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Strong TypeScript declarations for the game Screeps.

Travis npm


The type definitions are published on DefinitelyTyped. To install them, run the following.

# npm
npm install @types/screeps

# yarn
yarn add @types/screeps

Differences from Screeps-Typescript-Declarations

This repo has more activity and is considerably more up-to-date.

Breaking Changes:

  • Memory is typed by default. The added typings are:

    • CreepMemory
    • FlagMemory
    • SpawnMemory
    • RoomMemory

    If you like the idea of typed memory, but aren't ready to just jump fully in, you only need to make sure you define an interface for the above four types. Then you can extend them at a later time.


    interface CreepMemory { [name: string]: any };
    interface FlagMemory { [name: string]: any };
    interface SpawnMemory { [name: string]: any };
    interface RoomMemory { [name: string]: any };

    If you don't want to add types to the global Memory object, you will need to add the following interface along with the four above.


    interface Memory { [key: string]: any };
  • Any place in code that uses a constant (ex STRUCTURE_EXTENSION or FIND_MY_SPAWNS is now constrained to use literal types. Here is the list of the new types:

    BuildableStructureConstant (this is a subset of StructureConstant)
    MineralConstant (this is a subset of ResourceConstant)

    To update your code, you just need to change any string types to match one of the above. For example, if your code had:

    function getBody(): string[] {
      return [ WORK, MOVE, CARRY ];

    Change it to:

    function getBody(): BodyPartConstant[] {  // this line changed
      return [ WORK, MOVE, CARRY ];
  • Some original functions were incorrectly typed to not include null as a possible return. You may need to update your code to reflect this update (ex. findClosestByPath or findClosestByRange)

  • Game.getObjectById() now returns typed objects according to the type of the Id (ex. Id<StructureTower> returns StructureTower type).

    Use of string typed Id, is deprecated and may be removed in the future. When using string Ids, the type of the returned game object is unknown which requires manual type assertion. Previously this function returned any typed objects which could accidently be left untyped;

    If you have code like this (un-type-asserted use of Game.getObjectById)

    interface Memory{
      towerIds: string[];
    Memory.towerIds.forEach((towerId) => {
      const tower = Game.getObjectById(towerId); // type of returned tower is 'unknown' instead of 'any'
      tower.attack(targetCreep); // Error Object is of type unknown ts(2571)

    Change it store typed Ids:

    interface Memory{
      towerIds: Array<Id<StructureTower>>;
    Memory.towerIds.forEach((towerId) => {
      const tower = Game.getObjectById(towerId); // type of returned tower is StructureTower

    If you're already manually asserting the type of the game object, you're not required to change anything immediately however this is deprecated and may be removed in the future.

    const towerId: Id<StructureTower> = ""  as Id<StructureTower>;
    const tower1 = Game.getObjectById(towerId); // recommended use, returns StructureTower type
    const tower2 = Game.getObjectById<StructureTower>(""); // @deprecated returns StructureTower type
    const tower3 = Game.getObjectById("") as StructureTower; // @deprecated returns StructureTower type

    Id<T> types are assignable to string but the reverse is not allowed implicitly. To assign a string type to an Id<T> type, you must explicitly assert the type.

    const typedId: Id<Creep> = "123" as Id<Creep>; // assertion required
    const untypedId1: string = typedId; // no assertion required
  • Game objects have typed id properties id: Id<this>. These typed ids can by passed to Game.getObjectById() to receive typed game objects matching the type of the Id. See above bullet for more details. // has type Id<Creep>
    copy = Game.getObjectById( // returns type Creep // has type Id<StructureTower>

Additional (non-breaking) Features:

  • ConstructionSite can be optionally constrained by a structure type (ex. ConstructionSite<STRUCTURE_CONTAINER>). TypeScript will enforce that the type property of the ConstructionSite appropriately matches
  • Resource can optionally be constrained (ex. Resource<RESOURCE_ENERGY>)
  • Mineral can optionally be constrained by MineralConstant (ex. Mineral<RESOURCE_GHODIUM>)
  • Structure can optionally be constrained (ex Structure<STRUCTURE_SPAWN | STRUCTURE_EXTENSION>)
  • Screeps classes derived from Structure (ex StructureContainer) have their type property correspondingly constrained
  • LookAt results are now constrained to the type looked for
  • Results from Find-type functions are now constrained to have a RoomPosition
  • Typings for new RawMemory and RoomVisuals
  • New union type AnyCreep to represent Creep and PowerCreep


Issues and Pull Requests are welcome! Please read the Contributing Guidelines and Code of Conduct beforehand.