Strong TypeScript declarations for the game Screeps.
Clone or download
Latest commit c5a5539 Nov 9, 2018


Strong TypeScript declarations for the game Screeps.



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

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 };
  • 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)

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


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

Workarounds / Caveats

Due to some unresolved issues in TypeScript, a few parts of the API can't currenty be typed perfectly without tradeoffs.

Below is a list (feel free to open an issue if you have any ideas, or wish to discuss):

  • The API returned from store or carry (ex. returns an object with optional keys for each Resource Type, but is guaranteed to have a key for RESOURCE_ENERGY. This is currently not (perfectly) typable in TypeScript (see issues #13573 and #12215). The chosen workaround is to just manually list the types using a fake type _ResourceConstantSansEnergy