diff --git a/.gitignore b/.gitignore
index b64a527..5a2d900 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,6 +4,7 @@
 *.lock
 *.tsbuildinfo
 .vscode/
+devTestOnly/
 
 # package.json
 
diff --git a/packages/harmony-contract/src/events/event.ts b/packages/harmony-contract/src/events/event.ts
index 9462c21..19552a5 100644
--- a/packages/harmony-contract/src/events/event.ts
+++ b/packages/harmony-contract/src/events/event.ts
@@ -1,13 +1,12 @@
 import { AbiItemModel } from '../models/types';
-import { Messenger, RPCMethod, WSProvider } from '@harmony-js/network';
+import { LogSub } from '@harmony-js/network';
 import { Contract } from '../contract';
 import { decode as eventLogDecoder } from '../utils/decoder';
 import { inputLogFormatter, outputLogFormatter } from '../utils/formatter';
-export class EventMethod {
+export class EventMethod extends LogSub {
   params: any;
   methodKey: string;
   contract: Contract;
-  messenger?: Messenger;
   abiItem: AbiItemModel;
   constructor(
     methodKey: string,
@@ -15,57 +14,18 @@ export class EventMethod {
     abiItem: AbiItemModel,
     contract: Contract,
   ) {
+    super(inputLogFormatter(params), contract.wallet.messenger);
     this.methodKey = methodKey;
     this.contract = contract;
-    this.messenger = contract.wallet.messenger;
     this.params = params;
     this.abiItem = abiItem;
+    super.subscribe();
   }
-  send() {}
-  call() {}
-  estimateGas() {}
-  encodeABI() {}
-  subscribe(options: any) {
-    if (
-      options &&
-      typeof options.filter !== 'undefined' &&
-      typeof options.topics !== 'undefined'
-    ) {
-      throw new Error(
-        'Invalid subscription options: Only filter or topics are allowed and not both',
-      );
-    }
-    if (this.emitter && this.messenger) {
-      const messenger = this.messenger;
-      const emitter = this.emitter;
-      const inputOptions = inputLogFormatter(options);
-      // 1. getLog
-      // 2. subscribe pastlog
-      // 3. emit data
-      messenger
-        .send(RPCMethod.GetPastLogs, [inputOptions])
-        .then((logs: any) => {
-          logs.forEach((log: any) => {
-            const formattedLog = this.onNewSubscriptionItem(log);
-            emitter.emit('data', formattedLog);
-          });
-          messenger.subscribe('logs', [inputOptions] || []);
-        })
-        .catch((error) => {
-          emitter.emit('error', error);
-        });
-    }
-    return this.contract;
-    // return this.eventSubscriptionFactory
-    //   .createEventLogSubscription(
-    //     this.eventLogDecoder,
-    //     this.contract,
-    //     this.eventOptionsMapper.map(abiItemModel, this.contract, options),
-    //     abiItemModel,
-    //   )
-    //   .subscribe(callback);
-    // this.messenger.subscribe()
-  }
+
+  // call() {}
+  // estimateGas() {}
+  // encodeABI() {}
+
   onNewSubscriptionItem(subscriptionItem: any) {
     // const log = outputLogFormatter(subscriptionItem);
     const log = eventLogDecoder(
@@ -80,11 +40,4 @@ export class EventMethod {
 
     return log;
   }
-  get emitter() {
-    if (this.messenger && this.messenger.provider instanceof WSProvider) {
-      return this.messenger.provider.emitter;
-    } else {
-      return undefined;
-    }
-  }
 }
diff --git a/packages/harmony-core/src/blockchain.ts b/packages/harmony-core/src/blockchain.ts
index 7c93a85..7455d55 100644
--- a/packages/harmony-core/src/blockchain.ts
+++ b/packages/harmony-core/src/blockchain.ts
@@ -3,8 +3,10 @@ import {
   Messenger,
   ResponseMiddleware,
   WSProvider,
-  // SubscribeReturns,
-  SubscriptionMethod,
+  NewPendingTransactions,
+  NewHeaders,
+  LogSub,
+  Syncing,
 } from '@harmony-js/network';
 
 import {
@@ -217,19 +219,6 @@ class Blockchain extends HarmonyCore {
     return this.getRpcResult(result);
   }
 
-  /**
-   *
-   */
-  async syncing() {
-    const result = await this.messenger.send(
-      RPCMethod.Syncing,
-      [],
-      this.chainPrefix,
-    );
-
-    return this.getRpcResult(result);
-  }
-
   async net_peerCount() {
     const result = await this.messenger.send(RPCMethod.PeerCount, [], 'net');
 
@@ -322,13 +311,7 @@ class Blockchain extends HarmonyCore {
 
   newPendingTransactions() {
     if (this.messenger.provider instanceof WSProvider) {
-      // return this.messenger.subscribe(
-      //   RPCMethod.Subscribe,
-      //   ['newPendingTransactions'],
-      //   SubscribeReturns.method,
-      //   this.chainPrefix,
-      // );
-      return new SubscriptionMethod(['newPendingTransactions'], this.messenger);
+      return new NewPendingTransactions(this.messenger);
     } else {
       throw new Error('HttpProvider does not support this feature');
     }
@@ -336,13 +319,23 @@ class Blockchain extends HarmonyCore {
 
   newBlockHeaders() {
     if (this.messenger.provider instanceof WSProvider) {
-      // return this.messenger.subscribe(
-      //   RPCMethod.Subscribe,
-      //   ['newHeads'],
-      //   SubscribeReturns.method,
-      //   this.chainPrefix,
-      // );
-      return new SubscriptionMethod(['newHeads'], this.messenger);
+      return new NewHeaders(this.messenger);
+    } else {
+      throw new Error('HttpProvider does not support this feature');
+    }
+  }
+
+  syncing() {
+    if (this.messenger.provider instanceof WSProvider) {
+      return new Syncing(this.messenger);
+    } else {
+      throw new Error('HttpProvider does not support this feature');
+    }
+  }
+
+  logs(options: any) {
+    if (this.messenger.provider instanceof WSProvider) {
+      return new LogSub(options, this.messenger);
     } else {
       throw new Error('HttpProvider does not support this feature');
     }
diff --git a/packages/harmony-network/src/index.ts b/packages/harmony-network/src/index.ts
index 653c72f..b1af99d 100644
--- a/packages/harmony-network/src/index.ts
+++ b/packages/harmony-network/src/index.ts
@@ -21,6 +21,10 @@ export * from './tracker/subscribeTracker';
 
 // subscriptinos
 export * from './subscriptions/Subscription';
+export * from './subscriptions/LogSub';
+export * from './subscriptions/NewHeadersSub';
+export * from './subscriptions/NewPendingTransactionsSub';
+export * from './subscriptions/SyncingSub';
 // utils
 export * from './util';
 // types
diff --git a/packages/harmony-network/src/subscriptions/LogSub.ts b/packages/harmony-network/src/subscriptions/LogSub.ts
index 823982b..5300c27 100644
--- a/packages/harmony-network/src/subscriptions/LogSub.ts
+++ b/packages/harmony-network/src/subscriptions/LogSub.ts
@@ -1,9 +1,43 @@
 import { Messenger } from '../messenger/messenger';
 import { SubscriptionMethod } from './Subscription';
+import { RPCMethod } from '../rpcMethod/rpc';
 
 export class LogSub extends SubscriptionMethod {
-  constructor(params: any[] = ['logs'], messenger: Messenger) {
-    super(params, messenger);
+  constructor(options: any, messenger: Messenger) {
+    super('logs', options, messenger);
+    this.subscribe();
+  }
+
+  async subscribe() {
+    // if (
+    //   (this.options.fromBlock && this.options.fromBlock !== 'latest') ||
+    //   this.options.fromBlock === 0
+    // ) {
+    try {
+      const getPastLogs = await this.messenger.send(RPCMethod.GetPastLogs, [
+        ...this.options,
+      ]);
+
+      if (getPastLogs.isError()) {
+        this.emitter.emit('error', getPastLogs.message);
+      }
+
+      const logs = getPastLogs.result;
+
+      logs.forEach((log: any) => {
+        const formattedLog = this.onNewSubscriptionItem(log);
+
+        this.emitter.emit('data', formattedLog);
+      });
+
+      delete this.options.fromBlock;
+      super.start();
+      return this;
+    } catch (error) {
+      this.emitter.emit('error', error);
+    }
+    // }
+    // return this;
   }
 
   onNewSubscriptionItem(subscriptionItem: any) {
diff --git a/packages/harmony-network/src/subscriptions/NewHeadersSub.ts b/packages/harmony-network/src/subscriptions/NewHeadersSub.ts
index 805c156..70ba7d8 100644
--- a/packages/harmony-network/src/subscriptions/NewHeadersSub.ts
+++ b/packages/harmony-network/src/subscriptions/NewHeadersSub.ts
@@ -2,7 +2,8 @@ import { Messenger } from '../messenger/messenger';
 import { SubscriptionMethod } from './Subscription';
 
 export class NewHeaders extends SubscriptionMethod {
-  constructor(params: any[] = ['newHeads'], messenger: Messenger) {
-    super(params, messenger);
+  constructor(messenger: Messenger) {
+    super('newHeads', undefined, messenger);
+    this.start();
   }
 }
diff --git a/packages/harmony-network/src/subscriptions/NewPendingTransactionsSub.ts b/packages/harmony-network/src/subscriptions/NewPendingTransactionsSub.ts
index 58b2116..f77dae6 100644
--- a/packages/harmony-network/src/subscriptions/NewPendingTransactionsSub.ts
+++ b/packages/harmony-network/src/subscriptions/NewPendingTransactionsSub.ts
@@ -2,10 +2,8 @@ import { Messenger } from '../messenger/messenger';
 import { SubscriptionMethod } from './Subscription';
 
 export class NewPendingTransactions extends SubscriptionMethod {
-  constructor(
-    params: any[] = ['newPendingTransactions'],
-    messenger: Messenger,
-  ) {
-    super(params, messenger);
+  constructor(messenger: Messenger) {
+    super('newPendingTransactions', undefined, messenger);
+    this.start();
   }
 }
diff --git a/packages/harmony-network/src/subscriptions/Subscription.ts b/packages/harmony-network/src/subscriptions/Subscription.ts
index 2a7036e..bf9abba 100644
--- a/packages/harmony-network/src/subscriptions/Subscription.ts
+++ b/packages/harmony-network/src/subscriptions/Subscription.ts
@@ -4,19 +4,29 @@ import { WSProvider } from '../providers/ws';
 import { RPCRequestPayload } from '../types';
 
 export class SubscriptionMethod extends WSProvider {
-  params: any[];
+  param: any;
+  options: any;
   messenger: Messenger;
 
   subscriptionId: any = null;
-  constructor(params: any[], messenger: Messenger) {
+  constructor(param: any, options: any, messenger: Messenger) {
     super(messenger.provider.url);
-    this.params = params;
+    this.param = param;
+    this.options = options;
     this.messenger = messenger;
-    this.start();
   }
 
-  constructPayload(method: string, payload: any): RPCRequestPayload<any> {
+  constructPayload(
+    method: string,
+    param: any,
+    options?: any,
+  ): RPCRequestPayload<any> {
     let rpcMethod = method;
+    const payload: any = [];
+    payload.push(param);
+    if (options) {
+      payload.push(options);
+    }
     rpcMethod = this.messenger.setRPCPrefix(method, this.messenger.chainPrefix);
     return this.jsonRpc.toPayload(rpcMethod, payload);
   }
@@ -24,8 +34,8 @@ export class SubscriptionMethod extends WSProvider {
   async start() {
     const subscribePayload = this.constructPayload(
       RPCMethod.Subscribe,
-
-      this.params,
+      this.param,
+      this.options,
     );
     try {
       const id = await super.subscribe(subscribePayload);
@@ -46,9 +56,10 @@ export class SubscriptionMethod extends WSProvider {
     return this;
   }
   unsubscribe() {
-    const unsubscribePayload = this.constructPayload(RPCMethod.UnSubscribe, [
+    const unsubscribePayload = this.constructPayload(
+      RPCMethod.UnSubscribe,
       this.subscriptionId,
-    ]);
+    );
     return super.unsubscribe(unsubscribePayload);
   }
   onNewSubscriptionItem(subscriptionItem: any) {
diff --git a/packages/harmony-network/src/subscriptions/SyncingSub.ts b/packages/harmony-network/src/subscriptions/SyncingSub.ts
index bb670d3..3df0b66 100644
--- a/packages/harmony-network/src/subscriptions/SyncingSub.ts
+++ b/packages/harmony-network/src/subscriptions/SyncingSub.ts
@@ -3,13 +3,14 @@ import { SubscriptionMethod } from './Subscription';
 
 export class Syncing extends SubscriptionMethod {
   isSyncing: boolean | null;
-  constructor(params: any[] = ['syncing'], messenger: Messenger) {
-    super(params, messenger);
+  constructor(messenger: Messenger) {
+    super('syncing', undefined, messenger);
     this.isSyncing = null;
+    this.start();
   }
 
   onNewSubscriptionItem(subscriptionItem: any) {
-    const isSyncing = subscriptionItem.result.syncing;
+    const isSyncing = subscriptionItem.params.result.syncing;
 
     if (this.isSyncing === null) {
       this.isSyncing = isSyncing;
diff --git a/packages/harmony-transaction/src/transaction.ts b/packages/harmony-transaction/src/transaction.ts
index ca519f6..28451c2 100644
--- a/packages/harmony-transaction/src/transaction.ts
+++ b/packages/harmony-transaction/src/transaction.ts
@@ -15,7 +15,7 @@ import {
   HttpProvider,
   // WSProvider,
   // SubscribeReturns,
-  SubscriptionMethod,
+  NewHeaders,
 } from '@harmony-js/network';
 import { TxParams, TxStatus, TransasctionReceipt } from './types';
 import {
@@ -375,9 +375,7 @@ class Transaction {
     maxAttempts: number = 20,
   ): Promise<Transaction> {
     return new Promise((resolve, reject) => {
-      const newHeads = Promise.resolve(
-        new SubscriptionMethod(['newHeads'], this.messenger),
-      );
+      const newHeads = Promise.resolve(new NewHeaders(this.messenger));
       newHeads.then((p) => {
         p.onData(async (data: any) => {
           if (!this.blockNumbers.includes(data.number)) {