diff --git a/build.gradle b/build.gradle
--- a/build.gradle
+++ b/build.gradle
@@ -49,6 +49,8 @@ typescript {
     compilerOptions {
         types = []
         declaration = true
+        experimentalDecorators = true
+        //strict = true
         
         if(symbols != 'none') {
             sourceMap = true
diff --git a/src/main/ts/di/Annotations.ts b/src/main/ts/di/Annotations.ts
--- a/src/main/ts/di/Annotations.ts
+++ b/src/main/ts/di/Annotations.ts
@@ -10,28 +10,41 @@ type Injector<T> = {
     [k in keyof T]: Setter;
 };
 
+type Compatible<T1, T2> = T1 extends T2 ? any : never;
+
+type SetterType<T> = T extends (v: infer V) => void ? V : never;
+
+type Tuple<T = any> = Parameters<(...args: T[]) => void>;
+
+interface Newable<A extends Tuple, T> {
+    new (...params: A): T;
+    prototype: T;
+}
+
+type MapTuple<T, A extends (keyof T)[]> = { [K in keyof A] : K extends number ? T[ A[K] ] : A[K] };
+
 export class Builder<T, S> {
-    provides(name: string) {
+    provides() {
         return <C extends Constructor<T>>(constructor: C) => {
             return constructor;
         };
     }
 
     inject<K extends keyof S>(dependency: K) {
-        return <M extends keyof T>(target: any, memberName: M, descriptor: TypedPropertyDescriptor<Setter<S[K]>> ) => {
+        // K = "bar"
+        // M = "setValue"
+        // S[K] = Bar
+        // T[M] = (value: string) => void
+        // P[m] = (value: V) => void
+        return <P, M extends keyof (T | P)>(target: P, memberName: M, descriptor: TypedPropertyDescriptor<Compatible<T[M], Setter<S[K]>>>) => {
 
         };
     }
 
-    prop<K extends keyof S>(dependency: K) {
-        return <M extends keyof T>(target: any, memberName: M, descriptor: TypedPropertyDescriptor<S[K]> ) => {
+    dependencies<D extends (keyof S)[]>(...deps: D) {
+        return <C extends Constructor<T>>(constructor: MapTuple<S, D> extends ConstructorParameters<C> ? C : never) => {
+            return constructor;
+        } ;
+    }
 
-        };
-    }
 }
-
-export function inject<I extends Injector<I> >(dependency: string) {
-    return <M extends keyof I>(target: any, memberName: M, descriptor: TypedPropertyDescriptor<I[M]> ) => {
-
-    };
-}
diff --git a/src/test/ts/mock/Bar.ts b/src/test/ts/mock/Bar.ts
--- a/src/test/ts/mock/Bar.ts
+++ b/src/test/ts/mock/Bar.ts
@@ -3,10 +3,16 @@ import { Foo } from "./Foo";
 export class Bar {
     name = "bar";
 
-    foo: Foo;
+    foo: Foo | undefined;
 
-    constructor(_opts) {
+    constructor(_opts?: { foo?: Foo; }) {
         if (_opts && _opts.foo)
             this.foo = _opts.foo;
     }
+
+    getFoo() {
+        if (this.foo === undefined)
+            throw new Error("The foo isn't set");
+        return this.foo;
+    }
 }
diff --git a/src/test/ts/mock/Box.ts b/src/test/ts/mock/Box.ts
--- a/src/test/ts/mock/Box.ts
+++ b/src/test/ts/mock/Box.ts
@@ -2,22 +2,32 @@ import { Builder } from "../di/Annotatio
 import { Bar } from "./Bar";
 import { Foo } from "./Foo";
 
-export interface Injector<T> {
-    setValue(value: T);
-}
+const builder = new Builder<Box<Bar>, { bar: Bar; foo: Foo; obj: object }>();
 
-const builder = new Builder<Box<any>, { bar: Bar; foo: Foo}>();
+@builder.provides()
+@builder.dependencies("bar")
+export class Box<T> {
+    private _value: T | undefined;
 
-@builder.provides("barBox")
-export class Box<T> implements Injector<T> {
-    private _value: T;
+    constructor(value: T) {
+        this._value = value;
+    }
 
     @builder.inject("bar")
     setValue(value: T) {
         this._value = value;
     }
 
+
+    @builder.inject("foo")
+    setObj(value: object) {
+
+    }
+
     getValue() {
+        if (this._value === undefined)
+            throw new Error("Trying to get a value from the empty box");
+
         return this._value;
     }
-}
+}
\ No newline at end of file
diff --git a/src/test/ts/mock/config.ts b/src/test/ts/mock/config.ts
new file mode 100644
diff --git a/src/test/tsconfig.json b/src/test/tsconfig.json
--- a/src/test/tsconfig.json
+++ b/src/test/tsconfig.json
@@ -1,7 +1,7 @@
 {
     "extends": "../tsconfig",
     "compilerOptions": {
-        "rootDir": "ts",
+        //"rootDir": "ts",
         "baseUrl": ".",
         "rootDirs": [
             "ts",
diff --git a/src/tsconfig.json b/src/tsconfig.json
--- a/src/tsconfig.json
+++ b/src/tsconfig.json
@@ -4,6 +4,7 @@
         "experimentalDecorators": true,
         "noEmitOnError": true,
         "listFiles": true,
+        "strict": true,
         "types": [],
         "target": "ES5",
         "lib": ["es5", "es2015.promise", "es2015.symbol", "es2015.iterable", "dom", "scripthost"]