diff --git a/src/realm/dto/create-realm.dto.ts b/src/realm/dto/create-realm.dto.ts
new file mode 100644
index 0000000..be885c2
--- /dev/null
+++ b/src/realm/dto/create-realm.dto.ts
@@ -0,0 +1,32 @@
+import { IsString, IsOptional, IsUUID, ValidateNested, IsArray, IsEnum, IsDateString } from 'class-validator';
+import { Type } from 'class-transformer';
+import { BaseDto } from '../../_core/dto/base.dto';
+import { CreateAttachmentDto } from '../../attachment/dto/create_attachment.dto';
+import { CreateQuestionDto } from '../../question/dto/create-question.dto';
+import { CreateFormPageDto } from '../../formPage/dto/create-formPage.dto';
+import { CreateParticipantDto } from '../../participant/dto/create-participant.dto';
+import { CreateFormDto } from '../../form/dto/create-form.dto';
+
+export class CreateRealmDto extends BaseDto {
+  @IsString()
+  title: string;
+
+  @IsString()
+  description: string;
+
+  @IsArray()
+  @ValidateNested({ each: true })
+  @Type(() => CreateFormDto)
+  @IsOptional()
+  forms?: CreateFormDto[];
+
+  @IsArray()
+  @ValidateNested({ each: true })
+  @Type(() => CreateParticipantDto)
+  participant: CreateParticipantDto[];
+
+  @IsArray()
+  @ValidateNested({ each: true })
+  @Type(() => CreateParticipantDto)
+  owner: CreateParticipantDto;
+}
\ No newline at end of file
diff --git a/src/realm/dto/update-realm.dto.ts b/src/realm/dto/update-realm.dto.ts
new file mode 100644
index 0000000..536d50c
--- /dev/null
+++ b/src/realm/dto/update-realm.dto.ts
@@ -0,0 +1,4 @@
+import { PartialType } from '@nestjs/mapped-types';
+import { CreateRealmDto } from './create-realm.dto';
+
+export class UpdateRealmDto extends PartialType(CreateRealmDto) {}
diff --git a/src/realm/entity/realm.entity.ts b/src/realm/entity/realm.entity.ts
new file mode 100644
index 0000000..4e9bd32
--- /dev/null
+++ b/src/realm/entity/realm.entity.ts
@@ -0,0 +1,58 @@
+import { Prop, Schema, SchemaFactory } from '@nestjs/mongoose';
+import { Document } from 'mongoose';
+import { BaseEntity } from 'src/_core/entity/_base.entity';
+import * as mongoosePaginate from 'mongoose-paginate-v2';
+import { Attachment, AttachmentSchema } from '../../attachment/entity/attachment.entity';
+import { Option, OptionSchema } from '../../option/entity/option.entity';
+import { Answer, AnswerSchema } from '../../answer/entity/answer.entity';
+import { Question, QuestionSchema } from '../../question/entity/question.entity';
+import { Form, FormSchema } from '../../form/entity/form.entity';
+import { Participant, ParticipantSchema } from '../../participant/entity/participant.entity';
+
+@Schema({ _id: false, id: false }) // Disable _id and virtual id
+export class Realm extends BaseEntity {
+  @Prop({
+    type: String,
+    required: true,
+  })
+  title: string;
+
+  @Prop({
+    type: String,
+    required: true,
+  })
+  description: string;
+
+  @Prop({
+    type: [FormSchema],
+    default: [],
+  })
+  forms: Form[];
+
+  @Prop({
+    type: [ParticipantSchema],
+    default: [],
+  })
+  participants: Participant[];
+
+  @Prop({
+    type: ParticipantSchema,
+  })
+  owner: Participant;
+
+}
+
+export type RealmDocument = Realm & Document;
+export const RealmSchema = SchemaFactory.createForClass(Realm);
+RealmSchema.plugin(mongoosePaginate);
+
+// Transform the output to remove the internal '_id'
+RealmSchema.set('toJSON', {
+  transform: (doc: RealmDocument, ret: Realm & { _id?: any }) => {
+    delete ret._id;
+    return ret;
+  },
+});
+
+
+
diff --git a/src/realm/realm.controller.ts b/src/realm/realm.controller.ts
new file mode 100644
index 0000000..eefa58a
--- /dev/null
+++ b/src/realm/realm.controller.ts
@@ -0,0 +1,47 @@
+import { Controller, Get, Post, Patch, Delete, Param, Body, UsePipes, ValidationPipe, Query, ParseUUIDPipe, HttpCode, HttpStatus,} from '@nestjs/common';
+import { RealmService } from './realm.service';
+import { CreateRealmDto } from './dto/create-realm.dto';
+import { UpdateRealmDto } from './dto/update-realm.dto';
+import { Realm } from './entity/realm.entity';
+
+@Controller('realms')
+export class RealmController {
+  constructor(private readonly realmService: RealmService) {}
+
+  @Post()
+  @UsePipes(new ValidationPipe({ transform: true, whitelist: true }))
+  async create(@Body() body: CreateRealmDto): Promise<Realm> {
+    return this.realmService.create(body);
+  }
+
+  @Get('findAll')
+  async findAll(
+    @Query('page') page: string = '1',
+    @Query('limit') limit: string = '10',
+  ) {
+    // The service returns the full pagination object
+    return this.realmService.findAll(parseInt(page, 10), parseInt(limit, 10));
+  }
+
+  @Get(':id')
+  async findOne(
+    @Param('id', new ParseUUIDPipe()) id: string,
+  ): Promise<Realm | null> {
+    return this.realmService.findById(id);
+  }
+
+  @Patch(':id')
+  @UsePipes(new ValidationPipe({ transform: true, whitelist: true }))
+  async update(
+    @Param('id', new ParseUUIDPipe()) id: string,
+    @Body() body: UpdateRealmDto,
+  ): Promise<Realm | null> {
+    return this.realmService.update(id, body);
+  }
+
+  @Delete(':id')
+  @HttpCode(HttpStatus.NO_CONTENT)
+  async remove(@Param('id', new ParseUUIDPipe()) id: string): Promise<void> {
+    return this.realmService.remove(id);
+  }
+}
diff --git a/src/realm/realm.module.ts b/src/realm/realm.module.ts
new file mode 100644
index 0000000..2703a69
--- /dev/null
+++ b/src/realm/realm.module.ts
@@ -0,0 +1,16 @@
+import { Module } from '@nestjs/common';
+import { MongooseModule } from '@nestjs/mongoose';
+import { RealmService } from './realm.service';
+import { RealmController } from './realm.controller';
+import { Realm, RealmSchema } from './entity/realm.entity';
+
+@Module({
+  imports: [
+    MongooseModule.forFeature([
+      { name: Realm.name, schema: RealmSchema },
+    ]),
+  ],
+  controllers: [RealmController],
+  providers: [RealmService],
+})
+export class RealmModule {}
diff --git a/src/realm/realm.service.ts b/src/realm/realm.service.ts
new file mode 100644
index 0000000..e4500e3
--- /dev/null
+++ b/src/realm/realm.service.ts
@@ -0,0 +1,82 @@
+import { Injectable, NotFoundException } from '@nestjs/common';
+import { InjectModel } from '@nestjs/mongoose';
+import { Model } from 'mongoose';
+import { Realm, RealmDocument } from './entity/realm.entity';
+import { CreateRealmDto } from './dto/create-realm.dto';
+import { UpdateRealmDto } from './dto/update-realm.dto';
+import { PaginateModel } from '../participant/participant.service';
+
+@Injectable()
+export class RealmService {
+  constructor(
+    @InjectModel(Realm.name)
+    private readonly realmModel: PaginateModel<RealmDocument>,
+  ) {}
+
+  async create(data: CreateRealmDto): Promise<Realm> {
+    const realm = new this.realmModel({
+      ...data,
+      id: data.id || undefined, // Let BaseEntity generate UUID if not provided
+      metadata: data.metadata || { entries: [] },
+    });
+    return realm.save();
+  }
+
+  async findAll(
+    page = 1,
+    limit = 10,
+  ): Promise<{
+    docs: Realm[];
+    totalDocs: number;
+    limit: number;
+    page: number;
+    totalPages: number;
+    hasNextPage: boolean;
+    hasPrevPage: boolean;
+    nextPage: number | null;
+    prevPage: number | null;
+  }> {
+    // Selects all fields from the Realm entity for the response
+    return this.realmModel.paginate(
+      {},
+      { page, limit, lean: true },
+    );
+  }
+
+  async findById(id: string): Promise<Realm | null> {
+    const realm = await this.realmModel
+      .findOne({ id })
+      .lean()
+      .exec();
+    if (!realm) {
+      throw new NotFoundException(`Realm with ID "${id}" not found`);
+    }
+    return realm;
+  }
+
+  async update(
+    id: string,
+    data: UpdateRealmDto,
+  ): Promise<Realm | null> {
+    const updatedRealm = await this.realmModel
+      .findOneAndUpdate(
+        { id },
+        { $set: { ...data, updatedAt: new Date() } },
+        { new: true },
+      )
+      .lean()
+      .exec();
+
+    if (!updatedRealm) {
+      throw new NotFoundException(`Realm with ID "${id}" not found`);
+    }
+    return updatedRealm;
+  }
+
+  async remove(id: string): Promise<void> {
+    const result = await this.realmModel.deleteOne({ id }).exec();
+    if (result.deletedCount === 0) {
+      throw new NotFoundException(`Realm with ID "${id}" not found`);
+    }
+  }
+}