diff --git a/billing-finance-core/.env.example b/billing-finance-core/.env.example
new file mode 100644
index 0000000..ca8a203
--- /dev/null
+++ b/billing-finance-core/.env.example
@@ -0,0 +1,9 @@
+NODE_ENV=development
+PORT=3000
+DATABASE_URL=postgresql://postgres:postgres@localhost:5432/billing_finance_core
+JWT_SECRET=change-me
+JWT_PUBLIC_KEY=
+JWT_ISSUER=identity-gateway
+PAYMENT_WEBHOOK_SECRET=change-me
+STRIPE_API_KEY=
+APP_LOG_LEVEL=info
diff --git a/billing-finance-core/Dockerfile b/billing-finance-core/Dockerfile
new file mode 100644
index 0000000..1ce5958
--- /dev/null
+++ b/billing-finance-core/Dockerfile
@@ -0,0 +1,18 @@
+FROM node:20-alpine AS builder
+WORKDIR /app
+COPY package.json package-lock.json* ./
+RUN npm install
+COPY tsconfig.json nest-cli.json ./
+COPY prisma ./prisma
+COPY src ./src
+RUN npm run prisma:generate
+RUN npm run build
+
+FROM node:20-alpine
+WORKDIR /app
+ENV NODE_ENV=production
+COPY package.json package-lock.json* ./
+RUN npm install --omit=dev
+COPY --from=builder /app/dist ./dist
+COPY --from=builder /app/prisma ./prisma
+CMD ["node", "dist/main.js"]
diff --git a/billing-finance-core/README.md b/billing-finance-core/README.md
new file mode 100644
index 0000000..1a05b1f
--- /dev/null
+++ b/billing-finance-core/README.md
@@ -0,0 +1,77 @@
+# billing-finance-core
+
+Backend financeiro, billing, fiscal e CRM para uma plataforma SaaS multi-tenant.
+
+## Visão geral
+- **Multi-tenant desde o início** com isolamento por `tenantId`.
+- **Sem autenticação própria**: confia no `identity-gateway` via JWT interno.
+- **Core financeiro**: planos, assinaturas, invoices, pagamentos, conciliação.
+- **Fiscal (base)**: estrutura para emissão de NFS-e.
+- **CRM**: empresas, contatos e pipeline simples de negócios.
+
+## Stack
+- Node.js + TypeScript
+- NestJS
+- PostgreSQL + Prisma
+- Docker
+
+## Integração com identity-gateway
+- Todas as rotas são protegidas por JWT interno.
+- O token deve conter:
+  - `tenantId`
+  - `userId`
+  - `roles`
+- O guard valida `issuer` e assina com `JWT_PUBLIC_KEY` ou `JWT_SECRET`.
+
+## Modelo de dados (resumo)
+- **Tenant**: empresa cliente
+- **Plan**: preço, ciclo e limites
+- **Subscription**: tenant + plano
+- **Invoice**: contas a receber
+- **Payment**: pagamentos com gateway
+- **FiscalDocument**: base para NFS-e
+- **CRM**: companies, contacts, deals
+
+## Fluxo de cobrança
+1. Criar plano
+2. Criar assinatura
+3. Gerar invoice
+4. Criar pagamento via gateway
+5. Receber webhook e conciliar
+
+## Endpoints mínimos
+```
+POST   /tenants
+GET    /tenants
+POST   /plans
+GET    /plans
+POST   /subscriptions
+GET    /subscriptions
+POST   /invoices
+GET    /invoices
+POST   /payments/:invoiceId
+POST   /webhooks/:gateway
+GET    /crm/companies
+POST   /crm/deals
+GET    /health
+```
+
+## Configuração local
+```bash
+cp .env.example .env
+npm install
+npm run prisma:generate
+npm run prisma:migrate
+npm run start:dev
+```
+
+## Docker
+```bash
+docker compose up --build
+```
+
+## Estrutura
+- `src/core`: guard e contexto do tenant
+- `src/modules`: domínios de negócio
+- `prisma/`: schema e migrations
+- `docs/`: documentação técnica
diff --git a/billing-finance-core/docker-compose.yml b/billing-finance-core/docker-compose.yml
new file mode 100644
index 0000000..0c3be7a
--- /dev/null
+++ b/billing-finance-core/docker-compose.yml
@@ -0,0 +1,30 @@
+version: '3.9'
+
+services:
+  postgres:
+    image: postgres:15-alpine
+    environment:
+      POSTGRES_DB: billing_finance_core
+      POSTGRES_USER: postgres
+      POSTGRES_PASSWORD: postgres
+    ports:
+      - '5432:5432'
+    volumes:
+      - postgres_data:/var/lib/postgresql/data
+
+  billing-finance-core:
+    build: .
+    environment:
+      NODE_ENV: development
+      PORT: 3000
+      DATABASE_URL: postgresql://postgres:postgres@postgres:5432/billing_finance_core
+      JWT_SECRET: change-me
+      JWT_ISSUER: identity-gateway
+      PAYMENT_WEBHOOK_SECRET: change-me
+    ports:
+      - '3000:3000'
+    depends_on:
+      - postgres
+
+volumes:
+  postgres_data:
diff --git a/billing-finance-core/docs/architecture.md b/billing-finance-core/docs/architecture.md
new file mode 100644
index 0000000..f17af20
--- /dev/null
+++ b/billing-finance-core/docs/architecture.md
@@ -0,0 +1,18 @@
+# Arquitetura do billing-finance-core
+
+## Visão geral
+O serviço `billing-finance-core` é responsável pelo core financeiro, billing, fiscal e CRM da plataforma SaaS multi-tenant. Ele confia no `identity-gateway` para autenticação e recebe o `tenantId` via JWT interno.
+
+## Principais componentes
+- **Core**: Guard de autenticação JWT e contexto de tenant.
+- **Módulos de domínio**: tenants, planos, assinaturas, invoices, payments, fiscal e CRM.
+- **Gateways de pagamento**: padrão Strategy para Pix, boleto e cartão.
+- **Persistência**: PostgreSQL com Prisma e migrations.
+
+## Multi-tenant
+- Todas as rotas usam `tenantId` extraído do JWT interno.
+- Consultas sempre filtram por `tenantId`.
+
+## Integrações
+- **Identity Gateway**: JWT interno contendo `tenantId`, `userId`, `roles`.
+- **Gateways de pagamento**: integração via webhooks e reconciliação idempotente.
diff --git a/billing-finance-core/docs/billing-flow.md b/billing-finance-core/docs/billing-flow.md
new file mode 100644
index 0000000..3480d55
--- /dev/null
+++ b/billing-finance-core/docs/billing-flow.md
@@ -0,0 +1,18 @@
+# Fluxo de cobrança
+
+1. **Criação de plano**
+   - Define preço, ciclo de cobrança e limites.
+2. **Assinatura**
+   - Relaciona tenant e plano, define datas de ciclo e status.
+3. **Invoice**
+   - Conta a receber com vencimento e status.
+4. **Pagamento**
+   - Gateway escolhido gera pagamento (Pix, boleto, cartão).
+5. **Webhook**
+   - Gateway envia evento de pagamento.
+6. **Conciliação**
+   - Atualiza status do pagamento e invoice.
+
+## Status principais
+- **Invoice**: PENDING, PAID, OVERDUE, CANCELED
+- **Payment**: PENDING, CONFIRMED, FAILED, CANCELED
diff --git a/billing-finance-core/docs/fiscal.md b/billing-finance-core/docs/fiscal.md
new file mode 100644
index 0000000..caac2e4
--- /dev/null
+++ b/billing-finance-core/docs/fiscal.md
@@ -0,0 +1,12 @@
+# Fiscal (base)
+
+O módulo fiscal mantém informações básicas para emissão de NFS-e.
+
+## Campos
+- Número da nota
+- Status (DRAFT, ISSUED, CANCELED)
+- Links de PDF/XML
+
+## Integração futura
+- Preparado para integrar com provedor externo.
+- Não inclui regras municipais complexas.
diff --git a/billing-finance-core/nest-cli.json b/billing-finance-core/nest-cli.json
new file mode 100644
index 0000000..56167b3
--- /dev/null
+++ b/billing-finance-core/nest-cli.json
@@ -0,0 +1,4 @@
+{
+  "collection": "@nestjs/schematics",
+  "sourceRoot": "src"
+}
diff --git a/billing-finance-core/package.json b/billing-finance-core/package.json
new file mode 100644
index 0000000..86cf50a
--- /dev/null
+++ b/billing-finance-core/package.json
@@ -0,0 +1,38 @@
+{
+  "name": "billing-finance-core",
+  "version": "1.0.0",
+  "description": "Core financeiro, billing, fiscal e CRM para plataforma SaaS multi-tenant.",
+  "main": "dist/main.js",
+  "scripts": {
+    "build": "nest build",
+    "start": "nest start",
+    "start:dev": "nest start --watch",
+    "start:prod": "node dist/main.js",
+    "lint": "eslint \"src/**/*.ts\"",
+    "prisma:generate": "prisma generate",
+    "prisma:migrate": "prisma migrate deploy",
+    "prisma:studio": "prisma studio"
+  },
+  "dependencies": {
+    "@nestjs/common": "^10.3.0",
+    "@nestjs/core": "^10.3.0",
+    "@nestjs/platform-express": "^10.3.0",
+    "@prisma/client": "^5.20.0",
+    "class-transformer": "^0.5.1",
+    "class-validator": "^0.14.1",
+    "dotenv": "^16.4.5",
+    "jsonwebtoken": "^9.0.2",
+    "reflect-metadata": "^0.2.2",
+    "rxjs": "^7.8.1"
+  },
+  "devDependencies": {
+    "@nestjs/cli": "^10.4.2",
+    "@nestjs/schematics": "^10.1.2",
+    "@nestjs/testing": "^10.3.0",
+    "@types/jsonwebtoken": "^9.0.6",
+    "@types/node": "^20.14.11",
+    "prisma": "^5.20.0",
+    "ts-node": "^10.9.2",
+    "typescript": "^5.5.4"
+  }
+}
diff --git a/billing-finance-core/prisma/migrations/000_init/migration.sql b/billing-finance-core/prisma/migrations/000_init/migration.sql
new file mode 100644
index 0000000..c677820
--- /dev/null
+++ b/billing-finance-core/prisma/migrations/000_init/migration.sql
@@ -0,0 +1,166 @@
+-- CreateEnum
+CREATE TYPE "BillingCycle" AS ENUM ('MONTHLY', 'YEARLY');
+CREATE TYPE "SubscriptionStatus" AS ENUM ('ACTIVE', 'PAST_DUE', 'CANCELED', 'TRIAL');
+CREATE TYPE "InvoiceStatus" AS ENUM ('PENDING', 'PAID', 'OVERDUE', 'CANCELED');
+CREATE TYPE "PaymentStatus" AS ENUM ('PENDING', 'CONFIRMED', 'FAILED', 'CANCELED');
+CREATE TYPE "FiscalStatus" AS ENUM ('DRAFT', 'ISSUED', 'CANCELED');
+CREATE TYPE "DealStage" AS ENUM ('LEAD', 'PROPOSAL', 'NEGOTIATION', 'WON', 'LOST');
+
+-- CreateTable
+CREATE TABLE "Tenant" (
+    "id" TEXT NOT NULL,
+    "name" TEXT NOT NULL,
+    "taxId" TEXT,
+    "status" TEXT NOT NULL DEFAULT 'ACTIVE',
+    "createdAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    "updatedAt" TIMESTAMP(3) NOT NULL,
+
+    CONSTRAINT "Tenant_pkey" PRIMARY KEY ("id")
+);
+
+-- CreateTable
+CREATE TABLE "Plan" (
+    "id" TEXT NOT NULL,
+    "name" TEXT NOT NULL,
+    "priceCents" INTEGER NOT NULL,
+    "billingCycle" "BillingCycle" NOT NULL,
+    "softLimit" INTEGER,
+    "hardLimit" INTEGER,
+    "createdAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    "updatedAt" TIMESTAMP(3) NOT NULL,
+
+    CONSTRAINT "Plan_pkey" PRIMARY KEY ("id")
+);
+
+-- CreateTable
+CREATE TABLE "Subscription" (
+    "id" TEXT NOT NULL,
+    "tenantId" TEXT NOT NULL,
+    "planId" TEXT NOT NULL,
+    "status" "SubscriptionStatus" NOT NULL DEFAULT 'ACTIVE',
+    "startDate" TIMESTAMP(3) NOT NULL,
+    "nextDueDate" TIMESTAMP(3) NOT NULL,
+    "createdAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    "updatedAt" TIMESTAMP(3) NOT NULL,
+
+    CONSTRAINT "Subscription_pkey" PRIMARY KEY ("id")
+);
+
+-- CreateTable
+CREATE TABLE "Invoice" (
+    "id" TEXT NOT NULL,
+    "tenantId" TEXT NOT NULL,
+    "subscriptionId" TEXT,
+    "amountCents" INTEGER NOT NULL,
+    "dueDate" TIMESTAMP(3) NOT NULL,
+    "status" "InvoiceStatus" NOT NULL DEFAULT 'PENDING',
+    "paidAt" TIMESTAMP(3),
+    "createdAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    "updatedAt" TIMESTAMP(3) NOT NULL,
+
+    CONSTRAINT "Invoice_pkey" PRIMARY KEY ("id")
+);
+
+-- CreateTable
+CREATE TABLE "Payment" (
+    "id" TEXT NOT NULL,
+    "tenantId" TEXT NOT NULL,
+    "invoiceId" TEXT NOT NULL,
+    "gateway" TEXT NOT NULL,
+    "method" TEXT NOT NULL,
+    "externalId" TEXT,
+    "status" "PaymentStatus" NOT NULL DEFAULT 'PENDING',
+    "amountCents" INTEGER NOT NULL,
+    "createdAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    "updatedAt" TIMESTAMP(3) NOT NULL,
+
+    CONSTRAINT "Payment_pkey" PRIMARY KEY ("id")
+);
+
+-- CreateTable
+CREATE TABLE "FiscalDocument" (
+    "id" TEXT NOT NULL,
+    "tenantId" TEXT NOT NULL,
+    "invoiceId" TEXT,
+    "number" TEXT,
+    "status" "FiscalStatus" NOT NULL DEFAULT 'DRAFT',
+    "pdfUrl" TEXT,
+    "xmlUrl" TEXT,
+    "createdAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    "updatedAt" TIMESTAMP(3) NOT NULL,
+
+    CONSTRAINT "FiscalDocument_pkey" PRIMARY KEY ("id")
+);
+
+-- CreateTable
+CREATE TABLE "CrmCompany" (
+    "id" TEXT NOT NULL,
+    "tenantId" TEXT NOT NULL,
+    "name" TEXT NOT NULL,
+    "segment" TEXT,
+    "website" TEXT,
+    "createdAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    "updatedAt" TIMESTAMP(3) NOT NULL,
+
+    CONSTRAINT "CrmCompany_pkey" PRIMARY KEY ("id")
+);
+
+-- CreateTable
+CREATE TABLE "CrmContact" (
+    "id" TEXT NOT NULL,
+    "tenantId" TEXT NOT NULL,
+    "companyId" TEXT,
+    "name" TEXT NOT NULL,
+    "email" TEXT,
+    "phone" TEXT,
+    "createdAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    "updatedAt" TIMESTAMP(3) NOT NULL,
+
+    CONSTRAINT "CrmContact_pkey" PRIMARY KEY ("id")
+);
+
+-- CreateTable
+CREATE TABLE "CrmDeal" (
+    "id" TEXT NOT NULL,
+    "tenantId" TEXT NOT NULL,
+    "companyId" TEXT,
+    "name" TEXT NOT NULL,
+    "stage" "DealStage" NOT NULL DEFAULT 'LEAD',
+    "valueCents" INTEGER NOT NULL,
+    "expectedAt" TIMESTAMP(3),
+    "createdAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    "updatedAt" TIMESTAMP(3) NOT NULL,
+
+    CONSTRAINT "CrmDeal_pkey" PRIMARY KEY ("id")
+);
+
+-- Indexes
+CREATE INDEX "Subscription_tenantId_idx" ON "Subscription"("tenantId");
+CREATE INDEX "Subscription_planId_idx" ON "Subscription"("planId");
+CREATE INDEX "Invoice_tenantId_idx" ON "Invoice"("tenantId");
+CREATE INDEX "Invoice_subscriptionId_idx" ON "Invoice"("subscriptionId");
+CREATE INDEX "Payment_tenantId_idx" ON "Payment"("tenantId");
+CREATE INDEX "Payment_invoiceId_idx" ON "Payment"("invoiceId");
+CREATE UNIQUE INDEX "Payment_gateway_externalId_key" ON "Payment"("gateway", "externalId");
+CREATE INDEX "FiscalDocument_tenantId_idx" ON "FiscalDocument"("tenantId");
+CREATE INDEX "FiscalDocument_invoiceId_idx" ON "FiscalDocument"("invoiceId");
+CREATE INDEX "CrmCompany_tenantId_idx" ON "CrmCompany"("tenantId");
+CREATE INDEX "CrmContact_tenantId_idx" ON "CrmContact"("tenantId");
+CREATE INDEX "CrmContact_companyId_idx" ON "CrmContact"("companyId");
+CREATE INDEX "CrmDeal_tenantId_idx" ON "CrmDeal"("tenantId");
+CREATE INDEX "CrmDeal_companyId_idx" ON "CrmDeal"("companyId");
+
+-- Foreign Keys
+ALTER TABLE "Subscription" ADD CONSTRAINT "Subscription_tenantId_fkey" FOREIGN KEY ("tenantId") REFERENCES "Tenant"("id") ON DELETE RESTRICT ON UPDATE CASCADE;
+ALTER TABLE "Subscription" ADD CONSTRAINT "Subscription_planId_fkey" FOREIGN KEY ("planId") REFERENCES "Plan"("id") ON DELETE RESTRICT ON UPDATE CASCADE;
+ALTER TABLE "Invoice" ADD CONSTRAINT "Invoice_tenantId_fkey" FOREIGN KEY ("tenantId") REFERENCES "Tenant"("id") ON DELETE RESTRICT ON UPDATE CASCADE;
+ALTER TABLE "Invoice" ADD CONSTRAINT "Invoice_subscriptionId_fkey" FOREIGN KEY ("subscriptionId") REFERENCES "Subscription"("id") ON DELETE SET NULL ON UPDATE CASCADE;
+ALTER TABLE "Payment" ADD CONSTRAINT "Payment_invoiceId_fkey" FOREIGN KEY ("invoiceId") REFERENCES "Invoice"("id") ON DELETE RESTRICT ON UPDATE CASCADE;
+ALTER TABLE "Payment" ADD CONSTRAINT "Payment_tenantId_fkey" FOREIGN KEY ("tenantId") REFERENCES "Tenant"("id") ON DELETE RESTRICT ON UPDATE CASCADE;
+ALTER TABLE "FiscalDocument" ADD CONSTRAINT "FiscalDocument_tenantId_fkey" FOREIGN KEY ("tenantId") REFERENCES "Tenant"("id") ON DELETE RESTRICT ON UPDATE CASCADE;
+ALTER TABLE "FiscalDocument" ADD CONSTRAINT "FiscalDocument_invoiceId_fkey" FOREIGN KEY ("invoiceId") REFERENCES "Invoice"("id") ON DELETE SET NULL ON UPDATE CASCADE;
+ALTER TABLE "CrmCompany" ADD CONSTRAINT "CrmCompany_tenantId_fkey" FOREIGN KEY ("tenantId") REFERENCES "Tenant"("id") ON DELETE RESTRICT ON UPDATE CASCADE;
+ALTER TABLE "CrmContact" ADD CONSTRAINT "CrmContact_tenantId_fkey" FOREIGN KEY ("tenantId") REFERENCES "Tenant"("id") ON DELETE RESTRICT ON UPDATE CASCADE;
+ALTER TABLE "CrmContact" ADD CONSTRAINT "CrmContact_companyId_fkey" FOREIGN KEY ("companyId") REFERENCES "CrmCompany"("id") ON DELETE SET NULL ON UPDATE CASCADE;
+ALTER TABLE "CrmDeal" ADD CONSTRAINT "CrmDeal_tenantId_fkey" FOREIGN KEY ("tenantId") REFERENCES "Tenant"("id") ON DELETE RESTRICT ON UPDATE CASCADE;
+ALTER TABLE "CrmDeal" ADD CONSTRAINT "CrmDeal_companyId_fkey" FOREIGN KEY ("companyId") REFERENCES "CrmCompany"("id") ON DELETE SET NULL ON UPDATE CASCADE;
diff --git a/billing-finance-core/prisma/schema.prisma b/billing-finance-core/prisma/schema.prisma
new file mode 100644
index 0000000..4fe7f95
--- /dev/null
+++ b/billing-finance-core/prisma/schema.prisma
@@ -0,0 +1,195 @@
+generator client {
+  provider = "prisma-client-js"
+}
+
+datasource db {
+  provider = "postgresql"
+  url      = env("DATABASE_URL")
+}
+
+enum BillingCycle {
+  MONTHLY
+  YEARLY
+}
+
+enum SubscriptionStatus {
+  ACTIVE
+  PAST_DUE
+  CANCELED
+  TRIAL
+}
+
+enum InvoiceStatus {
+  PENDING
+  PAID
+  OVERDUE
+  CANCELED
+}
+
+enum PaymentStatus {
+  PENDING
+  CONFIRMED
+  FAILED
+  CANCELED
+}
+
+enum FiscalStatus {
+  DRAFT
+  ISSUED
+  CANCELED
+}
+
+enum DealStage {
+  LEAD
+  PROPOSAL
+  NEGOTIATION
+  WON
+  LOST
+}
+
+model Tenant {
+  id             String         @id @default(uuid())
+  name           String
+  taxId          String?
+  status         String         @default("ACTIVE")
+  createdAt      DateTime       @default(now())
+  updatedAt      DateTime       @updatedAt
+  subscriptions  Subscription[]
+  invoices       Invoice[]
+  payments       Payment[]
+  fiscalDocs     FiscalDocument[]
+  crmCompanies   CrmCompany[]
+  crmContacts    CrmContact[]
+  crmDeals       CrmDeal[]
+}
+
+model Plan {
+  id             String         @id @default(uuid())
+  name           String
+  priceCents     Int
+  billingCycle   BillingCycle
+  softLimit      Int?
+  hardLimit      Int?
+  createdAt      DateTime       @default(now())
+  updatedAt      DateTime       @updatedAt
+  subscriptions  Subscription[]
+}
+
+model Subscription {
+  id            String              @id @default(uuid())
+  tenantId      String
+  planId        String
+  status        SubscriptionStatus  @default(ACTIVE)
+  startDate     DateTime
+  nextDueDate   DateTime
+  createdAt     DateTime            @default(now())
+  updatedAt     DateTime            @updatedAt
+  tenant        Tenant              @relation(fields: [tenantId], references: [id])
+  plan          Plan                @relation(fields: [planId], references: [id])
+  invoices      Invoice[]
+
+  @@index([tenantId])
+  @@index([planId])
+}
+
+model Invoice {
+  id             String        @id @default(uuid())
+  tenantId       String
+  subscriptionId String?
+  amountCents    Int
+  dueDate        DateTime
+  status         InvoiceStatus @default(PENDING)
+  paidAt         DateTime?
+  createdAt      DateTime      @default(now())
+  updatedAt      DateTime      @updatedAt
+  tenant         Tenant        @relation(fields: [tenantId], references: [id])
+  subscription   Subscription? @relation(fields: [subscriptionId], references: [id])
+  payments       Payment[]
+
+  @@index([tenantId])
+  @@index([subscriptionId])
+}
+
+model Payment {
+  id            String        @id @default(uuid())
+  tenantId      String
+  invoiceId     String
+  gateway       String
+  method        String
+  externalId    String?
+  status        PaymentStatus @default(PENDING)
+  amountCents   Int
+  createdAt     DateTime      @default(now())
+  updatedAt     DateTime      @updatedAt
+  invoice       Invoice       @relation(fields: [invoiceId], references: [id])
+  tenant        Tenant        @relation(fields: [tenantId], references: [id])
+
+  @@index([tenantId])
+  @@index([invoiceId])
+  @@unique([gateway, externalId])
+}
+
+model FiscalDocument {
+  id          String       @id @default(uuid())
+  tenantId    String
+  invoiceId   String?
+  number      String?
+  status      FiscalStatus @default(DRAFT)
+  pdfUrl      String?
+  xmlUrl      String?
+  createdAt   DateTime     @default(now())
+  updatedAt   DateTime     @updatedAt
+  tenant      Tenant       @relation(fields: [tenantId], references: [id])
+  invoice     Invoice?     @relation(fields: [invoiceId], references: [id])
+
+  @@index([tenantId])
+  @@index([invoiceId])
+}
+
+model CrmCompany {
+  id        String    @id @default(uuid())
+  tenantId  String
+  name      String
+  segment   String?
+  website   String?
+  createdAt DateTime  @default(now())
+  updatedAt DateTime  @updatedAt
+  tenant    Tenant    @relation(fields: [tenantId], references: [id])
+  contacts  CrmContact[]
+  deals     CrmDeal[]
+
+  @@index([tenantId])
+}
+
+model CrmContact {
+  id        String   @id @default(uuid())
+  tenantId  String
+  companyId String?
+  name      String
+  email     String?
+  phone     String?
+  createdAt DateTime @default(now())
+  updatedAt DateTime @updatedAt
+  tenant    Tenant   @relation(fields: [tenantId], references: [id])
+  company   CrmCompany? @relation(fields: [companyId], references: [id])
+
+  @@index([tenantId])
+  @@index([companyId])
+}
+
+model CrmDeal {
+  id          String    @id @default(uuid())
+  tenantId    String
+  companyId   String?
+  name        String
+  stage       DealStage @default(LEAD)
+  valueCents  Int
+  expectedAt  DateTime?
+  createdAt   DateTime  @default(now())
+  updatedAt   DateTime  @updatedAt
+  tenant      Tenant    @relation(fields: [tenantId], references: [id])
+  company     CrmCompany? @relation(fields: [companyId], references: [id])
+
+  @@index([tenantId])
+  @@index([companyId])
+}
diff --git a/billing-finance-core/src/app.controller.ts b/billing-finance-core/src/app.controller.ts
new file mode 100644
index 0000000..8765d7e
--- /dev/null
+++ b/billing-finance-core/src/app.controller.ts
@@ -0,0 +1,9 @@
+import { Controller, Get } from '@nestjs/common';
+
+@Controller()
+export class AppController {
+  @Get('health')
+  getHealth() {
+    return { status: 'ok' };
+  }
+}
diff --git a/billing-finance-core/src/app.module.ts b/billing-finance-core/src/app.module.ts
new file mode 100644
index 0000000..8a238ed
--- /dev/null
+++ b/billing-finance-core/src/app.module.ts
@@ -0,0 +1,35 @@
+import { Module } from '@nestjs/common';
+import { APP_GUARD } from '@nestjs/core';
+import { AppController } from './app.controller';
+import { AuthGuard } from './core/auth.guard';
+import { PrismaService } from './lib/postgres';
+import { TenantModule } from './modules/tenants/tenant.module';
+import { PlanModule } from './modules/plans/plan.module';
+import { SubscriptionModule } from './modules/subscriptions/subscription.module';
+import { InvoiceModule } from './modules/invoices/invoice.module';
+import { PaymentModule } from './modules/payments/payment.module';
+import { WebhookModule } from './modules/webhooks/webhook.module';
+import { FiscalModule } from './modules/fiscal/fiscal.module';
+import { CrmModule } from './modules/crm/crm.module';
+
+@Module({
+  controllers: [AppController],
+  imports: [
+    TenantModule,
+    PlanModule,
+    SubscriptionModule,
+    InvoiceModule,
+    PaymentModule,
+    WebhookModule,
+    FiscalModule,
+    CrmModule,
+  ],
+  providers: [
+    PrismaService,
+    {
+      provide: APP_GUARD,
+      useClass: AuthGuard,
+    },
+  ],
+})
+export class AppModule {}
diff --git a/billing-finance-core/src/core/auth.guard.ts b/billing-finance-core/src/core/auth.guard.ts
new file mode 100644
index 0000000..b1820c3
--- /dev/null
+++ b/billing-finance-core/src/core/auth.guard.ts
@@ -0,0 +1,58 @@
+import {
+  CanActivate,
+  ExecutionContext,
+  Injectable,
+  UnauthorizedException,
+} from '@nestjs/common';
+import { Request } from 'express';
+import jwt, { JwtPayload } from 'jsonwebtoken';
+import { env } from '../lib/env';
+
+interface IdentityGatewayPayload extends JwtPayload {
+  tenantId: string;
+  userId: string;
+  roles: string[];
+}
+
+@Injectable()
+export class AuthGuard implements CanActivate {
+  canActivate(context: ExecutionContext): boolean {
+    const request = context.switchToHttp().getRequest<Request>();
+    if (request.path.startsWith('/webhooks')) {
+      const secret = request.headers['x-webhook-secret'];
+      if (secret && secret === env.webhookSecret) {
+        return true;
+      }
+    }
+    const authHeader = request.headers.authorization;
+
+    if (!authHeader?.startsWith('Bearer ')) {
+      throw new UnauthorizedException('Missing bearer token');
+    }
+
+    const token = authHeader.replace('Bearer ', '').trim();
+    try {
+      const verified = jwt.verify(
+        token,
+        env.jwtPublicKey || env.jwtSecret,
+        {
+          issuer: env.jwtIssuer,
+        },
+      ) as IdentityGatewayPayload;
+
+      if (!verified.tenantId || !verified.userId) {
+        throw new UnauthorizedException('Token missing tenant/user');
+      }
+
+      request.user = {
+        tenantId: verified.tenantId,
+        userId: verified.userId,
+        roles: verified.roles ?? [],
+      } as IdentityGatewayPayload;
+
+      return true;
+    } catch (error) {
+      throw new UnauthorizedException('Invalid token');
+    }
+  }
+}
diff --git a/billing-finance-core/src/core/enums.ts b/billing-finance-core/src/core/enums.ts
new file mode 100644
index 0000000..34cf3b4
--- /dev/null
+++ b/billing-finance-core/src/core/enums.ts
@@ -0,0 +1,39 @@
+export enum BillingCycle {
+  MONTHLY = 'MONTHLY',
+  YEARLY = 'YEARLY',
+}
+
+export enum SubscriptionStatus {
+  ACTIVE = 'ACTIVE',
+  PAST_DUE = 'PAST_DUE',
+  CANCELED = 'CANCELED',
+  TRIAL = 'TRIAL',
+}
+
+export enum InvoiceStatus {
+  PENDING = 'PENDING',
+  PAID = 'PAID',
+  OVERDUE = 'OVERDUE',
+  CANCELED = 'CANCELED',
+}
+
+export enum PaymentStatus {
+  PENDING = 'PENDING',
+  CONFIRMED = 'CONFIRMED',
+  FAILED = 'FAILED',
+  CANCELED = 'CANCELED',
+}
+
+export enum FiscalStatus {
+  DRAFT = 'DRAFT',
+  ISSUED = 'ISSUED',
+  CANCELED = 'CANCELED',
+}
+
+export enum DealStage {
+  LEAD = 'LEAD',
+  PROPOSAL = 'PROPOSAL',
+  NEGOTIATION = 'NEGOTIATION',
+  WON = 'WON',
+  LOST = 'LOST',
+}
diff --git a/billing-finance-core/src/core/tenant.context.ts b/billing-finance-core/src/core/tenant.context.ts
new file mode 100644
index 0000000..c58197b
--- /dev/null
+++ b/billing-finance-core/src/core/tenant.context.ts
@@ -0,0 +1,15 @@
+import { Request } from 'express';
+
+export interface TenantContextPayload {
+  tenantId: string;
+  userId: string;
+  roles: string[];
+}
+
+export const getTenantContext = (request: Request): TenantContextPayload => {
+  const user = request.user as TenantContextPayload | undefined;
+  if (!user) {
+    throw new Error('Tenant context missing from request.');
+  }
+  return user;
+};
diff --git a/billing-finance-core/src/database/prisma.schema b/billing-finance-core/src/database/prisma.schema
new file mode 100644
index 0000000..46fb117
--- /dev/null
+++ b/billing-finance-core/src/database/prisma.schema
@@ -0,0 +1,2 @@
+// Source of truth for database schema is /prisma/schema.prisma
+// This file documents the required structure inside src/database.
diff --git a/billing-finance-core/src/lib/env.ts b/billing-finance-core/src/lib/env.ts
new file mode 100644
index 0000000..0f87600
--- /dev/null
+++ b/billing-finance-core/src/lib/env.ts
@@ -0,0 +1,15 @@
+import * as dotenv from 'dotenv';
+
+dotenv.config();
+
+export const env = {
+  nodeEnv: process.env.NODE_ENV ?? 'development',
+  port: Number(process.env.PORT ?? 3000),
+  databaseUrl: process.env.DATABASE_URL ?? '',
+  jwtSecret: process.env.JWT_SECRET ?? '',
+  jwtPublicKey: process.env.JWT_PUBLIC_KEY ?? '',
+  jwtIssuer: process.env.JWT_ISSUER ?? 'identity-gateway',
+  webhookSecret: process.env.PAYMENT_WEBHOOK_SECRET ?? '',
+  stripeApiKey: process.env.STRIPE_API_KEY ?? '',
+  appLogLevel: process.env.APP_LOG_LEVEL ?? 'info',
+};
diff --git a/billing-finance-core/src/lib/logger.ts b/billing-finance-core/src/lib/logger.ts
new file mode 100644
index 0000000..0598917
--- /dev/null
+++ b/billing-finance-core/src/lib/logger.ts
@@ -0,0 +1,3 @@
+import { Logger } from '@nestjs/common';
+
+export const appLogger = new Logger('billing-finance-core');
diff --git a/billing-finance-core/src/lib/postgres.ts b/billing-finance-core/src/lib/postgres.ts
new file mode 100644
index 0000000..623d5e0
--- /dev/null
+++ b/billing-finance-core/src/lib/postgres.ts
@@ -0,0 +1,13 @@
+import { Injectable, OnModuleDestroy, OnModuleInit } from '@nestjs/common';
+import { PrismaClient } from '@prisma/client';
+
+@Injectable()
+export class PrismaService extends PrismaClient implements OnModuleInit, OnModuleDestroy {
+  async onModuleInit() {
+    await this.$connect();
+  }
+
+  async onModuleDestroy() {
+    await this.$disconnect();
+  }
+}
diff --git a/billing-finance-core/src/main.ts b/billing-finance-core/src/main.ts
new file mode 100644
index 0000000..19fb8b7
--- /dev/null
+++ b/billing-finance-core/src/main.ts
@@ -0,0 +1,15 @@
+import 'reflect-metadata';
+import { NestFactory } from '@nestjs/core';
+import { ValidationPipe } from '@nestjs/common';
+import { AppModule } from './app.module';
+import { env } from './lib/env';
+import { appLogger } from './lib/logger';
+
+async function bootstrap() {
+  const app = await NestFactory.create(AppModule, { logger: appLogger });
+  app.useGlobalPipes(new ValidationPipe({ whitelist: true, transform: true }));
+  await app.listen(env.port);
+  appLogger.log(`billing-finance-core running on port ${env.port}`);
+}
+
+bootstrap();
diff --git a/billing-finance-core/src/modules/crm/company.entity.ts b/billing-finance-core/src/modules/crm/company.entity.ts
new file mode 100644
index 0000000..481a070
--- /dev/null
+++ b/billing-finance-core/src/modules/crm/company.entity.ts
@@ -0,0 +1,9 @@
+export class CompanyEntity {
+  id: string;
+  tenantId: string;
+  name: string;
+  segment?: string;
+  website?: string;
+  createdAt: Date;
+  updatedAt: Date;
+}
diff --git a/billing-finance-core/src/modules/crm/contact.entity.ts b/billing-finance-core/src/modules/crm/contact.entity.ts
new file mode 100644
index 0000000..f235567
--- /dev/null
+++ b/billing-finance-core/src/modules/crm/contact.entity.ts
@@ -0,0 +1,10 @@
+export class ContactEntity {
+  id: string;
+  tenantId: string;
+  companyId?: string;
+  name: string;
+  email?: string;
+  phone?: string;
+  createdAt: Date;
+  updatedAt: Date;
+}
diff --git a/billing-finance-core/src/modules/crm/crm.controller.ts b/billing-finance-core/src/modules/crm/crm.controller.ts
new file mode 100644
index 0000000..7629f5c
--- /dev/null
+++ b/billing-finance-core/src/modules/crm/crm.controller.ts
@@ -0,0 +1,93 @@
+import { Body, Controller, Get, Post, Req } from '@nestjs/common';
+import { IsDateString, IsEnum, IsInt, IsOptional, IsString, Min } from 'class-validator';
+import { Request } from 'express';
+import { DealStage } from '../../core/enums';
+import { getTenantContext } from '../../core/tenant.context';
+import { CrmService } from './crm.service';
+
+class CreateCompanyDto {
+  @IsString()
+  name: string;
+
+  @IsOptional()
+  @IsString()
+  segment?: string;
+
+  @IsOptional()
+  @IsString()
+  website?: string;
+}
+
+class CreateContactDto {
+  @IsString()
+  name: string;
+
+  @IsOptional()
+  @IsString()
+  companyId?: string;
+
+  @IsOptional()
+  @IsString()
+  email?: string;
+
+  @IsOptional()
+  @IsString()
+  phone?: string;
+}
+
+class CreateDealDto {
+  @IsString()
+  name: string;
+
+  @IsOptional()
+  @IsString()
+  companyId?: string;
+
+  @IsOptional()
+  @IsEnum(DealStage)
+  stage?: DealStage;
+
+  @IsInt()
+  @Min(0)
+  valueCents: number;
+
+  @IsOptional()
+  @IsDateString()
+  expectedAt?: string;
+}
+
+@Controller('crm')
+export class CrmController {
+  constructor(private readonly crmService: CrmService) {}
+
+  @Get('companies')
+  listCompanies(@Req() req: Request) {
+    const { tenantId } = getTenantContext(req);
+    return this.crmService.listCompanies(tenantId);
+  }
+
+  @Post('companies')
+  createCompany(@Req() req: Request, @Body() body: CreateCompanyDto) {
+    const { tenantId } = getTenantContext(req);
+    return this.crmService.createCompany({ tenantId, ...body });
+  }
+
+  @Post('contacts')
+  createContact(@Req() req: Request, @Body() body: CreateContactDto) {
+    const { tenantId } = getTenantContext(req);
+    return this.crmService.createContact({ tenantId, ...body });
+  }
+
+  @Post('deals')
+  createDeal(@Req() req: Request, @Body() body: CreateDealDto) {
+    const { tenantId } = getTenantContext(req);
+    return this.crmService.createDeal({
+      tenantId,
+      companyId: body.companyId,
+      name: body.name,
+      stage: body.stage,
+      valueCents: body.valueCents,
+      expectedAt: body.expectedAt ? new Date(body.expectedAt) : undefined,
+    });
+  }
+}
diff --git a/billing-finance-core/src/modules/crm/crm.module.ts b/billing-finance-core/src/modules/crm/crm.module.ts
new file mode 100644
index 0000000..8400f46
--- /dev/null
+++ b/billing-finance-core/src/modules/crm/crm.module.ts
@@ -0,0 +1,11 @@
+import { Module } from '@nestjs/common';
+import { CrmController } from './crm.controller';
+import { CrmService } from './crm.service';
+import { PrismaService } from '../../lib/postgres';
+
+@Module({
+  controllers: [CrmController],
+  providers: [CrmService, PrismaService],
+  exports: [CrmService],
+})
+export class CrmModule {}
diff --git a/billing-finance-core/src/modules/crm/crm.service.ts b/billing-finance-core/src/modules/crm/crm.service.ts
new file mode 100644
index 0000000..0437638
--- /dev/null
+++ b/billing-finance-core/src/modules/crm/crm.service.ts
@@ -0,0 +1,60 @@
+import { Injectable } from '@nestjs/common';
+import { DealStage } from '../../core/enums';
+import { PrismaService } from '../../lib/postgres';
+
+interface CreateCompanyInput {
+  tenantId: string;
+  name: string;
+  segment?: string;
+  website?: string;
+}
+
+interface CreateContactInput {
+  tenantId: string;
+  companyId?: string;
+  name: string;
+  email?: string;
+  phone?: string;
+}
+
+interface CreateDealInput {
+  tenantId: string;
+  companyId?: string;
+  name: string;
+  stage?: DealStage;
+  valueCents: number;
+  expectedAt?: Date;
+}
+
+@Injectable()
+export class CrmService {
+  constructor(private readonly prisma: PrismaService) {}
+
+  createCompany(data: CreateCompanyInput) {
+    return this.prisma.crmCompany.create({ data });
+  }
+
+  listCompanies(tenantId: string) {
+    return this.prisma.crmCompany.findMany({
+      where: { tenantId },
+      orderBy: { createdAt: 'desc' },
+    });
+  }
+
+  createContact(data: CreateContactInput) {
+    return this.prisma.crmContact.create({ data });
+  }
+
+  createDeal(data: CreateDealInput) {
+    return this.prisma.crmDeal.create({
+      data: {
+        tenantId: data.tenantId,
+        companyId: data.companyId,
+        name: data.name,
+        stage: data.stage ?? DealStage.LEAD,
+        valueCents: data.valueCents,
+        expectedAt: data.expectedAt,
+      },
+    });
+  }
+}
diff --git a/billing-finance-core/src/modules/crm/deal.entity.ts b/billing-finance-core/src/modules/crm/deal.entity.ts
new file mode 100644
index 0000000..29f8e4f
--- /dev/null
+++ b/billing-finance-core/src/modules/crm/deal.entity.ts
@@ -0,0 +1,13 @@
+import { DealStage } from '../../core/enums';
+
+export class DealEntity {
+  id: string;
+  tenantId: string;
+  companyId?: string;
+  name: string;
+  stage: DealStage;
+  valueCents: number;
+  expectedAt?: Date;
+  createdAt: Date;
+  updatedAt: Date;
+}
diff --git a/billing-finance-core/src/modules/fiscal/fiscal.entity.ts b/billing-finance-core/src/modules/fiscal/fiscal.entity.ts
new file mode 100644
index 0000000..4056344
--- /dev/null
+++ b/billing-finance-core/src/modules/fiscal/fiscal.entity.ts
@@ -0,0 +1,13 @@
+import { FiscalStatus } from '../../core/enums';
+
+export class FiscalEntity {
+  id: string;
+  tenantId: string;
+  invoiceId?: string;
+  number?: string;
+  status: FiscalStatus;
+  pdfUrl?: string;
+  xmlUrl?: string;
+  createdAt: Date;
+  updatedAt: Date;
+}
diff --git a/billing-finance-core/src/modules/fiscal/fiscal.module.ts b/billing-finance-core/src/modules/fiscal/fiscal.module.ts
new file mode 100644
index 0000000..1e20ccf
--- /dev/null
+++ b/billing-finance-core/src/modules/fiscal/fiscal.module.ts
@@ -0,0 +1,9 @@
+import { Module } from '@nestjs/common';
+import { FiscalService } from './fiscal.service';
+import { PrismaService } from '../../lib/postgres';
+
+@Module({
+  providers: [FiscalService, PrismaService],
+  exports: [FiscalService],
+})
+export class FiscalModule {}
diff --git a/billing-finance-core/src/modules/fiscal/fiscal.service.ts b/billing-finance-core/src/modules/fiscal/fiscal.service.ts
new file mode 100644
index 0000000..1c44787
--- /dev/null
+++ b/billing-finance-core/src/modules/fiscal/fiscal.service.ts
@@ -0,0 +1,37 @@
+import { Injectable } from '@nestjs/common';
+import { FiscalStatus } from '../../core/enums';
+import { PrismaService } from '../../lib/postgres';
+
+interface CreateFiscalInput {
+  tenantId: string;
+  invoiceId?: string;
+  number?: string;
+  status?: FiscalStatus;
+  pdfUrl?: string;
+  xmlUrl?: string;
+}
+
+@Injectable()
+export class FiscalService {
+  constructor(private readonly prisma: PrismaService) {}
+
+  create(data: CreateFiscalInput) {
+    return this.prisma.fiscalDocument.create({
+      data: {
+        tenantId: data.tenantId,
+        invoiceId: data.invoiceId,
+        number: data.number,
+        status: data.status ?? FiscalStatus.DRAFT,
+        pdfUrl: data.pdfUrl,
+        xmlUrl: data.xmlUrl,
+      },
+    });
+  }
+
+  list(tenantId: string) {
+    return this.prisma.fiscalDocument.findMany({
+      where: { tenantId },
+      orderBy: { createdAt: 'desc' },
+    });
+  }
+}
diff --git a/billing-finance-core/src/modules/invoices/invoice.controller.ts b/billing-finance-core/src/modules/invoices/invoice.controller.ts
new file mode 100644
index 0000000..a36711d
--- /dev/null
+++ b/billing-finance-core/src/modules/invoices/invoice.controller.ts
@@ -0,0 +1,46 @@
+import { Body, Controller, Get, Post, Req } from '@nestjs/common';
+import { IsDateString, IsEnum, IsInt, IsOptional, IsString, Min } from 'class-validator';
+import { Request } from 'express';
+import { InvoiceStatus } from '../../core/enums';
+import { getTenantContext } from '../../core/tenant.context';
+import { InvoiceService } from './invoice.service';
+
+class CreateInvoiceDto {
+  @IsOptional()
+  @IsString()
+  subscriptionId?: string;
+
+  @IsInt()
+  @Min(1)
+  amountCents: number;
+
+  @IsDateString()
+  dueDate: string;
+
+  @IsOptional()
+  @IsEnum(InvoiceStatus)
+  status?: InvoiceStatus;
+}
+
+@Controller('invoices')
+export class InvoiceController {
+  constructor(private readonly invoiceService: InvoiceService) {}
+
+  @Post()
+  create(@Req() req: Request, @Body() body: CreateInvoiceDto) {
+    const { tenantId } = getTenantContext(req);
+    return this.invoiceService.create({
+      tenantId,
+      subscriptionId: body.subscriptionId,
+      amountCents: body.amountCents,
+      dueDate: new Date(body.dueDate),
+      status: body.status,
+    });
+  }
+
+  @Get()
+  list(@Req() req: Request) {
+    const { tenantId } = getTenantContext(req);
+    return this.invoiceService.list(tenantId);
+  }
+}
diff --git a/billing-finance-core/src/modules/invoices/invoice.entity.ts b/billing-finance-core/src/modules/invoices/invoice.entity.ts
new file mode 100644
index 0000000..708e0fa
--- /dev/null
+++ b/billing-finance-core/src/modules/invoices/invoice.entity.ts
@@ -0,0 +1,13 @@
+import { InvoiceStatus } from '../../core/enums';
+
+export class InvoiceEntity {
+  id: string;
+  tenantId: string;
+  subscriptionId?: string;
+  amountCents: number;
+  dueDate: Date;
+  status: InvoiceStatus;
+  paidAt?: Date;
+  createdAt: Date;
+  updatedAt: Date;
+}
diff --git a/billing-finance-core/src/modules/invoices/invoice.module.ts b/billing-finance-core/src/modules/invoices/invoice.module.ts
new file mode 100644
index 0000000..7095377
--- /dev/null
+++ b/billing-finance-core/src/modules/invoices/invoice.module.ts
@@ -0,0 +1,11 @@
+import { Module } from '@nestjs/common';
+import { InvoiceController } from './invoice.controller';
+import { InvoiceService } from './invoice.service';
+import { PrismaService } from '../../lib/postgres';
+
+@Module({
+  controllers: [InvoiceController],
+  providers: [InvoiceService, PrismaService],
+  exports: [InvoiceService],
+})
+export class InvoiceModule {}
diff --git a/billing-finance-core/src/modules/invoices/invoice.service.ts b/billing-finance-core/src/modules/invoices/invoice.service.ts
new file mode 100644
index 0000000..306ca81
--- /dev/null
+++ b/billing-finance-core/src/modules/invoices/invoice.service.ts
@@ -0,0 +1,36 @@
+import { Injectable } from '@nestjs/common';
+import { InvoiceStatus } from '../../core/enums';
+import { PrismaService } from '../../lib/postgres';
+
+interface CreateInvoiceInput {
+  tenantId: string;
+  subscriptionId?: string;
+  amountCents: number;
+  dueDate: Date;
+  status?: InvoiceStatus;
+}
+
+@Injectable()
+export class InvoiceService {
+  constructor(private readonly prisma: PrismaService) {}
+
+  create(data: CreateInvoiceInput) {
+    return this.prisma.invoice.create({
+      data: {
+        tenantId: data.tenantId,
+        subscriptionId: data.subscriptionId,
+        amountCents: data.amountCents,
+        dueDate: data.dueDate,
+        status: data.status ?? InvoiceStatus.PENDING,
+      },
+    });
+  }
+
+  list(tenantId: string) {
+    return this.prisma.invoice.findMany({
+      where: { tenantId },
+      include: { payments: true },
+      orderBy: { createdAt: 'desc' },
+    });
+  }
+}
diff --git a/billing-finance-core/src/modules/payments/gateways/boleto.gateway.ts b/billing-finance-core/src/modules/payments/gateways/boleto.gateway.ts
new file mode 100644
index 0000000..6f874e4
--- /dev/null
+++ b/billing-finance-core/src/modules/payments/gateways/boleto.gateway.ts
@@ -0,0 +1,30 @@
+import { randomUUID } from 'crypto';
+import { Invoice, Payment } from '@prisma/client';
+import { PaymentStatus } from '../../../core/enums';
+import { PaymentGateway, PaymentGatewayResult, PaymentWebhookResult } from './gateway.interface';
+
+export class BoletoGateway implements PaymentGateway {
+  name = 'boleto';
+
+  async createPayment(invoice: Invoice): Promise<PaymentGatewayResult> {
+    const externalId = `boleto_${randomUUID()}`;
+    return {
+      externalId,
+      status: PaymentStatus.PENDING,
+      metadata: {
+        barcode: `34191.79001 ${externalId.slice(0, 8)}`,
+      },
+    };
+  }
+
+  async handleWebhook(payload: any): Promise<PaymentWebhookResult> {
+    return {
+      externalId: payload?.externalId ?? '',
+      status: payload?.status ?? PaymentStatus.CONFIRMED,
+    };
+  }
+
+  async reconcile(payment: Payment): Promise<PaymentStatus> {
+    return payment.status;
+  }
+}
diff --git a/billing-finance-core/src/modules/payments/gateways/card.gateway.ts b/billing-finance-core/src/modules/payments/gateways/card.gateway.ts
new file mode 100644
index 0000000..6bd3550
--- /dev/null
+++ b/billing-finance-core/src/modules/payments/gateways/card.gateway.ts
@@ -0,0 +1,59 @@
+import { randomUUID } from 'crypto';
+import { Invoice, Payment } from '@prisma/client';
+import { PaymentStatus } from '../../../core/enums';
+import { env } from '../../../lib/env';
+import { appLogger } from '../../../lib/logger';
+import { PaymentGateway, PaymentGatewayResult, PaymentWebhookResult } from './gateway.interface';
+
+export class CardGateway implements PaymentGateway {
+  name = 'card';
+
+  async createPayment(invoice: Invoice): Promise<PaymentGatewayResult> {
+    if (!env.stripeApiKey) {
+      const externalId = `card_${randomUUID()}`;
+      return {
+        externalId,
+        status: PaymentStatus.PENDING,
+        metadata: { provider: 'mock' },
+      };
+    }
+
+    const response = await fetch('https://api.stripe.com/v1/payment_intents', {
+      method: 'POST',
+      headers: {
+        Authorization: `Bearer ${env.stripeApiKey}`,
+        'Content-Type': 'application/x-www-form-urlencoded',
+      },
+      body: new URLSearchParams({
+        amount: invoice.amountCents.toString(),
+        currency: 'brl',
+        'metadata[invoiceId]': invoice.id,
+      }),
+    });
+
+    if (!response.ok) {
+      const errorText = await response.text();
+      appLogger.error(`Stripe error: ${errorText}`);
+      return {
+        status: PaymentStatus.FAILED,
+      };
+    }
+
+    const payload = (await response.json()) as { id: string };
+    return {
+      externalId: payload.id,
+      status: PaymentStatus.PENDING,
+    };
+  }
+
+  async handleWebhook(payload: any): Promise<PaymentWebhookResult> {
+    return {
+      externalId: payload?.data?.object?.id ?? payload?.externalId ?? '',
+      status: payload?.status ?? PaymentStatus.CONFIRMED,
+    };
+  }
+
+  async reconcile(payment: Payment): Promise<PaymentStatus> {
+    return payment.status;
+  }
+}
diff --git a/billing-finance-core/src/modules/payments/gateways/gateway.interface.ts b/billing-finance-core/src/modules/payments/gateways/gateway.interface.ts
new file mode 100644
index 0000000..193a61e
--- /dev/null
+++ b/billing-finance-core/src/modules/payments/gateways/gateway.interface.ts
@@ -0,0 +1,22 @@
+import { Invoice, Payment } from '@prisma/client';
+import { PaymentStatus } from '../../../core/enums';
+
+export interface PaymentGatewayResult {
+  externalId?: string;
+  status: PaymentStatus;
+  redirectUrl?: string;
+  qrCode?: string;
+  metadata?: Record<string, unknown>;
+}
+
+export interface PaymentWebhookResult {
+  externalId: string;
+  status: PaymentStatus;
+}
+
+export interface PaymentGateway {
+  name: string;
+  createPayment(invoice: Invoice): Promise<PaymentGatewayResult>;
+  handleWebhook(payload: unknown, signature?: string): Promise<PaymentWebhookResult>;
+  reconcile(payment: Payment): Promise<PaymentStatus>;
+}
diff --git a/billing-finance-core/src/modules/payments/gateways/pix.gateway.ts b/billing-finance-core/src/modules/payments/gateways/pix.gateway.ts
new file mode 100644
index 0000000..8f5273a
--- /dev/null
+++ b/billing-finance-core/src/modules/payments/gateways/pix.gateway.ts
@@ -0,0 +1,28 @@
+import { randomUUID } from 'crypto';
+import { Invoice, Payment } from '@prisma/client';
+import { PaymentStatus } from '../../../core/enums';
+import { PaymentGateway, PaymentGatewayResult, PaymentWebhookResult } from './gateway.interface';
+
+export class PixGateway implements PaymentGateway {
+  name = 'pix';
+
+  async createPayment(invoice: Invoice): Promise<PaymentGatewayResult> {
+    const externalId = `pix_${randomUUID()}`;
+    return {
+      externalId,
+      status: PaymentStatus.PENDING,
+      qrCode: `PIX-QRCODE-${externalId}`,
+    };
+  }
+
+  async handleWebhook(payload: any): Promise<PaymentWebhookResult> {
+    return {
+      externalId: payload?.externalId ?? '',
+      status: payload?.status ?? PaymentStatus.CONFIRMED,
+    };
+  }
+
+  async reconcile(payment: Payment): Promise<PaymentStatus> {
+    return payment.status;
+  }
+}
diff --git a/billing-finance-core/src/modules/payments/payment.controller.ts b/billing-finance-core/src/modules/payments/payment.controller.ts
new file mode 100644
index 0000000..19fdd04
--- /dev/null
+++ b/billing-finance-core/src/modules/payments/payment.controller.ts
@@ -0,0 +1,39 @@
+import { Body, Controller, Param, Post, Req } from '@nestjs/common';
+import { IsEnum, IsString } from 'class-validator';
+import { Request } from 'express';
+import { getTenantContext } from '../../core/tenant.context';
+import { PaymentService } from './payment.service';
+
+enum PaymentMethod {
+  PIX = 'pix',
+  BOLETO = 'boleto',
+  CARD = 'card',
+}
+
+class CreatePaymentDto {
+  @IsEnum(PaymentMethod)
+  method: PaymentMethod;
+
+  @IsString()
+  gateway: string;
+}
+
+@Controller('payments')
+export class PaymentController {
+  constructor(private readonly paymentService: PaymentService) {}
+
+  @Post(':invoiceId')
+  create(
+    @Req() req: Request,
+    @Param('invoiceId') invoiceId: string,
+    @Body() body: CreatePaymentDto,
+  ) {
+    const { tenantId } = getTenantContext(req);
+    return this.paymentService.createPayment({
+      tenantId,
+      invoiceId,
+      method: body.method,
+      gateway: body.gateway,
+    });
+  }
+}
diff --git a/billing-finance-core/src/modules/payments/payment.entity.ts b/billing-finance-core/src/modules/payments/payment.entity.ts
new file mode 100644
index 0000000..126d6d3
--- /dev/null
+++ b/billing-finance-core/src/modules/payments/payment.entity.ts
@@ -0,0 +1,14 @@
+import { PaymentStatus } from '../../core/enums';
+
+export class PaymentEntity {
+  id: string;
+  tenantId: string;
+  invoiceId: string;
+  gateway: string;
+  method: string;
+  externalId?: string;
+  status: PaymentStatus;
+  amountCents: number;
+  createdAt: Date;
+  updatedAt: Date;
+}
diff --git a/billing-finance-core/src/modules/payments/payment.module.ts b/billing-finance-core/src/modules/payments/payment.module.ts
new file mode 100644
index 0000000..5ee4890
--- /dev/null
+++ b/billing-finance-core/src/modules/payments/payment.module.ts
@@ -0,0 +1,11 @@
+import { Module } from '@nestjs/common';
+import { PaymentController } from './payment.controller';
+import { PaymentService } from './payment.service';
+import { PrismaService } from '../../lib/postgres';
+
+@Module({
+  controllers: [PaymentController],
+  providers: [PaymentService, PrismaService],
+  exports: [PaymentService],
+})
+export class PaymentModule {}
diff --git a/billing-finance-core/src/modules/payments/payment.service.ts b/billing-finance-core/src/modules/payments/payment.service.ts
new file mode 100644
index 0000000..5853b5c
--- /dev/null
+++ b/billing-finance-core/src/modules/payments/payment.service.ts
@@ -0,0 +1,82 @@
+import { Injectable, NotFoundException } from '@nestjs/common';
+import { PrismaService } from '../../lib/postgres';
+import { PaymentStatus } from '../../core/enums';
+import { PaymentGateway } from './gateways/gateway.interface';
+import { PixGateway } from './gateways/pix.gateway';
+import { BoletoGateway } from './gateways/boleto.gateway';
+import { CardGateway } from './gateways/card.gateway';
+
+interface CreatePaymentInput {
+  tenantId: string;
+  invoiceId: string;
+  method: string;
+  gateway: string;
+}
+
+@Injectable()
+export class PaymentService {
+  private readonly gateways: Record<string, PaymentGateway>;
+
+  constructor(private readonly prisma: PrismaService) {
+    const available = [new PixGateway(), new BoletoGateway(), new CardGateway()];
+    this.gateways = available.reduce((acc, gateway) => {
+      acc[gateway.name] = gateway;
+      return acc;
+    }, {} as Record<string, PaymentGateway>);
+  }
+
+  private getGateway(name: string): PaymentGateway {
+    const gateway = this.gateways[name];
+    if (!gateway) {
+      throw new NotFoundException(`Gateway ${name} not supported`);
+    }
+    return gateway;
+  }
+
+  async createPayment(data: CreatePaymentInput) {
+    const invoice = await this.prisma.invoice.findFirst({
+      where: { id: data.invoiceId, tenantId: data.tenantId },
+    });
+
+    if (!invoice) {
+      throw new NotFoundException('Invoice not found');
+    }
+
+    const gateway = this.getGateway(data.gateway);
+    const gatewayResult = await gateway.createPayment(invoice);
+
+    return this.prisma.payment.create({
+      data: {
+        tenantId: data.tenantId,
+        invoiceId: invoice.id,
+        gateway: gateway.name,
+        method: data.method,
+        externalId: gatewayResult.externalId,
+        status: gatewayResult.status ?? PaymentStatus.PENDING,
+        amountCents: invoice.amountCents,
+      },
+    });
+  }
+
+  async reconcileByWebhook(gatewayName: string, payload: unknown) {
+    const gateway = this.getGateway(gatewayName);
+    const webhook = await gateway.handleWebhook(payload);
+
+    const existing = await this.prisma.payment.findFirst({
+      where: { gateway: gatewayName, externalId: webhook.externalId },
+    });
+
+    if (!existing) {
+      return { ignored: true, reason: 'payment-not-found' };
+    }
+
+    if (existing.status === webhook.status) {
+      return existing;
+    }
+
+    return this.prisma.payment.update({
+      where: { id: existing.id },
+      data: { status: webhook.status },
+    });
+  }
+}
diff --git a/billing-finance-core/src/modules/plans/plan.controller.ts b/billing-finance-core/src/modules/plans/plan.controller.ts
new file mode 100644
index 0000000..97273e6
--- /dev/null
+++ b/billing-finance-core/src/modules/plans/plan.controller.ts
@@ -0,0 +1,39 @@
+import { Body, Controller, Get, Post } from '@nestjs/common';
+import { IsEnum, IsInt, IsOptional, IsString, Min } from 'class-validator';
+import { BillingCycle } from '../../core/enums';
+import { PlanService } from './plan.service';
+
+class CreatePlanDto {
+  @IsString()
+  name: string;
+
+  @IsInt()
+  @Min(0)
+  priceCents: number;
+
+  @IsEnum(BillingCycle)
+  billingCycle: BillingCycle;
+
+  @IsOptional()
+  @IsInt()
+  softLimit?: number;
+
+  @IsOptional()
+  @IsInt()
+  hardLimit?: number;
+}
+
+@Controller('plans')
+export class PlanController {
+  constructor(private readonly planService: PlanService) {}
+
+  @Post()
+  create(@Body() body: CreatePlanDto) {
+    return this.planService.create(body);
+  }
+
+  @Get()
+  list() {
+    return this.planService.list();
+  }
+}
diff --git a/billing-finance-core/src/modules/plans/plan.entity.ts b/billing-finance-core/src/modules/plans/plan.entity.ts
new file mode 100644
index 0000000..82fdcea
--- /dev/null
+++ b/billing-finance-core/src/modules/plans/plan.entity.ts
@@ -0,0 +1,12 @@
+import { BillingCycle } from '../../core/enums';
+
+export class PlanEntity {
+  id: string;
+  name: string;
+  priceCents: number;
+  billingCycle: BillingCycle;
+  softLimit?: number;
+  hardLimit?: number;
+  createdAt: Date;
+  updatedAt: Date;
+}
diff --git a/billing-finance-core/src/modules/plans/plan.module.ts b/billing-finance-core/src/modules/plans/plan.module.ts
new file mode 100644
index 0000000..5dfb920
--- /dev/null
+++ b/billing-finance-core/src/modules/plans/plan.module.ts
@@ -0,0 +1,11 @@
+import { Module } from '@nestjs/common';
+import { PlanController } from './plan.controller';
+import { PlanService } from './plan.service';
+import { PrismaService } from '../../lib/postgres';
+
+@Module({
+  controllers: [PlanController],
+  providers: [PlanService, PrismaService],
+  exports: [PlanService],
+})
+export class PlanModule {}
diff --git a/billing-finance-core/src/modules/plans/plan.service.ts b/billing-finance-core/src/modules/plans/plan.service.ts
new file mode 100644
index 0000000..26b84c4
--- /dev/null
+++ b/billing-finance-core/src/modules/plans/plan.service.ts
@@ -0,0 +1,24 @@
+import { Injectable } from '@nestjs/common';
+import { BillingCycle } from '../../core/enums';
+import { PrismaService } from '../../lib/postgres';
+
+interface CreatePlanInput {
+  name: string;
+  priceCents: number;
+  billingCycle: BillingCycle;
+  softLimit?: number;
+  hardLimit?: number;
+}
+
+@Injectable()
+export class PlanService {
+  constructor(private readonly prisma: PrismaService) {}
+
+  create(data: CreatePlanInput) {
+    return this.prisma.plan.create({ data });
+  }
+
+  list() {
+    return this.prisma.plan.findMany({ orderBy: { createdAt: 'desc' } });
+  }
+}
diff --git a/billing-finance-core/src/modules/subscriptions/subscription.controller.ts b/billing-finance-core/src/modules/subscriptions/subscription.controller.ts
new file mode 100644
index 0000000..944ca61
--- /dev/null
+++ b/billing-finance-core/src/modules/subscriptions/subscription.controller.ts
@@ -0,0 +1,44 @@
+import { Body, Controller, Get, Post, Req } from '@nestjs/common';
+import { IsDateString, IsEnum, IsOptional, IsString } from 'class-validator';
+import { Request } from 'express';
+import { SubscriptionStatus } from '../../core/enums';
+import { getTenantContext } from '../../core/tenant.context';
+import { SubscriptionService } from './subscription.service';
+
+class CreateSubscriptionDto {
+  @IsString()
+  planId: string;
+
+  @IsDateString()
+  startDate: string;
+
+  @IsDateString()
+  nextDueDate: string;
+
+  @IsOptional()
+  @IsEnum(SubscriptionStatus)
+  status?: SubscriptionStatus;
+}
+
+@Controller('subscriptions')
+export class SubscriptionController {
+  constructor(private readonly subscriptionService: SubscriptionService) {}
+
+  @Post()
+  create(@Req() req: Request, @Body() body: CreateSubscriptionDto) {
+    const { tenantId } = getTenantContext(req);
+    return this.subscriptionService.create({
+      tenantId,
+      planId: body.planId,
+      startDate: new Date(body.startDate),
+      nextDueDate: new Date(body.nextDueDate),
+      status: body.status,
+    });
+  }
+
+  @Get()
+  list(@Req() req: Request) {
+    const { tenantId } = getTenantContext(req);
+    return this.subscriptionService.list(tenantId);
+  }
+}
diff --git a/billing-finance-core/src/modules/subscriptions/subscription.entity.ts b/billing-finance-core/src/modules/subscriptions/subscription.entity.ts
new file mode 100644
index 0000000..0dc88a1
--- /dev/null
+++ b/billing-finance-core/src/modules/subscriptions/subscription.entity.ts
@@ -0,0 +1,12 @@
+import { SubscriptionStatus } from '../../core/enums';
+
+export class SubscriptionEntity {
+  id: string;
+  tenantId: string;
+  planId: string;
+  status: SubscriptionStatus;
+  startDate: Date;
+  nextDueDate: Date;
+  createdAt: Date;
+  updatedAt: Date;
+}
diff --git a/billing-finance-core/src/modules/subscriptions/subscription.module.ts b/billing-finance-core/src/modules/subscriptions/subscription.module.ts
new file mode 100644
index 0000000..9a6d0eb
--- /dev/null
+++ b/billing-finance-core/src/modules/subscriptions/subscription.module.ts
@@ -0,0 +1,11 @@
+import { Module } from '@nestjs/common';
+import { SubscriptionController } from './subscription.controller';
+import { SubscriptionService } from './subscription.service';
+import { PrismaService } from '../../lib/postgres';
+
+@Module({
+  controllers: [SubscriptionController],
+  providers: [SubscriptionService, PrismaService],
+  exports: [SubscriptionService],
+})
+export class SubscriptionModule {}
diff --git a/billing-finance-core/src/modules/subscriptions/subscription.service.ts b/billing-finance-core/src/modules/subscriptions/subscription.service.ts
new file mode 100644
index 0000000..4be69f0
--- /dev/null
+++ b/billing-finance-core/src/modules/subscriptions/subscription.service.ts
@@ -0,0 +1,36 @@
+import { Injectable } from '@nestjs/common';
+import { SubscriptionStatus } from '../../core/enums';
+import { PrismaService } from '../../lib/postgres';
+
+interface CreateSubscriptionInput {
+  tenantId: string;
+  planId: string;
+  startDate: Date;
+  nextDueDate: Date;
+  status?: SubscriptionStatus;
+}
+
+@Injectable()
+export class SubscriptionService {
+  constructor(private readonly prisma: PrismaService) {}
+
+  create(data: CreateSubscriptionInput) {
+    return this.prisma.subscription.create({
+      data: {
+        tenantId: data.tenantId,
+        planId: data.planId,
+        startDate: data.startDate,
+        nextDueDate: data.nextDueDate,
+        status: data.status ?? SubscriptionStatus.ACTIVE,
+      },
+    });
+  }
+
+  list(tenantId: string) {
+    return this.prisma.subscription.findMany({
+      where: { tenantId },
+      include: { plan: true },
+      orderBy: { createdAt: 'desc' },
+    });
+  }
+}
diff --git a/billing-finance-core/src/modules/tenants/tenant.controller.ts b/billing-finance-core/src/modules/tenants/tenant.controller.ts
new file mode 100644
index 0000000..9474ecd
--- /dev/null
+++ b/billing-finance-core/src/modules/tenants/tenant.controller.ts
@@ -0,0 +1,31 @@
+import { Body, Controller, Get, Post } from '@nestjs/common';
+import { IsOptional, IsString } from 'class-validator';
+import { TenantService } from './tenant.service';
+
+class CreateTenantDto {
+  @IsString()
+  name: string;
+
+  @IsOptional()
+  @IsString()
+  taxId?: string;
+
+  @IsOptional()
+  @IsString()
+  status?: string;
+}
+
+@Controller('tenants')
+export class TenantController {
+  constructor(private readonly tenantService: TenantService) {}
+
+  @Post()
+  create(@Body() body: CreateTenantDto) {
+    return this.tenantService.create(body);
+  }
+
+  @Get()
+  list() {
+    return this.tenantService.list();
+  }
+}
diff --git a/billing-finance-core/src/modules/tenants/tenant.entity.ts b/billing-finance-core/src/modules/tenants/tenant.entity.ts
new file mode 100644
index 0000000..1ee4bb5
--- /dev/null
+++ b/billing-finance-core/src/modules/tenants/tenant.entity.ts
@@ -0,0 +1,8 @@
+export class TenantEntity {
+  id: string;
+  name: string;
+  taxId?: string;
+  status: string;
+  createdAt: Date;
+  updatedAt: Date;
+}
diff --git a/billing-finance-core/src/modules/tenants/tenant.module.ts b/billing-finance-core/src/modules/tenants/tenant.module.ts
new file mode 100644
index 0000000..eb1e370
--- /dev/null
+++ b/billing-finance-core/src/modules/tenants/tenant.module.ts
@@ -0,0 +1,11 @@
+import { Module } from '@nestjs/common';
+import { TenantController } from './tenant.controller';
+import { TenantService } from './tenant.service';
+import { PrismaService } from '../../lib/postgres';
+
+@Module({
+  controllers: [TenantController],
+  providers: [TenantService, PrismaService],
+  exports: [TenantService],
+})
+export class TenantModule {}
diff --git a/billing-finance-core/src/modules/tenants/tenant.service.ts b/billing-finance-core/src/modules/tenants/tenant.service.ts
new file mode 100644
index 0000000..3f94802
--- /dev/null
+++ b/billing-finance-core/src/modules/tenants/tenant.service.ts
@@ -0,0 +1,29 @@
+import { Injectable } from '@nestjs/common';
+import { PrismaService } from '../../lib/postgres';
+
+interface CreateTenantInput {
+  name: string;
+  taxId?: string;
+  status?: string;
+}
+
+@Injectable()
+export class TenantService {
+  constructor(private readonly prisma: PrismaService) {}
+
+  create(data: CreateTenantInput) {
+    return this.prisma.tenant.create({
+      data: {
+        name: data.name,
+        taxId: data.taxId,
+        status: data.status ?? 'ACTIVE',
+      },
+    });
+  }
+
+  list() {
+    return this.prisma.tenant.findMany({
+      orderBy: { createdAt: 'desc' },
+    });
+  }
+}
diff --git a/billing-finance-core/src/modules/webhooks/webhook.controller.ts b/billing-finance-core/src/modules/webhooks/webhook.controller.ts
new file mode 100644
index 0000000..fc70198
--- /dev/null
+++ b/billing-finance-core/src/modules/webhooks/webhook.controller.ts
@@ -0,0 +1,12 @@
+import { Body, Controller, Param, Post } from '@nestjs/common';
+import { WebhookService } from './webhook.service';
+
+@Controller('webhooks')
+export class WebhookController {
+  constructor(private readonly webhookService: WebhookService) {}
+
+  @Post(':gateway')
+  handle(@Param('gateway') gateway: string, @Body() payload: unknown) {
+    return this.webhookService.handleGatewayWebhook(gateway, payload);
+  }
+}
diff --git a/billing-finance-core/src/modules/webhooks/webhook.module.ts b/billing-finance-core/src/modules/webhooks/webhook.module.ts
new file mode 100644
index 0000000..4eec987
--- /dev/null
+++ b/billing-finance-core/src/modules/webhooks/webhook.module.ts
@@ -0,0 +1,11 @@
+import { Module } from '@nestjs/common';
+import { WebhookController } from './webhook.controller';
+import { WebhookService } from './webhook.service';
+import { PaymentService } from '../payments/payment.service';
+import { PrismaService } from '../../lib/postgres';
+
+@Module({
+  controllers: [WebhookController],
+  providers: [WebhookService, PaymentService, PrismaService],
+})
+export class WebhookModule {}
diff --git a/billing-finance-core/src/modules/webhooks/webhook.service.ts b/billing-finance-core/src/modules/webhooks/webhook.service.ts
new file mode 100644
index 0000000..be2a1c5
--- /dev/null
+++ b/billing-finance-core/src/modules/webhooks/webhook.service.ts
@@ -0,0 +1,11 @@
+import { Injectable } from '@nestjs/common';
+import { PaymentService } from '../payments/payment.service';
+
+@Injectable()
+export class WebhookService {
+  constructor(private readonly paymentService: PaymentService) {}
+
+  handleGatewayWebhook(gateway: string, payload: unknown) {
+    return this.paymentService.reconcileByWebhook(gateway, payload);
+  }
+}
diff --git a/billing-finance-core/tsconfig.json b/billing-finance-core/tsconfig.json
new file mode 100644
index 0000000..cb9e902
--- /dev/null
+++ b/billing-finance-core/tsconfig.json
@@ -0,0 +1,17 @@
+{
+  "compilerOptions": {
+    "module": "commonjs",
+    "declaration": true,
+    "removeComments": true,
+    "emitDecoratorMetadata": true,
+    "experimentalDecorators": true,
+    "allowSyntheticDefaultImports": true,
+    "target": "ES2021",
+    "sourceMap": true,
+    "outDir": "./dist",
+    "baseUrl": "./",
+    "incremental": true,
+    "skipLibCheck": true
+  },
+  "include": ["src/**/*.ts"]
+}