diff --git a/Dockerfile b/Dockerfile
index e1a8d8b..a72ca94 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,8 +1,5 @@
 FROM ruby:3.1.2
 
-# throw errors if Gemfile has been modified since Gemfile.lock
-RUN bundle config --global frozen 1
-
 # Get Rust
 RUN curl https://sh.rustup.rs -sSf | bash -s -- -y
 ENV PATH="/root/.cargo/bin:${PATH}"
diff --git a/Gemfile b/Gemfile
index fcaa28b..2a9914f 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,7 +1,7 @@
 source 'https://rubygems.org'
 
-gem 'scale_rb', '0.1.9'
-# gem "scale_rb", path: "/Users/wuminzhe/Projects/wuminzhe/scale_rb"
+gem 'scale_rb', '0.1.10'
+# gem 'scale_rb', path: '/workspaces/scale_rb'
 gem 'sinatra'
 
 gem 'async', '~> 2.5'
diff --git a/Gemfile.lock b/Gemfile.lock
index 6d67d3b..9534314 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -86,7 +86,7 @@ GEM
       rubyzip (~> 2.3)
     ruby2_keywords (0.0.5)
     rubyzip (2.3.2)
-    scale_rb (0.1.9)
+    scale_rb (0.1.10)
       base58
       blake2b_rs (~> 0.1.4)
       xxhash
@@ -119,7 +119,7 @@ DEPENDENCIES
   lightly
   mongo (~> 2)
   puma
-  scale_rb (= 0.1.9)
+  scale_rb (= 0.1.10)
   sinatra
 
 BUNDLED WITH
diff --git a/Rakefile b/Rakefile
index 52cb740..643603f 100644
--- a/Rakefile
+++ b/Rakefile
@@ -1,24 +1,41 @@
-require "scale_rb"
-require "./src/utils"
-require "./src/supplies"
-require "./src/metadata"
-require "./src/track-goerli"
-require "./src/track-pangolin"
-require "./config/config.rb"
+require 'scale_rb'
+require './src/utils'
+require './src/supplies'
+require './src/metadata'
+require './src/track-goerli'
+require './src/track-pangolin'
+require './src/storage'
+require './src/account'
+require './config/config'
 config = get_config
 
 task default: %w[gen_supplies_data_loop]
 
 task :update_metadata_loop do
   loop_do do
-    Rake::Task["update_darwinia_metadata"].invoke
-    Rake::Task["update_crab_metadata"].invoke
-    Rake::Task["update_pangolin_metadata"].invoke
+    Rake::Task['update_darwinia_metadata'].reenable
+    Rake::Task['update_darwinia_metadata'].invoke
+    Rake::Task['update_crab_metadata'].reenable
+    Rake::Task['update_crab_metadata'].invoke
+    Rake::Task['update_pangolin_metadata'].reenable
+    Rake::Task['update_pangolin_metadata'].invoke
   end
 end
 
 task :gen_supplies_data_loop do
-  loop_do { Rake::Task["gen_darwinia_supplies_data"].invoke }
+  loop_do do
+    Rake::Task['gen_darwinia_supplies_data'].reenable
+    Rake::Task['gen_darwinia_supplies_data'].invoke
+  end
+end
+
+task :update_nominees_loop do
+  loop_do(60 * 2) do
+    Rake::Task['update_nominees'].reenable
+    Rake::Task['update_nominees'].invoke('darwinia')
+    Rake::Task['update_nominees'].reenable
+    Rake::Task['update_nominees'].invoke('crab')
+  end
 end
 
 ##########################################
@@ -28,13 +45,13 @@ task :gen_darwinia_supplies_data do
   ethereum_rpc = config[:ethereum_rpc]
   darwinia_rpc = config[:darwinia_rpc]
   darwinia_metadata = JSON.parse(File.read(config[:metadata][:darwinia]))
-  generate_supplies("darwinia", ethereum_rpc, darwinia_rpc, darwinia_metadata)
+  generate_supplies('darwinia', ethereum_rpc, darwinia_rpc, darwinia_metadata)
 end
 
 task :update_darwinia_metadata do
   darwinia_rpc = config[:darwinia_rpc]
   darwinia_metadata_path = config[:metadata][:darwinia]
-  update_metadata("darwinia", darwinia_rpc, darwinia_metadata_path)
+  update_metadata('darwinia', darwinia_rpc, darwinia_metadata_path)
 end
 
 ##########################################
@@ -43,7 +60,7 @@ end
 task :update_crab_metadata do
   crab_rpc = config[:crab_rpc]
   crab_metadata_path = config[:metadata][:crab]
-  update_metadata("crab", crab_rpc, crab_metadata_path)
+  update_metadata('crab', crab_rpc, crab_metadata_path)
 end
 
 ##########################################
@@ -52,7 +69,7 @@ end
 task :update_pangolin_metadata do
   pangolin_rpc = config[:pangolin_rpc]
   pangolin_metadata_path = config[:metadata][:pangolin]
-  update_metadata("pangolin", pangolin_rpc, pangolin_metadata_path)
+  update_metadata('pangolin', pangolin_rpc, pangolin_metadata_path)
 end
 
 ##########################################
@@ -65,3 +82,75 @@ end
 task :update_pangolin_goerli_messages do
   track_pangolin
 end
+
+require 'logger'
+task :update_nominees, [:network_name] do |_t, args|
+  logger = Logger.new($stdout)
+  logger.level = Logger::DEBUG
+
+  network_name = args[:network_name]
+  logger.debug "updating #{network_name} nominees..."
+
+  rpc = config["#{network_name}_rpc".to_sym]
+  metadata = JSON.parse(File.read(config[:metadata][network_name.to_sym]))
+
+  ring_pool = get_storage(rpc, metadata, 'darwinia_staking', 'ring_pool', nil, nil)
+  kton_pool = get_storage(rpc, metadata, 'darwinia_staking', 'kton_pool', nil, nil)
+
+  # 1. Get all nominators with their nominees
+  # ---------------------------------------
+  # { nominator: nominee }
+  nominators =
+    get_storage(
+      rpc,
+      metadata,
+      'darwinia_staking',
+      'nominators',
+      nil,
+      nil
+    )
+
+  nominator_nominee_mapping =
+    nominators.map do |item|
+      nominator_address = "0x#{item[:storage_key][-40..]}"
+      nominee_address = item[:storage].to_hex
+      [nominator_address, nominee_address]
+    end.to_h
+
+  # 2. Get all nominators' staking info
+  # ---------------------------------------
+  # {
+  #   "nominator" => {:staked_ring=>10000000000000000000, :staked_kton=>0},
+  # }
+  nominator_addresses = nominator_nominee_mapping.keys
+  nominator_staking_infos = get_accounts_staking_info(rpc, metadata, nominator_addresses)
+
+  # 3. Sum up nominators' staking info of each nominee
+  # ---------------------------------------
+  # {
+  #   "nominee" => {:staked_ring=>total, :staked_kton=>total},
+  # }
+  result =
+    nominator_addresses.each_with_object({}) do |nominator_address, acc|
+      nominator_staking_info = nominator_staking_infos[nominator_address]
+      nominee_address = nominator_nominee_mapping[nominator_address]
+      acc[nominee_address] =
+        {
+          staked_ring: (acc[nominee_address]&.[](:staked_ring) || 0) + nominator_staking_info[:staked_ring],
+          staked_kton: (acc[nominee_address]&.[](:staked_kton) || 0) + nominator_staking_info[:staked_kton]
+        }
+    end
+
+  # 4. Calculate power of each nominee
+  # ---------------------------------------
+  nominee_powers = result.map do |nominee_address, staking_info|
+    power = calc_power(staking_info[:staked_ring], staking_info[:staked_kton], ring_pool, kton_pool)
+    [nominee_address, power]
+  end.to_h
+  logger.debug JSON.pretty_generate(nominee_powers)
+
+  # 5. write to file
+  # ---------------------------------------
+  logger.debug "writing #{network_name} nominees to file..."
+  write_data_to_file(nominee_powers, "#{network_name}-nominees.json")
+end
diff --git a/docker-compose.yml b/docker-compose.yml
index 0d725ad..755f7ab 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -12,16 +12,13 @@ services:
     command: rake gen_supplies_data_loop
     volumes:
       - ./data:/usr/src/app/data
-  update_goerli_pangolin_messages:
+  update_nominees:
     build: .
     env_file:
       - .env
-    command: rake update_goerli_pangolin_messages
-  update_pangolin_goerli_messages:
-    build: .
-    env_file:
-      - .env
-    command: rake update_pangolin_goerli_messages
+    command: rake update_nominees_loop
+    volumes:
+      - ./data:/usr/src/app/data
   server:
     build: .
     env_file:
diff --git a/src/account.rb b/src/account.rb
index b92a276..1f2597c 100644
--- a/src/account.rb
+++ b/src/account.rb
@@ -1,12 +1,13 @@
-require "scale_rb"
-require_relative "./utils"
+require 'scale_rb'
+require_relative './utils'
+require_relative './storage'
 
 def get_account_info(rpc, metadata, address)
   param = [c(address)]
 
   # RING
   info =
-    ScaleRb::HttpClient.get_storage2(rpc, "System", "Account", param, metadata)
+    ScaleRb::HttpClient.get_storage2(rpc, 'System', 'Account', param, metadata)
   free = info[:data][:free].to_f / 10**18
   reserved = info[:data][:reserved].to_f / 10**18
 
@@ -14,59 +15,70 @@ def get_account_info(rpc, metadata, address)
   kton_info =
     ScaleRb::HttpClient.get_storage2(
       rpc,
-      "Assets",
-      "Account",
+      'Assets',
+      'Account',
       [1026] + param,
-      metadata,
+      metadata
     )
-  kton_free = kton_info ? kton_info[
-      :balance
-    ].to_f / 10**18 : 0
+  kton_free = if kton_info
+                kton_info[
+                    :balance
+                  ].to_f / 10**18
+              else
+                0
+              end
 
   # LOCKS
   locks =
-    ScaleRb::HttpClient.get_storage2(rpc, "Balances", "Locks", param, metadata)
+    ScaleRb::HttpClient.get_storage2(rpc, 'Balances', 'Locks', param, metadata)
   locked = locks.reduce(0) { |sum, lock| lock[:amount] + sum }.to_f / 10**18
 
   # DEPOSITS
   deposits =
     ScaleRb::HttpClient.get_storage2(
       rpc,
-      "Deposit",
-      "Deposits",
+      'Deposit',
+      'Deposits',
       param,
-      metadata,
+      metadata
     )
-  deposits = deposits ? 
-    deposits.map do |deposit|
-      deposit[:value] = deposit[:value].to_f / 10**18
-      deposit[:start_time] = Time.at(deposit[:start_time] / 1000)
-      deposit[:expired_time] = Time.at(deposit[:expired_time] / 1000)
-      deposit
-    end : []
+  deposits = if deposits
+               deposits.map do |deposit|
+                 deposit[:value] = deposit[:value].to_f / 10**18
+                 deposit[:start_time] = Time.at(deposit[:start_time] / 1000)
+                 deposit[:expired_time] = Time.at(deposit[:expired_time] / 1000)
+                 deposit
+               end
+             else
+               []
+             end
 
   # STAKING LEDGER
   ledger =
     ScaleRb::HttpClient.get_storage2(
       rpc,
-      "DarwiniaStaking",
-      "Ledgers",
+      'DarwiniaStaking',
+      'Ledgers',
       param,
-      metadata,
+      metadata
     )
 
   staked_ring =  ledger ? ledger[:staked_ring].to_f / 10**18 : 0
-  unstaking_ring = ledger ? 
-    (ledger[:unstaking_ring].map do |item|
-      [item[0].to_f / 10**18, item[1]]
-    end.reduce(0) { |sum, item| sum + item[0] } )
-    : 0
+  unstaking_ring = if ledger
+                     (ledger[:unstaking_ring].map do |item|
+                        [item[0].to_f / 10**18, item[1]]
+                      end.reduce(0) { |sum, item| sum + item[0] })
+                   else
+                     0
+                   end
   staked_kton = ledger ? ledger[:staked_kton].to_f / 10**18 : 0
-  unstaking_kton = ledger ? 
-    (ledger[:unstaking_kton].map do |item|
-      [item[0].to_f / 10**18, item[1]]
-    end.reduce(0) { |sum, item| sum + item[0] } )
-    : 0
+  unstaking_kton = if ledger
+                     (ledger[:unstaking_kton].map do |item|
+                        [item[0].to_f / 10**18, item[1]]
+                      end.reduce(0) { |sum, item| sum + item[0] })
+                   else
+                     0
+                   end
 
   {
     ring:
@@ -75,21 +87,116 @@ def get_account_info(rpc, metadata, address)
       kton_free + staked_kton + unstaking_kton,
     items: {
       transferable: free - locked,
-      reserved: reserved,
-      locked: locked,
-      deposits: deposits,
+      reserved:,
+      locked:,
+      deposits:,
       staking: ledger
     }
   }
 end
 
-# require_relative "../config/config.rb"
+def staked_ring_in_deposits(ledger, deposits)
+  if deposits.nil?
+    0
+  else
+    # id => deposit
+    all_deposits = deposits.select { |deposit| deposit[:in_use] == true }.map { |deposit| [deposit[:id], deposit] }.to_h
+
+    deposit_ids_in_ledger = ledger[:staked_deposits] # + ledger[:unstaking_deposits]
+    deposit_ids_in_ledger.reduce(0) do |sum, deposit_id|
+      all_deposits.key?(deposit_id) ? sum + all_deposits[deposit_id][:value] : sum
+    end
+  end
+end
+
+def get_all_deposits(rpc, metadata)
+  # DEPOSITS
+  storages = get_storage(rpc, metadata, 'deposit', 'deposits', nil, nil)
+  storages.each_with_object({}) do |storage, acc|
+    acc["0x#{storage[:storage_key][-40..]}"] = storage[:storage]
+  end
+end
+
+def get_all_ledgers(rpc, metadata)
+  # STAKING LEDGER
+  storages = get_storage(rpc, metadata, 'darwinia_staking', 'ledgers', nil, nil)
+  storages.each_with_object({}) do |storage, acc|
+    acc["0x#{storage[:storage_key][-40..]}"] = storage[:storage]
+  end
+end
+
+def get_accounts_staking_info(rpc, metadata, addresses)
+  all_deposits = get_all_deposits(rpc, metadata)
+  all_ledgers = get_all_ledgers(rpc, metadata)
+
+  addresses.map(&:downcase).reduce({}) do |acc, address|
+    ledger = all_ledgers[address]
+    deposits = all_deposits[address]
+
+    # staked ring in ledger + staked ring in deposits
+    staked_ring =
+      if ledger
+        ledger[:staked_ring] +
+          # ledger[:unstaking_ring].reduce(0) { |sum, item| sum + item[0] } +
+          # 这个account的ledger 和 这个account的所有deposits
+          staked_ring_in_deposits(ledger, deposits)
+      else
+        0
+      end
+
+    # staked kton in ledger
+    staked_kton = ledger ? ledger[:staked_kton] : 0
+
+    acc.merge(
+      {
+        address => {
+          staked_ring:,
+          staked_kton:
+        }
+      }
+    )
+  end
+end
+
+def get_nominee_staking_info(rpc, metadata, nominee_address)
+  result = get_storage(rpc, metadata, 'darwinia_staking', 'exposures', nominee_address, nil)
+
+  nominators = result[:nominators].map do |nominator|
+    nominator[:who].to_hex
+  end
+  get_accounts_staking_info(rpc, metadata, nominators)
+end
+
+def get_nominee_power(rpc, metadata, address)
+  staking_info = get_nominee_staking_info(rpc, metadata, address.downcase)
+  total = staking_info.values.each_with_object({ staked_ring: 0, staked_kton: 0 }) do |info, acc|
+    acc[:staked_ring] += info[:staked_ring]
+    acc[:staked_kton] += info[:staked_kton]
+  end
+
+  ring_pool = get_storage(rpc, metadata, 'darwinia_staking', 'ring_pool', nil, nil)
+  kton_pool = get_storage(rpc, metadata, 'darwinia_staking', 'kton_pool', nil, nil)
+
+  calc_power(total[:staked_ring], total[:staked_kton], ring_pool, kton_pool)
+end
+
+# require_relative '../config/config'
 # config = get_config
 # crab_metadata = JSON.parse(File.read(config[:metadata][:crab]))
 # crab_rpc = config[:crab_rpc]
 
-# p get_account_info(
-#     crab_rpc,
-#     crab_metadata,
-#     "0x20FF2599f29876D5a5345a5cD6592BEd749CECEa",
-#   )
+# result = get_account_staking_info(
+#   crab_rpc,
+#   crab_metadata,
+#   '0x17863f9473ce423ba00C9A3B13Be3af48B93f531'
+# )
+# puts JSON.pretty_generate(result)
+
+# puts get_all_deposits(crab_rpc, crab_metadata)
+# all_ledgers = get_all_ledgers(crab_rpc, crab_metadata)
+# puts all_ledgers['0x82373ccc6ed8ced89293307efdcf31b73b8c49c8']
+# puts get_accounts_staking_info(crab_rpc, crab_metadata,
+#                                %w[0x17863f9473ce423ba00C9A3B13Be3af48B93f531 0x82373ccc6ed8ced89293307efdcf31b73b8c49c8])
+
+# puts get_nominee_power(crab_rpc, crab_metadata, '0x0a1287977578F888bdc1c7627781AF1cc000e6ab'.downcase)
+# puts get_nominee_staking_info(crab_rpc, crab_metadata, '0x0a1287977578F888bdc1c7627781AF1cc000e6ab')
diff --git a/src/server.rb b/src/server.rb
index 99dd9be..7d18fa8 100644
--- a/src/server.rb
+++ b/src/server.rb
@@ -240,6 +240,20 @@
 ##############################################################################
 # General
 ##############################################################################
+get '/:network/nominees' do
+  network = params[:network].downcase
+  unless %w[darwinia crab pangolin].include?(network)
+    raise_with 404,
+               "network #{network} not found, only `darwinia`, `crab` and `pangolin` are supported"
+  end
+
+  result = File.read("./data/#{network}-nominees.json")
+  result = JSON.parse(result)
+
+  content_type :json
+  { code: 0, data: result }.to_json
+end
+
 get '/:network/metadata' do
   network = params[:network].downcase
   unless %w[darwinia crab pangolin].include?(network)
@@ -253,7 +267,7 @@
 end
 
 get '/:network/accounts/:address' do
-  network = network = params[:network].downcase
+  network = params[:network].downcase
   unless %w[darwinia crab pangolin].include?(network)
     raise_with 404,
                "network #{network} not found, only `darwinia`, `crab` and `pangolin` are supported"
diff --git a/src/utils.rb b/src/utils.rb
index f60743e..8380245 100644
--- a/src/utils.rb
+++ b/src/utils.rb
@@ -55,7 +55,24 @@ def matches_time_span_pattern?(input_string)
   !!(input_string =~ regex)
 end
 
-puts matches_time_span_pattern?('12')
+# https://github.com/darwinia-network/darwinia2.0-staking-ui/blob/8f9d88b4c874c36cedf140f0a288250507d3b293/src/utils/misc.ts#L5
+def calc_power(staked_ring, staked_kton, ring_pool, kton_pool)
+  raise 'ring_pool is zero' if ring_pool.zero?
+
+  d = kton_pool.zero? ? 0 : ring_pool.to_f / kton_pool
+  1_000_000_000 * (staked_ring + staked_kton * d) / (ring_pool * 2)
+end
+
+def write_data_to_file(data, filename)
+  data_dir = './data'
+  FileUtils.mkdir_p(data_dir) unless File.directory?(data_dir)
+  File.write(
+    File.join(data_dir, filename),
+    data.to_json
+  )
+end
+
+# puts matches_time_span_pattern?('12')
 
 # require "scale_rb"
 # require "eth"
@@ -71,4 +88,3 @@ def matches_time_span_pattern?(input_string)
 #       ]
 #     )
 #   )
-