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Aave V4 TypeScript Quickstart

AaveKit TypeScript for Aave V4 provides a type-safe, low-level API client for interacting with Aave V4. It offers a lightweight abstraction over the GraphQL API and is ideal for server-to-server communication.

Built with a modular, functional approach inspired by the viem client-actions architecture, the SDK structures functionality into distinct, reusable actions focused on specific protocol features like lending, borrowing, and data retrieval.

Getting Started

To get started, follow the steps below.

1. Install SDK

First, install the @aave/client package using your package manager of choice.

npm install @aave/client@next

2. Set Up Client

Then, create an AaveClient instance that will be used to interact with the protocol.

client.ts
import { AaveClient } from "@aave/client";

export const client = AaveClient.create();

3. Start Building

You can now use the @aave/client/actions to interact with the Aave Protocol. Here’s a basic example to query supported chains:

example.ts
import { ChainsFilter } from "@aave/client";
import { chains } from "@aave/client/actions";

import { client } from "./client";

// Fetch all chains supported by Aave
const result = await chains(client, {
  query: { filter: ChainsFilter.ALL },
});

if (result.isOk()) {
  console.log("Chains:", result.value);
} else {
  console.error("Error:", result.error);
}

Server-Side Rendering

AaveClient supports SSR hand-off through the ssr option. Create a server-side client, run your queries, serialize client.extractData(), then hydrate a browser client with that snapshot.

import { AaveClient, type SSRData, ChainsFilter } from "@aave/client";
import { chains } from "@aave/client/actions";

const client = AaveClient.create({
  ssr: { isServer: true },
});

await chains(client, {
  query: { filter: ChainsFilter.ALL },
});

const initialState: SSRData = client.extractData();

// Serialize into the HTML: <script>window.__AAVE_SSR_DATA__ = ${JSON.stringify(initialState)}</script>

If the snapshot arrives after the client is created, call client.restoreData(initialState) to hydrate the cache later.

Display Configuration

The optional display config transforms how assets are presented across queries. Transforms are applied after the cache, so the cache always stores untransformed data.

client.ts
import { AaveClient } from "@aave/client";

export const client = AaveClient.create({
  display: {
    // Show wrapped native tokens (e.g. WETH) as the native asset (e.g. ETH)
    showWrappedNativeReserveAsNative: true,
    // Per-asset overrides, keyed by chain ID and address
    assetOverrides: [
      {
        chainId: 1,
        address: "0xAeBf0Bb9f57E89260d57f31AF34eB58657d96Ce0",
        display: { name: "PT USDe (May 2026)", symbol: "PT USDe", icon: "https://…" },
      },
    ],
  },
});
  • showWrappedNativeReserveAsNative: when true, wrapped native tokens are shown using the native asset’s name, symbol, and icon within reserve contexts (Reserve, HubAsset, Asset). Wallet balance, reward payout, and swap queries are unaffected. The underlying isWrappedNativeToken flag and token address are preserved.
  • assetOverrides: per-asset display overrides applied globally across all queries, keyed by chainId and address. Each entry takes a display object with optional name, symbol, and icon.

If both settings target the same token, assetOverrides takes precedence.

Result Objects

AaveKit handles errors with Result<T, E>, which represents one of two states:

  • Ok<T>: A successful result containing a value of type T
  • Err<E>: A failure containing an error of type E
Example
import { ok, err, Result } from "@aave/client";

function parseId(s: string): Result<number, Error> {
  if (/^\d+$/.test(s)) {
    return ok(Number(s));
  }
  return err(new Error("ID must be a number"));
}

With a Result<T, E>, use the isOk() and isErr() methods to check the outcome and narrow the type.

TypeScript
const result: Result<number, Error> = parseId("123");

if (result.isOk()) {
  console.log(result.value); // 123
} else {
  console.error(result.error); // Error
}

This approach avoids reliance on try/catch blocks and promotes predictable, type-safe code by ensuring errors are handled explicitly.

AaveKit builds its Result object on NeverThrow.

ResultAsync<T, E> is the async, thenable variant of Result<T, E>. Awaiting it resolves to a Result<T, E>.

TypeScript
import { ResultAsync } from "@aave/client";

function fetchUser(id: number): ResultAsync<{ name: string }, Error> {
  return ResultAsync.fromPromise(
    fetch(`/api/users/${id}`).then((r) => r.json()),
    () => new Error("Not found"),
  );
}

const result = await fetchUser(1);

if (result.isOk()) {
  console.log(result.value); // { name: "John" }
} else {
  console.error(result.error); // Error
}

Result objects can be chained:

Chaining
function divide(a: number, b: number): Result<number, string> {
  return b === 0 ? err("Division by zero") : ok(a / b);
}

const result = parseId("42").andThen((num) => divide(num, 2));

if (result.isOk()) {
  console.log("Result:", result.value);
} else {
  console.error("Error:", result.error);
}

You can also provide a default value if the result is an error:

Default Value
const value = parseId("invalid").unwrapOr(0); // 0

See the NeverThrow documentation for more information.

Integrations

AaveKit TypeScript includes first-class support for viem, ethers v6, Privy, thirdweb and Turnkey wallets.

Ensure you have viem package installed in your project.

npm install viem@2

Send Aave Transactions

Among the actions provided by AaveKit TypeScript, some are specifically designed to handle protocol interactions such as supplying, borrowing, withdrawing, repaying, and more.

There are two main types of transaction actions:

  • Simple transactions: single-step transactions that can be sent directly to the wallet.
  • Complex transactions: transactions that may require prior approvals before they can be executed.

To send transactions, follow the steps below.

1. Import the Helper

First, import the sendWith helper function for the wallet library of your choice.

Import the sendWith helper from the @aave/client/viem entry point.

Viem
import { sendWith } from "@aave/client/viem";

2. Send the Transaction

Then, use the sendWith helper to send the transaction.

To demonstrate how this helper works, assume we have a transaction action named foobar.

import { foobar } from "@aave/client/actions";
import { client } from "./client";

const result = await foobar(client);

To send the transaction, chain the action with sendWith for your wallet library, then use client.waitForTransaction to wait until it’s confirmed and indexed by AaveKit API.

import { foobar } from "@aave/client/actions";
import { sendWith } from "@aave/client/viem";
import { createWalletClient, http } from "viem";
import { privateKeyToAccount } from "viem/accounts";

import { client } from "./client";

const wallet = createWalletClient({
  account: privateKeyToAccount("<PRIVATE_KEY>"),
  transport: http(),
});

const result = await foobar(client)
  .andThen(sendWith(wallet))
  .andThen(client.waitForTransaction);

3. Handle the Result

Finally, handle the result of the operation.

TypeScript
if (result.isErr()) {
  switch (result.error.name) {
    case "CancelError":
      // The user cancelled the operation
      return;

    case "SigningError":
      // Most likely the user rejected the transaction
      console.error(`Failed to sign the transaction: ${result.error.message}`);
      break;

    case "TimeoutError":
      console.error(`Transaction timed out: ${result.error.message}`);
      break;

    case "TransactionError":
      console.error(`Transaction failed: ${result.error.message}`);
      break;

    case "ValidationError":
      console.error(
        "Insufficient balance:",
        `required: ${result.error.cause.required.value.toDisplayString(2)}`,
        `available: ${result.error.cause.available.value.toDisplayString(2)}`,
      );
      break;

    case "UnexpectedError":
      console.error(result.error.message);
      break;
  }
  return;
} else {
  console.log(result.value.txHash); // TxHash
}

You’ve sent the transaction.

Sign Typed Data

Some Aave operations require EIP-712 typed data signatures for the following:

  • ERC-20 Permits: Authorize exact amount transfers without separate approval transactions
  • Swap Intents: Sign swap orders for intent-based swaps

Permits are available for ERC-20 tokens that implement EIP-2612.

Import the signing helpers for your wallet library.

Import the signTypedDataWith or permitWith helpers from the @aave/client/viem entry point.

Viem
import { signTypedDataWith, permitWith } from "@aave/client/viem";

Then, use them as described in the specific operation guide.

Next Steps