TypeScript SDK: View and Query

Purpose

Guide read-only access to chain data in @aptos-labs/ts-sdk: view functions, balance, account info, resources, and modules.

ALWAYS

1. Use aptos.getBalance({ accountAddress }) for APT balance – not deprecated getAccountCoinAmount / getAccountAPTAmount.
2. Use aptos.view() for Move view functions – pass function, functionArguments, and optional typeArguments.
3. Use bigint for u128/u256 view return values – cast result[0] to BigInt(...) when the Move function returns u128/u256.
4. Pass address as string or AccountAddress – SDK accepts AccountAddressInput (string or AccountAddress).

NEVER

1. Do not use deprecated getAccountCoinAmount or getAccountAPTAmount – use getBalance().
2. Do not use number for u128/u256 – precision loss; use bigint.
3. Do not assume view returns are always strings – types vary (number, bigint, string, boolean, array).

---

getBalance (APT)

const balance = await aptos.getBalance({
  accountAddress: account.accountAddress
});
// balance is bigint in octas (1 APT = 100_000_000 octas)
const apt = balance / 100_000_000n;
const remainder = balance % 100_000_000n;
console.log(`${apt}.${remainder.toString().padStart(8, "0")} APT`);

---

getAccountInfo

const accountInfo = await aptos.getAccountInfo({
  accountAddress: "0x1"
});
// accountInfo: { sequence_number, authentication_key, ... }

---

view() – Move view functions

// No type arguments
const result = await aptos.view({
  payload: {
    function: `${MODULE_ADDRESS}::counter::get_count`,
    functionArguments: [accountAddress]
  }
});
const count = Number(result[0]);

// With type arguments (e.g. coin type)
const balanceResult = await aptos.view({
  payload: {
    function: "0x1::coin::balance",
    typeArguments: ["0x1::aptos_coin::AptosCoin"],
    functionArguments: [accountAddress]
  }
});
const coinBalance = BigInt(balanceResult[0] as string);

// Multiple return values
// Move: public fun get_listing(addr): (address, u64, bool)
const [seller, price, isActive] = await aptos.view({
  payload: {
    function: `${MODULE_ADDRESS}::marketplace::get_listing`,
    functionArguments: [listingAddress]
  }
});
const listing = {
  seller: seller as string,
  price: BigInt(price as string),
  isActive: isActive as boolean
};

---

getAccountResources

const resources = await aptos.getAccountResources({
  accountAddress: account.accountAddress
});
// resources: Array<MoveResource>
const counterResource = resources.find((r) => r.type === `${MODULE_ADDRESS}::counter::Counter`);

---

getAccountResource (single type)

const resource = await aptos.getAccountResource({
  accountAddress: account.accountAddress,
  resourceType: `${MODULE_ADDRESS}::counter::Counter`
});
// resource.data has the struct fields
const value = (resource?.data as { value: number })?.value;

---

getAccountModules

const modules = await aptos.getAccountModules({
  accountAddress: modulePublisherAddress
});
// modules: MoveModuleBytecode[] (ABI, bytecode)

---

getModule (single module by name)

const module = await aptos.getModule({
  accountAddress: modulePublisherAddress,
  moduleName: "counter"
});

---

Pagination (resources / modules)

Use cursor-based options when available:

const { resources, cursor } = await aptos.getAccountResourcesPage({
  accountAddress: account.accountAddress,
  options: { limit: 10, cursor: nextCursor }
});

---

Type handling for view results

Move return type	TypeScript	Example
u8..u64	number or bigint	Number(result[0]) or BigInt(result[0])
u128, u256	bigint	BigInt(result[0] as string)
address	string	result[0] as string
bool	boolean	result[0] as boolean
vector	array	result[0] as T[]

---

Common mistakes

Mistake	Correct approach
Using getAccountCoinAmount	Use aptos.getBalance({ accountAddress })
Using number for u128	Use BigInt(result[0] as string)
Forgetting typeArguments for generic view	Add typeArguments: [coinType] when Move function is generic

---

References

• SDK: src/internal/view.ts, src/api/account.ts, balance/getBalance in internal
• Pattern: TYPESCRIPT_SDK.md
• Related: ts-sdk-client, ts-sdk-types, use-ts-sdk