diff --git a/api-v3/src/asset-master/inventory-browser.service.ts b/api-v3/src/asset-master/inventory-browser.service.ts
new file mode 100644
index 0000000..6e5cef6
--- /dev/null
+++ b/api-v3/src/asset-master/inventory-browser.service.ts
@@ -0,0 +1,176 @@
+import { BadRequestException, Injectable, NotFoundException } from '@nestjs/common';
+import { DataSource } from 'typeorm';
+import type { InventoryBrowserQueryDto } from './dto/inventory-browser-query.dto';
+
+type ParentContext = {
+  id: string;
+  code: string;
+  name: string;
+  typeCode: string;
+};
+
+@Injectable()
+export class InventoryBrowserService {
+  constructor(private readonly dataSource: DataSource) {}
+
+  async areas(query: InventoryBrowserQueryDto) {
+    const params: unknown[] = [];
+    const conditions = [
+      "type.operational_role='AREA'",
+      "area.information_status<>'INACTIVE'",
+      'type.is_active=true',
+    ];
+    const add = (value: unknown): string => {
+      params.push(value);
+      return `$${params.length}`;
+    };
+
+    if (query.search?.trim()) {
+      const p = add(`%${query.search.trim()}%`);
+      conditions.push(`(area.code ILIKE ${p} OR area.name ILIKE ${p} OR COALESCE(area.common_name,'') ILIKE ${p})`);
+    }
+    if (query.operatorCompanyId) {
+      const p = add(query.operatorCompanyId);
+      conditions.push(`EXISTS (
+        SELECT 1 FROM area_company_relations relation
+        WHERE relation.area_id=area.id
+          AND relation.company_id=${p}::uuid
+          AND relation.relation_role='OPERATOR'
+          AND relation.valid_until IS NULL
+      )`);
+    }
+
+    const data = await this.dataSource.query(`
+      SELECT
+        area.id,area.code,area.name,area.common_name AS "commonName",
+        JSONB_BUILD_OBJECT('id',type.id,'code',type.code,'name',type.name) AS type,
+        area.information_status AS "informationStatus",
+        area.operational_status AS "operationalStatus",
+        (
+          SELECT JSONB_BUILD_OBJECT('id',company.id,'code',company.code,'name',company.name)
+          FROM area_company_relations relation
+          JOIN assets company ON company.id=relation.company_id
+          WHERE relation.area_id=area.id
+            AND relation.relation_role='OPERATOR'
+            AND relation.valid_until IS NULL
+          ORDER BY relation.valid_from DESC,relation.created_at DESC
+          LIMIT 1
+        ) AS "currentOperator",
+        (
+          SELECT COUNT(*)::integer
+          FROM assets yacimiento
+          JOIN asset_types ytype ON ytype.id=yacimiento.asset_type_id
+          WHERE yacimiento.parent_id=area.id
+            AND lower(ytype.code)='yacimiento'
+            AND yacimiento.information_status<>'INACTIVE'
+        ) AS "yacimientoCount",
+        (
+          SELECT COUNT(*)::integer
+          FROM assets inventory
+          WHERE inventory.is_inventory_instance=true
+            AND inventory.information_status<>'INACTIVE'
+            AND inventory.operational_area_id=area.id
+        ) AS "inventoryCount"
+      FROM assets area
+      JOIN asset_types type ON type.id=area.asset_type_id
+      WHERE ${conditions.join(' AND ')}
+      ORDER BY area.name,area.code
+    `, params);
+
+    return { data, meta: { count: data.length } };
+  }
+
+  async children(parentId: string, query: InventoryBrowserQueryDto) {
+    const parent = await this.parent(parentId);
+    const allowedChildType = this.allowedChildType(parent.typeCode);
+    if (!allowedChildType) return { parent, data: [], meta: { count: 0, hasMore: false } };
+
+    const params: unknown[] = [parentId, allowedChildType];
+    const conditions = [
+      'asset.parent_id=$1::uuid',
+      'lower(type.code)=lower($2)',
+      "asset.information_status<>'INACTIVE'",
+      'type.is_active=true',
+    ];
+    if (allowedChildType === 'instalacion' || allowedChildType === 'subinstalacion') {
+      conditions.push('asset.is_inventory_instance=true');
+    }
+    if (query.search?.trim()) {
+      params.push(`%${query.search.trim()}%`);
+      const p = `$${params.length}`;
+      conditions.push(`(asset.code ILIKE ${p} OR asset.name ILIKE ${p} OR COALESCE(asset.common_name,'') ILIKE ${p})`);
+    }
+
+    params.push(201);
+    const limit = `$${params.length}`;
+    const rows = await this.dataSource.query(`
+      SELECT
+        asset.id,asset.code,asset.name,asset.common_name AS "commonName",
+        JSONB_BUILD_OBJECT('id',type.id,'code',type.code,'name',type.name) AS type,
+        CASE WHEN parent_asset.id IS NULL THEN NULL ELSE JSONB_BUILD_OBJECT(
+          'id',parent_asset.id,'code',parent_asset.code,'name',parent_asset.name
+        ) END AS parent,
+        asset.information_status AS "informationStatus",
+        asset.operational_status AS "operationalStatus",
+        asset.is_inventory_instance AS "isInventoryInstance",
+        CASE WHEN family.id IS NULL THEN NULL ELSE JSONB_BUILD_OBJECT(
+          'id',family.id,'code',family.code,'name',family.name,'level',family.level
+        ) END AS "inventoryFamily",
+        (
+          SELECT COUNT(*)::integer
+          FROM assets child
+          WHERE child.parent_id=asset.id
+            AND child.information_status<>'INACTIVE'
+            AND (
+              lower(type.code)='area'
+              OR child.is_inventory_instance=true
+              OR EXISTS (
+                SELECT 1 FROM asset_types child_type
+                WHERE child_type.id=child.asset_type_id AND lower(child_type.code)='yacimiento'
+              )
+            )
+        ) AS "childrenCount",
+        EXISTS (SELECT 1 FROM asset_geometries geometry WHERE geometry.asset_id=asset.id) AS "hasGeometry",
+        asset.updated_at AS "updatedAt"
+      FROM assets asset
+      JOIN asset_types type ON type.id=asset.asset_type_id
+      LEFT JOIN assets parent_asset ON parent_asset.id=asset.parent_id
+      LEFT JOIN inventory_families family ON family.id=asset.inventory_family_id
+      WHERE ${conditions.join(' AND ')}
+      ORDER BY asset.name,asset.code
+      LIMIT ${limit}
+    `, params);
+
+    const hasMore = rows.length > 200;
+    const data = hasMore ? rows.slice(0,200) : rows;
+    return { parent, data, meta: { count: data.length, hasMore } };
+  }
+
+  private async parent(parentId: string): Promise<ParentContext> {
+    const [parent] = await this.dataSource.query(`
+      SELECT asset.id,asset.code,asset.name,type.code AS "typeCode"
+      FROM assets asset
+      JOIN asset_types type ON type.id=asset.asset_type_id
+      WHERE asset.id=$1::uuid AND asset.information_status<>'INACTIVE'
+    `,[parentId]) as ParentContext[];
+    if (!parent) {
+      throw new NotFoundException({ code:'INVENTORY_BROWSER_PARENT_NOT_FOUND',message:'El nivel de Inventario no existe' });
+    }
+    if (!['area','yacimiento','instalacion','subinstalacion'].includes(parent.typeCode.toLowerCase())) {
+      throw new BadRequestException({
+        code:'INVENTORY_BROWSER_PARENT_TYPE_INVALID',
+        message:'La navegación de Inventarios admite Área → Yacimiento → Instalación → Subinstalación',
+      });
+    }
+    return parent;
+  }
+
+  private allowedChildType(typeCode: string): string | null {
+    switch (typeCode.toLowerCase()) {
+      case 'area': return 'yacimiento';
+      case 'yacimiento': return 'instalacion';
+      case 'instalacion': return 'subinstalacion';
+      default: return null;
+    }
+  }
+}