diff --git a/package.json b/package.json
index 582a989..825f9f9 100644
--- a/package.json
+++ b/package.json
@@ -10,7 +10,7 @@
   },
   "scripts": {
     "build": "esbuild --bundle --format=esm --minify --sourcemap --outdir=dist src/index.ts",
-    "build-tests": "esbuild --bundle --minify --outdir=dist/test test/*.ts"
+    "build-tests": "esbuild --bundle --minify --outdir=dist/tests tests/*.ts"
   },
   "devDependencies": {
     "esbuild": "^0.17.18"
diff --git a/src/index.ts b/src/index.ts
index e69de29..97e079e 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -0,0 +1,28 @@
+export interface Machine_T<S,E> {
+  states: Array<State_T<S,E>>
+}
+export interface State_T<S,E> {
+  name: S;
+  ons: Array<On_T<S,E>>;
+}
+export interface On_T<S,E> {
+  eventName: E;
+  reactions: Array<Do_T | Goto_T<S>>;
+};
+export interface Do_T {
+  type: 'Do';
+  fn: DoFn_T;
+};
+export type DoFn_T = (ctx,e,self)=>any;
+export interface Goto_T<S> {
+  type: 'Goto';
+  targetStateName: S;
+};
+
+export const Machine = function<S,E>(...states:Array<State_T<S,E>>) : Machine_T<S,E> { return {states}; };
+export const State = function<S,E>(name:S, ...ons:Array<On_T<S,E>>) : State_T<S,E>{ return {name, ons}; };
+export const On = function<S,E>(eventName:E, ...reactions:Array<Do_T | Goto_T<S>>) : On_T<S,E>{ return {eventName, reactions}; };
+export const Do = function(fn:DoFn_T) : Do_T{ return {type:'Do', fn}; };
+export const Goto = function<S>(targetStateName:S) : Goto_T<S> { return {type:'Goto', targetStateName} };
+export const Spawn = function(){};
+export const Unspawn = function(){};
\ No newline at end of file
diff --git a/src/tests/00-basic.ts b/src/tests/00-basic.ts
new file mode 100644
index 0000000..f22f633
--- /dev/null
+++ b/src/tests/00-basic.ts
@@ -0,0 +1,34 @@
+import { Machine, State, On, Do, Goto, Spawn, Unspawn } from '../index';
+
+const beginTimer = ()=>{};
+
+type S = 'green' | 'yellow' | 'red';
+type E = 'entry' | 'timer-finished';
+
+const machine = 
+  Machine(
+    State('green',
+      On('entry', 
+        Do(beginTimer)
+      ),
+      On('timer-finished',
+        Goto('yellow')
+      )
+    ),
+    State('yellow',
+      On('entry', 
+        Do(beginTimer)
+      ),
+      On('timer-finished',
+        Goto('red')
+      )
+    ),
+    State('red',
+      On('entry', 
+        Do(beginTimer)
+      ),
+      On('timer-finished',
+        Goto('green')
+      )
+    ),
+  );
\ No newline at end of file