diff --git a/bindings/nodejs/examples/client/04-get-output.ts b/bindings/nodejs/examples/client/04-get-output.ts
index 1b439c3f11..5141243ba9 100644
--- a/bindings/nodejs/examples/client/04-get-output.ts
+++ b/bindings/nodejs/examples/client/04-get-output.ts
@@ -1,7 +1,7 @@
 // Copyright 2021-2023 IOTA Stiftung
 // SPDX-License-Identifier: Apache-2.0
 
-import { Client, initLogger } from '@iota/sdk';
+import { Client, initLogger, OutputId } from '@iota/sdk';
 require('dotenv').config({ path: '.env' });
 
 // Run with command:
@@ -22,7 +22,9 @@ async function run() {
     });
     try {
         const output = await client.getOutput(
-            '0x022aefa73dff09b35b21ab5493412b0d354ad07a970a12b71e8087c6f3a7b8660000',
+            new OutputId(
+                '0x022aefa73dff09b35b21ab5493412b0d354ad07a970a12b71e8087c6f3a7b866000000000000',
+            ),
         );
         console.log('Output: ', output);
     } catch (error) {
diff --git a/bindings/nodejs/examples/client/05-get-address-balance.ts b/bindings/nodejs/examples/client/05-get-address-balance.ts
index e8563c2c3f..7dc1a5fb62 100644
--- a/bindings/nodejs/examples/client/05-get-address-balance.ts
+++ b/bindings/nodejs/examples/client/05-get-address-balance.ts
@@ -1,7 +1,13 @@
 // Copyright 2021-2023 IOTA Stiftung
 // SPDX-License-Identifier: Apache-2.0
 
-import { Client, CommonOutput, SecretManager, initLogger } from '@iota/sdk';
+import {
+    Client,
+    CommonOutput,
+    SecretManager,
+    initLogger,
+    OutputId,
+} from '@iota/sdk';
 require('dotenv').config({ path: '.env' });
 
 // Run with command:
@@ -45,7 +51,9 @@ async function run() {
         });
 
         // Get outputs by their IDs
-        const addressOutputs = await client.getOutputs(outputIdsResponse.items);
+        const addressOutputs = await client.getOutputs(
+            outputIdsResponse.items.map((id) => new OutputId(id)),
+        );
 
         // Calculate the total amount and native tokens
         let totalAmount = BigInt(0);
diff --git a/bindings/nodejs/examples/how_tos/client/get-outputs.ts b/bindings/nodejs/examples/how_tos/client/get-outputs.ts
index 6382a7f5c6..48bccc9b0e 100644
--- a/bindings/nodejs/examples/how_tos/client/get-outputs.ts
+++ b/bindings/nodejs/examples/how_tos/client/get-outputs.ts
@@ -1,7 +1,7 @@
 // Copyright 2021-2023 IOTA Stiftung
 // SPDX-License-Identifier: Apache-2.0
 
-import { Client, initLogger } from '@iota/sdk';
+import { Client, initLogger, OutputId } from '@iota/sdk';
 require('dotenv').config({ path: '.env' });
 
 // Run with command:
@@ -33,7 +33,9 @@ async function run() {
         console.log('First output of query:');
         console.log('ID: ', outputIdsResponse.items[0]);
 
-        const outputs = await client.getOutputs(outputIdsResponse.items);
+        const outputs = await client.getOutputs(
+            outputIdsResponse.items.map((id) => new OutputId(id)),
+        );
         console.log(outputs[0]);
     } catch (error) {
         console.error('Error: ', error);
diff --git a/bindings/nodejs/lib/types/block/id.ts b/bindings/nodejs/lib/types/block/id.ts
index a2fbf268c1..557b41c1fe 100644
--- a/bindings/nodejs/lib/types/block/id.ts
+++ b/bindings/nodejs/lib/types/block/id.ts
@@ -2,6 +2,28 @@
 // SPDX-License-Identifier: Apache-2.0
 
 import { HexEncodedString } from '../utils';
+import { SlotIndex } from './slot';
+
+/**
+ * Base class for IDs with a hex encoded slot index at the end.
+ */
+export class IdWithSlotIndex extends String {
+    slotIndex(): SlotIndex {
+        const numberString = super.slice(-8);
+        const chunks = [];
+        for (
+            let i = 0, charsLength = numberString.length;
+            i < charsLength;
+            i += 2
+        ) {
+            chunks.push(numberString.substring(i, i + 2));
+        }
+        const separated = chunks.map((n) => parseInt(n, 16));
+        const buf = Uint8Array.from(separated).buffer;
+        const view = new DataView(buf);
+        return view.getUint32(0, true);
+    }
+}
 
 /**
  * An Account ID represented as hex-encoded string.
@@ -21,13 +43,18 @@ export type NftId = HexEncodedString;
 /**
  * A Block ID represented as hex-encoded string.
  */
-export type BlockId = HexEncodedString;
+export class BlockId extends IdWithSlotIndex {}
 
 /**
  * A Token ID represented as hex-encoded string.
  */
 export type TokenId = HexEncodedString;
 
+/**
+ * A Transaction ID represented as hex-encoded string.
+ */
+export class TransactionId extends IdWithSlotIndex {}
+
 /**
  * A Foundry ID represented as hex-encoded string.
  */
diff --git a/bindings/nodejs/lib/types/block/input/input.ts b/bindings/nodejs/lib/types/block/input/input.ts
index 39f0ba5062..b5f2dff5b7 100644
--- a/bindings/nodejs/lib/types/block/input/input.ts
+++ b/bindings/nodejs/lib/types/block/input/input.ts
@@ -1,7 +1,8 @@
 // Copyright 2023 IOTA Stiftung
 // SPDX-License-Identifier: Apache-2.0
 
-import { HexEncodedString } from '../../utils';
+import { Transform, Type } from 'class-transformer';
+import { TransactionId } from '../id';
 import { OutputId } from '../output';
 
 /**
@@ -33,7 +34,9 @@ class UTXOInput extends Input {
     /**
      * The transaction ID.
      */
-    readonly transactionId: HexEncodedString;
+    @Type(() => TransactionId)
+    @Transform(({ value }) => new TransactionId(value), { toClassOnly: true })
+    readonly transactionId: TransactionId;
     /**
      * The output index.
      */
@@ -43,10 +46,7 @@ class UTXOInput extends Input {
      * @param transactionId The ID of the transaction it is an input of.
      * @param transactionOutputIndex The index of the input within the transaction.
      */
-    constructor(
-        transactionId: HexEncodedString,
-        transactionOutputIndex: number,
-    ) {
+    constructor(transactionId: TransactionId, transactionOutputIndex: number) {
         super(InputType.UTXO);
         this.transactionId = transactionId;
         this.transactionOutputIndex = transactionOutputIndex;
diff --git a/bindings/nodejs/lib/types/block/output/output.ts b/bindings/nodejs/lib/types/block/output/output.ts
index c72e96dd8c..35a651a592 100644
--- a/bindings/nodejs/lib/types/block/output/output.ts
+++ b/bindings/nodejs/lib/types/block/output/output.ts
@@ -9,13 +9,32 @@ import { Feature, FeatureDiscriminator, NativeTokenFeature } from './feature';
 
 // Temp solution for not double parsing JSON
 import { plainToInstance, Type } from 'class-transformer';
-import { HexEncodedString, NumericString, u64 } from '../../utils';
+import { NumericString, u64 } from '../../utils';
 import { TokenScheme, TokenSchemeDiscriminator } from './token-scheme';
-import { AccountId, NftId, AnchorId, DelegationId } from '../id';
+import { AccountId, NftId, AnchorId, DelegationId, TransactionId } from '../id';
 import { EpochIndex } from '../../block/slot';
 import { NativeToken } from '../../models/native-token';
 
-export type OutputId = HexEncodedString;
+export class OutputId extends String {
+    transactionId(): TransactionId {
+        return new TransactionId(this.slice(74));
+    }
+    outputIndex(): number {
+        const numberString = this.slice(-4);
+        const chunks = [];
+        for (
+            let i = 0, charsLength = numberString.length;
+            i < charsLength;
+            i += 2
+        ) {
+            chunks.push(numberString.substring(i, i + 2));
+        }
+        const separated = chunks.map((n) => parseInt(n, 16));
+        const buf = Uint8Array.from(separated).buffer;
+        const view = new DataView(buf);
+        return view.getUint16(0, true);
+    }
+}
 
 /**
  * All of the output types.
diff --git a/bindings/nodejs/lib/types/block/slot/commitment.ts b/bindings/nodejs/lib/types/block/slot/commitment.ts
index 232703f319..5982beccb4 100644
--- a/bindings/nodejs/lib/types/block/slot/commitment.ts
+++ b/bindings/nodejs/lib/types/block/slot/commitment.ts
@@ -2,6 +2,7 @@
 // SPDX-License-Identifier: Apache-2.0
 
 import { u64 } from '../..';
+import { IdWithSlotIndex } from '../id';
 
 /**
  * Timeline is divided into slots, and each slot has a corresponding slot index.
@@ -21,7 +22,7 @@ type EpochIndex = number;
 /**
  * Identifier of a slot commitment
  */
-type SlotCommitmentId = string;
+class SlotCommitmentId extends IdWithSlotIndex {}
 
 /**
  * A BLAKE2b-256 hash of concatenating multiple sparse merkle tree roots of a slot.
diff --git a/bindings/nodejs/lib/types/client/bridge/client.ts b/bindings/nodejs/lib/types/client/bridge/client.ts
index aa3ea3ef26..5bd79f7de2 100644
--- a/bindings/nodejs/lib/types/client/bridge/client.ts
+++ b/bindings/nodejs/lib/types/client/bridge/client.ts
@@ -17,6 +17,7 @@ import type {
     OutputId,
     Payload,
     SlotIndex,
+    SlotCommitmentId,
 } from '../../block';
 import type { PreparedTransactionData } from '../prepared-transaction-data';
 import type {
@@ -223,21 +224,21 @@ export interface __GetTransactionMetadataMethod__ {
 export interface __GetCommitmentMethod__ {
     name: 'getCommitment';
     data: {
-        commitmentId: HexEncodedString;
+        commitmentId: SlotCommitmentId;
     };
 }
 
 export interface __GetUtxoChangesMethod__ {
     name: 'getUtxoChanges';
     data: {
-        commitmentId: HexEncodedString;
+        commitmentId: SlotCommitmentId;
     };
 }
 
 export interface __GetUtxoChangesFullMethod__ {
     name: 'getUtxoChangesFull';
     data: {
-        commitmentId: HexEncodedString;
+        commitmentId: SlotCommitmentId;
     };
 }
 
diff --git a/bindings/nodejs/lib/types/client/prepared-transaction-data.ts b/bindings/nodejs/lib/types/client/prepared-transaction-data.ts
index 9af6cb57eb..141662507e 100644
--- a/bindings/nodejs/lib/types/client/prepared-transaction-data.ts
+++ b/bindings/nodejs/lib/types/client/prepared-transaction-data.ts
@@ -3,11 +3,11 @@
 
 import { Type } from 'class-transformer';
 import { Address, AddressDiscriminator } from '../block/address';
-import { Output, OutputDiscriminator, OutputId } from '../block/output/output';
+import { Output, OutputDiscriminator } from '../block/output/output';
 import { Transaction } from '../block/payload/signed_transaction';
 import { IOutputMetadataResponse } from '../models/api';
 import { Bip44 } from '../secret_manager';
-import { NumericString } from '../utils';
+import { HexEncodedString, NumericString } from '../utils';
 
 /**
  * Helper struct for offline signing.
@@ -28,7 +28,7 @@ export class PreparedTransactionData {
     /**
      * Mana rewards by input.
      */
-    manaRewards?: { [outputId: OutputId]: NumericString };
+    manaRewards?: { [outputId: HexEncodedString]: NumericString };
 }
 
 /**
diff --git a/bindings/nodejs/lib/types/models/api/block-id-response.ts b/bindings/nodejs/lib/types/models/api/block-id-response.ts
index fff073e335..47f17f48e1 100644
--- a/bindings/nodejs/lib/types/models/api/block-id-response.ts
+++ b/bindings/nodejs/lib/types/models/api/block-id-response.ts
@@ -1,7 +1,8 @@
 // Copyright 2023 IOTA Stiftung
 // SPDX-License-Identifier: Apache-2.0
 
-import type { HexEncodedString } from '../../utils/hex-encoding';
+import { BlockId } from '../../block';
+
 /**
  * Block id response.
  */
@@ -9,5 +10,5 @@ export interface IBlockIdResponse {
     /**
      * The block id.
      */
-    blockId: HexEncodedString;
+    blockId: BlockId;
 }
diff --git a/bindings/nodejs/lib/types/models/api/plugins/indexer/output-response.ts b/bindings/nodejs/lib/types/models/api/plugins/indexer/output-response.ts
index 2bf8b46c3c..f00c5db191 100644
--- a/bindings/nodejs/lib/types/models/api/plugins/indexer/output-response.ts
+++ b/bindings/nodejs/lib/types/models/api/plugins/indexer/output-response.ts
@@ -1,8 +1,8 @@
 // Copyright 2023 IOTA Stiftung
 // SPDX-License-Identifier: Apache-2.0
 
+import { OutputId } from '../../../../block/output/output';
 import { NumericString } from '../../../../utils';
-import type { HexEncodedString } from '../../../../utils/hex-encoding';
 
 /**
  * Details of an outputs response from the indexer plugin.
@@ -23,5 +23,5 @@ export interface IOutputsResponse {
     /**
      * The output IDs (transaction hash + output index) of the outputs on this address.
      */
-    items: HexEncodedString[];
+    items: OutputId[];
 }
diff --git a/bindings/nodejs/lib/types/models/api/tips-response.ts b/bindings/nodejs/lib/types/models/api/tips-response.ts
index 5316610d27..b1c07c7304 100644
--- a/bindings/nodejs/lib/types/models/api/tips-response.ts
+++ b/bindings/nodejs/lib/types/models/api/tips-response.ts
@@ -1,7 +1,8 @@
 // Copyright 2023 IOTA Stiftung
 // SPDX-License-Identifier: Apache-2.0
 
-import type { HexEncodedString } from '../../utils/hex-encoding';
+import { BlockId } from '../../block/id';
+
 /**
  * Response from the tips endpoint.
  */
@@ -9,5 +10,5 @@ export interface ITipsResponse {
     /**
      * The block ids of the tip.
      */
-    tips: HexEncodedString[];
+    tips: BlockId[];
 }
diff --git a/bindings/nodejs/lib/types/models/block-metadata.ts b/bindings/nodejs/lib/types/models/block-metadata.ts
index ba7cee6f57..0f6029c87e 100644
--- a/bindings/nodejs/lib/types/models/block-metadata.ts
+++ b/bindings/nodejs/lib/types/models/block-metadata.ts
@@ -1,11 +1,9 @@
 // Copyright 2023 IOTA Stiftung
 // SPDX-License-Identifier: Apache-2.0
 
-import type { HexEncodedString } from '../utils/hex-encoding';
 import { BlockState, TransactionState } from './state';
 import { BlockFailureReason } from './block-failure-reason';
-import { Block } from '../block';
-import { TransactionId } from '../wallet';
+import { Block, BlockId, TransactionId } from '../block';
 import { TransactionFailureReason } from './transaction-failure-reason';
 
 /**
@@ -15,7 +13,7 @@ export interface IBlockMetadata {
     /**
      * The block id.
      */
-    blockId: HexEncodedString;
+    blockId: BlockId;
     /**
      * The block state.
      */
diff --git a/bindings/nodejs/lib/types/utils/bridge/utils.ts b/bindings/nodejs/lib/types/utils/bridge/utils.ts
index 00617c7043..8360aab79c 100644
--- a/bindings/nodejs/lib/types/utils/bridge/utils.ts
+++ b/bindings/nodejs/lib/types/utils/bridge/utils.ts
@@ -224,7 +224,7 @@ export interface __VerifyTransactionSemantic__ {
         inputs: InputSigningData[];
         protocolParameters: ProtocolParameters;
         unlocks?: Unlock[];
-        manaRewards?: { [outputId: OutputId]: NumericString };
+        manaRewards?: { [outputId: HexEncodedString]: NumericString };
     };
 }
 
diff --git a/bindings/nodejs/lib/types/wallet/event.ts b/bindings/nodejs/lib/types/wallet/event.ts
index 990aed38ca..10b8884e79 100644
--- a/bindings/nodejs/lib/types/wallet/event.ts
+++ b/bindings/nodejs/lib/types/wallet/event.ts
@@ -4,15 +4,10 @@
 import type { OutputData } from './output';
 import { InclusionState } from './transaction';
 import { InputSigningData, Remainder } from '../client';
-import { Transaction, SignedTransactionPayload } from '../block';
+import { Transaction, SignedTransactionPayload, TransactionId } from '../block';
 import { OutputResponse } from '../models';
 import { HexEncodedString } from '../utils';
 
-/**
- * A Transaction ID represented as hex-encoded string.
- */
-export type TransactionId = string;
-
 /**
  * All of the wallet event types.
  */
diff --git a/bindings/nodejs/lib/types/wallet/participation.ts b/bindings/nodejs/lib/types/wallet/participation.ts
index 9c0a84e887..9b5c0c2f03 100644
--- a/bindings/nodejs/lib/types/wallet/participation.ts
+++ b/bindings/nodejs/lib/types/wallet/participation.ts
@@ -2,7 +2,7 @@
 // SPDX-License-Identifier: Apache-2.0
 
 import type { INode } from '../client';
-import type { OutputId } from '../block/output';
+import { HexEncodedString } from '../utils';
 
 /**
  * An object containing an account's entire participation overview.
@@ -16,7 +16,7 @@ export interface ParticipationOverview {
  */
 export interface Participations {
     [eventId: ParticipationEventId]: {
-        [outputId: OutputId]: TrackedParticipationOverview;
+        [outputId: HexEncodedString]: TrackedParticipationOverview;
     };
 }
 
diff --git a/bindings/nodejs/lib/types/wallet/signed-transaction-data.ts b/bindings/nodejs/lib/types/wallet/signed-transaction-data.ts
index b2043bae99..def0268ba5 100644
--- a/bindings/nodejs/lib/types/wallet/signed-transaction-data.ts
+++ b/bindings/nodejs/lib/types/wallet/signed-transaction-data.ts
@@ -4,8 +4,7 @@
 import { Type } from 'class-transformer';
 import { SignedTransactionPayload } from '../block/payload/signed_transaction';
 import { InputSigningData } from '../client';
-import { OutputId } from '../block/output';
-import { NumericString } from '../utils';
+import { HexEncodedString, NumericString } from '../utils';
 
 /** The signed transaction with inputs data */
 export class SignedTransactionData {
@@ -16,5 +15,5 @@ export class SignedTransactionData {
     @Type(() => InputSigningData)
     inputsData!: InputSigningData;
     /** Mana rewards by input */
-    manaRewards?: { [outputId: OutputId]: NumericString };
+    manaRewards?: { [outputId: HexEncodedString]: NumericString };
 }
diff --git a/bindings/nodejs/lib/types/wallet/transaction-options.ts b/bindings/nodejs/lib/types/wallet/transaction-options.ts
index 10249d9a17..3f88d2b72d 100644
--- a/bindings/nodejs/lib/types/wallet/transaction-options.ts
+++ b/bindings/nodejs/lib/types/wallet/transaction-options.ts
@@ -1,7 +1,7 @@
 // Copyright 2024 IOTA Stiftung
 // SPDX-License-Identifier: Apache-2.0
 
-import { AccountAddress, AccountId, Bech32Address } from '../block';
+import { AccountAddress, AccountId, Bech32Address, OutputId } from '../block';
 import { TaggedDataPayload } from '../block/payload/tagged';
 import { Burn } from '../client';
 import { u256, HexEncodedString, NumericString, u64 } from '../utils';
@@ -18,9 +18,9 @@ export interface TransactionOptions {
      * If custom inputs are provided, only those are used.
      * If also other additional inputs should be used, `mandatoryInputs` should be used instead.
      */
-    customInputs?: string[];
+    customInputs?: OutputId[];
     /** Inputs that must be used for the transaction. */
-    mandatoryInputs?: string[];
+    mandatoryInputs?: OutputId[];
     /** Specifies what needs to be burned during input selection. */
     burn?: Burn;
     /** Optional note, that is only stored locally. */
diff --git a/bindings/nodejs/lib/types/wallet/transaction.ts b/bindings/nodejs/lib/types/wallet/transaction.ts
index 9f4d65e0ae..290bf7d344 100644
--- a/bindings/nodejs/lib/types/wallet/transaction.ts
+++ b/bindings/nodejs/lib/types/wallet/transaction.ts
@@ -1,7 +1,8 @@
 // Copyright 2021-2023 IOTA Stiftung
 // SPDX-License-Identifier: Apache-2.0
 
-import { Type } from 'class-transformer';
+import { Transform, Type } from 'class-transformer';
+import { BlockId, TransactionId } from '../block';
 import { SignedTransactionPayload } from '../block/payload/signed_transaction';
 import { OutputResponse } from '../models/api';
 
@@ -23,13 +24,17 @@ export class TransactionWithMetadata {
     @Type(() => SignedTransactionPayload)
     payload!: SignedTransactionPayload;
     /** The block id in which the transaction payload was included */
-    blockId?: string;
+    @Type(() => BlockId)
+    @Transform(({ value }) => new BlockId(value), { toClassOnly: true })
+    blockId?: BlockId;
     /** The inclusion state of the transaction */
     inclusionState!: InclusionState;
     /** The creation time */
     timestamp!: string;
     /** The transaction id */
-    transactionId!: string;
+    @Type(() => TransactionId)
+    @Transform(({ value }) => new TransactionId(value), { toClassOnly: true })
+    transactionId!: TransactionId;
     /** The network id in which the transaction was sent */
     networkId!: string;
     /** If the transaction was created by the wallet or someone else */
diff --git a/bindings/nodejs/lib/types/wallet/wallet.ts b/bindings/nodejs/lib/types/wallet/wallet.ts
index af3953ee98..31de56761b 100644
--- a/bindings/nodejs/lib/types/wallet/wallet.ts
+++ b/bindings/nodejs/lib/types/wallet/wallet.ts
@@ -8,10 +8,10 @@ import {
     NftId,
     TokenId,
 } from '../block/id';
-import { DecayedMana, u256, u64 } from '../utils';
+import { DecayedMana, HexEncodedString, u256, u64 } from '../utils';
 import { IClientOptions } from '../client';
 import { Bip44, SecretManagerType } from '../secret_manager/secret-manager';
-import { Bech32Address, OutputId } from '../block';
+import { Bech32Address } from '../block';
 
 /** Options for the Wallet builder. */
 export interface WalletOptions {
@@ -51,7 +51,7 @@ export interface Balance {
      * Outputs with multiple unlock conditions and if they can currently be spent or not. If there is a
      * TimelockUnlockCondition or ExpirationUnlockCondition this can change at any time
      */
-    potentiallyLockedOutputs: { [outputId: OutputId]: boolean };
+    potentiallyLockedOutputs: { [outputId: HexEncodedString]: boolean };
 }
 
 /** The balance of the base coin */
diff --git a/bindings/nodejs/lib/utils/utils.ts b/bindings/nodejs/lib/utils/utils.ts
index e75d8997ec..0609d7072f 100644
--- a/bindings/nodejs/lib/utils/utils.ts
+++ b/bindings/nodejs/lib/utils/utils.ts
@@ -466,7 +466,7 @@ export class Utils {
         inputs: InputSigningData[],
         protocolParameters: ProtocolParameters,
         unlocks?: Unlock[],
-        manaRewards?: { [outputId: OutputId]: NumericString },
+        manaRewards?: { [outputId: HexEncodedString]: NumericString },
     ): string {
         const conflictReason = callUtilsMethod({
             name: 'verifyTransactionSemantic',
diff --git a/bindings/nodejs/lib/wallet/wallet.ts b/bindings/nodejs/lib/wallet/wallet.ts
index 6611def1fe..0bf0f27452 100644
--- a/bindings/nodejs/lib/wallet/wallet.ts
+++ b/bindings/nodejs/lib/wallet/wallet.ts
@@ -1522,7 +1522,7 @@ export class Wallet {
      * included (referenced by a milestone). Returns the included block id.
      */
     async reissueTransactionUntilIncluded(
-        transactionId: string,
+        transactionId: TransactionId,
         interval?: number,
         maxAttempts?: number,
     ): Promise<string> {
diff --git a/bindings/nodejs/tests/types/ids.spec.ts b/bindings/nodejs/tests/types/ids.spec.ts
new file mode 100644
index 0000000000..bf1bbc1d74
--- /dev/null
+++ b/bindings/nodejs/tests/types/ids.spec.ts
@@ -0,0 +1,21 @@
+// Copyright 2024 IOTA Stiftung
+// SPDX-License-Identifier: Apache-2.0
+
+import { expect, describe, it } from '@jest/globals';
+import { BlockId, OutputId, TransactionId } from '../../';
+
+describe('ID tests', () => {
+
+    it('get slot index', async () => {
+        const blockId = new BlockId("0x52fdfc072182654f163f5f0f9a621d729566c74d10037c4d7bbb0407d1e2c64900000000")
+        expect(blockId.slotIndex()).toEqual(0);
+        const transactionId = new TransactionId("0x52fdfc072182654f163f5f0f9a621d729566c74d10037c4d7bbb0407d1e2c64901000000")
+        expect(transactionId.slotIndex()).toEqual(1);
+    });
+
+    it('get output index', async () => {
+        const outputId = new OutputId("0x52fdfc072182654f163f5f0f9a621d729566c74d10037c4d7bbb0407d1e2c649000000002a00")
+        expect(outputId.transactionId().slotIndex()).toEqual(0);
+        expect(outputId.outputIndex()).toEqual(42);
+    });
+});
diff --git a/bindings/wasm/tests/utilityMethods.spec.ts b/bindings/wasm/tests/utilityMethods.spec.ts
index 5c56aa27ce..5b02f47f2d 100644
--- a/bindings/wasm/tests/utilityMethods.spec.ts
+++ b/bindings/wasm/tests/utilityMethods.spec.ts
@@ -1,4 +1,4 @@
-import { Utils } from '../node/lib';
+import { OutputId, Utils } from '../node/lib';
 
 describe('Utils methods', () => {
     it('generates and validates mnemonic', async () => {
@@ -50,7 +50,7 @@ describe('Utils methods', () => {
 
     it('hash output id', async () => {
         const outputId =
-            '0x0000000000000000000000000000000000000000000000000000000000000000000000000000';
+            new OutputId('0x0000000000000000000000000000000000000000000000000000000000000000000000000000');
 
         const accountId = Utils.computeAccountId(outputId);