Below is the API for the OCaml standard library. It's directly copied over from the OCaml Manual, formatted to the Reason syntax and styled accordingly. The API docs are work-in-progress; we'll be polishing these gradually!
If you're targeting JavaScript, the API docs for BuckleScript includes all of below, plus JS-specific APIs.
module Cl: sig .. end
val mk : ?loc:Ast_helper.loc -> ?attrs:Ast_helper.attrs -> Parsetree.class_expr_desc -> Parsetree.class_expr
val attr : Parsetree.class_expr -> Parsetree.attribute -> Parsetree.class_expr
val constr : ?loc:Ast_helper.loc -> ?attrs:Ast_helper.attrs -> Ast_helper.lid -> Parsetree.core_type list -> Parsetree.class_expr
val structure : ?loc:Ast_helper.loc -> ?attrs:Ast_helper.attrs -> Parsetree.class_structure -> Parsetree.class_expr
val fun_ : ?loc:Ast_helper.loc -> ?attrs:Ast_helper.attrs -> Asttypes.label -> Parsetree.expression option -> Parsetree.pattern -> Parsetree.class_expr -> Parsetree.class_expr
val apply : ?loc:Ast_helper.loc -> ?attrs:Ast_helper.attrs -> Parsetree.class_expr -> (Asttypes.label * Parsetree.expression) list -> Parsetree.class_expr
val let_ : ?loc:Ast_helper.loc -> ?attrs:Ast_helper.attrs -> Asttypes.rec_flag -> Parsetree.value_binding list -> Parsetree.class_expr -> Parsetree.class_expr
val constraint_ : ?loc:Ast_helper.loc -> ?attrs:Ast_helper.attrs -> Parsetree.class_expr -> Parsetree.class_type -> Parsetree.class_expr
val extension : ?loc:Ast_helper.loc -> ?attrs:Ast_helper.attrs -> Parsetree.extension -> Parsetree.class_expr