Evolutions

Evolution is a process in which a Pokémon changes into a different species of Pokémon.

EvolutionChain

Evolution chains are essentially family trees. They start with the lowest stage within a family and detail evolution conditions for each as well as Pokémon they can evolve into up through the hierarchy.

Property	Type	Required	Description
id	number	Yes	The identifier for this resource.
chain	ChainLink	Yes	The base chain link object. Each link contains evolution details for a Pokémon in the chain. Each link references the next Pokémon in the natural evolution order.
baby_trigger_item	NamedAPIResource	Yes	The item that a Pokémon would be holding when mating that would trigger the egg hatching a baby Pokémon rather than a basic Pokémon.

ChainLink

Property	Type	Required	Description
is_baby	boolean	Yes	Whether or not this link is for a baby Pokémon. This would only ever be true on the base link.
species	NamedAPIResource	Yes	The Pokémon species at this point in the evolution chain.
evolution_details	Array<EvolutionDetail>	Yes	All details regarding the specific details of the referenced Pokémon species evolution.
evolves_to	Array<ChainLink>	Yes	A List of chain objects.

EvolutionDetail

Property	Type	Required	Description
item	NamedAPIResource	Yes	The item required to cause evolution this into Pokémon species.
trigger	NamedAPIResource	Yes	The type of event that triggers evolution into this Pokémon species.
gender	GenderId	Yes	The id of the gender of the evolving Pokémon species must be in order to evolve into this Pokémon species.
held_item	NamedAPIResource	Yes	The item the evolving Pokémon species must be holding during the evolution trigger event to evolve into this Pokémon species.
known_move	NamedAPIResource	Yes	The move that must be known by the evolving Pokémon species during the evolution trigger event in order to evolve into this Pokémon species.
known_move_type	NamedAPIResource	Yes	The evolving Pokémon species must know a move with this type during the evolution trigger event in order to evolve into this Pokémon species.
location	NamedAPIResource	Yes	The location the evolution must be triggered at.
min_level	number	Yes	The minimum required level of the evolving Pokémon species to evolve into this Pokémon species.
min_happiness	number	Yes	The minimum required level of happiness the evolving Pokémon species to evolve into this Pokémon species.
min_beauty	number	Yes	The minimum required level of beauty the evolving Pokémon species to evolve into this Pokémon species.
min_affection	number	Yes	The minimum required level of affection the evolving Pokémon species to evolve into this Pokémon species.
needs_overworld_rain	boolean	Yes	Whether or not it must be raining in the overworld to cause evolution this Pokémon species.
party_species	NamedAPIResource	Yes	The Pokémon species that must be in the players party in order for the evolving Pokémon species to evolve into this Pokémon species.
party_type	NamedAPIResource	Yes	The player must have a Pokémon of this type in their party during the evolution trigger event in order for the evolving Pokémon species to evolve into this Pokémon species.
relative_physical_stats	RelativePhysicalStatEvolution	Yes	The required relation between the Pokémon's Attack and Defense stats. 1 means Attack > Defense. 0 means Attack = Defense. -1 means Attack < Defense.
time_of_day	TimeOfDay	Yes	The required time of day. Day or night.
trade_species	NamedAPIResource	Yes	Pokémon species for which this one must be traded.
turn_upside_down	boolean	Yes	Whether or not the 3DS needs to be turned upside-down as this Pokémon levels up.

EvolutionTrigger

Evolution triggers are the events and conditions that cause a Pokémon to evolve. Check out Bulbapedia for greater detail.

Property	Type	Required	Description
id	number	Yes	The identifier for this resource.
name	string	Yes	The name for this resource.
names	Array<Name>	Yes	The name of this resource listed in different languages.
pokemon_species	Array<NamedAPIResource>	Yes	A list of pokemon species that result from this evolution trigger.