diff --git a/__tests__/__snapshots__/ain.test.ts.snap b/__tests__/__snapshots__/ain.test.ts.snap
index b476fa9..1ef7e02 100644
--- a/__tests__/__snapshots__/ain.test.ts.snap
+++ b/__tests__/__snapshots__/ain.test.ts.snap
@@ -169,6 +169,20 @@ Object {
 }
 `;
 
+exports[`ain-js Database getProofHash 1`] = `"0x88496dfee3566db91f487aa4cbf69a0c42a3e2a5d0a65bfd4897d699e8734785"`;
+
+exports[`ain-js Database getStateInfo 1`] = `
+Object {
+  "#num_children": 1,
+  "#state_ph": "0x985a1f057d5047b1dee392127eb776571fbbe79da7ae6114f8f8f18c4f786135",
+  "#tree_bytes": 1840,
+  "#tree_height": 2,
+  "#tree_max_siblings": 1,
+  "#tree_size": 3,
+  "#version": "erased",
+}
+`;
+
 exports[`ain-js Database matchFunction 1`] = `
 Object {
   "matched_config": Object {
diff --git a/__tests__/ain.test.ts b/__tests__/ain.test.ts
index 6c91916..f586760 100644
--- a/__tests__/ain.test.ts
+++ b/__tests__/ain.test.ts
@@ -1,8 +1,9 @@
 // @ts-nocheck
 import Ain from '../src/ain';
+import Wallet from '../src/wallet';
 import { TransactionBody, SetOperation, TransactionInput } from '../src/types';
 import axios from 'axios';
-import { fail, eraseProtoVer } from './test_util';
+import { fail, eraseProtoVer, eraseStateVersion } from './test_util';
 const {
   test_keystore,
   test_pw,
@@ -72,8 +73,77 @@ describe('ain-js', function() {
     });
   });
 
+  describe('Provider', function() {
+    it('getAddress', async function() {
+      const address = await ain.provider.getAddress();
+      expect(address).not.toBeNull();
+    });
+  });
+
   describe('Wallet', function() {
-    let addresses = []
+    it('countDecimals', function() {
+      expect(Wallet.countDecimals(0)).toBe(0);  // '0'
+      expect(Wallet.countDecimals(1)).toBe(0);  // '1'
+      expect(Wallet.countDecimals(10)).toBe(0);  // '10'
+      expect(Wallet.countDecimals(100)).toBe(0);  // '100'
+      expect(Wallet.countDecimals(1000)).toBe(0);  // '1000'
+      expect(Wallet.countDecimals(10000)).toBe(0);  // '10000'
+      expect(Wallet.countDecimals(100000)).toBe(0);  // '100000'
+      expect(Wallet.countDecimals(1000000)).toBe(0);  // '1000000'
+      expect(Wallet.countDecimals(10000000)).toBe(0);  // '10000000'
+      expect(Wallet.countDecimals(100000000)).toBe(0);  // '100000000'
+      expect(Wallet.countDecimals(1000000000)).toBe(0);  // '1000000000'
+      expect(Wallet.countDecimals(1234567890)).toBe(0);  // '1234567890'
+      expect(Wallet.countDecimals(-1)).toBe(0);  // '-1'
+      expect(Wallet.countDecimals(-1000000000)).toBe(0);  // '-1000000000'
+      expect(Wallet.countDecimals(11)).toBe(0);  // '11'
+      expect(Wallet.countDecimals(101)).toBe(0);  // '101'
+      expect(Wallet.countDecimals(1001)).toBe(0);  // '1001'
+      expect(Wallet.countDecimals(10001)).toBe(0);  // '10001'
+      expect(Wallet.countDecimals(100001)).toBe(0);  // '100001'
+      expect(Wallet.countDecimals(1000001)).toBe(0);  // '1000001'
+      expect(Wallet.countDecimals(10000001)).toBe(0);  // '10000001'
+      expect(Wallet.countDecimals(100000001)).toBe(0);  // '100000001'
+      expect(Wallet.countDecimals(1000000001)).toBe(0);  // '1000000001'
+      expect(Wallet.countDecimals(-11)).toBe(0);  // '-11'
+      expect(Wallet.countDecimals(-1000000001)).toBe(0);  // '-1000000001'
+      expect(Wallet.countDecimals(0.1)).toBe(1);  // '0.1'
+      expect(Wallet.countDecimals(0.01)).toBe(2);  // '0.01'
+      expect(Wallet.countDecimals(0.001)).toBe(3);  // '0.001'
+      expect(Wallet.countDecimals(0.0001)).toBe(4);  // '0.0001'
+      expect(Wallet.countDecimals(0.00001)).toBe(5);  // '0.00001'
+      expect(Wallet.countDecimals(0.000001)).toBe(6);  // '0.000001'
+      expect(Wallet.countDecimals(0.0000001)).toBe(7);  // '1e-7'
+      expect(Wallet.countDecimals(0.00000001)).toBe(8);  // '1e-8'
+      expect(Wallet.countDecimals(0.000000001)).toBe(9);  // '1e-9'
+      expect(Wallet.countDecimals(0.0000000001)).toBe(10);  // '1e-10'
+      expect(Wallet.countDecimals(-0.1)).toBe(1);  // '-0.1'
+      expect(Wallet.countDecimals(-0.0000000001)).toBe(10);  // '-1e-10'
+      expect(Wallet.countDecimals(1.2)).toBe(1);  // '1.2'
+      expect(Wallet.countDecimals(0.12)).toBe(2);  // '0.12'
+      expect(Wallet.countDecimals(0.012)).toBe(3);  // '0.012'
+      expect(Wallet.countDecimals(0.0012)).toBe(4);  // '0.0012'
+      expect(Wallet.countDecimals(0.00012)).toBe(5);  // '0.00012'
+      expect(Wallet.countDecimals(0.000012)).toBe(6);  // '0.000012'
+      expect(Wallet.countDecimals(0.0000012)).toBe(7);  // '0.0000012'
+      expect(Wallet.countDecimals(0.00000012)).toBe(8);  // '1.2e-7'
+      expect(Wallet.countDecimals(0.000000012)).toBe(9);  // '1.2e-8'
+      expect(Wallet.countDecimals(0.0000000012)).toBe(10);  // '1.2e-9'
+      expect(Wallet.countDecimals(-1.2)).toBe(1);  // '-1.2'
+      expect(Wallet.countDecimals(-0.0000000012)).toBe(10);  // '-1.2e-9'
+      expect(Wallet.countDecimals(1.03)).toBe(2);  // '1.03'
+      expect(Wallet.countDecimals(1.003)).toBe(3);  // '1.003'
+      expect(Wallet.countDecimals(1.0003)).toBe(4);  // '1.0003'
+      expect(Wallet.countDecimals(1.00003)).toBe(5);  // '1.00003'
+      expect(Wallet.countDecimals(1.000003)).toBe(6);  // '1.000003'
+      expect(Wallet.countDecimals(1.0000003)).toBe(7);  // '1.0000003'
+      expect(Wallet.countDecimals(1.00000003)).toBe(8);  // '1.00000003'
+      expect(Wallet.countDecimals(1.000000003)).toBe(9);  // '1.000000003'
+      expect(Wallet.countDecimals(1.0000000003)).toBe(10);  // '1.0000000003'
+      expect(Wallet.countDecimals(-1.03)).toBe(2);  // '-1.03'
+      expect(Wallet.countDecimals(-1.0000000003)).toBe(10);  // '-1.0000000003'
+    });
+
     it('create', function() {
       const beforeLength = ain.wallet.length;
       ain.wallet.create(2);
@@ -204,6 +274,16 @@ describe('ain-js', function() {
       expect(balance).toBeGreaterThan(0);
     });
 
+    it('getNonce', async function() {
+      const nonce = await ain.wallet.getNonce();
+      expect(nonce).toBe(0);
+    });
+
+    it('getTimestamp', async function() {
+      const timestamp = await ain.wallet.getTimestamp();
+      expect(timestamp).toBe(0);
+    });
+
     it('transfer with isDryrun = true', async function() {
       const balanceBefore = await ain.wallet.getBalance();
       const response = await ain.wallet.transfer({
@@ -222,6 +302,64 @@ describe('ain-js', function() {
       expect(balanceAfter).toBe(balanceBefore - 100);
     });
 
+    it('transfer with a zero value', async function() {
+      const balanceBefore = await ain.wallet.getBalance();
+      try {
+        const response = await ain.wallet.transfer({
+            to: '0xbA58D93edD8343C001eC5f43E620712Ba8C10813',
+            value: 0,  // a zero value
+            nonce: -1 });
+        fail('should not happen');
+      } catch(e) {
+        expect(e.message).toBe('Non-positive transfer value.');
+      } finally {
+        const balanceAfter = await ain.wallet.getBalance();
+        expect(balanceAfter).toBe(balanceBefore);
+      }
+    });
+
+    it('transfer with a negative value', async function() {
+      const balanceBefore = await ain.wallet.getBalance();
+      try {
+        const response = await ain.wallet.transfer({
+            to: '0xbA58D93edD8343C001eC5f43E620712Ba8C10813',
+            value: -0.1,  // a negative value
+            nonce: -1 });
+        fail('should not happen');
+      } catch(e) {
+        expect(e.message).toBe('Non-positive transfer value.');
+      } finally {
+        const balanceAfter = await ain.wallet.getBalance();
+        expect(balanceAfter).toBe(balanceBefore);
+      }
+    });
+
+    it('transfer with a value of up to 6 decimals', async function() {
+      const balanceBefore = await ain.wallet.getBalance();
+      const response = await ain.wallet.transfer({
+          to: '0xbA58D93edD8343C001eC5f43E620712Ba8C10813',
+          value: 0.000001,  // of 6 decimals
+          nonce: -1 });
+      const balanceAfter = await ain.wallet.getBalance();
+      expect(balanceAfter).toBe(balanceBefore - 0.000001);
+    });
+
+    it('transfer with a value of more than 6 decimals', async function() {
+      const balanceBefore = await ain.wallet.getBalance();
+      try {
+        const response = await ain.wallet.transfer({
+            to: '0xbA58D93edD8343C001eC5f43E620712Ba8C10813',
+            value: 0.0000001,  // of 7 decimals
+            nonce: -1 });
+        fail('should not happen');
+      } catch(e) {
+        expect(e.message).toBe('Transfer value of more than 6 decimals.');
+      } finally {
+        const balanceAfter = await ain.wallet.getBalance();
+        expect(balanceAfter).toBe(balanceBefore);
+      }
+    });
+
     it('chainId', function() {
       // chainId = 0
       ain.setProvider(test_node_2, 0);
@@ -340,22 +478,115 @@ describe('ain-js', function() {
       await waitUntilTxFinalized(createApps.result.tx_hash);
     });
 
-    it('getBlock', async function () {
-      const block = await ain.getBlock(3)
-      const hash = block.hash || "";
-      expect(await ain.getBlock(hash)).toStrictEqual(block);
+    it('getLastBlock', async function () {
+      const block = await ain.getLastBlock()
+      expect(block).not.toBeNull();
+      expect(block.hash).not.toBeNull();
+      expect(block.number).toBeGreaterThan(0);
+    });
+
+    it('getLastBlockNumber', async function () {
+      const number = await ain.getLastBlockNumber()
+      expect(number).not.toBeNull();
+      expect(number).toBeGreaterThan(0);
+    });
+
+    it('getBlockByNumber', async function () {
+      const lastBlock = await ain.getLastBlock();
+      expect(lastBlock).not.toBeNull();
+      expect(lastBlock.number).not.toBeNull();
+      const block = await ain.getBlockByNumber(lastBlock.number)
+      expect(block).not.toBeNull();
+      expect(block.number).toBe(lastBlock.number);
+      expect(block.hash).toBe(lastBlock.hash);
+    });
+
+    it('getBlockByHash', async function () {
+      const lastBlock = await ain.getLastBlock();
+      expect(lastBlock).not.toBeNull();
+      expect(lastBlock.hash).not.toBeNull();
+      const block = await ain.getBlockByHash(lastBlock.hash)
+      expect(block).not.toBeNull();
+      expect(block.number).toBe(lastBlock.number);
+      expect(block.hash).toBe(lastBlock.hash);
+    });
+
+    it('getBlockList', async function () {
+      const lastBlockNumber = await ain.getLastBlockNumber();
+      expect(lastBlockNumber).not.toBeNull();
+      expect(lastBlockNumber).toBeGreaterThanOrEqual(0);
+      const blockList = await ain.getBlockList(lastBlockNumber - 1, lastBlockNumber + 1)
+      expect(blockList).not.toBeNull();
+      expect(blockList.length).toBe(2);
+      expect(blockList[0].number).toBe(lastBlockNumber - 1);
+      expect(blockList[1].number).toBe(lastBlockNumber);
+    });
+
+    it('getBlockHeadersList', async function () {
+      const lastBlockNumber = await ain.getLastBlockNumber();
+      expect(lastBlockNumber).not.toBeNull();
+      expect(lastBlockNumber).toBeGreaterThanOrEqual(0);
+      const blockList = await ain.getBlockHeadersList(lastBlockNumber - 1, lastBlockNumber + 1)
+      expect(blockList).not.toBeNull();
+      expect(blockList.length).toBe(2);
+      expect(blockList[0].number).toBe(lastBlockNumber - 1);
+      expect(blockList[1].number).toBe(lastBlockNumber);
     });
 
-    it('getProposer', async function () {
-      const proposer = await ain.getProposer(1);
-      const hash = (await ain.getBlock(1)).hash || "";
-      expect(await ain.getProposer(hash)).toBe(proposer);
+    it('getBlockTransactionCountByNumber', async function () {
+      const lastBlockNumber = await ain.getLastBlockNumber();
+      expect(lastBlockNumber).not.toBeNull();
+      expect(lastBlockNumber).toBeGreaterThanOrEqual(0);
+      const txCount = await ain.getBlockTransactionCountByNumber(lastBlockNumber)
+      expect(txCount).not.toBeNull();
     });
 
-    it('getValidators', async function () {
-      const validators = await ain.getValidators(4);
-      const hash = (await ain.getBlock(4)).hash || "";
-      expect(await ain.getValidators(hash)).toStrictEqual(validators);
+    it('getBlockTransactionCountByHash', async function () {
+      const lastBlock= await ain.getLastBlock();
+      expect(lastBlock).not.toBeNull();
+      expect(lastBlock.hash).not.toBeNull();
+      const txCount = await ain.getBlockTransactionCountByHash(lastBlock.hash)
+      expect(txCount).not.toBeNull();
+    });
+
+    it('getValidatorInfo', async function () {
+      const lastBlock = await ain.getLastBlock();
+      expect(lastBlock).not.toBeNull();
+      expect(lastBlock.proposer).not.toBeNull();
+      const info = await ain.getValidatorInfo(lastBlock.proposer);
+      expect(info).not.toBeNull();
+    });
+
+    it('getValidatorsByNumber', async function () {
+      const lastBlock = await ain.getLastBlock();
+      expect(lastBlock).not.toBeNull();
+      expect(lastBlock.number).not.toBeNull();
+      const validators = await ain.getValidatorsByNumber(lastBlock.number);
+      expect(validators).toStrictEqual(lastBlock.validators);
+    });
+
+    it('getValidatorsByHash', async function () {
+      const lastBlock = await ain.getLastBlock();
+      expect(lastBlock).not.toBeNull();
+      expect(lastBlock.number).not.toBeNull();
+      const validators = await ain.getValidatorsByHash(lastBlock.hash);
+      expect(validators).toStrictEqual(lastBlock.validators);
+    });
+
+    it('getProposerByNumber', async function () {
+      const lastBlock = await ain.getLastBlock();
+      expect(lastBlock).not.toBeNull();
+      expect(lastBlock.number).not.toBeNull();
+      const proposer = await ain.getProposerByNumber(lastBlock.number);
+      expect(proposer).toBe(lastBlock.proposer);
+    });
+
+    it('getProposerByHash', async function () {
+      const lastBlock = await ain.getLastBlock();
+      expect(lastBlock).not.toBeNull();
+      expect(lastBlock.hash).not.toBeNull();
+      const proposer = await ain.getProposerByHash(lastBlock.hash);
+      expect(proposer).toBe(lastBlock.proposer);
     });
 
     // TODO(liayoo): add getTransactionResult method and test case for it.
@@ -397,8 +628,8 @@ describe('ain-js', function() {
       })
     });
 
-    it('getTransaction for sendTransaction with isDryrun = true', async function () {
-      const tx = await ain.getTransaction(targetTxHash);
+    it('getTransactionByHash for sendTransaction with isDryrun = true', async function () {
+      const tx = await ain.getTransactionByHash(targetTxHash);
       expect(tx).toStrictEqual(null);  // The tx is NOT in the blockchain.
     });
 
@@ -415,8 +646,8 @@ describe('ain-js', function() {
       })
     });
 
-    it('getTransaction for sendTransaction', async function () {
-      const tx = await ain.getTransaction(targetTxHash);
+    it('getTransactionByHash for sendTransaction', async function () {
+      const tx = await ain.getTransactionByHash(targetTxHash);
       expect(tx.transaction.tx_body.operation).toStrictEqual(targetTx);
     });
 
@@ -643,6 +874,29 @@ describe('ain-js', function() {
       expect(thrownError.code).toEqual(30401);
       expect(thrownError.message).toEqual('Invalid batch transaction format.');
     });
+
+    it('getPendingTransactions', async function () {
+      const txs = await ain.getPendingTransactions();
+      expect(txs).not.toBeNull();
+    });
+
+    it('getTransactionPoolSizeUtilization', async function () {
+      const txs = await ain.getTransactionPoolSizeUtilization();
+      expect(txs).not.toBeNull();
+    });
+
+    it('getTransactionByBlockHashAndIndex', async function () {
+      const genesisBlockNumber = 0;
+      const genesisBlock = await ain.getBlockByNumber(genesisBlockNumber);
+      const tx = await ain.getTransactionByBlockHashAndIndex(genesisBlock.hash, 0);
+      expect(tx).not.toBeNull();
+    });
+
+    it('getTransactionByBlockNumberAndIndex', async function () {
+      const genesisBlockNumber = 0;
+      const tx = await ain.getTransactionByBlockNumberAndIndex(genesisBlockNumber, 0);
+      expect(tx).not.toBeNull();
+    });
   });
 
   describe('Database', function() {
@@ -1119,6 +1373,39 @@ describe('ain-js', function() {
       })
     });
 
+    it('getStateProof', async function() {
+      await ain.db.ref('/values/blockchain_params').getStateProof()
+      .then(res => {
+        expect(res).not.toBeNull();
+      })
+      .catch(error => {
+        console.log("error:", error);
+        fail('should not happen');
+      })
+    });
+
+    it('getProofHash', async function() {
+      await ain.db.ref('/values/blockchain_params').getProofHash()
+      .then(res => {
+        expect(res).toMatchSnapshot();
+      })
+      .catch(error => {
+        console.log("error:", error);
+        fail('should not happen');
+      })
+    });
+
+    it('getStateInfo', async function() {
+      await ain.db.ref('/rules/transfer/$from/$to/$key/value').getStateInfo()
+      .then(res => {
+        expect(eraseStateVersion(res)).toMatchSnapshot();
+      })
+      .catch(error => {
+        console.log("error:", error);
+        fail('should not happen');
+      })
+    });
+
     /*it('on and off', function(done) {
       try {
         ain.db.ref().on('value', (snap:any) => console.log)
diff --git a/__tests__/test_util.ts b/__tests__/test_util.ts
index 473ad7a..8b9dd47 100644
--- a/__tests__/test_util.ts
+++ b/__tests__/test_util.ts
@@ -1,6 +1,16 @@
+import { set } from 'lodash';
+
 export declare function fail(error?: any): never;
 
-export function eraseProtoVer(retVal) {
-  retVal.protoVer = 'erased';
-  return retVal;
+export function eraseProtoVer(result) {
+  const erased = JSON.parse(JSON.stringify(result));
+  set(erased, 'protoVer', 'erased');
+  return erased;
+}
+
+export function eraseStateVersion(result) {
+  const erased = JSON.parse(JSON.stringify(result));
+  set(erased, '#version', 'erased');
+  return erased;
 }
+
diff --git a/package.json b/package.json
index fbc305e..bb8aa59 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@ainblockchain/ain-js",
-  "version": "1.6.3",
+  "version": "1.7.0",
   "description": "",
   "main": "lib/ain.js",
   "scripts": {
diff --git a/src/ain-db/ref.ts b/src/ain-db/ref.ts
index e769764..43ac5d5 100755
--- a/src/ain-db/ref.ts
+++ b/src/ain-db/ref.ts
@@ -11,6 +11,7 @@ import {
   EvalRuleInput,
   EvalOwnerInput,
   MatchInput,
+  StateInfoInput,
   GetOptions,
 } from '../types';
 import Ain from '../ain';
@@ -347,6 +348,42 @@ export default class Reference {
     return this._ain.provider.send('ain_matchOwner', request);
   }
 
+  /**
+   * Fetches the state proof of a global blockchain state path.
+   * @param {StateInfoInput} params The state info input.
+   * @returns {Promise<any>} The return value of the blockchain API.
+   */
+  getStateProof(params?: StateInfoInput): Promise<any> {
+    const request = {
+      ref: Reference.extendPath(this.path, params ? params.ref : undefined)
+    }
+    return this._ain.provider.send('ain_getStateProof', request);
+  }
+
+  /**
+   * Fetches the proof hash of a global blockchain state path.
+   * @param {StateInfoInput} params The state info input.
+   * @returns {Promise<any>} The return value of the blockchain API.
+   */
+  getProofHash(params?: StateInfoInput): Promise<any> {
+    const request = {
+      ref: Reference.extendPath(this.path, params ? params.ref : undefined)
+    }
+    return this._ain.provider.send('ain_getProofHash', request);
+  }
+
+  /**
+   * Fetches the state information of a global blockchain state path.
+   * @param {StateInfoInput} params The state info input.
+   * @returns {Promise<any>} The return value of the blockchain API.
+   */
+  getStateInfo(params?: StateInfoInput): Promise<any> {
+    const request = {
+      ref: Reference.extendPath(this.path, params ? params.ref : undefined)
+    }
+    return this._ain.provider.send('ain_getStateInfo', request);
+  }
+
   // TODO(liayoo): Add this function.
   ///**
   // * Attaches an listener for database events.
diff --git a/src/ain.ts b/src/ain.ts
index 05b69c2..49c4411 100755
--- a/src/ain.ts
+++ b/src/ain.ts
@@ -85,43 +85,144 @@ export default class Ain {
   }
 
   /**
-   * Fetches a block with a block hash or block number.
-   * @param {string | number} blockHashOrBlockNumber The block hash or block number.
+   * Fetches the last block.
+   * @returns {Promise<Block>}
+   */
+  getLastBlock(): Promise<Block> {
+    return this.provider.send('ain_getLastBlock', {});
+  }
+
+  /**
+   * Fetches the last block number.
+   * @returns {Promise<Number>}
+   */
+  getLastBlockNumber(): Promise<Block> {
+    return this.provider.send('ain_getLastBlockNumber', {});
+  }
+
+  /**
+   * Fetches a block with a block number.
+   * @param {number} blockNumber The block number.
    * @param {boolean} returnTransactionObjects If it's true, returns a block with full transaction objects.
    * Otherwise, returns a block with only transaction hashes.
    * @returns {Promise<Block>}
    */
-  getBlock(blockHashOrBlockNumber: string | number, returnTransactionObjects?: boolean): Promise<Block> {
-    const byHash = typeof blockHashOrBlockNumber === 'string'
-    const rpcMethod = byHash ? 'ain_getBlockByHash' : 'ain_getBlockByNumber';
-    const data = Object.assign({},
-        { getFullTransactions: !!returnTransactionObjects,
-          [byHash ? 'hash' : 'number']: blockHashOrBlockNumber });
-    return this.provider.send(rpcMethod, data);
+  getBlockByNumber(blockNumber: number, returnTransactionObjects?: boolean): Promise<Block> {
+    const data =
+        Object.assign({}, { getFullTransactions: !!returnTransactionObjects, number: blockNumber });
+    return this.provider.send('ain_getBlockByNumber', data);
+  }
+
+  /**
+   * Fetches a block with a block hash.
+   * @param {string} blockHash The block hash.
+   * @param {boolean} returnTransactionObjects If it's true, returns a block with full transaction objects.
+   * Otherwise, returns a block with only transaction hashes.
+   * @returns {Promise<Block>}
+   */
+  getBlockByHash(blockHash: string, returnTransactionObjects?: boolean): Promise<Block> {
+    const data =
+        Object.assign({}, { getFullTransactions: !!returnTransactionObjects, hash: blockHash });
+    return this.provider.send('ain_getBlockByHash', data);
+  }
+
+  /**
+   * Fetches blocks with a block number range.
+   * @param {number} from The begining block number (inclusive).
+   * @param {number} to The ending block number (exclusive).
+   * @returns {Promise<Array<Block>>}
+   */
+  getBlockList(from: number, to: number): Promise<Array<Block>> {
+    return this.provider.send('ain_getBlockList', { from, to });
   }
 
   /**
-   * Fetches the forger's address of a block with a block hash or block number.
-   * @param {string | number} blockHashOrBlockNumber The block hash or block number.
+   * Fetches block headers with a block number range.
+   * @param {number} from The begining block number (inclusive).
+   * @param {number} to The ending block number (exclusive).
+   * @returns {Promise<Array<Block>>}
+   */
+  getBlockHeadersList(from: number, to: number): Promise<Array<Block>> {
+    return this.provider.send('ain_getBlockHeadersList', { from, to });
+  }
+
+  /**
+   * Fetches block transaction count with a block number.
+   * @param {number} number The block number.
+   * @returns {Promise<Number>}
+   */
+  getBlockTransactionCountByNumber(number: number): Promise<Number> {
+    return this.provider.send('ain_getBlockTransactionCountByNumber', { number });
+  }
+
+  /**
+   * Fetches block transaction count with a block hash.
+   * @param {string} hash The block hash.
+   * @returns {Promise<Number>}
+   */
+  getBlockTransactionCountByHash(hash: string): Promise<Number> {
+    return this.provider.send('ain_getBlockTransactionCountByHash', { hash });
+  }
+
+  /**
+   * Fetches the information of the given validator address.
+   * @param {string} address The validator address.
+   * @returns {Promise<any>}
+   */
+  getValidatorInfo(address: string): Promise<any> {
+    return this.provider.send('ain_getValidatorInfo', { address });
+  }
+
+  /**
+   * Fetches the validator list of a block with a block number.
+   * @param {number} blockNumber The block number.
+   * @returns {Promise<any>}
+   */
+  getValidatorsByNumber(blockNumber: number): Promise<any> {
+    return this.provider.send('ain_getValidatorsByNumber', { number: blockNumber });
+  }
+
+  /**
+   * Fetches the validator list of a block with a block hash.
+   * @param {string} blockHash The block hash.
+   * @returns {Promise<any>}
+   */
+  getValidatorsByHash(blockHash: string): Promise<any> {
+    return this.provider.send('ain_getValidatorsByHash', { hash: blockHash });
+  }
+
+  /**
+   * Fetches the block proproser's address of a block with a block number.
+   * @param {number} blockNumber The block number.
    * @returns {Promise<string>}
    */
-  getProposer(blockHashOrBlockNumber: string | number): Promise<string> {
-    const byHash = typeof blockHashOrBlockNumber === 'string'
-    const rpcMethod = byHash ? 'ain_getProposerByHash' : 'ain_getProposerByNumber';
-    return this.provider.send(rpcMethod,
-        {[byHash ? 'hash' : 'number']: blockHashOrBlockNumber});
+  getProposerByNumber(blockNumber: number): Promise<string> {
+    return this.provider.send('ain_getProposerByNumber', { number: blockNumber });
   }
 
   /**
-   * Fetches the validator list of a block with a block hash or block number.
-   * @param {string | number} blockHashOrBlockNumber The block hash or block number.
-   * @returns {Promise<string[]>}
+   * Fetches the block proproser's address of a block with a block hash.
+   * @param {string} blockHash The block hash.
+   * @returns {Promise<string>}
    */
-  getValidators(blockHashOrBlockNumber: string | number): Promise<string[]> {
-    const byHash = typeof blockHashOrBlockNumber === 'string'
-    const rpcMethod = byHash ? 'ain_getValidatorsByHash' : 'ain_getValidatorsByNumber';
-    return this.provider.send(rpcMethod,
-        {[byHash ? 'hash' : 'number']: blockHashOrBlockNumber});
+  getProposerByHash(blockHash: string): Promise<string> {
+    return this.provider.send('ain_getProposerByHash', { hash: blockHash });
+  }
+
+  /**
+   * Fetches pending transaction.
+   * @returns {Promise<any>}
+   */
+  getPendingTransactions(): Promise<any> {
+    return this.provider.send('ain_getPendingTransactions', {});
+  }
+
+  /**
+   * Fetches transaction pool size utilization.
+   * @returns {Promise<any>}
+   */
+  getTransactionPoolSizeUtilization(): Promise<any> {
+    return this.provider.send('ain_getTransactionPoolSizeUtilization', {});
   }
 
   /**
@@ -129,10 +230,30 @@ export default class Ain {
    * @param {string} transactionHash The transaction hash.
    * @returns {Promise<TransactionInfo>}
    */
-  getTransaction(transactionHash: string): Promise<TransactionInfo> {
+  getTransactionByHash(transactionHash: string): Promise<TransactionInfo> {
     return this.provider.send('ain_getTransactionByHash', { hash: transactionHash });
   }
 
+  /**
+   * Fetches a transaction's information with a block hash and an index.
+   * @param {string} blockHash The block hash.
+   * @param {number} index The transaction index in the block
+   * @returns {Promise<TransactionInfo>}
+   */
+  getTransactionByBlockHashAndIndex(blockHash: string, index: Number): Promise<TransactionInfo> {
+    return this.provider.send('ain_getTransactionByBlockHashAndIndex', { block_hash: blockHash, index });
+  }
+ 
+  /**
+   * Fetches a transaction's information with a block hash and an index.
+   * @param {string} blockNumber The block number.
+   * @param {number} index The transaction index in the block
+   * @returns {Promise<TransactionInfo>}
+   */
+  getTransactionByBlockNumberAndIndex(blockNumber: Number, index: Number): Promise<TransactionInfo> {
+    return this.provider.send('ain_getTransactionByBlockNumberAndIndex', { block_number: blockNumber, index });
+  }
+
   /**
    * Fetches a blockchain app's state usage information with an app name.
    * @param {string} appName The blockchain app name.
diff --git a/src/provider.ts b/src/provider.ts
index e1ec746..247a80e 100644
--- a/src/provider.ts
+++ b/src/provider.ts
@@ -37,6 +37,14 @@ export default class Provider {
     this.httpClient = axios.create(axiosConfig);
   }
 
+  /**
+   * Fetches the blockchain node's address.
+   * @returns {Promise<number>} The address value.
+   */
+  getAddress(): Promise<number> {
+    return this.send('ain_getAddress', {})
+  }
+
   /**
    * Creates a JSON-RPC payload and sends it to the network.
    * @param {string} rpcMethod The JSON-RPC method.
diff --git a/src/signer/default-signer.ts b/src/signer/default-signer.ts
index cfa5a89..014f3bf 100644
--- a/src/signer/default-signer.ts
+++ b/src/signer/default-signer.ts
@@ -124,31 +124,11 @@ export class DefaultSigner implements Signer {
     }
     let nonce = transactionInput.nonce;
     if (nonce === undefined) {
-      nonce = await this.getNonce({ address, from: "pending" });
+      nonce = await this.wallet.getNonce({ address, from: "pending" });
     }
     const timestamp = transactionInput.timestamp ? transactionInput.timestamp : Date.now();
     const gasPrice = transactionInput.gas_price || 0;
     const billing = transactionInput.billing;
     return Object.assign(tx, { nonce, timestamp, gas_price: gasPrice, billing });
   }
-
-  /**
-   * Fetches an account's nonce value, which is the current transaction count of the account.
-   * @param {object} args The ferch options.
-   * It may contain a string 'address' value and a string 'from' value.
-   * The 'address' is the address of the account to get the nonce of,
-   * and the 'from' is the source of the data.
-   * It could be either the pending transaction pool ("pending") or
-   * the committed blocks ("committed"). The default value is "committed".
-   * @returns {Promise<number>} The nonce value.
-   */
-  getNonce(args: { address?: string, from?: string }): Promise<number> {
-    if (!args) { args = {}; }
-    const address = args.address ? Ain.utils.toChecksumAddress(args.address)
-      : this.getAddress(args.address);
-    if (args.from !== undefined && args.from !== 'pending' && args.from !== 'committed') {
-      throw Error("'from' should be either 'pending' or 'committed'");
-    }
-    return this.provider.send('ain_getNonce', { address, from: args.from })
-  }
-}
\ No newline at end of file
+  };
diff --git a/src/types.ts b/src/types.ts
index d8c8452..15fa14e 100755
--- a/src/types.ts
+++ b/src/types.ts
@@ -291,6 +291,13 @@ export interface MatchInput {
   is_global?: boolean;
 }
 
+/**
+ * An interface for state information input.
+ */
+export interface StateInfoInput {
+  ref?: string;
+}
+
 /**
  * An interface for state usage information.
  */
diff --git a/src/wallet.ts b/src/wallet.ts
index fef037b..12512e2 100755
--- a/src/wallet.ts
+++ b/src/wallet.ts
@@ -2,7 +2,9 @@ import { Accounts, Account, TransactionBody, V3Keystore, V3KeystoreOptions } fro
 import Ain from './ain';
 import { validateMnemonic, mnemonicToSeedSync } from 'bip39';
 import Reference from './ain-db/ref';
-const AIN_HD_DERIVATION_PATH = "m/44'/412'/0'/0/"; /* default wallet address for AIN */
+// TODO(platfowner): Migrate to Ethereum HD derivation path 'm/44'/60'/0'/0/'.
+const AIN_HD_DERIVATION_PATH = "m/44'/412'/0'/0/";  // The hardware wallet derivation path of AIN
+const MAX_TRANSFERABLE_DECIMALS = 6;  // The maximum decimals of transferable values
 
 /**
  * A class for AI Network wallets.
@@ -58,6 +60,25 @@ export default class Wallet {
     return this.accounts[checksummed].public_key;
   }
 
+  /**
+   * Counts the given number's decimals.
+   * @param {number} value The number.
+   * @returns {number} The decimal count.
+   */
+  static countDecimals(value: number): number {
+    const decimalExponentRegex = /^-{0,1}(\d*\.{0,1}\d*)e-(\d+)$/gm;
+
+    if (Math.floor(value) === value) {
+      return 0;
+    }
+    const valueString = value.toString();
+    const matches = decimalExponentRegex.exec(valueString);
+    if (matches) {
+      return Number(matches[2]) + Wallet.countDecimals(Number(matches[1]));
+    }
+    return valueString.split('.')[1].length || 0; 
+  }
+
   /**
    * Creates new accounts and adds them to the wallet.
    * @param {number} numberOfAccounts The number of accounts to create.
@@ -227,6 +248,46 @@ export default class Wallet {
     return this.ain.db.ref(`/accounts/${addr}/balance`).getValue();
   }
 
+  /**
+   * Fetches an account's nonce value, which is the current transaction count of the account.
+   * @param {object} args The ferch options.
+   * It may contain a string 'address' value and a string 'from' value.
+   * The 'address' is the address of the account to get the nonce of,
+   * and the 'from' is the source of the data.
+   * It could be either the pending transaction pool ("pending") or
+   * the committed blocks ("committed"). The default value is "committed".
+   * @returns {Promise<number>} The nonce value.
+   */
+  getNonce(args: { address?: string, from?: string }): Promise<number> {
+    if (!args) { args = {}; }
+    const address = args.address ? Ain.utils.toChecksumAddress(args.address)
+      : this.getImpliedAddress(args.address);
+    if (args.from !== undefined && args.from !== 'pending' && args.from !== 'committed') {
+      throw Error("'from' should be either 'pending' or 'committed'");
+    }
+    return this.ain.provider.send('ain_getNonce', { address, from: args.from })
+  }
+
+  /**
+   * Fetches an account's timestamp value, which is the current transaction count of the account.
+   * @param {object} args The ferch options.
+   * It may contain a string 'address' value and a string 'from' value.
+   * The 'address' is the address of the account to get the timestamp of,
+   * and the 'from' is the source of the data.
+   * It could be either the pending transaction pool ("pending") or
+   * the committed blocks ("committed"). The default value is "committed".
+   * @returns {Promise<number>} The timestamp value.
+   */
+  getTimestamp(args: { address?: string, from?: string }): Promise<number> {
+    if (!args) { args = {}; }
+    const address = args.address ? Ain.utils.toChecksumAddress(args.address)
+      : this.getImpliedAddress(args.address);
+    if (args.from !== undefined && args.from !== 'pending' && args.from !== 'committed') {
+      throw Error("'from' should be either 'pending' or 'committed'");
+    }
+    return this.ain.provider.send('ain_getTimestamp', { address, from: args.from })
+  }
+
   /**
    * Sends a transfer transaction to the network.
    * @param {{to: string, value: number, from?: string, nonce?: number, gas_price?: number}} input The input parameters of the transaction.
@@ -236,6 +297,13 @@ export default class Wallet {
   transfer(input: {to: string, value: number, from?: string, nonce?: number, gas_price?: number}, isDryrun: boolean = false): Promise<any> {
     const address = this.getImpliedAddress(input.from);
     const toAddress = Ain.utils.toChecksumAddress(input.to);
+    if (!(input.value > 0)) {
+      throw Error(`Non-positive transfer value.`);
+    }
+    const decimalCount = Wallet.countDecimals(input.value);
+    if (decimalCount > MAX_TRANSFERABLE_DECIMALS) {
+      throw Error(`Transfer value of more than ${MAX_TRANSFERABLE_DECIMALS} decimals.`);
+    }
     const transferRef = this.ain.db.ref(`/transfer/${address}/${toAddress}`).push() as Reference;
     return transferRef.setValue({
         ref: '/value', address, value: input.value, nonce: input.nonce, gas_price: input.gas_price }, isDryrun);