diff --git a/index.d.ts b/index.d.ts
new file mode 100644
index 00000000..1b8b8e46
--- /dev/null
+++ b/index.d.ts
@@ -0,0 +1,82 @@
+export type ExtractAttribute =
+  (entity: any) => string;
+
+export type AssignEntity =
+  (obj: any, key: string, entity: any, input: any, schema: SchemaValue) => void;
+
+export type MergeIntoEntity =
+  (entityA: any, entityB: any, entityKey: string) => void;
+
+export type SchemaOptions = {
+  idAttribute?: string | ExtractAttribute;
+  meta?: any;
+  assignEntity?: AssignEntity;
+}
+
+export type IterableSchemaOptions = {
+  schemaAttribute?: string | ExtractAttribute;
+}
+
+export type UnionSchemaOptions = {
+  schemaAttribute: string | ExtractAttribute;
+}
+
+export type NormalizeOptions = {
+  assignEntity?: AssignEntity;
+  mergeIntoEntity?: MergeIntoEntity;
+}
+
+export type NormalizeInput = Object | Array<Object>;
+
+export type NormalizeOutput = {
+  result: any;
+  entities?: any;
+}
+
+export class Schema {
+  constructor (key: string, options?: SchemaOptions);
+
+  define(schema: SchemaMap): void;
+  getKey(): string;
+  getIdAttribute(): string;
+  getMeta(prop: string): any;
+}
+
+export class IterableSchema {
+  constructor (schema: SchemaValue, options?: IterableSchemaOptions);
+
+  getItemSchema(): SchemaValue;
+}
+
+export class UnionSchema {
+  constructor (schema: SchemaValue, options: UnionSchemaOptions);
+
+  getItemSchema(): SchemaValue;
+}
+
+export type SchemaValue = Schema | IterableSchema | UnionSchema | SchemaMap;
+
+export type SchemaMap = {
+  [key: string]: SchemaValue;
+}
+
+export function arrayOf(
+  schema: SchemaValue,
+  options?: IterableSchemaOptions
+): IterableSchema;
+
+export function valuesOf(
+  schema: SchemaValue,
+  options?: IterableSchemaOptions
+): IterableSchema;
+
+export function unionOf(
+  schema: SchemaValue,
+  options?: UnionSchemaOptions
+): UnionSchema;
+
+export function normalize(
+  input: NormalizeInput,
+  schema: SchemaValue,
+  options?: NormalizeOptions
+): NormalizeOutput;
diff --git a/package.json b/package.json
index d5850173..50f3654d 100644
--- a/package.json
+++ b/package.json
@@ -3,6 +3,7 @@
   "version": "2.1.0",
   "description": "Normalizes JSON according to schema for Redux and Flux applications",
   "main": "lib/index.js",
+  "typings": "index.d.ts",
   "repository": {
     "type": "git",
     "url": "https://github.com/paularmstrong/normalizr.git"
@@ -44,6 +45,8 @@
     "chai": "^3.2.0",
     "mocha": "^2.4.5",
     "rimraf": "^2.4.2",
+    "typescript": "^1.8.10",
+    "typescript-definition-tester": "0.0.4",
     "webpack": "^1.13.0"
   },
   "dependencies": {
diff --git a/test/typescript.js b/test/typescript.js
new file mode 100644
index 00000000..eb49855a
--- /dev/null
+++ b/test/typescript.js
@@ -0,0 +1,14 @@
+import * as tt from 'typescript-definition-tester';
+
+describe('TypeScript definitions', function () {
+  this.timeout(0);
+
+  it('compile against index.d.ts', (done) => {
+    tt.compileDirectory(
+      __dirname + '/typescript',
+      fileName => fileName.match(/\.ts$/),
+      () => done()
+    );
+  });
+
+});
diff --git a/test/typescript/normalize.ts b/test/typescript/normalize.ts
new file mode 100644
index 00000000..101ce597
--- /dev/null
+++ b/test/typescript/normalize.ts
@@ -0,0 +1,45 @@
+import {Schema, normalize, arrayOf, unionOf, valuesOf} from "../../index.d.ts";
+
+const isObject = function (obj: any) {
+  return typeof obj === 'object';
+};
+
+const assignEntity = function (output: any, key: string, value: any) {
+  if (key === "timestamp") {
+    output[key] = Date.now()
+  }
+  output[key] = value;
+};
+
+const mergeIntoEntity = function (entityA: any, entityB: any, entityKey: string) {
+  for (const key in entityB) {
+    if (!entityB.hasOwnProperty(key)) {
+      continue;
+    }
+
+    if (!entityA.hasOwnProperty(key)) {
+      entityA[key] = entityB[key];
+      continue;
+    }
+
+    if (isObject(entityA[key]) && isObject(entityB[key])) {
+      // Merge the two entities.
+      continue;
+    }
+  }
+};
+
+const user = new Schema("users");
+const group = new Schema("groups", { assignEntity });
+const member = unionOf({ users: user, groups: group }, { schemaAttribute: "type" });
+
+group.define({
+  members: arrayOf(member),
+  owner: member,
+  relations: valuesOf(member)
+});
+
+const normalizeWithObject = normalize({}, { group });
+const normalizeWithArray = normalize([], { groups: arrayOf(group) });
+const normalizeWithAssignEntity = normalize([], { groups: arrayOf(group) }, { assignEntity });
+const normalizeWithMergeIntoEntity = normalize([], { groups: arrayOf(group) }, { mergeIntoEntity });
diff --git a/test/typescript/schema.ts b/test/typescript/schema.ts
new file mode 100644
index 00000000..81b10e46
--- /dev/null
+++ b/test/typescript/schema.ts
@@ -0,0 +1,38 @@
+import {Schema, IterableSchema, UnionSchema, SchemaValue} from "../../index.d.ts";
+
+const idAttribute = "slug";
+const meta = { removeProps: ["year", "publisher"] };
+
+const generateSlug = function (entity: any) {
+  if (entity.slug != null) {
+    return "slug";
+  }
+  return "id";
+};
+
+const assignEntity = function (output: any, key: string, value: any, input: any, schema: SchemaValue) {
+  const itemSchema = (schema instanceof IterableSchema || schema instanceof UnionSchema) ?
+    schema.getItemSchema() : schema;
+  const removeProps = (itemSchema instanceof Schema) ?
+    itemSchema.getMeta("removeProps") : null;
+  if (!removeProps || removeProps.indexOf(key) < 0) {
+    output[key] = value;
+  }
+};
+
+const schemaWithKey = new Schema("articles");
+const schemaWithStringIdAttribute = new Schema("articles", { idAttribute });
+const schemaWithFunctionIdAttribute = new Schema("articles", { idAttribute: generateSlug });
+const schemaWithMeta = new Schema("articles", { meta });
+const schemaWithAssignEntity = new Schema("articles", { meta, assignEntity });
+
+const someKey: string = schemaWithKey.getKey();
+const someIdAttribute: string = schemaWithStringIdAttribute.getIdAttribute();
+const someOtherIdAttribute: string = schemaWithFunctionIdAttribute.getIdAttribute();
+const someMeta: any = schemaWithMeta.getMeta("removeProps");
+
+const article = new Schema("articles");
+const user = new Schema("users");
+article.define({
+  author: user
+});