Codsworth

Codsworth is a domestic-model Mister Handy purchased by the Sole Survivor, in service to them and their family before the Great War in Sanctuary Hills, as a butler from 2077 to 2287. He can be recruited as a potential companion upon reaching a trigger point in Concord during the quest Out of Time and returning to him.

Background
Codsworth is a Mister Handy robotic butler for the Sole Survivor's family before the Great War. He was bought by the family not long before October 23, 2077, as evidenced by the Mr. Handy box in the laundry room of the Sole Survivor's home. He was not granted entry to Vault 111, as claimed by the Vault-Tec rep, and was left behind when the war was announced on television. Codsworth is reunited with the Survivor after 210 years of roaming around Sanctuary Hills, still loyal to his owner.

At first, Codsworth seems cheerful and oblivious to what has happened. During the first ten years after the war, Codsworth tried to keep himself busy by doing futile housekeeping work, such as keeping the nuclear fallout-tainted floors waxed, dusting a collapsed house, and polishing a rusted car. However, talking to him further reveals that he is actually very depressed about the state of the world, and was deeply affected by his two-centuries-long isolation. To cope, he pretended that nothing happened. At some point after the bombs fell, Codsworth visited the town of Concord—mentioning that the locals only "pummeled [him] with sticks a few times" and "shot at [him] on a few occasions" before he retreated to Sanctuary.

Codsworth is known to say the Sole Survivor's chosen name if it is an option, although it may be shortened, extended, or have a word omitted. A list of spoken names can be found here.

Quests

 * War Never Changes: Codsworth will act as the family's butler in this quest, providing small bits of dialogue and interaction.
 * Out of Time: The Sole Survivor has the option to team up with Codsworth and scout the area of what once was Sanctuary Hills.

Effects of player's actions
Reaching the maximum affinity with Codsworth grants the Robot Sympathy perk. The perk gives +10 Energy Resistance against any robots' energy weapons.

Other interactions
Codsworth occasionally provides the Sole Survivor with purified water and jokes.

Fallout: The Board Game
Codsworth can be found randomly when taking a card from the loot deck. While Codsworth is the active companion, the player character can exhaust him to trade with any other player character on the map.

When the player character performs the camp action, he will become unexhausted. However, if the player character has the Vilified trait, he must be discarded.

Appearances
Codsworth appears in Fallout 4 and Fallout: The Board Game.

Behind the scenes

 * Codsworth occassionally hums and whistles real-world tunes, such as La Marseillaise and Rule, Britannia!.
 * Codsworth's name and interactions, namely the ability to tell jokes and dispense purified water, are similar to that of Wadsworth from Fallout 3.
 * Codsworth will correctly say uncommon spellings of names such as Cori and Borri. Cori being the name of a villager from The Elder Scrolls: Arena and Borri being the name of one of the Greybeards from The Elder Scrolls: Skyrim.

Bugs

 * Codsworth may sometimes stay in one place when dismissed to a settlement (even if outside the building boundary), and rarely move around or perform tasks except to fight hostile enemies.
 * Assigning Codsworth to a settlement resource may have no effect, despite indicating that he is assigned to it in the workshop menu.
 * Pre-War Codsworth's body will always reflect the Sole Survivor's living room.
 * As stated in the notes section, Codsworth will become available as a companion after discovering Concord on the map. It is not necessary to complete or even start When Freedom Calls. Simply going to Concord and returning to Codsworth is enough. However, if Codsworth is sent to another settlement before the companion dialogue is complete, he will not acknowledge any attempt to speak to him until he is sent back to Sanctuary and the proper dialogue is completed. On PC, this can be cleared with the console command.
 * Codsworth will refuse to inspect/hack a terminal, despite being equipped with a hacking module at a robot workbench from the Automatron add-on.
 * Until the quest Out of Time is completed, Codsworth will always return to Sanctuary upon companion dismissal because  is applied by the quest   until both   is set to 1 and the Out of Time's stage 200 (waiting until the player character leaves the museum to stop the quest) is complete. The easiest way to resolve this without advancing or disrupting the main quest is the console command.