/moolah-sdk-core` directly.

```bash
pnpm add @lista-dao/moolah-lending-sdk
pnpm add viem@^2.22.10
```

`viem` is a direct dependency of both packages (`viem@^2.22.10`), so you do not need it to *use* the SDK — but you will use it to execute the returned steps. Install a version in the same range so your package manager dedupes to one copy: **two viem instances cause client and type mismatches** across the `publicClients` boundary.

## Writing transactions: builders, not senders

`build*Params` methods return an ordered array of step descriptors. Each carries a `params` object with `{ to, abi, functionName, args, value, chainId, data }`, plus an optional `meta`. Execute them in order with your own wallet client.

```typescript
import { parseUnits } from "viem";

const supplySteps = await sdk.buildSupplyParams({ chainId: 56, marketId, assets: parseUnits("100", 18), walletAddress });
const borrowSteps = await sdk.buildBorrowParams({ chainId: 56, marketId, assets: parseUnits("50", 18), walletAddress });

// Collateral must land before the borrow, so run the supply steps first.
for (const step of [...supplySteps, ...borrowSteps]) {
  // `params.to` maps onto viem's `address`; `chainId` and `data` are extra
  // fields that `writeContract` does not accept.
  const hash = await walletClient.writeContract({
    address: step.params.to,
    abi: step.params.abi,
    functionName: step.params.functionName,
    args: step.params.args,
    value: step.params.value,
  });
  await publicClient.waitForTransactionReceipt({ hash });
}
```

Three things about that loop:

* **Execute every step, in order, and never dedupe by `step`.** A builder prepends `"approve"` steps when an allowance is needed.
* **Ethereum mainnet USDT emits *****two***** approve steps** when a non-zero but insufficient allowance already exists — a reset to `0` (flagged `meta.reset === true`) followed by the real approve — because that contract rejects non-zero → non-zero allowance changes. A sufficient allowance emits none at all.
* **The SDK's "supply" is the collateral side.** `buildSupplyParams` calls `supplyCollateral`; Moolah's own `supply` — lending the loan asset — has no builder and is reached through a vault.

## Known gaps

Verified against `@lista-dao/moolah-lending-sdk@1.0.11` / `@lista-dao/moolah-sdk-core@1.0.12` — re-check these once the SDK ships a new release:

* **Do not resolve addresses from `getContractAddress` / `getContractAddressOptional`.** Several entries in the bundled address book are unset — on BNB Chain as well as Ethereum. The first throws, the second returns the **zero address**, which is the more dangerous failure since a caller can send to it. Use the [Smart Contract](/for-developer/lista-lending/smart-contract.md) tables instead.
* `getBrokerUserPositions` and `getMarketUserDataWithBroker` do not work on Ethereum.
* Native-asset (ETH) markets and vaults are not detected correctly — use the ERC-20 paths.
* `getBrokerFixedTerms` decodes with the `LendingBroker` ABI, so it does not support a `CreditBroker`, whose `FixedTermAndRate` carries a fourth field (`termType`).

## Reading market state

`getMarketExtraInfo` and `getMarketUserData` return the market's live economic state — `LLTV`, `borrowRate`, `utilRate`, `priceRate`, `minLoan`, and the user's `collateral`, `borrowed`, `loanable`, `withdrawable`, `LTV`. `getMarketRuntimeData` returns extra info, write config and user data in one call.

**`priceRate` is loan tokens per one collateral token** — `collateral × priceRate` is a loan-denominated value. Inverting it inverts every LTV and liquidation figure you derive from it.

Human-scaled amounts come back as `Decimal` (a fixed-point helper with `add`/`sub`/`mul`/`div`, rounding controls and comparisons); raw on-chain integers — borrow shares, timestamps, rate caps, the `MarketParams` struct — stay `bigint`.

## See also

* [Integration Patterns](/for-developer/lista-lending/integration-patterns.md) — provider and broker models.
* [Moolah Lending API](/for-developer/services/lending-api.md) — the REST surface the API-sourced reads use.


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

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

Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters:

```
GET https://docs.bsc.lista.org/for-developer/lista-lending/sdk.md?ask=<question>&goal=<user_goal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case.

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.