diff --git a/NAMESPACE b/NAMESPACE
index bda2ac1..28a4d33 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -4,6 +4,8 @@ S3method(print,ts_object)
 S3method(ts_compile,character)
 S3method(ts_compile,default)
 S3method(ts_compile,ts_function)
+S3method(ts_compile,ts_overload)
+export(is_overload)
 export(ts_character)
 export(ts_compile)
 export(ts_dataframe)
@@ -13,3 +15,4 @@ export(ts_integer)
 export(ts_list)
 export(ts_logical)
 export(ts_numeric)
+export(ts_overload)
diff --git a/R/compile.R b/R/compile.R
index ef8b1c6..0fd22d6 100644
--- a/R/compile.R
+++ b/R/compile.R
@@ -1,10 +1,10 @@
 #' @export
-ts_compile <- function(f, file = NULL, ...) {
+ts_compile <- function(f, ..., file = NULL) {
     UseMethod("ts_compile")
 }
 
 #' @export
-ts_compile.ts_function <- function(f, file = NULL, name = deparse(substitute(f))) {
+ts_compile.ts_function <- function(f, name = deparse(substitute(f)), ...) {
     inputs <- attr(f, "args")
     result <- attr(f, "result")
 
@@ -14,10 +14,17 @@ ts_compile.ts_function <- function(f, file = NULL, name = deparse(substitute(f))
     sprintf("const %s = (%s) => Promise<%s>;", name, fn_args, result$type_fn)
 }
 
+#' @export
+ts_compile.ts_overload <- function(f, file = NULL, name = deparse(substitute(f))) {
+    cmt <- sprintf("\n// %s overloads", name)
+    oloads <- sapply(f, ts_compile, name = name)
+    paste(cmt, paste(oloads, collapse = "\n"), sep = "\n")
+}
+
 #' @export
 ts_compile.character <- function(
     f,
-    file = sprintf("%s.ts", tools::file_path_sans_ext(f))) {
+    file = sprintf("%s.d.ts", tools::file_path_sans_ext(f))) {
     if (length(f) > 1) {
         return(sapply(f, ts_compile))
     }
@@ -53,6 +60,6 @@ ts_compile.character <- function(
 }
 
 #' @export
-ts_compile.default <- function(f) {
+ts_compile.default <- function(f, ...) {
     warning("Not supported")
 }
diff --git a/R/function.R b/R/function.R
index a7f94e6..ff2e9b8 100644
--- a/R/function.R
+++ b/R/function.R
@@ -14,13 +14,27 @@ parse_args <- function(x, mc) {
     args
 }
 
-# TS function
+#' TS function definition
+#'
+#' @param f an R function
+#' @param ... argument definitions, OR function overloads
+#' @param result return type (ignored if overloads are provided)
 #' @export
 ts_function <- function(f, ..., result = NULL) {
     args <- list(...)
-    if (!is_object(result)) {
+    if (!is.null(result) && !is_object(result)) {
         stop("Invalid return type")
     }
+    if (any(is_overload(args))) {
+        if (!all(is_overload(args))) {
+            stop("Cannot mix overloads with standard arguments")
+        }
+        z <- lapply(args, function(x) {
+            do.call(ts_function, c(list(f), x$args, list(result = x$result)))
+        })
+        class(z) <- "ts_overload"
+        return(z)
+    }
 
     fn <- function(...) {
         mc <- match.call(f)
@@ -32,3 +46,15 @@ ts_function <- function(f, ..., result = NULL) {
     class(fn) <- c("ts_function", class(f))
     fn
 }
+
+#' @export
+is_overload <- function(x) {
+    sapply(x, inherits, what = "ts_overload")
+}
+
+#' @export
+ts_overload <- function(..., result = NULL) {
+    structure(list(args = list(...), result = result),
+        class = "ts_overload"
+    )
+}
diff --git a/R/types.R b/R/types.R
index 7c221fc..e83e883 100644
--- a/R/types.R
+++ b/R/types.R
@@ -6,12 +6,14 @@
 #' @param type_fn The type of the object that Typescript expects to recieve from R.
 #' @param default The default value of the object.
 #' @param check A function that checks the object and returns it if it is valid. This operates on the R side and is mostly for development and debugging purposes. It is up to the developer to ensure that all functions return the correct type of object always.
+#' @param generic logical, if `TRUE` then the object is a generic type.
 #'
 #' @md
 object <- function(type = "any",
                    type_fn = "any",
                    default = NULL,
-                   check = function() stop("Not implemented")) {
+                   check = function() stop("Not implemented"),
+                   generic = FALSE) {
     e <- environment()
 
     e$attr <- function(name, value) {
diff --git a/README.Rmd b/README.Rmd
index da80666..9c5ae85 100644
--- a/README.Rmd
+++ b/README.Rmd
@@ -102,9 +102,9 @@ myfun(1:5)
 
 myfun("hello world")
 
-cat(readLines("tests/testthat/app/app.R"), sep = "\n")
+cat(readLines("tests/testthat/app.R"), sep = "\n")
 
-ts_compile("tests/testthat/app/app.R", file = "")
+ts_compile("tests/testthat/app.R", file = "")
 ```
 
 ## TODO
@@ -114,3 +114,5 @@ ts_compile("tests/testthat/app/app.R", file = "")
 - [ ] Add support for conditional return types
 
   e.g., `const sample = <T, N extends number>(x: T[], n: N) => N extends 1 ? T : T[]`
+
+- [ ] Function overloads? Perhaps just a wrapper around several function definitions...
diff --git a/README.md b/README.md
index aa1cacb..3cd1bfd 100644
--- a/README.md
+++ b/README.md
@@ -98,19 +98,35 @@ myfun(1:5)
 myfun("hello world")
 #> Error: Expected a number
 
-cat(readLines("tests/testthat/app/app.R"), sep = "\n")
+cat(readLines("tests/testthat/app.R"), sep = "\n")
 #> library(ts)
 #> 
 #> fn_mean <- ts_function(mean, x = ts_numeric(), result = ts_numeric(1))
 #> fn_first <- ts_function(function(x) x[1],
 #>     x = ts_character(-1), result = ts_character(1)
 #> )
+#> 
+#> sample_one <- ts_function(
+#>     sample,
+#>     ts_overload(
+#>         x = ts_numeric(),
+#>         result = ts_numeric(1)
+#>     ),
+#>     ts_overload(
+#>         x = ts_character(),
+#>         result = ts_character(1)
+#>     )
+#> )
 
-ts_compile("tests/testthat/app/app.R", file = "")
+ts_compile("tests/testthat/app.R", file = "")
 #> import type { Character, Numeric } from 'rserve-ts';
 #> 
 #> const fn_first = (x: string | string[]) => Promise<Character<1>)>;
 #> const fn_mean = (x: number | number[]) => Promise<Numeric<1>)>;
+#> 
+#> // sample_one overloads
+#> const sample_one = (x: number | number[]) => Promise<Numeric<1>)>;
+#> const sample_one = (x: string | string[]) => Promise<Character<1>)>;
 ```
 
 ## TODO
@@ -123,3 +139,6 @@ ts_compile("tests/testthat/app/app.R", file = "")
     
     e.g., `const sample = <T, N extends number>(x: T[], n: N) => N
     extends 1 ? T : T[]`
+
+  - [ ] Function overloads? Perhaps just a wrapper around several
+    function definitions…
diff --git a/man/object.Rd b/man/object.Rd
index 1e98170..ce42aaf 100644
--- a/man/object.Rd
+++ b/man/object.Rd
@@ -8,7 +8,8 @@ object(
   type = "any",
   type_fn = "any",
   default = NULL,
-  check = function() stop("Not implemented")
+  check = function() stop("Not implemented"),
+  generic = FALSE
 )
 }
 \arguments{
@@ -19,6 +20,8 @@ object(
 \item{default}{The default value of the object.}
 
 \item{check}{A function that checks the object and returns it if it is valid. This operates on the R side and is mostly for development and debugging purposes. It is up to the developer to ensure that all functions return the correct type of object always.}
+
+\item{generic}{logical, if \code{TRUE} then the object is a generic type.}
 }
 \description{
 This is the base type for all typed objects. It is not meant to be used directly.
diff --git a/man/ts_function.Rd b/man/ts_function.Rd
new file mode 100644
index 0000000..61df748
--- /dev/null
+++ b/man/ts_function.Rd
@@ -0,0 +1,18 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/function.R
+\name{ts_function}
+\alias{ts_function}
+\title{TS function definition}
+\usage{
+ts_function(f, ..., result = NULL)
+}
+\arguments{
+\item{f}{an R function}
+
+\item{...}{argument definitions, OR function overloads}
+
+\item{result}{return type (ignored if overloads are provided)}
+}
+\description{
+TS function definition
+}
diff --git a/tests/testthat/app.R b/tests/testthat/app.R
new file mode 100644
index 0000000..1821a31
--- /dev/null
+++ b/tests/testthat/app.R
@@ -0,0 +1,18 @@
+library(ts)
+
+fn_mean <- ts_function(mean, x = ts_numeric(), result = ts_numeric(1))
+fn_first <- ts_function(function(x) x[1],
+    x = ts_character(-1), result = ts_character(1)
+)
+
+sample_one <- ts_function(
+    sample,
+    ts_overload(
+        x = ts_numeric(),
+        result = ts_numeric(1)
+    ),
+    ts_overload(
+        x = ts_character(),
+        result = ts_character(1)
+    )
+)
diff --git a/tests/testthat/app.d.ts b/tests/testthat/app.d.ts
new file mode 100644
index 0000000..3a34907
--- /dev/null
+++ b/tests/testthat/app.d.ts
@@ -0,0 +1,5 @@
+import type { Character, Numeric, PE.Numeric<1>,  } from 'rserve-ts';
+
+const fn_first = (x: string | string[]) => Promise<Character<1>)>;
+const fn_mean = (x: number | number[]) => Promise<Numeric<1>)>;
+c("const sample_one = (x: number | number[]) => Promise<Numeric<1>)>;", "const sample_one = (x: string | string[]) => Promise<Character<1>)>;")
diff --git a/tests/testthat/app/app.R b/tests/testthat/app/app.R
deleted file mode 100644
index 08143b4..0000000
--- a/tests/testthat/app/app.R
+++ /dev/null
@@ -1,6 +0,0 @@
-library(ts)
-
-fn_mean <- ts_function(mean, x = ts_numeric(), result = ts_numeric(1))
-fn_first <- ts_function(function(x) x[1],
-    x = ts_character(-1), result = ts_character(1)
-)
diff --git a/tests/testthat/app/app.ts b/tests/testthat/app/app.ts
deleted file mode 100644
index 8155de3..0000000
--- a/tests/testthat/app/app.ts
+++ /dev/null
@@ -1,4 +0,0 @@
-import { types } from 'rserve-ts';
-
-const fn_first = (x: string | string[]) => Promise<RTYPE.Character<1>)>;
-const fn_mean = (x: number | number[]) => Promise<RTYPE.Numeric<1>)>;
diff --git a/tests/testthat/functions.R b/tests/testthat/functions.R
new file mode 100644
index 0000000..26cfc00
--- /dev/null
+++ b/tests/testthat/functions.R
@@ -0,0 +1,17 @@
+# overload input/return types
+sample_one <- ts_function(
+    sample,
+    ts_overload(
+        x = ts_numeric(),
+        result = ts_numeric(1)
+    ),
+    ts_overload(
+        x = ts_character(),
+        result = ts_character(1)
+    )
+)
+ts_compile(sample_one)
+
+# compile to:
+# const sample_one = (x: number) => Promise<number>;
+# const sample_one = (x: string) => Promise<string>;