diff --git a/Gemfile b/Gemfile
index 53b5cbc..d06a793 100644
--- a/Gemfile
+++ b/Gemfile
@@ -23,7 +23,7 @@ gem 'devise_token_auth'
 gem 'discard', '>= 1.0.0'
 gem 'faker', '>= 1.9.1', require: false
 gem 'graphiql-rails', '>= 1.5.0'
-gem 'graphql', '1.9.2'
+gem 'graphql', '1.9.5'
 gem 'graphql-guard', '~> 1.2.1'
 gem 'kaminari', '>= 1.1.1'
 gem 'loofah', '>= 2.2.3'
diff --git a/Gemfile.lock b/Gemfile.lock
index c8605e4..2ee55e2 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -148,7 +148,7 @@ GEM
     graphiql-rails (1.7.0)
       railties
       sprockets-rails
-    graphql (1.9.2)
+    graphql (1.9.5)
     graphql-guard (1.2.2)
       graphql (>= 1.6.0, < 2)
     hashdiff (0.4.0)
@@ -351,7 +351,7 @@ DEPENDENCIES
   factory_bot_rails (>= 4.0.0)
   faker (>= 1.9.1)
   graphiql-rails (>= 1.5.0)
-  graphql (= 1.9.2)
+  graphql (= 1.9.5)
   graphql-guard (~> 1.2.1)
   kaminari (>= 1.1.1)
   listen (>= 3.0.5, < 3.2)
@@ -380,4 +380,4 @@ RUBY VERSION
    ruby 2.6.0p0
 
 BUNDLED WITH
-   1.17.2
+   1.17.3
diff --git a/app/graphql/mutations/resend_transaction_mutation.rb b/app/graphql/mutations/resend_transaction_mutation.rb
new file mode 100644
index 0000000..fb56419
--- /dev/null
+++ b/app/graphql/mutations/resend_transaction_mutation.rb
@@ -0,0 +1,69 @@
+# frozen_string_literal: true
+
+module Mutations
+  class ResendTransactionMutation < Types::Base::BaseMutation
+    description 'Given an old transaction, resend it with new parameters or gas prices'
+
+    argument :id, ID,
+             required: true,
+             description: 'ID of the transaction to be resent'
+    argument :transaction_hash, String,
+             required: true,
+             description: 'Transaction hash'
+    argument :transaction_object, Types::Scalar::JSONObject,
+             required: true,
+             description: 'The JSONified transaction data object'
+    argument :signed_transaction, String,
+             required: true,
+             description: 'Signed transaction in HEX format'
+
+    field :watched_transaction, Types::WatchedTransaction::WatchedTransactionType,
+          null: true,
+          description: 'Newly created transaction'
+    field :errors, [UserErrorType],
+          null: false,
+          description: <<~EOS
+            Mutation errors
+
+            Operation Errors:
+            - Previous transaction not found
+            - Unauthorized action
+            - Nonce is not the same as the previous
+          EOS
+
+    def resolve(id:, transaction_hash:, transaction_object:, signed_transaction:)
+      key = :watched_transaction
+
+      unless (old = WatchingTransaction.find_by(id: id))
+        return form_error(key, 'transaction_object', 'Previous transaction not found')
+      end
+
+      attrs = {
+        txhash: transaction_hash,
+        transaction_object: transaction_object,
+        signed_transaction: signed_transaction
+      }
+
+      result, tx_or_errors = WatchingTransaction.resend(
+        context.fetch(:current_user, nil),
+        old,
+        attrs
+      )
+
+      case result
+      when :unauthorized_action
+        form_error(key, 'id', 'Unauthorized action')
+      when :invalid_nonce
+        form_error(key, 'transaction_object', 'Nonce is not the same as the previous')
+      when :invalid_data
+        model_errors(key, tx_or_errors)
+      when :ok
+        model_result(key, tx_or_errors)
+      end
+    end
+
+    def self.authorized?(object, context)
+      super && context.fetch(:current_user, nil)
+    end
+  end
+end
diff --git a/app/graphql/mutations/watch_transaction_mutation.rb b/app/graphql/mutations/watch_transaction_mutation.rb
new file mode 100644
index 0000000..d02103e
--- /dev/null
+++ b/app/graphql/mutations/watch_transaction_mutation.rb
@@ -0,0 +1,55 @@
+# frozen_string_literal: true
+
+module Mutations
+  class WatchTransactionMutation < Types::Base::BaseMutation
+    description 'Given a transaction, save it to the database to be resent'
+
+    argument :transaction_hash, String,
+             required: true,
+             description: 'Transaction hash'
+    argument :transaction_object, Types::Scalar::JSONObject,
+             required: true,
+             description: 'The JSONified transaction data object'
+    argument :signed_transaction, String,
+             required: true,
+             description: 'Signed transaction in HEX format'
+
+    field :watched_transaction, Types::WatchedTransaction::WatchedTransactionType,
+          null: true,
+          description: 'Newly created transaction'
+    field :errors, [UserErrorType],
+          null: false,
+          description: <<~EOS
+            Mutation errors
+
+            Operation Errors:
+            - Invalid transaction object
+          EOS
+
+    def resolve(transaction_hash:, transaction_object:, signed_transaction:)
+      key = :watched_transaction
+
+      attrs = {
+        txhash: transaction_hash,
+        transaction_object: transaction_object,
+        signed_transaction: signed_transaction
+      }
+
+      result, tx_or_errors = WatchingTransaction.watch(
+        context.fetch(:current_user),
+        attrs
+      )
+
+      case result
+      when :invalid_data
+        model_errors(key, tx_or_errors)
+      when :ok
+        model_result(key, tx_or_errors)
+      end
+    end
+
+    def self.authorized?(object, context)
+      super && context.fetch(:current_user, nil)
+    end
+  end
+end
diff --git a/app/graphql/resolvers/watched_transaction_resolver.rb b/app/graphql/resolvers/watched_transaction_resolver.rb
new file mode 100644
index 0000000..bd925b0
--- /dev/null
+++ b/app/graphql/resolvers/watched_transaction_resolver.rb
@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+
+module Resolvers
+  class WatchedTransactionResolver < Resolvers::Base
+    type Types::WatchedTransaction::WatchedTransactionType, null: true
+
+    argument :txhash, String,
+             required: true,
+             description: 'Find the last watched transaction in the group with that txhash'
+
+    def resolve(txhash:)
+      unless (tx = WatchingTransaction.find_by(txhash: txhash))
+        return nil
+      end
+
+      WatchingTransaction.where(group_id: tx.group_id).order('created_at ASC').last
+    end
+
+    def self.authorized?(object, context)
+      super && context.fetch(:current_user, nil)
+    end
+  end
+end
diff --git a/app/graphql/schema.graphql b/app/graphql/schema.graphql
index 1c4fc00..60a664c 100644
--- a/app/graphql/schema.graphql
+++ b/app/graphql/schema.graphql
@@ -792,6 +792,16 @@ Industry for KYC submission
 """
 scalar IndustryValue
 
+"""
+Represents untyped JSON
+"""
+scalar JSON
+
+"""
+The JSONified data object
+"""
+scalar JSONObject
+
 """
 A customer's KYC submission
 """
@@ -1135,6 +1145,11 @@ type Mutation {
   """
   rejectKyc(input: RejectKycMutationInput!): RejectKycMutationPayload
 
+  """
+  Given an old transaction, resend it with new parameters or gas prices
+  """
+  resendTransaction(input: ResendTransactionMutationInput!): ResendTransactionMutationPayload
+
   """
   As the current user, submit a KYC to access more features of the app.
 
@@ -1171,6 +1186,11 @@ type Mutation {
   Can only unpost a comment you posted.
   """
   unpostComment(input: UnpostCommentMutationInput!): UnpostCommentMutationPayload
+
+  """
+  Given a transaction, save it to the database to be resent
+  """
+  watchTransaction(input: WatchTransactionMutationInput!): WatchTransactionMutationPayload
 }
 
 """
@@ -1587,6 +1607,16 @@ type Query {
     """
     id: String!
   ): AuthorizedUser
+
+  """
+  Given a transaction txhash, find the last watched transaction in the group with that txhash.
+  """
+  watchedTransaction(
+    """
+    Find the last watched transaction in the group with that txhash
+    """
+    txhash: String!
+  ): WatchedTransaction
 }
 
 """
@@ -1652,6 +1682,61 @@ A rejection rason represented by a string that comes form `RejectionReason.value
 """
 scalar RejectionReasonValue
 
+"""
+Autogenerated input type of ResendTransactionMutation
+"""
+input ResendTransactionMutationInput {
+  """
+  A unique identifier for the client performing the mutation.
+  """
+  clientMutationId: String
+
+  """
+  ID of the transaction to be resent
+  """
+  id: ID!
+
+  """
+  Signed transaction in HEX format
+  """
+  signedTransaction: String!
+
+  """
+  Transaction hash
+  """
+  transactionHash: String!
+
+  """
+  The JSONified transaction data object
+  """
+  transactionObject: JSONObject!
+}
+
+"""
+Autogenerated return type of ResendTransactionMutation
+"""
+type ResendTransactionMutationPayload {
+  """
+  A unique identifier for the client performing the mutation.
+  """
+  clientMutationId: String
+
+  """
+  Mutation errors
+
+  Operation Errors:
+  - Previous transaction not found
+  - Unauthorized action
+  - Nonce is not the same as the previous
+  """
+  errors: [UserError!]!
+
+  """
+  Newly created transaction
+  """
+  watchedTransaction: WatchedTransaction
+}
+
 """
 Customer residence proof for KYC submission
 """
@@ -2413,4 +2498,72 @@ enum VotingStageEnum {
   Voters reveal their vote
   """
   REVEAL
+}
+
+"""
+Autogenerated input type of WatchTransactionMutation
+"""
+input WatchTransactionMutationInput {
+  """
+  A unique identifier for the client performing the mutation.
+  """
+  clientMutationId: String
+
+  """
+  Signed transaction in HEX format
+  """
+  signedTransaction: String!
+
+  """
+  Transaction hash
+  """
+  transactionHash: String!
+
+  """
+  The JSONified transaction data object
+  """
+  transactionObject: JSONObject!
+}
+
+"""
+Autogenerated return type of WatchTransactionMutation
+"""
+type WatchTransactionMutationPayload {
+  """
+  A unique identifier for the client performing the mutation.
+  """
+  clientMutationId: String
+
+  """
+  Mutation errors
+
+  Operation Errors:
+  - Invalid transaction object
+  """
+  errors: [UserError!]!
+
+  """
+  Newly created transaction
+  """
+  watchedTransaction: WatchedTransaction
+}
+
+"""
+Transactions that are being watched in the blockchain
+"""
+type WatchedTransaction {
+  """
+  UUID of the watched transaction
+  """
+  id: ID!
+
+  """
+  The JSONified transaction data object
+  """
+  transactionObject: JSON!
+
+  """
+  Signer of the transaction
+  """
+  user: User!
 }
\ No newline at end of file
diff --git a/app/graphql/types/mutation_type.rb b/app/graphql/types/mutation_type.rb
index b2d53f7..fa5a474 100644
--- a/app/graphql/types/mutation_type.rb
+++ b/app/graphql/types/mutation_type.rb
@@ -18,5 +18,8 @@ class MutationType < Types::Base::BaseObject
     field :unpost_comment, mutation: Mutations::UnpostCommentMutation
     field :ban_comment, mutation: Mutations::BanCommentMutation
     field :unban_comment, mutation: Mutations::UnbanCommentMutation
+
+    field :watch_transaction, mutation: Mutations::WatchTransactionMutation
+    field :resend_transaction, mutation: Mutations::ResendTransactionMutation
   end
 end
diff --git a/app/graphql/types/query_type.rb b/app/graphql/types/query_type.rb
index e7d4f7c..63f6b83 100644
--- a/app/graphql/types/query_type.rb
+++ b/app/graphql/types/query_type.rb
@@ -74,6 +74,12 @@ def current_user
             Search for the current user's transactions.
           EOS
 
+    field :watched_transaction,
+          resolver: Resolvers::WatchedTransactionResolver,
+          description: <<~EOS
+            Given a transaction txhash, find the last watched transaction in the group with that txhash.
+          EOS
+
     field :countries,
           resolver: Resolvers::CountriesResolver,
           description: 'List of countries to determine nationality for KYC'
diff --git a/app/graphql/types/scalar/json_object.rb b/app/graphql/types/scalar/json_object.rb
new file mode 100644
index 0000000..1f99b33
--- /dev/null
+++ b/app/graphql/types/scalar/json_object.rb
@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+module Types
+  module Scalar
+    class JSONObject < Types::Base::BaseScalar
+      description <<~EOS
+        The JSONified data object
+      EOS
+
+      def self.coerce_input(input, _context)
+        data = JSON.parse(input)
+        unless data.is_a?(Hash)
+          raise GraphQL::CoercionError, "#{input.inspect} is not a JSON object"
+        end
+
+        data
+      rescue JSON::ParserError
+        raise GraphQL::CoercionError, "#{input.inspect} is not a valid JSON"
+      end
+
+      def self.coerce_result(value, _context)
+        value
+      end
+    end
+  end
+end
diff --git a/app/graphql/types/watched_transaction/watched_transaction_type.rb b/app/graphql/types/watched_transaction/watched_transaction_type.rb
new file mode 100644
index 0000000..377661a
--- /dev/null
+++ b/app/graphql/types/watched_transaction/watched_transaction_type.rb
@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+module Types
+  module WatchedTransaction
+    class WatchedTransactionType < Types::Base::BaseObject
+      description 'Transactions that are being watched in the blockchain'
+
+      field :id, ID,
+            null: false,
+            description: 'UUID of the watched transaction'
+
+      field :user, Types::User::UserType,
+            null: false,
+            description: 'Signer of the transaction'
+
+      field :transaction_object, GraphQL::Types::JSON,
+            null: false,
+            description: 'The JSONified transaction data object'
+    end
+  end
+end
diff --git a/app/models/watching_transaction.rb b/app/models/watching_transaction.rb
new file mode 100644
index 0000000..a245488
--- /dev/null
+++ b/app/models/watching_transaction.rb
@@ -0,0 +1,105 @@
+# frozen_string_literal: true
+
+require 'ethereum_api'
+
+class WatchingTransaction < ApplicationRecord
+  before_create :set_uuid
+
+  belongs_to :user
+
+  validates :transaction_object,
+            presence: true
+  validates :signed_transaction,
+            presence: true
+  validates :txhash,
+            presence: true,
+            uniqueness: true
+
+  def set_uuid
+    self.id ||= SecureRandom.uuid
+    self.group_id ||= id
+  end
+
+  def transaction_object
+    JSON.parse(super)
+  end
+
+  def transaction_object=(value)
+    super(JSON.generate(value))
+  end
+
+  def txhash=(value)
+    super(value&.downcase)
+  end
+
+  class << self
+    def watch(user, attrs)
+      tx = WatchingTransaction.new(
+        user: user,
+        transaction_object: attrs.fetch(:transaction_object, nil),
+        signed_transaction: attrs.fetch(:signed_transaction, nil),
+        txhash: attrs.fetch(:txhash, nil)
+      )
+
+      return [:invalid_data, tx.errors] unless tx.valid?
+      return [:database_error, tx.errors] unless tx.save
+
+      [:ok, tx]
+    end
+
+    def resend(user, watching_transaction, attrs)
+      transaction_object = attrs.fetch(:transaction_object, nil)
+      unless user.id == watching_transaction.user.id
+        return [:unauthorized_action, nil]
+      end
+      unless transaction_object.fetch('nonce', nil) == watching_transaction.transaction_object['nonce']
+        return [:invalid_nonce, nil]
+      end
+
+      tx = WatchingTransaction.new(
+        user: user,
+        transaction_object: transaction_object,
+        signed_transaction: attrs.fetch(:signed_transaction, nil),
+        txhash: attrs.fetch(:txhash, nil),
+        group_id: watching_transaction.group_id
+      )
+
+      return [:invalid_data, tx.errors] unless tx.valid?
+      return [:database_error, tx.errors] unless tx.save
+
+      [:ok, tx]
+    end
+
+    def resend_transactions
+      group_size = WatchingTransaction.group(:group_id).count
+      WatchingTransaction.order('created_at ASC').each do |tx|
+        ok_tx, data = EthereumApi.get_transaction_by_hash(tx.txhash)
+        if ok_tx == :error
+          Rails.logger.info 'Failed to get transaction by hash. Killing job..'
+          break
+        end
+        unless data
+          if group_size[tx.group_id] == 1
+            ok_send, txhash = EthereumApi.send_raw_transaction(tx.signed_transaction)
+            if ok_send == :ok
+              Rails.logger.info "Resent transaction #{tx.txhash}, new hash is #{txhash}"
+              tx.update_attributes(txhash: txhash)
+            else
+              Rails.logger.info "Failed to resend #{tx.txhash}"
+            end
+          else
+            Rails.logger.info "Destroying dropped transaction #{tx.txhash}"
+            tx.destroy
+            group_size[tx.group_id] -= 1
+          end
+          next
+        end
+
+        unless data['block_number'].nil?
+          Rails.logger.info "Destroying transactions from mined group #{tx.group_id}"
+          WatchingTransaction.where(group_id: tx.group_id).destroy_all
+        end
+      end
+    end
+  end
+end
diff --git a/db/migrate/20190826132750_create_watching_transactions.rb b/db/migrate/20190826132750_create_watching_transactions.rb
new file mode 100644
index 0000000..885879d
--- /dev/null
+++ b/db/migrate/20190826132750_create_watching_transactions.rb
@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+class CreateWatchingTransactions < ActiveRecord::Migration[5.2]
+  def change
+    create_table :watching_transactions, id: false do |t|
+      t.string :id, limit: 36, primary_key: true, null: false
+      t.string :group_id, limit: 36, index: true, null: false
+      t.string :transaction_object, null: false
+      t.string :signed_transaction, null: false
+      t.string :txhash
+      t.references :user, foreign_key: true
+      t.timestamps
+    end
+
+    add_index :watching_transactions, :txhash, unique: true
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index dc8d6ed..fed95fd 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 # This file is auto-generated from the current state of the database. Instead
 # of editing this file, please use the migrations feature of Active Record to
 # incrementally modify your database, and then regenerate this schema definition.
@@ -12,202 +10,219 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20_190_226_235_957) do
-  create_table 'active_storage_attachments', options: 'ENGINE=InnoDB DEFAULT CHARSET=utf8', force: :cascade do |t|
-    t.string 'name', null: false
-    t.string 'record_type', null: false
-    t.bigint 'record_id', null: false
-    t.bigint 'blob_id', null: false
-    t.datetime 'created_at', null: false
-    t.index ['blob_id'], name: 'index_active_storage_attachments_on_blob_id'
-    t.index %w[record_type record_id name blob_id], name: 'index_active_storage_attachments_uniqueness', unique: true
-  end
-
-  create_table 'active_storage_blobs', options: 'ENGINE=InnoDB DEFAULT CHARSET=utf8', force: :cascade do |t|
-    t.string 'key', null: false
-    t.string 'filename', null: false
-    t.string 'content_type'
-    t.text 'metadata'
-    t.bigint 'byte_size', null: false
-    t.string 'checksum', null: false
-    t.datetime 'created_at', null: false
-    t.index ['key'], name: 'index_active_storage_blobs_on_key', unique: true
-  end
-
-  create_table 'challenges', options: 'ENGINE=InnoDB DEFAULT CHARSET=utf8', force: :cascade do |t|
-    t.string 'challenge'
-    t.boolean 'proven', default: false
-    t.bigint 'user_id'
-    t.datetime 'created_at', null: false
-    t.datetime 'updated_at', null: false
-    t.index ['user_id'], name: 'index_challenges_on_user_id'
-  end
-
-  create_table 'comment_hierarchies', id: false, options: 'ENGINE=InnoDB DEFAULT CHARSET=utf8', force: :cascade do |t|
-    t.integer 'ancestor_id', null: false
-    t.integer 'descendant_id', null: false
-    t.integer 'generations', null: false
-    t.index %w[ancestor_id descendant_id generations], name: 'comment_anc_desc_idx', unique: true
-    t.index ['descendant_id'], name: 'comment_desc_idx'
-  end
-
-  create_table 'comment_likes', options: 'ENGINE=InnoDB DEFAULT CHARSET=utf8', force: :cascade do |t|
-    t.bigint 'user_id'
-    t.bigint 'comment_id'
-    t.index ['comment_id'], name: 'index_comment_likes_on_comment_id'
-    t.index %w[user_id comment_id], name: 'index_comment_likes_on_user_id_and_comment_id', unique: true
-    t.index ['user_id'], name: 'index_comment_likes_on_user_id'
-  end
-
-  create_table 'comments', options: 'ENGINE=InnoDB DEFAULT CHARSET=utf8', force: :cascade do |t|
-    t.text 'body'
-    t.integer 'stage', default: 1
-    t.bigint 'user_id'
-    t.integer 'likes', default: 0
-    t.integer 'parent_id'
-    t.datetime 'discarded_at'
-    t.datetime 'created_at', null: false
-    t.datetime 'updated_at', null: false
-    t.boolean 'is_banned', default: false, null: false
-    t.index ['discarded_at'], name: 'index_comments_on_discarded_at'
-    t.index ['stage'], name: 'index_comments_on_stage'
-    t.index ['user_id'], name: 'index_comments_on_user_id'
-  end
-
-  create_table 'groups', options: 'ENGINE=InnoDB DEFAULT CHARSET=utf8', force: :cascade do |t|
-    t.string 'name', null: false
-    t.datetime 'created_at', null: false
-    t.datetime 'updated_at', null: false
-  end
-
-  create_table 'groups_users', id: false, options: 'ENGINE=InnoDB DEFAULT CHARSET=utf8', force: :cascade do |t|
-    t.bigint 'user_id', null: false
-    t.bigint 'group_id', null: false
-    t.index %w[user_id group_id], name: 'index_groups_users_on_user_id_and_group_id', unique: true
-  end
-
-  create_table 'kycs', options: 'ENGINE=InnoDB DEFAULT CHARSET=utf8', force: :cascade do |t|
-    t.integer 'status'
-    t.string 'first_name'
-    t.string 'last_name'
-    t.integer 'gender'
-    t.date 'birthdate'
-    t.string 'nationality'
-    t.string 'birth_country'
-    t.string 'phone_number'
-    t.integer 'employment_status'
-    t.string 'employment_industry'
-    t.string 'income_range'
-    t.integer 'identification_proof_type'
-    t.date 'identification_proof_expiration_date'
-    t.string 'identification_proof_number'
-    t.integer 'residence_proof_type'
-    t.string 'country'
-    t.string 'address'
-    t.string 'address_details'
-    t.string 'city'
-    t.string 'state'
-    t.string 'postal_code'
-    t.string 'verification_code'
-    t.date 'expiration_date'
-    t.string 'rejection_reason'
-    t.string 'approval_txhash'
-    t.datetime 'discarded_at'
-    t.bigint 'user_id'
-    t.bigint 'officer_id'
-    t.datetime 'created_at', null: false
-    t.datetime 'updated_at', null: false
-    t.bigint 'users_id'
-    t.index ['discarded_at'], name: 'index_kycs_on_discarded_at'
-    t.index ['officer_id'], name: 'index_kycs_on_officer_id'
-    t.index ['status'], name: 'index_kycs_on_status'
-    t.index ['user_id'], name: 'index_kycs_on_user_id'
-    t.index ['users_id'], name: 'index_kycs_on_users_id'
-  end
-
-  create_table 'nonces', options: 'ENGINE=InnoDB DEFAULT CHARSET=utf8', force: :cascade do |t|
-    t.string 'server'
-    t.integer 'nonce'
-    t.datetime 'created_at', null: false
-    t.datetime 'updated_at', null: false
-  end
-
-  create_table 'proposal_likes', options: 'ENGINE=InnoDB DEFAULT CHARSET=utf8', force: :cascade do |t|
-    t.bigint 'user_id'
-    t.bigint 'proposal_id'
-    t.index ['proposal_id'], name: 'index_proposal_likes_on_proposal_id'
-    t.index %w[user_id proposal_id], name: 'index_proposal_likes_on_user_id_and_proposal_id', unique: true
-    t.index ['user_id'], name: 'index_proposal_likes_on_user_id'
-  end
-
-  create_table 'proposals', options: 'ENGINE=InnoDB DEFAULT CHARSET=utf8', force: :cascade do |t|
-    t.string 'proposal_id', default: '', null: false
-    t.bigint 'user_id'
-    t.integer 'stage', default: 1
-    t.integer 'likes', default: 0
-    t.datetime 'created_at', null: false
-    t.datetime 'updated_at', null: false
-    t.bigint 'comment_id'
-    t.index ['comment_id'], name: 'index_proposals_on_comment_id'
-    t.index ['proposal_id'], name: 'index_proposals_on_proposal_id', unique: true
-    t.index ['stage'], name: 'index_proposals_on_stage'
-    t.index ['user_id'], name: 'index_proposals_on_user_id'
-  end
-
-  create_table 'test_images', options: 'ENGINE=InnoDB DEFAULT CHARSET=utf8', force: :cascade do |t|
-  end
-
-  create_table 'transactions', options: 'ENGINE=InnoDB DEFAULT CHARSET=utf8', force: :cascade do |t|
-    t.string 'title'
-    t.string 'txhash'
-    t.string 'status', default: 'pending'
-    t.integer 'block_number'
-    t.bigint 'user_id'
-    t.datetime 'created_at', null: false
-    t.datetime 'updated_at', null: false
-    t.integer 'transaction_type'
-    t.string 'project'
-    t.index ['txhash'], name: 'index_transactions_on_txhash', unique: true
-    t.index ['user_id'], name: 'index_transactions_on_user_id'
-  end
-
-  create_table 'user_audits', options: 'ENGINE=InnoDB DEFAULT CHARSET=utf8', force: :cascade do |t|
-    t.integer 'user_id', null: false
-    t.string 'event', null: false
-    t.string 'field', null: false
-    t.string 'old_value', null: false
-    t.string 'new_value', null: false
-    t.datetime 'created_at', null: false
-    t.datetime 'updated_at', null: false
-  end
-
-  create_table 'users', options: 'ENGINE=InnoDB DEFAULT CHARSET=utf8', force: :cascade do |t|
-    t.string 'provider', default: 'address', null: false
-    t.string 'uid', default: '', null: false
-    t.datetime 'remember_created_at'
-    t.integer 'sign_in_count', default: 0, null: false
-    t.datetime 'current_sign_in_at'
-    t.datetime 'last_sign_in_at'
-    t.string 'current_sign_in_ip'
-    t.string 'last_sign_in_ip'
-    t.string 'address', default: '0x0', null: false
-    t.text 'tokens'
-    t.datetime 'created_at', null: false
-    t.datetime 'updated_at', null: false
-    t.string 'username', limit: 20
-    t.string 'email', limit: 254
-    t.boolean 'is_banned', default: false, null: false
-    t.index ['address'], name: 'index_users_on_address', unique: true
-    t.index ['email'], name: 'index_users_on_email', unique: true
-    t.index %w[uid provider], name: 'index_users_on_uid_and_provider', unique: true
-    t.index ['username'], name: 'index_users_on_username', unique: true
-  end
-
-  add_foreign_key 'challenges', 'users'
-  add_foreign_key 'comments', 'users'
-  add_foreign_key 'kycs', 'users'
-  add_foreign_key 'kycs', 'users', column: 'users_id'
-  add_foreign_key 'proposals', 'comments'
-  add_foreign_key 'proposals', 'users'
-  add_foreign_key 'transactions', 'users'
+ActiveRecord::Schema.define(version: 2019_08_26_132750) do
+
+  create_table "active_storage_attachments", options: "ENGINE=InnoDB DEFAULT CHARSET=utf8", force: :cascade do |t|
+    t.string "name", null: false
+    t.string "record_type", null: false
+    t.bigint "record_id", null: false
+    t.bigint "blob_id", null: false
+    t.datetime "created_at", null: false
+    t.index ["blob_id"], name: "index_active_storage_attachments_on_blob_id"
+    t.index ["record_type", "record_id", "name", "blob_id"], name: "index_active_storage_attachments_uniqueness", unique: true
+  end
+
+  create_table "active_storage_blobs", options: "ENGINE=InnoDB DEFAULT CHARSET=utf8", force: :cascade do |t|
+    t.string "key", null: false
+    t.string "filename", null: false
+    t.string "content_type"
+    t.text "metadata"
+    t.bigint "byte_size", null: false
+    t.string "checksum", null: false
+    t.datetime "created_at", null: false
+    t.index ["key"], name: "index_active_storage_blobs_on_key", unique: true
+  end
+
+  create_table "challenges", options: "ENGINE=InnoDB DEFAULT CHARSET=utf8", force: :cascade do |t|
+    t.string "challenge"
+    t.boolean "proven", default: false
+    t.bigint "user_id"
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["user_id"], name: "index_challenges_on_user_id"
+  end
+
+  create_table "comment_hierarchies", id: false, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8", force: :cascade do |t|
+    t.integer "ancestor_id", null: false
+    t.integer "descendant_id", null: false
+    t.integer "generations", null: false
+    t.index ["ancestor_id", "descendant_id", "generations"], name: "comment_anc_desc_idx", unique: true
+    t.index ["descendant_id"], name: "comment_desc_idx"
+  end
+
+  create_table "comment_likes", options: "ENGINE=InnoDB DEFAULT CHARSET=utf8", force: :cascade do |t|
+    t.bigint "user_id"
+    t.bigint "comment_id"
+    t.index ["comment_id"], name: "index_comment_likes_on_comment_id"
+    t.index ["user_id", "comment_id"], name: "index_comment_likes_on_user_id_and_comment_id", unique: true
+    t.index ["user_id"], name: "index_comment_likes_on_user_id"
+  end
+
+  create_table "comments", options: "ENGINE=InnoDB DEFAULT CHARSET=utf8", force: :cascade do |t|
+    t.text "body"
+    t.integer "stage", default: 1
+    t.bigint "user_id"
+    t.integer "likes", default: 0
+    t.integer "parent_id"
+    t.datetime "discarded_at"
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.boolean "is_banned", default: false, null: false
+    t.index ["discarded_at"], name: "index_comments_on_discarded_at"
+    t.index ["stage"], name: "index_comments_on_stage"
+    t.index ["user_id"], name: "index_comments_on_user_id"
+  end
+
+  create_table "groups", options: "ENGINE=InnoDB DEFAULT CHARSET=utf8", force: :cascade do |t|
+    t.string "name", null: false
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+  end
+
+  create_table "groups_users", id: false, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8", force: :cascade do |t|
+    t.bigint "user_id", null: false
+    t.bigint "group_id", null: false
+    t.index ["user_id", "group_id"], name: "index_groups_users_on_user_id_and_group_id", unique: true
+  end
+
+  create_table "kycs", options: "ENGINE=InnoDB DEFAULT CHARSET=utf8", force: :cascade do |t|
+    t.integer "status"
+    t.string "first_name"
+    t.string "last_name"
+    t.integer "gender"
+    t.date "birthdate"
+    t.string "nationality"
+    t.string "birth_country"
+    t.string "phone_number"
+    t.integer "employment_status"
+    t.string "employment_industry"
+    t.string "income_range"
+    t.integer "identification_proof_type"
+    t.date "identification_proof_expiration_date"
+    t.string "identification_proof_number"
+    t.integer "residence_proof_type"
+    t.string "country"
+    t.string "address"
+    t.string "address_details"
+    t.string "city"
+    t.string "state"
+    t.string "postal_code"
+    t.string "verification_code"
+    t.date "expiration_date"
+    t.string "rejection_reason"
+    t.string "approval_txhash"
+    t.datetime "discarded_at"
+    t.bigint "user_id"
+    t.bigint "officer_id"
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.bigint "users_id"
+    t.index ["discarded_at"], name: "index_kycs_on_discarded_at"
+    t.index ["officer_id"], name: "index_kycs_on_officer_id"
+    t.index ["status"], name: "index_kycs_on_status"
+    t.index ["user_id"], name: "index_kycs_on_user_id"
+    t.index ["users_id"], name: "index_kycs_on_users_id"
+  end
+
+  create_table "nonces", options: "ENGINE=InnoDB DEFAULT CHARSET=utf8", force: :cascade do |t|
+    t.string "server"
+    t.integer "nonce"
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+  end
+
+  create_table "proposal_likes", options: "ENGINE=InnoDB DEFAULT CHARSET=utf8", force: :cascade do |t|
+    t.bigint "user_id"
+    t.bigint "proposal_id"
+    t.index ["proposal_id"], name: "index_proposal_likes_on_proposal_id"
+    t.index ["user_id", "proposal_id"], name: "index_proposal_likes_on_user_id_and_proposal_id", unique: true
+    t.index ["user_id"], name: "index_proposal_likes_on_user_id"
+  end
+
+  create_table "proposals", options: "ENGINE=InnoDB DEFAULT CHARSET=utf8", force: :cascade do |t|
+    t.string "proposal_id", default: "", null: false
+    t.bigint "user_id"
+    t.integer "stage", default: 1
+    t.integer "likes", default: 0
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.bigint "comment_id"
+    t.index ["comment_id"], name: "index_proposals_on_comment_id"
+    t.index ["proposal_id"], name: "index_proposals_on_proposal_id", unique: true
+    t.index ["stage"], name: "index_proposals_on_stage"
+    t.index ["user_id"], name: "index_proposals_on_user_id"
+  end
+
+  create_table "test_images", options: "ENGINE=InnoDB DEFAULT CHARSET=utf8", force: :cascade do |t|
+  end
+
+  create_table "transactions", options: "ENGINE=InnoDB DEFAULT CHARSET=utf8", force: :cascade do |t|
+    t.string "title"
+    t.string "txhash"
+    t.string "status", default: "pending"
+    t.integer "block_number"
+    t.bigint "user_id"
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.integer "transaction_type"
+    t.string "project"
+    t.bigint "group_id"
+    t.index ["group_id"], name: "index_transactions_on_group_id"
+    t.index ["txhash"], name: "index_transactions_on_txhash", unique: true
+    t.index ["user_id"], name: "index_transactions_on_user_id"
+  end
+
+  create_table "user_audits", options: "ENGINE=InnoDB DEFAULT CHARSET=utf8", force: :cascade do |t|
+    t.integer "user_id", null: false
+    t.string "event", null: false
+    t.string "field", null: false
+    t.string "old_value", null: false
+    t.string "new_value", null: false
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+  end
+
+  create_table "users", options: "ENGINE=InnoDB DEFAULT CHARSET=utf8", force: :cascade do |t|
+    t.string "provider", default: "address", null: false
+    t.string "uid", default: "", null: false
+    t.datetime "remember_created_at"
+    t.integer "sign_in_count", default: 0, null: false
+    t.datetime "current_sign_in_at"
+    t.datetime "last_sign_in_at"
+    t.string "current_sign_in_ip"
+    t.string "last_sign_in_ip"
+    t.string "address", default: "0x0", null: false
+    t.text "tokens"
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.string "username", limit: 20
+    t.string "email", limit: 254
+    t.boolean "is_banned", default: false, null: false
+    t.index ["address"], name: "index_users_on_address", unique: true
+    t.index ["email"], name: "index_users_on_email", unique: true
+    t.index ["uid", "provider"], name: "index_users_on_uid_and_provider", unique: true
+    t.index ["username"], name: "index_users_on_username", unique: true
+  end
+
+  create_table "watching_transactions", id: :string, limit: 36, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8", force: :cascade do |t|
+    t.string "group_id", limit: 36, null: false
+    t.string "transaction_object", null: false
+    t.string "signed_transaction", null: false
+    t.string "txhash"
+    t.bigint "user_id"
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["group_id"], name: "index_watching_transactions_on_group_id"
+    t.index ["txhash"], name: "index_watching_transactions_on_txhash", unique: true
+    t.index ["user_id"], name: "index_watching_transactions_on_user_id"
+  end
+
+  add_foreign_key "challenges", "users"
+  add_foreign_key "comments", "users"
+  add_foreign_key "kycs", "users"
+  add_foreign_key "kycs", "users", column: "users_id"
+  add_foreign_key "proposals", "comments"
+  add_foreign_key "proposals", "users"
+  add_foreign_key "transactions", "users"
+  add_foreign_key "watching_transactions", "users"
 end
diff --git a/lib/ethereum_api.rb b/lib/ethereum_api.rb
index 20cf6a0..c246c26 100644
--- a/lib/ethereum_api.rb
+++ b/lib/ethereum_api.rb
@@ -16,6 +16,14 @@ def get_block_by_block_number(block_number)
       unwrap_result(request_ethereum_server('eth_getBlockByNumber', [block_number, false]))
     end
 
+    def get_transaction_by_hash(txhash)
+      unwrap_result(request_ethereum_server('eth_getTransactionByHash', [txhash]))
+    end
+
+    def send_raw_transaction(data)
+      unwrap_result(request_ethereum_server('eth_sendRawTransaction', [data]))
+    end
+
     private
 
     def request_ethereum_server(method_name, method_args)
diff --git a/lib/scheduler.rb b/lib/scheduler.rb
index 2a78b29..536373e 100644
--- a/lib/scheduler.rb
+++ b/lib/scheduler.rb
@@ -48,4 +48,11 @@
   puts 'Cleaning up old challenges took too long.'
 end
 
+scheduler.every '5m' do
+  puts 'Watching transactions'
+  WatchingTransaction.resend_transactions
+rescue Rufus::Scheduler::TimeoutError
+  puts 'Watching transactions took too long.'
+end
+
 scheduler.join
diff --git a/test/factories/watching_transactions.rb b/test/factories/watching_transactions.rb
new file mode 100644
index 0000000..52ec586
--- /dev/null
+++ b/test/factories/watching_transactions.rb
@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+require 'faker'
+
+static_nonce = Random.rand(1001..2000)
+
+FactoryBot.define do
+  sequence(:transaction_object) do |_|
+    { 'nonce' => Random.rand(1..1000) }
+  end
+  sequence(:fixed_transaction_object) do |_|
+    { 'nonce' => static_nonce }
+  end
+  sequence(:signed_transaction) { |_| SecureRandom.hex(32) }
+  sequence(:id) { |_| SecureRandom.hex(32) }
+
+  factory :watching_transaction, class: 'WatchingTransaction' do
+    txhash { generate(:txhash) }
+    transaction_object { generate(:fixed_transaction_object) }
+    signed_transaction { generate(:signed_transaction) }
+    association :user, factory: :user
+  end
+
+  factory :watch_transaction, class: 'Hash' do
+    transactionHash { generate(:txhash) }
+    transactionObject { JSON.generate(generate(:transaction_object)) }
+    signedTransaction { generate(:signed_transaction) }
+
+    factory :watch_transaction_resend do
+      id { generate(:id) }
+      transactionObject { JSON.generate(generate(:fixed_transaction_object)) }
+    end
+  end
+end
diff --git a/test/graphql/resend_transaction_mutation_test.rb b/test/graphql/resend_transaction_mutation_test.rb
new file mode 100644
index 0000000..5e2f282
--- /dev/null
+++ b/test/graphql/resend_transaction_mutation_test.rb
@@ -0,0 +1,76 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+class ResendTransactionMutationTest < ActiveSupport::TestCase
+  QUERY = <<~EOS
+    mutation($id: ID!, $transactionHash: String!, $transactionObject: JSONObject!, $signedTransaction: String!) {
+      resendTransaction(input: { id: $id, transactionHash: $transactionHash, transactionObject: $transactionObject, signedTransaction: $signedTransaction }) {
+        watchedTransaction {
+          id
+          user {
+            address
+          }
+          transactionObject
+        }
+        errors {
+          field
+          message
+        }
+      }
+    }
+  EOS
+
+  test 'resend transaction mutation should work' do
+    old_transaction = create(:watching_transaction)
+    attrs = attributes_for(:watch_transaction_resend, id: old_transaction.id)
+
+    tx_result = DaoServerSchema.execute(
+      QUERY,
+      context: { current_user: old_transaction.user },
+      variables: attrs
+    )
+
+    assert_nil tx_result['errors'],
+               'should work and have no errors'
+    assert_empty tx_result['data']['resendTransaction']['errors'],
+                 'should have no errors'
+
+    data = tx_result['data']['resendTransaction']['watchedTransaction']
+
+    assert_equal JSON.parse(attrs[:transactionObject])['nonce'], data['transactionObject']['nonce'],
+                 'nonce should be the same'
+  end
+
+  test 'resend transaction should fail safely' do
+    unauthorized_result = DaoServerSchema.execute(
+      QUERY,
+      context: {},
+      variables: {}
+    )
+
+    assert_not_empty unauthorized_result['errors'],
+                     'should fail without a user'
+
+    old_transaction = create(:watching_transaction)
+    attrs = attributes_for(:watch_transaction_resend)
+
+    invalid_group_result = DaoServerSchema.execute(
+      QUERY,
+      context: { current_user: old_transaction.user },
+      variables: attrs
+    )
+
+    assert_not_empty invalid_group_result['data']['resendTransaction']['errors'],
+                     'should fail with invalid id'
+
+    invalid_nonce_result = DaoServerSchema.execute(
+      QUERY,
+      context: { current_user: old_transaction.user },
+      variables: attributes_for(:watch_transaction, id: old_transaction.id)
+    )
+
+    assert_not_empty invalid_nonce_result['data']['resendTransaction']['errors'],
+                     'should fail with invalid nonce'
+  end
+end
diff --git a/test/graphql/watch_transaction_mutation_test.rb b/test/graphql/watch_transaction_mutation_test.rb
new file mode 100644
index 0000000..43d7895
--- /dev/null
+++ b/test/graphql/watch_transaction_mutation_test.rb
@@ -0,0 +1,55 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+class WatchTransactionMutationTest < ActiveSupport::TestCase
+  QUERY = <<~EOS
+    mutation($transactionHash: String!, $transactionObject: JSONObject!, $signedTransaction: String!) {
+      watchTransaction(input: { transactionHash: $transactionHash, transactionObject: $transactionObject, signedTransaction: $signedTransaction }) {
+        watchedTransaction {
+          id
+          user {
+            address
+          }
+          transactionObject
+        }
+        errors {
+          field
+          message
+        }
+      }
+    }
+  EOS
+
+  test 'watch transaction mutation should work' do
+    user = create(:user)
+    attrs = attributes_for(:watch_transaction)
+
+    tx_result = DaoServerSchema.execute(
+      QUERY,
+      context: { current_user: user },
+      variables: attrs
+    )
+
+    assert_nil tx_result['errors'],
+               'should work and have no errors'
+    assert_empty tx_result['data']['watchTransaction']['errors'],
+                 'should have no errors'
+
+    data = tx_result['data']['watchTransaction']['watchedTransaction']
+
+    assert_equal JSON.parse(attrs[:transactionObject]), data['transactionObject'],
+                 'transactionObject should be the same'
+  end
+
+  test 'watch transaction should fail safely' do
+    unauthorized_result = DaoServerSchema.execute(
+      QUERY,
+      context: {},
+      variables: {}
+    )
+
+    assert_not_empty unauthorized_result['errors'],
+                     'should fail without a user'
+  end
+end
diff --git a/test/graphql/watched_transaction_query_test.rb b/test/graphql/watched_transaction_query_test.rb
new file mode 100644
index 0000000..f6fa32a
--- /dev/null
+++ b/test/graphql/watched_transaction_query_test.rb
@@ -0,0 +1,51 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+class WatchedTransactionQueryTest < ActiveSupport::TestCase
+  QUERY = <<~EOS
+    query($txhash: String!) {
+      watchedTransaction(txhash: $txhash) {
+        id
+        user {
+          displayName
+        }
+        transactionObject
+      }
+    }
+  EOS
+
+  test 'watched transaction should work' do
+    first_transaction = create(:watching_transaction)
+    last_transaction = create(
+      :watching_transaction,
+      group_id: first_transaction.group_id,
+      user: first_transaction.user,
+      created_at: Date.current + 1
+    )
+    result = DaoServerSchema.execute(
+      QUERY,
+      context: { current_user: first_transaction.user },
+      variables: { txhash: first_transaction.txhash }
+    )
+
+    assert_nil result['errors'],
+               'should work and have no errors'
+
+    data = result['data']['watchedTransaction']
+
+    assert_not_empty data,
+                     'watchedTransaction type should work'
+    assert_equal last_transaction.id, data['id'],
+                 'should return last transaction from group'
+
+    empty_result = DaoServerSchema.execute(
+      QUERY,
+      context: { current_user: first_transaction.user },
+      variables: { txhash: 'NON_EXISTENT_TXHASH' }
+    )
+
+    assert_nil empty_result['data']['watchedTransaction'],
+               'data should be empty on invalid txhash'
+  end
+end
diff --git a/test/models/watching_transaction_test.rb b/test/models/watching_transaction_test.rb
new file mode 100644
index 0000000..697f02b
--- /dev/null
+++ b/test/models/watching_transaction_test.rb
@@ -0,0 +1,178 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+class WatchingTransactionTest < ActiveSupport::TestCase
+  test 'watch should work' do
+    user = create(:user)
+    attrs = attributes_for(:watching_transaction)
+    ok, tx = WatchingTransaction.watch(user, attrs)
+
+    assert_equal :ok, ok,
+                 'should work'
+    assert_equal user.id, tx.user.id,
+                 'should have correct user id'
+  end
+
+  test 'resend should work' do
+    user = create(:user)
+    watching_transaction = create(:watching_transaction, user: user)
+    attrs = attributes_for(:watching_transaction)
+
+    ok, tx = WatchingTransaction.resend(user, watching_transaction, attrs)
+
+    assert_equal :ok, ok,
+                 'should work'
+    assert_equal watching_transaction.group_id, tx.group_id,
+                 'should have the same group as the previous transaction'
+  end
+
+  test 'resend transactions should keep all if none is mined' do
+    user = create(:user)
+    group_id = SecureRandom.uuid
+    size = SecureRandom.rand(1..6)
+    size.times do
+      FactoryBot.create(:watching_transaction, group_id: group_id, user: user)
+    end
+
+    pending_stub = stub_request(:post, EthereumApi::SERVER_URL)
+                   .with(body: /eth_getTransactionByHash/)
+                   .to_return(
+                     body: {
+                       result: {
+                         'block_number' => nil
+                       }
+                     }.to_json
+                   )
+
+    WatchingTransaction.resend_transactions
+
+    assert_requested(pending_stub, times: size)
+    assert_equal size, WatchingTransaction.where(group_id: group_id).count,
+                 'should work'
+  end
+
+  test 'resend transactions should destroy all if one is mined' do
+    user = create(:user)
+    group_id = SecureRandom.uuid
+    size = SecureRandom.rand(1..6)
+    transaction_group = (1..size).map do
+      FactoryBot.create(:watching_transaction, group_id: group_id, user: user)
+    end
+
+    pending_stub = stub_request(:post, EthereumApi::SERVER_URL)
+                   .with(body: /eth_getTransactionByHash/)
+                   .to_return(
+                     body: {
+                       result: {
+                         'block_number' => nil
+                       }
+                     }.to_json
+                   )
+
+    mined_stub = stub_request(:post, EthereumApi::SERVER_URL)
+                 .with(body: /eth_getTransactionByHash.*#{transaction_group.sample.txhash}/)
+                 .to_return(
+                   body: {
+                     result: {
+                       'block_number' => SecureRandom.hex(8)
+                     }
+                   }.to_json
+                 )
+
+    WatchingTransaction.resend_transactions
+
+    assert_requested(pending_stub, times: size)
+    assert_requested(mined_stub, times: 1)
+    assert_equal 0, WatchingTransaction.where(group_id: group_id).count,
+                 'should destroy all if one is mined'
+  end
+
+  test 'resend transactions should resend latest if rest are dropped' do
+    user = create(:user)
+    group_id = SecureRandom.uuid
+    size = SecureRandom.rand(1..6)
+    size.times do
+      FactoryBot.create(:watching_transaction, group_id: group_id, user: user)
+    end
+    latest = FactoryBot.create(:watching_transaction, group_id: group_id, user: user, created_at: Date.current + 1)
+
+    dropped_stub = stub_request(:post, EthereumApi::SERVER_URL)
+                   .with(body: /eth_getTransactionByHash/)
+                   .to_return(
+                     body: {
+                       result: nil
+                     }.to_json
+                   )
+
+    new_txhash = generate(:txhash)
+    send_transaction_stub = stub_request(:post, EthereumApi::SERVER_URL)
+                            .with(body: /eth_sendRawTransaction/)
+                            .to_return(
+                              body: {
+                                result: new_txhash
+                              }.to_json
+                            )
+
+    WatchingTransaction.resend_transactions
+
+    assert_requested(dropped_stub, times: size + 1)
+    assert_requested(send_transaction_stub, times: 1)
+    assert_equal 1, WatchingTransaction.where(group_id: group_id).count,
+                 'should work'
+
+    resent = WatchingTransaction.find_by(id: latest.id)
+    assert_equal new_txhash, resent.txhash,
+                 'should update txhash for resent transaction'
+  end
+
+  test 'resend transactions should keep all if get transaction fails' do
+    user = create(:user)
+    group_id = SecureRandom.uuid
+    size = SecureRandom.rand(1..6)
+    size.times do
+      FactoryBot.create(:watching_transaction, group_id: group_id, user: user)
+    end
+
+    get_failed_stub = stub_request(:post, EthereumApi::SERVER_URL)
+                      .with(body: /eth_getTransactionByHash/)
+                      .to_return(status: [500, 'Internal Server Error'])
+
+    WatchingTransaction.resend_transactions
+
+    assert_requested(get_failed_stub, times: 1)
+    assert_equal size, WatchingTransaction.where(group_id: group_id).count,
+                 'should work'
+  end
+
+  test 'resend transactions should keep latest if send transaction fails' do
+    user = create(:user)
+    group_id = SecureRandom.uuid
+    size = SecureRandom.rand(1..6)
+    size.times do
+      FactoryBot.create(:watching_transaction, group_id: group_id, user: user)
+    end
+    latest = FactoryBot.create(:watching_transaction, group_id: group_id, user: user, created_at: Date.current + 1)
+
+    dropped_stub = stub_request(:post, EthereumApi::SERVER_URL)
+                   .with(body: /eth_getTransactionByHash/)
+                   .to_return(
+                     body: {
+                       result: nil
+                     }.to_json
+                   )
+
+    send_transaction_failed_stub = stub_request(:post, EthereumApi::SERVER_URL)
+                                   .with(body: /eth_sendRawTransaction/)
+                                   .to_return(status: [500, 'Internal Server Error'])
+
+    WatchingTransaction.resend_transactions
+
+    assert_requested(dropped_stub, times: size + 1)
+    assert_requested(send_transaction_failed_stub, times: 1)
+
+    not_resent = WatchingTransaction.find_by(id: latest.id)
+    assert_equal latest.txhash, not_resent.txhash,
+                 'should keep txhash'
+  end
+end