diff --git a/apps/api/prisma/schema.prisma b/apps/api/prisma/schema.prisma
index 449dc92..5772958 100644
--- a/apps/api/prisma/schema.prisma
+++ b/apps/api/prisma/schema.prisma
@@ -19,7 +19,9 @@ model Tenant {
   createdAt   DateTime  @default(now()) @map("created_at")
   expiresAt   DateTime? @map("expires_at")
 
-  users User[]
+  users          User[]
+  fielCredential FielCredential?
+  satSyncJobs    SatSyncJob[]
 
   @@map("tenants")
 }
@@ -62,3 +64,75 @@ enum Role {
   contador
   visor
 }
+
+// ============================================
+// SAT Sync Models
+// ============================================
+
+model FielCredential {
+  id                   String   @id @default(uuid())
+  tenantId             String   @unique @map("tenant_id")
+  rfc                  String   @db.VarChar(13)
+  cerData              Bytes    @map("cer_data")
+  keyData              Bytes    @map("key_data")
+  keyPasswordEncrypted Bytes    @map("key_password_encrypted")
+  encryptionIv         Bytes    @map("encryption_iv")
+  encryptionTag        Bytes    @map("encryption_tag")
+  serialNumber         String?  @map("serial_number") @db.VarChar(50)
+  validFrom            DateTime @map("valid_from")
+  validUntil           DateTime @map("valid_until")
+  isActive             Boolean  @default(true) @map("is_active")
+  createdAt            DateTime @default(now()) @map("created_at")
+  updatedAt            DateTime @updatedAt @map("updated_at")
+
+  tenant Tenant @relation(fields: [tenantId], references: [id], onDelete: Cascade)
+
+  @@map("fiel_credentials")
+}
+
+model SatSyncJob {
+  id              String        @id @default(uuid())
+  tenantId        String        @map("tenant_id")
+  type            SatSyncType
+  status          SatSyncStatus @default(pending)
+  dateFrom        DateTime      @map("date_from") @db.Date
+  dateTo          DateTime      @map("date_to") @db.Date
+  cfdiType        CfdiSyncType? @map("cfdi_type")
+  satRequestId    String?       @map("sat_request_id") @db.VarChar(50)
+  satPackageIds   String[]      @map("sat_package_ids")
+  cfdisFound      Int           @default(0) @map("cfdis_found")
+  cfdisDownloaded Int           @default(0) @map("cfdis_downloaded")
+  cfdisInserted   Int           @default(0) @map("cfdis_inserted")
+  cfdisUpdated    Int           @default(0) @map("cfdis_updated")
+  progressPercent Int           @default(0) @map("progress_percent")
+  errorMessage    String?       @map("error_message")
+  startedAt       DateTime?     @map("started_at")
+  completedAt     DateTime?     @map("completed_at")
+  createdAt       DateTime      @default(now()) @map("created_at")
+  retryCount      Int           @default(0) @map("retry_count")
+  nextRetryAt     DateTime?     @map("next_retry_at")
+
+  tenant Tenant @relation(fields: [tenantId], references: [id], onDelete: Cascade)
+
+  @@index([tenantId])
+  @@index([status])
+  @@index([status, nextRetryAt])
+  @@map("sat_sync_jobs")
+}
+
+enum SatSyncType {
+  initial
+  daily
+}
+
+enum SatSyncStatus {
+  pending
+  running
+  completed
+  failed
+}
+
+enum CfdiSyncType {
+  emitidos
+  recibidos
+}
diff --git a/packages/shared/src/index.ts b/packages/shared/src/index.ts
index d9adc8f..614f976 100644
--- a/packages/shared/src/index.ts
+++ b/packages/shared/src/index.ts
@@ -8,6 +8,7 @@ export * from './types/impuestos';
 export * from './types/alertas';
 export * from './types/reportes';
 export * from './types/calendario';
+export * from './types/sat';
 
 // Constants
 export * from './constants/plans';
diff --git a/packages/shared/src/types/sat.ts b/packages/shared/src/types/sat.ts
new file mode 100644
index 0000000..fdee3e7
--- /dev/null
+++ b/packages/shared/src/types/sat.ts
@@ -0,0 +1,132 @@
+// ============================================
+// FIEL (e.firma) Types
+// ============================================
+
+export interface FielUploadRequest {
+  cerFile: string;  // Base64
+  keyFile: string;  // Base64
+  password: string;
+}
+
+export interface FielStatus {
+  configured: boolean;
+  rfc?: string;
+  serialNumber?: string;
+  validFrom?: string;
+  validUntil?: string;
+  isExpired?: boolean;
+  daysUntilExpiration?: number;
+}
+
+// ============================================
+// SAT Sync Types
+// ============================================
+
+export type SatSyncType = 'initial' | 'daily';
+export type SatSyncStatus = 'pending' | 'running' | 'completed' | 'failed';
+export type CfdiSyncType = 'emitidos' | 'recibidos';
+
+export interface SatSyncJob {
+  id: string;
+  tenantId: string;
+  type: SatSyncType;
+  status: SatSyncStatus;
+  dateFrom: string;
+  dateTo: string;
+  cfdiType?: CfdiSyncType;
+  satRequestId?: string;
+  satPackageIds: string[];
+  cfdisFound: number;
+  cfdisDownloaded: number;
+  cfdisInserted: number;
+  cfdisUpdated: number;
+  progressPercent: number;
+  errorMessage?: string;
+  startedAt?: string;
+  completedAt?: string;
+  createdAt: string;
+  retryCount: number;
+}
+
+export interface SatSyncStatusResponse {
+  hasActiveSync: boolean;
+  currentJob?: SatSyncJob;
+  lastCompletedJob?: SatSyncJob;
+  totalCfdisSynced: number;
+}
+
+export interface SatSyncHistoryResponse {
+  jobs: SatSyncJob[];
+  total: number;
+  page: number;
+  limit: number;
+}
+
+export interface StartSyncRequest {
+  type?: SatSyncType;
+  dateFrom?: string;
+  dateTo?: string;
+}
+
+export interface StartSyncResponse {
+  jobId: string;
+  message: string;
+}
+
+// ============================================
+// SAT Web Service Types
+// ============================================
+
+export interface SatAuthResponse {
+  token: string;
+  expiresAt: Date;
+}
+
+export interface SatDownloadRequest {
+  rfcSolicitante: string;
+  fechaInicio: Date;
+  fechaFin: Date;
+  tipoSolicitud: 'CFDI' | 'Metadata';
+  tipoComprobante?: 'I' | 'E' | 'T' | 'N' | 'P';
+  rfcEmisor?: string;
+  rfcReceptor?: string;
+}
+
+export interface SatDownloadRequestResponse {
+  idSolicitud: string;
+  codEstatus: string;
+  mensaje: string;
+}
+
+export interface SatVerifyResponse {
+  codEstatus: string;
+  estadoSolicitud: number;  // 1=Aceptada, 2=EnProceso, 3=Terminada, 4=Error, 5=Rechazada, 6=Vencida
+  codigoEstadoSolicitud: string;
+  numeroCfdis: number;
+  mensaje: string;
+  paquetes: string[];
+}
+
+export interface SatPackageResponse {
+  paquete: string;  // Base64 ZIP
+}
+
+// ============================================
+// SAT Error Codes
+// ============================================
+
+export const SAT_STATUS_CODES: Record<string, string> = {
+  '5000': 'Solicitud recibida con éxito',
+  '5002': 'Se agotó el límite de solicitudes',
+  '5004': 'No se encontraron CFDIs',
+  '5005': 'Solicitud duplicada',
+};
+
+export const SAT_REQUEST_STATUS: Record<number, string> = {
+  1: 'Aceptada',
+  2: 'En proceso',
+  3: 'Terminada',
+  4: 'Error',
+  5: 'Rechazada',
+  6: 'Vencida',
+};