diff --git a/server/Gemfile b/server/Gemfile
index 262e9a80..3c375a05 100644
--- a/server/Gemfile
+++ b/server/Gemfile
@@ -9,7 +9,7 @@ group :development do
   gem 'rack'
   gem 'text'
   gem 'procrastinate'
-  
+
   gem 'stackprof'
   gem 'perfer'
 end
@@ -17,7 +17,7 @@ end
 group :test do
   gem 'rspec', '~> 3.0.0.beta'
   gem 'rake-compiler'
-  
+
   # Needed for testing itself.
   #
   gem 'simplecov', :require => false # Will install simplecov-html as a dependency
@@ -34,7 +34,7 @@ group :test do
   gem 'hiredis'
   gem 'redis'
   gem 'sqlite3'
-  
+
   gem 'fast-stemmer', :require => 'stemmer'
   gem 'ruby-stemmer', :require => 'lingua/stemmer'
 
diff --git a/server/Gemfile.lock b/server/Gemfile.lock
index c347e61b..b45cae76 100644
--- a/server/Gemfile.lock
+++ b/server/Gemfile.lock
@@ -1,8 +1,8 @@
 PATH
   remote: .
   specs:
-    picky (4.20.0)
-      activesupport (~> 3)
+    picky (4.21.0)
+      activesupport
       multi_json (~> 1.3)
       rack_fast_escape (~> 2009.0)
       text (~> 1.2)
@@ -10,87 +10,92 @@ PATH
 GEM
   remote: https://rubygems.org/
   specs:
-    activemodel (3.2.16)
-      activesupport (= 3.2.16)
-      builder (~> 3.0.0)
-    activerecord (3.2.16)
-      activemodel (= 3.2.16)
-      activesupport (= 3.2.16)
-      arel (~> 3.0.2)
-      tzinfo (~> 0.3.29)
-    activesupport (3.2.16)
-      i18n (~> 0.6, >= 0.6.4)
-      multi_json (~> 1.0)
-    arel (3.0.3)
+    activemodel (4.1.0)
+      activesupport (= 4.1.0)
+      builder (~> 3.1)
+    activerecord (4.1.0)
+      activemodel (= 4.1.0)
+      activesupport (= 4.1.0)
+      arel (~> 5.0.0)
+    activesupport (4.1.0)
+      i18n (~> 0.6, >= 0.6.9)
+      json (~> 1.7, >= 1.7.7)
+      minitest (~> 5.1)
+      thread_safe (~> 0.1)
+      tzinfo (~> 1.1)
+    arel (5.0.1.20140414130214)
     backports (2.6.7)
-    builder (3.0.4)
-    coverband (0.0.15)
+    builder (3.2.2)
+    coverband (0.0.24)
       json
       redis
       simplecov
     diff-lcs (1.2.5)
-    docile (1.1.2)
+    docile (1.1.3)
     fast-stemmer (1.0.2)
     ffi (1.0.11)
-    highline (1.6.20)
-    hiredis (0.4.5)
+    highline (1.6.21)
+    hiredis (0.5.2)
     hitimes (1.1.1)
     i18n (0.6.9)
     json (1.8.1)
-    mime-types (2.1)
-    multi_json (1.8.4)
+    mime-types (2.2)
+    minitest (5.3.3)
+    multi_json (1.9.3)
     path (1.3.3)
     perfer (0.2.1)
       backports (~> 2.6.3)
       ffi (~> 1.0.11)
       hitimes (~> 1.1.1)
       path (~> 1.3.1)
-    picky-client (4.19.7)
-      activesupport (~> 3)
+    picky-client (4.21.0)
+      activesupport
       yajl-ruby (~> 1.2)
     procrastinate (0.6.0)
       state_machine (~> 1.1)
     rack (1.5.2)
     rack-mount (0.8.3)
       rack (>= 1.0.0)
-    rack-protection (1.5.2)
+    rack-protection (1.5.3)
       rack
     rack_fast_escape (2009.06.24)
       url_escape
-    rake (10.1.1)
+    rake (10.3.1)
     rake-compiler (0.9.2)
       rake
     redis (3.0.7)
     rest-client (1.6.7)
       mime-types (>= 1.16)
-    rspec (3.0.0.beta1)
-      rspec-core (= 3.0.0.beta1)
-      rspec-expectations (= 3.0.0.beta1)
-      rspec-mocks (= 3.0.0.beta1)
-    rspec-core (3.0.0.beta1)
-      rspec-support (= 3.0.0.beta1)
-    rspec-expectations (3.0.0.beta1)
-      diff-lcs (>= 1.1.3, < 2.0)
-      rspec-support (= 3.0.0.beta1)
-    rspec-mocks (3.0.0.beta1)
-      rspec-support (= 3.0.0.beta1)
-    rspec-support (3.0.0.beta1)
+    rspec (3.0.0.beta2)
+      rspec-core (= 3.0.0.beta2)
+      rspec-expectations (= 3.0.0.beta2)
+      rspec-mocks (= 3.0.0.beta2)
+    rspec-core (3.0.0.beta2)
+      rspec-support (= 3.0.0.beta2)
+    rspec-expectations (3.0.0.beta2)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (= 3.0.0.beta2)
+    rspec-mocks (3.0.0.beta2)
+      rspec-support (= 3.0.0.beta2)
+    rspec-support (3.0.0.beta2)
     ruby-stemmer (0.9.3)
     simplecov (0.8.2)
       docile (~> 1.1.0)
       multi_json
       simplecov-html (~> 0.8.0)
     simplecov-html (0.8.0)
-    sinatra (1.4.4)
+    sinatra (1.4.5)
       rack (~> 1.4)
       rack-protection (~> 1.4)
       tilt (~> 1.3, >= 1.3.4)
-    sqlite3 (1.3.8)
-    stackprof (0.2.5)
+    sqlite3 (1.3.9)
+    stackprof (0.2.6)
     state_machine (1.2.0)
     text (1.2.3)
+    thread_safe (0.3.3)
     tilt (1.4.1)
-    tzinfo (0.3.38)
+    tzinfo (1.1.0)
+      thread_safe (~> 0.1)
     url_escape (2009.06.24)
     uuidtools (2.1.4)
     www-delicious (0.4.0)
diff --git a/server/lib/picky/category_indexing.rb b/server/lib/picky/category_indexing.rb
index 1a1f7be6..b5b8fe3a 100644
--- a/server/lib/picky/category_indexing.rb
+++ b/server/lib/picky/category_indexing.rb
@@ -73,7 +73,17 @@ def key_format
     def key_format?
       key_format
     end
-    
+
+    # Return the key format.
+    #
+    # If no key_format is defined on the category
+    # and the source has no key format, ask
+    # the index for one.
+    #
+    def id
+      @id ||= @index.id
+    end
+
     def static?
       @index.static? # || @static
     end
@@ -83,7 +93,7 @@ def static?
     def from
       @from || name
     end
-    
+
     # Return an appropriate source.
     #
     # If we have no explicit source, we'll check the index for one.
diff --git a/server/lib/picky/category_realtime.rb b/server/lib/picky/category_realtime.rb
index ca243234..447a158b 100644
--- a/server/lib/picky/category_realtime.rb
+++ b/server/lib/picky/category_realtime.rb
@@ -1,7 +1,7 @@
 module Picky
 
   class Category
-    
+
     class Picky::IdNotGivenException < StandardError; end
 
     # Removes an indexed object with the
@@ -20,9 +20,9 @@ def remove id
     #
     def add object, where = :unshift
       if from.respond_to? :call
-        add_text object.id, from.call(object), where
+        add_text object.send(id), from.call(object), where
       else
-        add_text object.id, object.send(from), where
+        add_text object.send(id), object.send(from), where
       end
     end
 
@@ -30,20 +30,20 @@ def add object, where = :unshift
     # adds it again.
     #
     def replace object, where = :unshift
-      remove object.id
+      remove object.send id
       add object, where
     end
-    
+
     # Replaces just part of the indexed data.
     #
     # Note: Takes a hash as opposed to the add/replace method.
     #
     def replace_from hash #, id = (hash[:id] || hash['id'] || raise(IdNotGivenException.new)).send(key_format)
       return unless text = hash[from] || hash[from.to_s]
-      
+
       raise IdNotGivenException.new unless id = hash[:id] || hash['id']
       id = id.send key_format if key_format?
-      
+
       remove id
       add_text id, text
     end
@@ -71,13 +71,13 @@ def add_text id, text_or_tokens, where = :unshift
       else
         tokens = text_or_tokens
       end
-      
+
       format = key_format?
       tokens.each { |text| add_tokenized_token id, text, where, format }
     rescue NoMethodError => e
       show_informative_add_text_error_message_for e
     end
-    
+
     def show_informative_add_text_error_message_for e
       if e.name == :each
         raise %Q{#{e.message}. You probably set tokenize: false on category "#{name}". It will need an Enumerator of previously tokenized tokens.}
@@ -90,7 +90,7 @@ def show_informative_add_text_error_message_for e
     #
     def add_tokenized_token id, text, where = :unshift, format = true, static = false
       return unless text
-      
+
       id = id.send key_format if format
       # text = text.to_sym if @symbols # SYMBOLS.
       id.freeze
diff --git a/server/lib/picky/index.rb b/server/lib/picky/index.rb
index 988e7374..b4a522d7 100644
--- a/server/lib/picky/index.rb
+++ b/server/lib/picky/index.rb
@@ -126,7 +126,7 @@ def initialize name
 
       instance_eval(&Proc.new) if block_given?
     end
-    
+
     # TODO Doc.
     #
     def static
@@ -149,7 +149,7 @@ def backend backend = nil
         @backend ||= Backends::Memory.new
       end
     end
-    
+
     # The directory used by this index.
     #
     # Note: Used @directory ||=, but needs to be dynamic.
@@ -157,7 +157,7 @@ def backend backend = nil
     def directory
       ::File.join(Picky.root, 'index', PICKY_ENVIRONMENT, name.to_s)
     end
-    
+
     # Restrict categories to the given ones.
     #
     # Functionally equivalent as if indexes didn't
@@ -380,7 +380,7 @@ def to_s
       ].compact
       "#{self.class}(#{s.join(', ')})"
     end
-    
+
     # Displays the structure as a tree.
     #
     def to_tree_s indent = 0
diff --git a/server/lib/picky/index_indexing.rb b/server/lib/picky/index_indexing.rb
index 0573feb8..0e6e459b 100644
--- a/server/lib/picky/index_indexing.rb
+++ b/server/lib/picky/index_indexing.rb
@@ -89,6 +89,17 @@ def unblock_source
       @source.respond_to?(:call) ? @source.call : @source
     end
 
+    # API method.
+    #
+    # Defines the name of the ID method to use on the indexed object.
+    #
+    # === Parameters
+    # * name: Method name of the ID.
+    #
+    def id name = nil
+      @id_name = name || @id_name || :id
+    end
+
     # Define a key_format on the index.
     #
     # Parameter is a method name to use on the key (e.g. :to_i, :to_s, :strip, :split).
diff --git a/server/lib/picky/indexers/parallel.rb b/server/lib/picky/indexers/parallel.rb
index 7bd28914..1f8ea993 100644
--- a/server/lib/picky/indexers/parallel.rb
+++ b/server/lib/picky/indexers/parallel.rb
@@ -58,15 +58,17 @@ def process source_for_prepare, categories, scheduler = Scheduler.new
       def index_flush objects, file, category, cache, tokenizer
         comma   = ?,
         newline = ?\n
-        
+
         # Optimized, therefore duplicate code.
         #
+        id = category.id
+        from = category.from
         objects.each do |object|
-          tokens = object.send category.from
+          tokens = object.send from
           tokens, _ = tokenizer.tokenize tokens if tokenizer # Note: Originals not needed. TODO Optimize?
           tokens.each do |token_text|
             next unless token_text
-            cache << object.id << comma << token_text << newline
+            cache << object.send(id) << comma << token_text << newline
           end
         end
 
diff --git a/server/spec/functional/id_spec.rb b/server/spec/functional/id_spec.rb
new file mode 100644
index 00000000..c3695dfa
--- /dev/null
+++ b/server/spec/functional/id_spec.rb
@@ -0,0 +1,66 @@
+# encoding: utf-8
+#
+require 'spec_helper'
+
+describe "id option" do
+
+  it 'can be given a different id (in-ruby based)' do
+    data = Picky::Index.new :id do
+      id :number
+      category :text
+    end
+
+    require 'ostruct'
+
+    thing = OpenStruct.new number: 1, text: "ohai"
+    other = OpenStruct.new number: 2, text: "ohai kthxbye"
+
+    data.add thing
+    data.add other
+
+    try = Picky::Search.new data
+
+    try.search("text:kthxbye").ids.should == [2]
+  end
+
+  it 'can be given a different id (source based)' do
+    require 'ostruct'
+
+    things = []
+    things << OpenStruct.new(number: 1, text: "ohai")
+    things << OpenStruct.new(number: 2, text: "ohai kthxbye")
+
+    data = Picky::Index.new :id do
+      source { things }
+
+      key_format :to_i
+      id :number # TODO :format => :to_i
+      category :text
+    end
+
+    data.index
+
+    try = Picky::Search.new data
+
+    try.search("text:kthxbye").ids.should == [2]
+  end
+
+  it 'default is id' do
+    index = Picky::Index.new :id do
+      category :text
+    end
+
+    require 'ostruct'
+
+    thing = OpenStruct.new id: 1, text: "ohai"
+    other = OpenStruct.new id: 2, text: "ohai kthxbye"
+
+    index.add thing
+    index.add other
+
+    try = Picky::Search.new index
+
+    try.search("text:kthxbye").ids.should == [2]
+  end
+
+end
\ No newline at end of file