diff --git a/app/__test__/data/mutation.simple.test.ts b/app/__test__/data/mutation.simple.test.ts
index dd385af..b54bca8 100644
--- a/app/__test__/data/mutation.simple.test.ts
+++ b/app/__test__/data/mutation.simple.test.ts
@@ -16,7 +16,7 @@ describe("Mutator simple", async () => {
       new TextField("label", { required: true, minLength: 1 }),
       new NumberField("count", { default_value: 0 })
    ]);
-   const em = new EntityManager([items], connection);
+   const em = new EntityManager<any>([items], connection);
 
    await em.connection.kysely.schema
       .createTable("items")
@@ -175,4 +175,18 @@ describe("Mutator simple", async () => {
          { id: 8, label: "keep", count: 0 }
       ]);
    });
+
+   test("insertMany", async () => {
+      const oldCount = (await em.repo(items).count()).count;
+      const inserts = [{ label: "insert 1" }, { label: "insert 2" }];
+      const { data } = await em.mutator(items).insertMany(inserts);
+
+      expect(data.length).toBe(2);
+      expect(data.map((d) => ({ label: d.label }))).toEqual(inserts);
+      const newCount = (await em.repo(items).count()).count;
+      expect(newCount).toBe(oldCount + inserts.length);
+
+      const { data: data2 } = await em.repo(items).findMany();
+      expect(data2).toEqual(data);
+   });
 });
diff --git a/app/__test__/data/prototype.test.ts b/app/__test__/data/prototype.test.ts
index 9d3eebd..f905775 100644
--- a/app/__test__/data/prototype.test.ts
+++ b/app/__test__/data/prototype.test.ts
@@ -13,6 +13,7 @@ import {
    PolymorphicRelation,
    TextField
 } from "../../src/data";
+import { DummyConnection } from "../../src/data/connection/DummyConnection";
 import {
    FieldPrototype,
    type FieldSchema,
@@ -21,6 +22,7 @@ import {
    boolean,
    date,
    datetime,
+   em,
    entity,
    enumm,
    json,
@@ -272,4 +274,29 @@ describe("prototype", () => {
 
       const obj: Schema<typeof test> = {} as any;
    });
+
+   test("schema", async () => {
+      const _em = em(
+         {
+            posts: entity("posts", { name: text() }),
+            comments: entity("comments", { some: text() })
+         },
+         (relation, { posts, comments }) => {
+            relation(posts).manyToOne(comments);
+         }
+      );
+
+      type LocalDb = (typeof _em)["DB"];
+
+      const es = [
+         new Entity("posts", [new TextField("name")]),
+         new Entity("comments", [new TextField("some")])
+      ];
+      const _em2 = new EntityManager(es, new DummyConnection(), [
+         new ManyToOneRelation(es[0], es[1])
+      ]);
+
+      // @ts-ignore
+      expect(_em2.toJSON()).toEqual(_em.toJSON());
+   });
 });
diff --git a/app/__test__/data/specs/Mutator.spec.ts b/app/__test__/data/specs/Mutator.spec.ts
index 04bd8a3..5552543 100644
--- a/app/__test__/data/specs/Mutator.spec.ts
+++ b/app/__test__/data/specs/Mutator.spec.ts
@@ -22,7 +22,7 @@ describe("[data] Mutator (base)", async () => {
       new TextField("hidden", { hidden: true }),
       new TextField("not_fillable", { fillable: false })
    ]);
-   const em = new EntityManager([entity], dummyConnection);
+   const em = new EntityManager<any>([entity], dummyConnection);
    await em.schema().sync({ force: true });
 
    const payload = { label: "item 1", count: 1 };
@@ -61,7 +61,7 @@ describe("[data] Mutator (ManyToOne)", async () => {
    const posts = new Entity("posts", [new TextField("title")]);
    const users = new Entity("users", [new TextField("username")]);
    const relations = [new ManyToOneRelation(posts, users)];
-   const em = new EntityManager([posts, users], dummyConnection, relations);
+   const em = new EntityManager<any>([posts, users], dummyConnection, relations);
    await em.schema().sync({ force: true });
 
    test("RelationMutator", async () => {
@@ -192,7 +192,7 @@ describe("[data] Mutator (OneToOne)", async () => {
    const users = new Entity("users", [new TextField("username")]);
    const settings = new Entity("settings", [new TextField("theme")]);
    const relations = [new OneToOneRelation(users, settings)];
-   const em = new EntityManager([users, settings], dummyConnection, relations);
+   const em = new EntityManager<any>([users, settings], dummyConnection, relations);
    await em.schema().sync({ force: true });
 
    test("insertOne: missing ref", async () => {
@@ -276,7 +276,7 @@ describe("[data] Mutator (ManyToMany)", async () => {
 
 describe("[data] Mutator (Events)", async () => {
    const entity = new Entity("test", [new TextField("label")]);
-   const em = new EntityManager([entity], dummyConnection);
+   const em = new EntityManager<any>([entity], dummyConnection);
    await em.schema().sync({ force: true });
    const events = new Map<string, any>();
 
diff --git a/app/src/data/connection/DummyConnection.ts b/app/src/data/connection/DummyConnection.ts
new file mode 100644
index 0000000..451575d
--- /dev/null
+++ b/app/src/data/connection/DummyConnection.ts
@@ -0,0 +1,7 @@
+import { Connection } from "./Connection";
+
+export class DummyConnection extends Connection {
+   constructor() {
+      super(undefined as any);
+   }
+}
diff --git a/app/src/data/entities/Mutator.ts b/app/src/data/entities/Mutator.ts
index 53b4cb2..3f81c6e 100644
--- a/app/src/data/entities/Mutator.ts
+++ b/app/src/data/entities/Mutator.ts
@@ -276,4 +276,39 @@ export class Mutator<DB = any, TB extends keyof DB = any, Data = Omit<DB[TB], "i
 
       return (await this.many(query)) as any;
    }
+
+   async insertMany(data: Data[]): Promise<MutatorResponse<DB[TB][]>> {
+      const entity = this.entity;
+      if (entity.type === "system" && this.__unstable_disable_system_entity_creation) {
+         throw new Error(`Creation of system entity "${entity.name}" is disabled`);
+      }
+
+      const validated: any[] = [];
+      for (const row of data) {
+         const validatedData = {
+            ...entity.getDefaultObject(),
+            ...(await this.getValidatedData(row, "create"))
+         };
+
+         // check if required fields are present
+         const required = entity.getRequiredFields();
+         for (const field of required) {
+            if (
+               typeof validatedData[field.name] === "undefined" ||
+               validatedData[field.name] === null
+            ) {
+               throw new Error(`Field "${field.name}" is required`);
+            }
+         }
+
+         validated.push(validatedData);
+      }
+
+      const query = this.conn
+         .insertInto(entity.name)
+         .values(validated)
+         .returning(entity.getSelect());
+
+      return (await this.many(query)) as any;
+   }
 }
diff --git a/app/src/data/prototype/index.ts b/app/src/data/prototype/index.ts
index 8bdd07b..0e44138 100644
--- a/app/src/data/prototype/index.ts
+++ b/app/src/data/prototype/index.ts
@@ -1,3 +1,5 @@
+import { DummyConnection } from "data/connection/DummyConnection";
+import { EntityManager } from "data/entities/EntityManager";
 import type { Generated } from "kysely";
 import { MediaField, type MediaFieldConfig, type MediaItem } from "media/MediaField";
 import {
@@ -7,6 +9,7 @@ import {
    type DateFieldConfig,
    Entity,
    type EntityConfig,
+   type EntityRelation,
    EnumField,
    type EnumFieldConfig,
    type Field,
@@ -240,6 +243,57 @@ export function relation<Local extends Entity>(local: Local) {
    };
 }
 
+class EntityManagerPrototype<Entities extends Record<string, Entity>> extends EntityManager<
+   Schema<Entities>
+> {
+   constructor(
+      public __entities: Entities,
+      relations: EntityRelation[]
+   ) {
+      super(Object.values(__entities), new DummyConnection(), relations);
+   }
+}
+
+export function em<Entities extends Record<string, Entity>>(
+   entities: Entities,
+   schema?: (rel: typeof relation, entities: Entities) => void
+) {
+   const relations: EntityRelation[] = [];
+   const relationProxy = (local: Entity) => {
+      return new Proxy(relation(local), {
+         get(target, prop) {
+            if (typeof target[prop] === "function") {
+               return (...args: any[]) => {
+                  const result = target[prop](...args);
+                  relations.push(result);
+                  return result;
+               };
+            }
+            return target[prop];
+         }
+      });
+   };
+
+   if (schema) {
+      schema(relationProxy, entities);
+   }
+
+   const e = new EntityManagerPrototype(entities, relations);
+   return {
+      DB: e.__entities as unknown as Schemas<Entities>,
+      entities: e.__entities,
+      relations,
+      indices: [],
+      toJSON: () => {
+         return e.toJSON() as unknown as {
+            entities: Schemas<Entities>;
+            relations: EntityRelation[];
+            indices: any[];
+         };
+      }
+   };
+}
+
 export type InferEntityFields<T> = T extends Entity<infer _N, infer Fields>
    ? {
         [K in keyof Fields]: Fields[K] extends { _type: infer Type; _required: infer Required }
@@ -291,18 +345,9 @@ export type InferField<Field> = Field extends { _type: infer Type; _required: in
       : Type | undefined
    : never;
 
-const n = number();
-type T2 = InferField<typeof n>;
-
-const users = entity("users", {
-   name: text(),
-   email: text(),
-   created_at: datetime(),
-   updated_at: datetime()
-});
-type TUsersFields = InferEntityFields<typeof users>;
-type TUsers = Schema<typeof users>;
-type TUsers2 = Simplify<OptionalUndefined<Schema<typeof users>>>;
+export type Schemas<T extends Record<string, Entity>> = {
+   [K in keyof T]: Schema<T[K]>;
+};
 
 export type InsertSchema<T> = Simplify<OptionalUndefined<InferEntityFields<T>>>;
 export type Schema<T> = Simplify<{ id: Generated<number> } & InsertSchema<T>>;