#Modules and exports

Modules are .rts files that you import with @use.

• module <name> declares the module name (required when importing without as, and it must be the first statement).
• export exposes a name from a module.
• @use ./path.rts or @use ./path.rts as alias imports a module into its request, or into the whole file when it comes before the first ### line.
• If you omit as, the module name becomes the alias.
• Modules are cached, so top-level mutable state can persist across runs.

Example:

# helpers.rts
module helpers
export fn authHeader(token) {
  return token ? "Bearer " + token : ""
}

# @use ./rts/helpers.rts
Authorization: {{= helpers.authHeader(vars.get("auth.token")) }}

Modules have access to rts and, when the host provides it, request. A module cannot declare these names or stdlib, but it can declare any other name, including a standard library name such as json. Pass other host objects (env, vars, last, response, trace, stream, or a test block's t) as function arguments. These objects expire when the block or expression passing them returns. stdlib is a deprecated alias for rts.