diff --git a/schema.graphql b/schema.graphql
index d878043..d00e599 100644
--- a/schema.graphql
+++ b/schema.graphql
@@ -39,7 +39,7 @@ type Token @entity {
     createdTimestamp: Int        
 
     "datatoken creation transaction id"                         
-    tx: Bytes        
+    tx: String!        
 
     "block number when it was created"                                   
     block: Int                                            
@@ -84,7 +84,7 @@ type Nft @entity{
     "block time nft was created"
     createdTimestamp: Int!                                  
     "nft creation transaction id"
-    tx: Bytes   
+    tx: String!   
     "block number when it was created"                                            
     block: Int                                              
 }
@@ -163,7 +163,7 @@ type Pool @entity {
     "block time when pool was created"
     createdTimestamp: Int!      
     "pool creation transaction id"                            
-    tx: Bytes    
+    tx: String!    
     "block number when it was created"                                          
     block: Int                                              
 
@@ -211,7 +211,7 @@ type PoolTransaction @entity {
   "block time when pool was created"
   timestamp: Int!      
   "pool creation transaction id"                            
-  tx: Bytes    
+  tx: String!    
   "block number when it was created"                                          
   block: Int       
 
@@ -253,7 +253,7 @@ type Order @entity {
   consumerMarketAmmount: BigDecimal                           #call contract to get fee ammount
 
   createdTimestamp: Int!
-  tx: Bytes
+  tx: String!
   block: Int!
 }
 
@@ -268,7 +268,7 @@ type TokenTransaction @entity {
   gasUsed: BigDecimal!
   gasPrice: BigDecimal!
   createdTimestamp: Int!
-  tx: Bytes!
+  tx: String!
 }
 
 type User @entity {
@@ -303,7 +303,7 @@ type FixedRateExchange @entity {
   swaps: [FixedRateExchangeSwap!] @derivedFrom(field: "exchangeId")
 
   createdTimestamp: Int!
-  tx: Bytes
+  tx: String!
   block: Int!
 }
 
@@ -322,7 +322,7 @@ type FixedRateExchangeUpdate @entity {
 
   block: Int!
   createdTimestamp: Int!
-  tx: Bytes!
+  tx: String!
 }
 
 type FixedRateExchangeSwap @entity {
@@ -333,7 +333,7 @@ type FixedRateExchangeSwap @entity {
   dataTokenAmount: BigDecimal!
   block: Int!
   createdTimestamp: Int!
-  tx: Bytes!
+  tx: String!
 }
 
 
@@ -364,7 +364,7 @@ type DispenserTransaction @entity {
 
   block: Int!
   createdTimestamp: Int!
-  tx: Bytes!
+  tx: String!
 }
 
 type PoolSnapshot @entity {
@@ -402,25 +402,36 @@ type GlobalStats @entity {
     orderCount: BigInt                                     
 
     "number of pools for all factories"
-    poolCount: Int!       
+    poolCount: Int!
     "number of finalized pools for all factories"                                  
-    finalizedPoolCount: Int!                   
+    finalizedPoolCount: Int!          
     "probably remove due to inconsistencies and imposibility to calculate"             
-    totalOrderVolume: BigDecimal                            
+    totalOrderVolume: BigDecimal
 }
 
 
+ enum NftUpdateType {
+  METADATA_CREATED,
+  METADATA_UPDATED,
+  STATE_UPDATED,
+  TOKENURI_UPDATED
+}
+
 type NftUpdate @entity {
   id: ID! # update tx +  nft address
-  datatoken: Nft!
+  
+  nft: Nft!
 
  "user that made the update"
   userAddress: String!
 
-  "state of the asset in this update"  
+  "state of the asset in this update"
   assetState: Int!
 
+  "type of the update: metadata created, metadata update, state update, token uri update"
+  type: NftUpdateType!
+
   block: Int!
   timestamp: Int!
-  tx: Bytes!
+  tx: String!
 }
diff --git a/src/mappings/dispenser.ts b/src/mappings/dispenser.ts
index 92e6ce3..3e20388 100644
--- a/src/mappings/dispenser.ts
+++ b/src/mappings/dispenser.ts
@@ -53,7 +53,7 @@ export function handleTokensDispensed(event: TokensDispensed): void {
   dispenserTransaction.user = user.id
 
   dispenserTransaction.createdTimestamp = event.block.timestamp.toI32()
-  dispenserTransaction.tx = event.transaction.hash
+  dispenserTransaction.tx = event.transaction.hash.toHex()
   dispenserTransaction.block = event.block.number.toI32()
   dispenserTransaction.save()
 }
diff --git a/src/mappings/erc20Templates.ts b/src/mappings/erc20Templates.ts
index df786a2..34e8c3b 100644
--- a/src/mappings/erc20Templates.ts
+++ b/src/mappings/erc20Templates.ts
@@ -46,7 +46,7 @@ export function handleOrderStarted(event: OrderStarted): void {
   order.consumerMarket = consumeMarket.id
 
   order.createdTimestamp = event.block.timestamp.toI32()
-  order.tx = event.transaction.hash
+  order.tx = event.transaction.hash.toHex()
   order.block = event.block.number.toI32()
 
   order.save()
diff --git a/src/mappings/erc721Factory.ts b/src/mappings/erc721Factory.ts
index e390db1..8d3ffa9 100644
--- a/src/mappings/erc721Factory.ts
+++ b/src/mappings/erc721Factory.ts
@@ -12,7 +12,7 @@ export function handleNftCreated(event: NFTCreated): void {
   nft.name = event.params.tokenName
   nft.symbol = ''
   nft.createdTimestamp = event.block.timestamp.toI32()
-  nft.tx = event.transaction.hash
+  nft.tx = event.transaction.hash.toHex()
   nft.block = event.block.number.toI32()
 
   nft.save()
@@ -23,7 +23,7 @@ export function handleNewToken(event: TokenCreated): void {
   token.isDatatoken = true
   token.address = event.params.newTokenAddress.toHexString()
   token.createdTimestamp = event.block.timestamp.toI32()
-  token.tx = event.transaction.hash
+  token.tx = event.transaction.hash.toHex()
   token.block = event.block.number.toI32()
 
   token.name = event.params.name
diff --git a/src/mappings/fixedRateExchange.ts b/src/mappings/fixedRateExchange.ts
index 2bccc78..82b6a4d 100644
--- a/src/mappings/fixedRateExchange.ts
+++ b/src/mappings/fixedRateExchange.ts
@@ -48,7 +48,7 @@ export function handleRateChange(event: ExchangeRateChanged): void {
   )
   newExchangeUpdate.oldPrice = fixedRateExchange.price
   newExchangeUpdate.createdTimestamp = event.block.timestamp.toI32()
-  newExchangeUpdate.tx = event.transaction.hash
+  newExchangeUpdate.tx = event.transaction.hash.toHex()
   newExchangeUpdate.block = event.block.number.toI32()
 
   fixedRateExchange.price = weiToDecimal(
@@ -84,7 +84,7 @@ export function handleActivated(event: ExchangeActivated): void {
   newExchangeUpdate.oldActive = fixedRateExchange.active
   newExchangeUpdate.newActive = true
   newExchangeUpdate.createdTimestamp = event.block.timestamp.toI32()
-  newExchangeUpdate.tx = event.transaction.hash
+  newExchangeUpdate.tx = event.transaction.hash.toHex()
   newExchangeUpdate.block = event.block.number.toI32()
 
   fixedRateExchange.active = true
@@ -107,7 +107,7 @@ export function handleDeactivated(event: ExchangeDeactivated): void {
   newExchangeUpdate.newActive = false
 
   newExchangeUpdate.createdTimestamp = event.block.timestamp.toI32()
-  newExchangeUpdate.tx = event.transaction.hash
+  newExchangeUpdate.tx = event.transaction.hash.toHex()
   newExchangeUpdate.block = event.block.number.toI32()
 
   fixedRateExchange.active = false
@@ -129,7 +129,7 @@ export function handleAllowedSwapperChanged(
   )
 
   newExchangeUpdate.createdTimestamp = event.block.timestamp.toI32()
-  newExchangeUpdate.tx = event.transaction.hash
+  newExchangeUpdate.tx = event.transaction.hash.toHex()
   newExchangeUpdate.block = event.block.number.toI32()
   newExchangeUpdate.oldAllowedSwapper = fixedRateExchange.allowedSwapper
 
@@ -159,7 +159,7 @@ export function handleSwap(event: Swapped): void {
     )
   )
   swap.createdTimestamp = event.block.timestamp.toI32()
-  swap.tx = event.transaction.hash
+  swap.tx = event.transaction.hash.toHex()
   swap.block = event.block.number.toI32()
 
   swap.exchangeId = event.params.exchangeId.toHex()
diff --git a/src/mappings/nftUpdate.ts b/src/mappings/nftUpdate.ts
index 77e6151..2327be2 100644
--- a/src/mappings/nftUpdate.ts
+++ b/src/mappings/nftUpdate.ts
@@ -1,14 +1,104 @@
+import { Nft, NftUpdate } from '../@types/schema'
 import {
   MetadataCreated,
   MetadataState,
   MetadataUpdated,
   TokenURIUpdate
 } from '../@types/templates/ERC721Template/ERC721Template'
+import { NftUpdateType } from './utils/constants'
 
-export function handleCreated(event: MetadataCreated): void {}
+function getId(tx: string, nftAddress: string): string {
+  return `${tx}-${nftAddress}`
+}
 
-export function handleUpdated(event: MetadataUpdated): void {}
+export function handleCreated(event: MetadataCreated): void {
+  const nftAddress = event.address.toHex()
+  const nft = Nft.load(nftAddress)
+  if (!nft) return
 
-export function handleState(event: MetadataState): void {}
+  nft.assetState = event.params.state
 
-export function handleUriUpdate(event: TokenURIUpdate): void {}
+  const nftUpdate = new NftUpdate(
+    getId(event.transaction.hash.toHex(), nftAddress)
+  )
+
+  nftUpdate.type = NftUpdateType.METADATA_CREATED
+  nftUpdate.userAddress = event.params.createdBy.toHex()
+  nftUpdate.assetState = event.params.state
+
+  nftUpdate.timestamp = event.block.timestamp.toI32()
+  nftUpdate.tx = event.transaction.hash.toHex()
+  nftUpdate.block = event.block.number.toI32()
+
+  nftUpdate.save()
+  nft.save()
+}
+
+export function handleUpdated(event: MetadataUpdated): void {
+  const nftAddress = event.address.toHex()
+  const nft = Nft.load(nftAddress)
+  if (!nft) return
+
+  nft.assetState = event.params.state
+
+  const nftUpdate = new NftUpdate(
+    getId(event.transaction.hash.toHex(), nftAddress)
+  )
+
+  nftUpdate.type = NftUpdateType.METADATA_UPDATED
+  nftUpdate.userAddress = event.params.updatedBy.toHex()
+  nftUpdate.assetState = event.params.state
+
+  nftUpdate.timestamp = event.block.timestamp.toI32()
+  nftUpdate.tx = event.transaction.hash.toHex()
+  nftUpdate.block = event.block.number.toI32()
+
+  nftUpdate.save()
+  nft.save()
+}
+
+export function handleState(event: MetadataState): void {
+  const nftAddress = event.address.toHex()
+  const nft = Nft.load(nftAddress)
+  if (!nft) return
+
+  nft.assetState = event.params.state
+
+  const nftUpdate = new NftUpdate(
+    getId(event.transaction.hash.toHex(), nftAddress)
+  )
+
+  nftUpdate.type = NftUpdateType.STATE_UPDATED
+  nftUpdate.userAddress = event.params.updatedBy.toHex()
+  nftUpdate.assetState = event.params.state
+
+  nftUpdate.timestamp = event.block.timestamp.toI32()
+  nftUpdate.tx = event.transaction.hash.toHex()
+  nftUpdate.block = event.block.number.toI32()
+
+  nftUpdate.save()
+  nft.save()
+}
+
+export function handleTokenUriUpdate(event: TokenURIUpdate): void {
+  const nftAddress = event.address.toHex()
+  const nft = Nft.load(nftAddress)
+
+  if (!nft) return
+
+  nft.tokenUri = event.params.tokenURI
+
+  const nftUpdate = new NftUpdate(
+    getId(event.transaction.hash.toHex(), nftAddress)
+  )
+
+  nftUpdate.type = NftUpdateType.TOKENURI_UPDATED
+  nftUpdate.userAddress = event.params.updatedBy.toHex()
+
+  nftUpdate.timestamp = event.block.timestamp.toI32()
+  nftUpdate.tx = event.transaction.hash.toHex()
+  nftUpdate.block = event.block.number.toI32()
+
+  nftUpdate.save()
+  nft.save()
+}
diff --git a/src/mappings/poolFactory.ts b/src/mappings/poolFactory.ts
index e06f115..1b1a9e4 100644
--- a/src/mappings/poolFactory.ts
+++ b/src/mappings/poolFactory.ts
@@ -1,26 +1,20 @@
 import { BPoolCreated } from '../@types/FactoryRouter/FactoryRouter'
 import { Pool } from '../@types/schema'
-import { getPoolToken } from './utils/poolUtils'
+import { getToken } from './utils/tokenUtils'
 
 export function handleNewPool(event: BPoolCreated): void {
   const pool = new Pool(event.params.newBPoolAddress.toHex())
 
-  const baseToken = getPoolToken(
-    event.params.newBPoolAddress.toHex(),
-    event.params.basetokenAddress.toHex()
-  )
+  const baseToken = getToken(event.params.basetokenAddress.toHex())
   pool.baseToken = baseToken.id
 
-  const datatoken = getPoolToken(
-    event.params.newBPoolAddress.toHex(),
-    event.params.datatokenAddress.toHex()
-  )
+  const datatoken = getToken(event.params.datatokenAddress.toHex())
   pool.datatoken = datatoken.id
 
   pool.owner = event.params.registeredBy.toHex()
 
   pool.createdTimestamp = event.block.timestamp.toI32()
-  pool.tx = event.transaction.hash
+  pool.tx = event.transaction.hash.toHex()
   pool.block = event.block.number.toI32()
 
   pool.save()
diff --git a/src/mappings/utils/constants.ts b/src/mappings/utils/constants.ts
index e8d5d7e..ce99faa 100644
--- a/src/mappings/utils/constants.ts
+++ b/src/mappings/utils/constants.ts
@@ -25,3 +25,10 @@ export enum PoolTransactionType {
   SWAP = 'SWAP',
   SETUP = 'SETUP'
 }
+
+export enum NftUpdateType {
+  METADATA_CREATED = 'METADATA_CREATED',
+  METADATA_UPDATED = 'METADATA_UPDATED',
+  STATE_UPDATED = 'STATE_UPDATED',
+  TOKENURI_UPDATED = 'TOKENURI_UPDATED'
+}
diff --git a/subgraph.yaml b/subgraph.yaml
index 14f1214..f40e0b0 100644
--- a/subgraph.yaml
+++ b/subgraph.yaml
@@ -118,7 +118,7 @@ templates:
         - event: PublishMarketFees(indexed address,indexed address,uint256)
           handler: handlePublishMarketFees
         - event: ConsumeMarketFees(indexed address,indexed address,uint256)
-          handler: handleConsumeMarketFees
+          handler: handleConsumeMarketFees 
   - kind: ethereum/contract
     name: BFactory
     network: barge
@@ -194,6 +194,6 @@ templates:
         - event: MetadataState(indexed address,uint8,uint256,uint256)
           handler: handleState
         - event: TokenURIUpdate(indexed address,string,uint256,uint256,uint256)
-          handler: handleUriUpdate
+          handler: handleTokenUriUpdate
 features:
   - nonFatalErrors