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 Te: sig .. end
val mk : ?attrs:Ast_helper.attrs -> ?docs:Docstrings.docs -> ?params:(Parsetree.core_type * Asttypes.variance) list -> ?priv:Asttypes.private_flag -> Ast_helper.lid -> Parsetree.extension_constructor list -> Parsetree.type_extension
val constructor : ?loc:Ast_helper.loc -> ?attrs:Ast_helper.attrs -> ?docs:Docstrings.docs -> ?info:Docstrings.info -> Ast_helper.str -> Parsetree.extension_constructor_kind -> Parsetree.extension_constructor
val decl : ?loc:Ast_helper.loc -> ?attrs:Ast_helper.attrs -> ?docs:Docstrings.docs -> ?info:Docstrings.info -> ?args:Parsetree.core_type list -> ?res:Parsetree.core_type -> Ast_helper.str -> Parsetree.extension_constructor
val rebind : ?loc:Ast_helper.loc -> ?attrs:Ast_helper.attrs -> ?docs:Docstrings.docs -> ?info:Docstrings.info -> Ast_helper.str -> Ast_helper.lid -> Parsetree.extension_constructor