created_at2018-02-27 06:31:02.809308
updated_at2024-01-15 20:12:13.88362
descriptionBuild tool for deploying Rust WASM code to Screeps game servers
Shane Madden (shanemadden)




Linux Build Status version badge dependency status

Build tool for deploying Rust WASM repositories to Screeps game servers.

cargo-screeps wraps wasm-pack, adding the ability to trim node.js and web javascript code from the output files, and allows uploading directly to Screeps servers.

The other main project in this organization is screeps-game-api, type-safe bindings to the in-game Screeps API.

These two tools go together well, but do not depend on eachother. cargo-screeps can compile and upload any screeps WASM project buildable with wasm-bindgen's wasm-pack, and screeps-game-api is usable in any project built with wasm-pack.

Build Options


Configured in [build] config section. No required settings.

  1. runs wasm-pack --target nodejs to build the rust source for Screeps: World bots, or wasm-pack --target web to build Screeps: Arena bots
  2. Modifies the generated module's javascript loader file to be compatibile with Screeps; adds a polyfill for TextEncoder/TextDecoder, and replaces the node-compatible module loader function with one that works with Screeps: World when the build_mode is set to world (the default)


Runs the deployment mode specified by the --mode setting, or the default_deploy_mode configuration setting if none is specified.

  1. runs build
  2. depending on whether the mode uploads (has authentication credentials) or copies (has a destination), proceeds to deploy the built code

If copying (when destination is defined):

  1. copies compiled .js/.mjs and .wasm/.bin files from the directories specified in include_files (default pkg and javascript) to the specified directory and branch
  2. if pruning is enabled, deletes all other files in <destination directory>/<branch name>/

If uploading (when auth_token or username and password are defined):

  1. reads compiled .js and .wasm files from the directories specified in include_files (default pkg and javascript).
  2. reads screeps.toml for upload options
  3. uploads all read files to server on the specified branch, using filenames as the filenames on the server


A shortcut for cargo screeps deploy -m upload.


A shortcut for cargo screeps deploy -m copy.

Configuration Options

No namespace

  • default_deploy_mode: controls what mode cargo screeps deploy uses if the --mode/-m option is not set.


This configures general build options.

  • build_mode: The game that modules should be built for; world or arena.
  • build_profile: The build profile that should be used; release, dev, or profiling.
  • out_name: The name used for the module created by wasm-pack within the pkg directory. Defaults to the name of your crate as defined in Cargo.toml.
  • extra_options: Any extra command line flags you'd like to be passed to wasm-pack, such as enabling features.

Any of these options can be overridden for a given mode with its own build section. For instance,

extra_options = ["--features=alliance_behavior"]

would cause a feature on your crate named alliance_behavior to be built when running the upload mode.

Configuration modes

Configuration modes can either copy the built files to a destination directory, or upload to a destination server using the Screeps API.

A mode should either have a filesystem destination to copy to, or authentication credentials (and optionally, server information) to upload to.

Optionally, it also have a sub-table [] to override any of the global [build] options.

Copy Options

Options for deploying to a filesystem location.

  • destination: the directory to copy files into

    If this path is not absolute, it is interpreted as relative to screeps.toml.

  • branch: the "branch" to copy into

    This is the subdirectory of destination which the js/wasm files will be copied into. Default is "default".

  • prune: if true, extra files found in the destination/branch directory will be deleted. Default is false.

Upload Options

Options for deploying to a Screeps server.

  • auth_token: an auth token for your Screeps account

  • username: your Screeps username or email

  • password: your Screeps password

    Either an auth_token or your username/password can be supplied. When both are set the auth token is used. For private servers, set a password using screepsmod-auth.

  • branch: the "branch" to copy into

    This is the "branch" on the screeps server to deploy to. Default is "default".

  • prefix: if set, adds a URL prefix to the upload path. Use "ptr" or "season" to upload to the public test realm and seasonal servers, respectively.

  • hostname: the hostname to upload to

    For example, this could be, localhost or Default is

  • ssl: whether to connect to the server using ssl

    This should generally be true for the main server and false for private servers. Default is true.

  • port: port to connect to server with

    This should generally be set to 21025 for private servers. Default is 443.

Updating cargo screeps

To update cargo-screeps, simply repeat the install process with the --force (-f) flag.

After updating, you'll want to do a full cargo clean to remove any old artifacts which were built using the older version of cargo-screeps.

cargo install -f cargo-screeps
cargo clean
cargo screeps build
Commit count: 585

cargo fmt