diff --git a/apps/core/src/app.module.ts b/apps/core/src/app.module.ts
index d14e90f..9c0981d 100644
--- a/apps/core/src/app.module.ts
+++ b/apps/core/src/app.module.ts
@@ -7,9 +7,10 @@ import { CampaignsModule } from './campaigns/campaigns.module';
 import { InvestmentsModule } from './investments/investments.module';
 import { DeployModule } from './deploy/deploy.module';
 import { LoansModule } from './loans/loans.module';
+import { ParticipationTokenModule } from './participation-token/participation-token.module';
 
 @Module({
-  imports: [PrismaModule, SorobanModule, CampaignsModule, InvestmentsModule, DeployModule, LoansModule],
+  imports: [PrismaModule, SorobanModule, CampaignsModule, InvestmentsModule, DeployModule, LoansModule,ParticipationTokenModule],
   controllers: [AppController],
   providers: [AppService],
 })
diff --git a/apps/core/src/participation-token/dto/buy.dto.ts b/apps/core/src/participation-token/dto/buy.dto.ts
new file mode 100644
index 0000000..4a1aca9
--- /dev/null
+++ b/apps/core/src/participation-token/dto/buy.dto.ts
@@ -0,0 +1,27 @@
+import { IsString, IsNotEmpty, IsNumber, IsPositive } from 'class-validator';
+
+export class BuyDto {
+  @IsString()
+  @IsNotEmpty()
+  contractId: string;
+
+  @IsString()
+  @IsNotEmpty()
+  usdcAddress: string;
+
+  @IsString()
+  @IsNotEmpty()
+  payer: string;
+
+  @IsString()
+  @IsNotEmpty()
+  beneficiary: string;
+
+  @IsNumber()
+  @IsPositive()
+  amount: number;
+
+  @IsString()
+  @IsNotEmpty()
+  callerPublicKey: string;
+}
diff --git a/apps/core/src/participation-token/participation-token.controller.ts b/apps/core/src/participation-token/participation-token.controller.ts
new file mode 100644
index 0000000..33e2545
--- /dev/null
+++ b/apps/core/src/participation-token/participation-token.controller.ts
@@ -0,0 +1,16 @@
+import { Controller, Post, Body } from '@nestjs/common';
+import { ParticipationTokenService } from './participation-token.service';
+import { BuyDto } from './dto/buy.dto';
+
+@Controller('participation-token')
+export class ParticipationTokenController {
+  constructor(
+    private readonly participationTokenService: ParticipationTokenService,
+  ) {}
+
+  @Post('buy')
+  async buy(@Body() dto: BuyDto) {
+    const unsignedXdr = await this.participationTokenService.buy(dto);
+    return { unsignedXdr };
+  }
+}
diff --git a/apps/core/src/participation-token/participation-token.module.ts b/apps/core/src/participation-token/participation-token.module.ts
new file mode 100644
index 0000000..32655ce
--- /dev/null
+++ b/apps/core/src/participation-token/participation-token.module.ts
@@ -0,0 +1,9 @@
+import { Module } from '@nestjs/common';
+import { ParticipationTokenController } from './participation-token.controller';
+import { ParticipationTokenService } from './participation-token.service';
+
+@Module({
+  controllers: [ParticipationTokenController],
+  providers: [ParticipationTokenService],
+})
+export class ParticipationTokenModule {}
diff --git a/apps/core/src/participation-token/participation-token.service.ts b/apps/core/src/participation-token/participation-token.service.ts
new file mode 100644
index 0000000..4f98bd8
--- /dev/null
+++ b/apps/core/src/participation-token/participation-token.service.ts
@@ -0,0 +1,22 @@
+import { Injectable } from '@nestjs/common';
+import { SorobanService } from '../soroban/soroban.service';
+import { BuyDto } from './dto/buy.dto';
+
+@Injectable()
+export class ParticipationTokenService {
+  constructor(private readonly soroban: SorobanService) {}
+
+  buy(dto: BuyDto): Promise<string> {
+    return this.soroban.buildContractCallTransaction(
+      dto.contractId,
+      'buy',
+      {
+        usdc: dto.usdcAddress,
+        payer: dto.payer,
+        beneficiary: dto.beneficiary,
+        amount: dto.amount,
+      },
+      dto.callerPublicKey,
+    );
+  }
+}