diff --git a/.changeset/bright-coins-kneel.md b/.changeset/bright-coins-kneel.md
new file mode 100644
index 0000000000..6eb9511feb
--- /dev/null
+++ b/.changeset/bright-coins-kneel.md
@@ -0,0 +1,8 @@
+---
+"@medusajs/medusa": patch
+"medusa-fulfillment-webshipper": patch
+"medusa-interfaces": patch
+"@medusajs/utils": patch
+---
+
+chore(medusa, interfaces, utils, webshiper): Uniformise class checks
diff --git a/packages/medusa-fulfillment-webshipper/src/services/webshipper-fulfillment.js b/packages/medusa-fulfillment-webshipper/src/services/webshipper-fulfillment.js
index 616c7da67a..cc9ccb612e 100644
--- a/packages/medusa-fulfillment-webshipper/src/services/webshipper-fulfillment.js
+++ b/packages/medusa-fulfillment-webshipper/src/services/webshipper-fulfillment.js
@@ -10,7 +10,7 @@ class WebshipperFulfillmentService extends AbstractFulfillmentService {
     { logger, totalsService, claimService, swapService, orderService },
     options
   ) {
-    super()
+    super(...arguments)
 
     this.options_ = options
 
diff --git a/packages/medusa-interfaces/src/file-service.js b/packages/medusa-interfaces/src/file-service.js
index 103e8bb49e..d59ded3128 100644
--- a/packages/medusa-interfaces/src/file-service.js
+++ b/packages/medusa-interfaces/src/file-service.js
@@ -3,8 +3,15 @@ import BaseService from "./base-service"
 /**
  * Interface for file connectors
  * @interface
+ * @deprecated use AbstractFileService from @medusajs/medusa instead
  */
 class BaseFileService extends BaseService {
+  static _isFileService = true
+
+  static isFileService(obj) {
+    return obj?.constructor?._isFileService
+  }
+
   constructor() {
     super()
   }
diff --git a/packages/medusa-interfaces/src/fulfillment-service.js b/packages/medusa-interfaces/src/fulfillment-service.js
index 912480a0b0..880c7d6b08 100644
--- a/packages/medusa-interfaces/src/fulfillment-service.js
+++ b/packages/medusa-interfaces/src/fulfillment-service.js
@@ -5,8 +5,15 @@ import BaseService from "./base-service"
  * provides the necessary methods for creating, authorizing and managing
  * fulfillment orders.
  * @interface
+ * @deprecated use AbstractFulfillmentService from @medusajs/medusa instead
  */
 class BaseFulfillmentService extends BaseService {
+  static _isFulfillmentService = true
+
+  static isFulfillmentService(obj) {
+    return obj?.constructor?._isFulfillmentService
+  }
+
   constructor() {
     super()
   }
@@ -102,7 +109,7 @@ class BaseFulfillmentService extends BaseService {
     return []
   }
 
-  retrieveDocuments(fulfillmentData, documentType) { 
+  retrieveDocuments(fulfillmentData, documentType) {
     throw Error("retrieveDocuments must be overridden by the child class")
   }
 }
diff --git a/packages/medusa-interfaces/src/notification-service.js b/packages/medusa-interfaces/src/notification-service.js
index 39171d99fa..04ed883a11 100644
--- a/packages/medusa-interfaces/src/notification-service.js
+++ b/packages/medusa-interfaces/src/notification-service.js
@@ -3,8 +3,15 @@ import BaseService from "./base-service"
 /**
  * Interface for Notification Providers
  * @interface
+ * @deprecated use AbstractNotificationService from @medusajs/medusa instead
  */
 class BaseNotificationService extends BaseService {
+  static _isNotificationService = true
+
+  static isNotificationService(obj) {
+    return obj?.constructor?._isNotificationService
+  }
+
   constructor() {
     super()
   }
diff --git a/packages/medusa-interfaces/src/oauth-service.js b/packages/medusa-interfaces/src/oauth-service.js
index 6b4947b57a..f001d75254 100644
--- a/packages/medusa-interfaces/src/oauth-service.js
+++ b/packages/medusa-interfaces/src/oauth-service.js
@@ -5,6 +5,12 @@ import BaseService from "./base-service"
  * @interface
  */
 class BaseOauthService extends BaseService {
+  static _isOauthService = true
+
+  static isOauthService(obj) {
+    return obj?.constructor?._isOauthService
+  }
+
   constructor() {
     super()
   }
diff --git a/packages/medusa-interfaces/src/payment-service.js b/packages/medusa-interfaces/src/payment-service.js
index 9d5d957269..7492d4304e 100644
--- a/packages/medusa-interfaces/src/payment-service.js
+++ b/packages/medusa-interfaces/src/payment-service.js
@@ -5,8 +5,15 @@ import BaseService from "./base-service"
  * provides the necessary methods for creating, authorizing and managing
  * payments.
  * @interface
+ * @deprecated use AbstractPaymentProcessor from @medusajs/medusa instead
  */
 class BasePaymentService extends BaseService {
+  static _isPaymentService = true
+
+  static isPaymentService(obj) {
+    return obj?.constructor?._isPaymentService
+  }
+
   constructor() {
     super()
   }
diff --git a/packages/medusa-interfaces/src/search-service.js b/packages/medusa-interfaces/src/search-service.js
index 9678480e2c..df818a2d83 100644
--- a/packages/medusa-interfaces/src/search-service.js
+++ b/packages/medusa-interfaces/src/search-service.js
@@ -3,8 +3,15 @@ import BaseService from "./base-service"
 /**
  * The interface that all search services must implement.
  * @interface
+ * @deprecated use AbstractSearchService from @medusajs/utils instead
  */
 class SearchService extends BaseService {
+  static _isSearchService = true
+
+  static isSearchService(obj) {
+    return obj?.constructor?._isSearchService
+  }
+
   constructor() {
     super()
   }
diff --git a/packages/medusa/src/interfaces/batch-job-strategy.ts b/packages/medusa/src/interfaces/batch-job-strategy.ts
index 386a601900..6767268edd 100644
--- a/packages/medusa/src/interfaces/batch-job-strategy.ts
+++ b/packages/medusa/src/interfaces/batch-job-strategy.ts
@@ -33,11 +33,16 @@ export abstract class AbstractBatchJobStrategy
   extends TransactionBaseService
   implements IBatchJobStrategy
 {
+  static _isBatchJobStrategy = true
   static identifier: string
   static batchType: string
 
   protected abstract batchJobService_: BatchJobService
 
+  static isBatchJobStrategy(object): object is IBatchJobStrategy {
+    return object?.constructor?._isBatchJobStrategy
+  }
+
   async prepareBatchJobForProcessing(
     batchJob: CreateBatchJobInput,
     // eslint-disable-next-line @typescript-eslint/no-unused-vars
@@ -107,9 +112,3 @@ export abstract class AbstractBatchJobStrategy
     })
   }
 }
-
-export function isBatchJobStrategy(
-  object: unknown
-): object is IBatchJobStrategy {
-  return object instanceof AbstractBatchJobStrategy
-}
diff --git a/packages/medusa/src/interfaces/cart-completion-strategy.ts b/packages/medusa/src/interfaces/cart-completion-strategy.ts
index eb7ade83d5..5381414d81 100644
--- a/packages/medusa/src/interfaces/cart-completion-strategy.ts
+++ b/packages/medusa/src/interfaces/cart-completion-strategy.ts
@@ -30,16 +30,15 @@ export abstract class AbstractCartCompletionStrategy
   extends TransactionBaseService
   implements ICartCompletionStrategy
 {
+  static _isCartCompletionStrategy = true
+
+  static isCartCompletionStrategy(object): object is ICartCompletionStrategy {
+    return object?.constructor?._isCartCompletionStrategy
+  }
+
   abstract complete(
     cartId: string,
     idempotencyKey: IdempotencyKey,
     context: RequestContext
   ): Promise<CartCompletionResponse>
 }
-
-export function isCartCompletionStrategy(obj: unknown): boolean {
-  return (
-    typeof (obj as AbstractCartCompletionStrategy).complete === "function" ||
-    obj instanceof AbstractCartCompletionStrategy
-  )
-}
diff --git a/packages/medusa/src/interfaces/file-service.ts b/packages/medusa/src/interfaces/file-service.ts
index 62aeb27d68..e1c504121d 100644
--- a/packages/medusa/src/interfaces/file-service.ts
+++ b/packages/medusa/src/interfaces/file-service.ts
@@ -55,6 +55,12 @@ export abstract class AbstractFileService
   extends TransactionBaseService
   implements IFileService
 {
+  static _isFileService = true
+
+  static isFileService(object): object is AbstractFileService {
+    return object?.constructor?._isFileService
+  }
+
   abstract upload(
     fileData: Express.Multer.File
   ): Promise<FileServiceUploadResult>
@@ -77,7 +83,3 @@ export abstract class AbstractFileService
     fileData: GetUploadedFileType
   ): Promise<string>
 }
-
-export const isFileService = (object: unknown): boolean => {
-  return object instanceof AbstractFileService
-}
diff --git a/packages/medusa/src/interfaces/fulfillment-service.ts b/packages/medusa/src/interfaces/fulfillment-service.ts
index 0b33049e09..b9ca14a6c1 100644
--- a/packages/medusa/src/interfaces/fulfillment-service.ts
+++ b/packages/medusa/src/interfaces/fulfillment-service.ts
@@ -1,6 +1,7 @@
 import { MedusaContainer } from "@medusajs/types"
 import { Cart, Fulfillment, LineItem, Order } from "../models"
 import { CreateReturnType } from "../types/fulfillment-provider"
+import { TransactionBaseService } from "./transaction-base-service"
 
 type FulfillmentProviderData = Record<string, unknown>
 type ShippingOptionData = Record<string, unknown>
@@ -44,7 +45,7 @@ type ShippingMethodData = Record<string, unknown>
  *
  * ---
  */
-export interface FulfillmentService {
+export interface FulfillmentService extends TransactionBaseService {
   /**
    * @ignore
    *
@@ -389,7 +390,16 @@ export interface FulfillmentService {
   ): Promise<any>
 }
 
-export abstract class AbstractFulfillmentService implements FulfillmentService {
+export abstract class AbstractFulfillmentService
+  extends TransactionBaseService
+  implements FulfillmentService
+{
+  static _isFulfillmentService = true
+
+  static isFulfillmentService(object): boolean {
+    return object?.constructor?._isFulfillmentService
+  }
+
   /**
    * You can use the `constructor` of your fulfillment provider to access the different services in Medusa through dependency injection.
    * You can also use the constructor to initialize your integration with the third-party provider. For example, if you use a client to connect to the third-party provider’s APIs, you can initialize it in the constructor and use it in other methods in the service.
@@ -415,7 +425,9 @@ export abstract class AbstractFulfillmentService implements FulfillmentService {
   protected constructor(
     protected readonly container: MedusaContainer,
     protected readonly config?: Record<string, unknown> // eslint-disable-next-line @typescript-eslint/no-empty-function
-  ) {}
+  ) {
+    super(container, config)
+  }
 
   /**
    * The `FulfillmentProvider` entity has 2 properties: `identifier` and `is_installed`. The `identifier` property in the class is used when the fulfillment provider is created in the database.
diff --git a/packages/medusa/src/interfaces/notification-service.ts b/packages/medusa/src/interfaces/notification-service.ts
index 6b9d9ba8ff..3f7a0cd2f7 100644
--- a/packages/medusa/src/interfaces/notification-service.ts
+++ b/packages/medusa/src/interfaces/notification-service.ts
@@ -1,5 +1,4 @@
 import { TransactionBaseService } from "./transaction-base-service"
-import BaseNotificationService from "medusa-interfaces/dist/notification-service"
 
 type ReturnedData = {
   to: string
@@ -25,8 +24,13 @@ export abstract class AbstractNotificationService
   extends TransactionBaseService
   implements INotificationService
 {
+  static _isNotificationService = true
   static identifier: string
 
+  static isNotificationService(object): boolean {
+    return object?.constructor?._isNotificationService
+  }
+
   getIdentifier(): string {
     return (this.constructor as any).identifier
   }
@@ -43,10 +47,3 @@ export abstract class AbstractNotificationService
     attachmentGenerator: unknown
   ): Promise<ReturnedData>
 }
-
-export const isNotificationService = (obj: unknown): boolean => {
-  return (
-    obj instanceof AbstractNotificationService ||
-    obj instanceof BaseNotificationService
-  )
-}
diff --git a/packages/medusa/src/interfaces/payment-processor.ts b/packages/medusa/src/interfaces/payment-processor.ts
index 818dabaaad..97ac9771e4 100644
--- a/packages/medusa/src/interfaces/payment-processor.ts
+++ b/packages/medusa/src/interfaces/payment-processor.ts
@@ -676,6 +676,12 @@ export abstract class AbstractPaymentProcessor implements PaymentProcessor {
     protected readonly config?: Record<string, unknown> // eslint-disable-next-line @typescript-eslint/no-empty-function
   ) {}
 
+  static _isPaymentProcessor = true
+
+  static isPaymentProcessor(object): boolean {
+    return object?.constructor?._isPaymentProcessor
+  }
+
   /**
    * The `PaymentProvider` entity has 2 properties: `id` and `is_installed`. The `identifier` property in the payment processor service is used when the payment processor is added to the database.
    *
@@ -768,18 +774,6 @@ export abstract class AbstractPaymentProcessor implements PaymentProcessor {
   >
 }
 
-/**
- * Return if the input object is AbstractPaymentProcessor
- * @param obj
- */
-export function isPaymentProcessor(obj: unknown): boolean {
-  return obj instanceof AbstractPaymentProcessor
-}
-
-/**
- * Utility function to determine if an object is a processor error
- * @param obj
- */
 export function isPaymentProcessorError(
   obj: any
 ): obj is PaymentProcessorError {
diff --git a/packages/medusa/src/interfaces/payment-service.ts b/packages/medusa/src/interfaces/payment-service.ts
index 8aa27d0903..a055c59fae 100644
--- a/packages/medusa/src/interfaces/payment-service.ts
+++ b/packages/medusa/src/interfaces/payment-service.ts
@@ -146,6 +146,12 @@ export abstract class AbstractPaymentService
   extends TransactionBaseService
   implements PaymentService
 {
+  static _isPaymentService = true
+
+  static isPaymentService(object): boolean {
+    return object?.constructor?._isPaymentService
+  }
+
   protected constructor(container: unknown, config?: Record<string, unknown>) {
     super(container, config)
   }
@@ -258,11 +264,3 @@ export abstract class AbstractPaymentService
    */
   public abstract getStatus(data: Data): Promise<PaymentSessionStatus>
 }
-
-/**
- * Return if the input object is one of AbstractPaymentService or PaymentService or AbstractPaymentPluginService
- * @param obj
- */
-export function isPaymentService(obj: unknown): boolean {
-  return obj instanceof AbstractPaymentService || obj instanceof PaymentService
-}
diff --git a/packages/medusa/src/interfaces/price-selection-strategy.ts b/packages/medusa/src/interfaces/price-selection-strategy.ts
index c5bfc7828f..8a7a61fe0a 100644
--- a/packages/medusa/src/interfaces/price-selection-strategy.ts
+++ b/packages/medusa/src/interfaces/price-selection-strategy.ts
@@ -32,6 +32,12 @@ export abstract class AbstractPriceSelectionStrategy
   extends TransactionBaseService
   implements IPriceSelectionStrategy
 {
+  static _isPriceSelectionStrategy = true
+
+  static isPriceSelectionStrategy(object): boolean {
+    return object?.constructor?._isPriceSelectionStrategy
+  }
+
   public abstract calculateVariantPrice(
     data: {
       variantId: string
@@ -46,16 +52,6 @@ export abstract class AbstractPriceSelectionStrategy
   }
 }
 
-export function isPriceSelectionStrategy(
-  // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  object: any
-): object is IPriceSelectionStrategy {
-  return (
-    typeof object.calculateVariantPrice === "function" &&
-    typeof object.withTransaction === "function"
-  )
-}
-
 export type PriceSelectionContext = {
   cart_id?: string
   customer_id?: string
diff --git a/packages/medusa/src/interfaces/tax-calculation-strategy.ts b/packages/medusa/src/interfaces/tax-calculation-strategy.ts
index 3125a794a5..82b7e0215e 100644
--- a/packages/medusa/src/interfaces/tax-calculation-strategy.ts
+++ b/packages/medusa/src/interfaces/tax-calculation-strategy.ts
@@ -2,6 +2,7 @@ import { LineItem } from "../models/line-item"
 import { TaxCalculationContext } from "./tax-service"
 import { LineItemTaxLine } from "../models/line-item-tax-line"
 import { ShippingMethodTaxLine } from "../models/shipping-method-tax-line"
+import { TransactionBaseService } from "./transaction-base-service"
 
 export interface ITaxCalculationStrategy {
   /**
@@ -19,9 +20,22 @@ export interface ITaxCalculationStrategy {
   ): Promise<number>
 }
 
-export function isTaxCalculationStrategy(
-  // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  object: any
-): object is ITaxCalculationStrategy {
-  return typeof object.calculate === "function"
+export abstract class AbstractTaxCalculationStrategy
+  extends TransactionBaseService
+  implements ITaxCalculationStrategy
+{
+  static _isTaxCalculationStrategy = true
+
+  static isTaxCalculationStrategy(object): boolean {
+    return (
+      typeof object.calculate === "function" ||
+      object?.constructor?._isTaxCalculationStrategy
+    )
+  }
+
+  abstract calculate(
+    items: LineItem[],
+    taxLines: (ShippingMethodTaxLine | LineItemTaxLine)[],
+    calculationContext: TaxCalculationContext
+  ): Promise<number>
 }
diff --git a/packages/medusa/src/interfaces/tax-service.ts b/packages/medusa/src/interfaces/tax-service.ts
index 551c4f9087..31c74c3ef4 100644
--- a/packages/medusa/src/interfaces/tax-service.ts
+++ b/packages/medusa/src/interfaces/tax-service.ts
@@ -1,5 +1,3 @@
-import { BaseService } from "medusa-interfaces"
-
 import { LineItem } from "../models/line-item"
 import { Region } from "../models/region"
 import { Address } from "../models/address"
@@ -7,6 +5,7 @@ import { ShippingMethod } from "../models/shipping-method"
 import { Customer } from "../models/customer"
 import { ProviderTaxLine, TaxServiceRate } from "../types/tax-service"
 import { LineAllocationsMap } from "../types/totals"
+import { TransactionBaseService } from "./transaction-base-service"
 
 /**
  * A shipping method and the tax rates that have been configured to apply to the
@@ -61,11 +60,16 @@ export interface ITaxService {
 }
 
 export abstract class AbstractTaxService
-  extends BaseService
+  extends TransactionBaseService
   implements ITaxService
 {
+  static _isTaxService = true
   protected static identifier: string
 
+  static isTaxService(object): boolean {
+    return object?.constructor?._isTaxService
+  }
+
   public getIdentifier(): string {
     if (!(this.constructor as typeof AbstractTaxService).identifier) {
       throw new Error(`Missing static property "identifier".`)
diff --git a/packages/medusa/src/interfaces/transaction-base-service.ts b/packages/medusa/src/interfaces/transaction-base-service.ts
index 87158f0dc0..3130eddd53 100644
--- a/packages/medusa/src/interfaces/transaction-base-service.ts
+++ b/packages/medusa/src/interfaces/transaction-base-service.ts
@@ -14,7 +14,7 @@ export abstract class TransactionBaseService {
     protected readonly __configModule__?: Record<string, unknown>,
     protected readonly __moduleDeclaration__?: Record<string, unknown>
   ) {
-    this.manager_ = __container__.manager
+    this.manager_ = __container__?.manager
   }
 
   withTransaction(transactionManager?: EntityManager): this {
diff --git a/packages/medusa/src/loaders/__tests__/plugins.spec.ts b/packages/medusa/src/loaders/__tests__/plugins.spec.ts
index 9ae20ab702..373c438ec4 100644
--- a/packages/medusa/src/loaders/__tests__/plugins.spec.ts
+++ b/packages/medusa/src/loaders/__tests__/plugins.spec.ts
@@ -9,7 +9,11 @@ import { createMedusaContainer } from "medusa-core-utils"
 import { resolve } from "path"
 import { DataSource, EntityManager } from "typeorm"
 import Logger from "../logger"
-import { MEDUSA_PROJECT_NAME, registerServices, registerStrategies } from "../plugins"
+import {
+  MEDUSA_PROJECT_NAME,
+  registerServices,
+  registerStrategies,
+} from "../plugins"
 
 // ***** TEMPLATES *****
 const buildServiceTemplate = (name: string): string => {
@@ -32,7 +36,7 @@ const buildBatchJobStrategyTemplate = (name: string, type: string): string => {
   return `
   import { AbstractBatchJobStrategy } from "../../../../interfaces/batch-job-strategy"
 
-  class ${name}BatchStrategy extends AbstractBatchJobStrategy{
+  class ${name}BatchStrategy extends AbstractBatchJobStrategy {
     static identifier = '${name}-identifier';
     static batchType = '${type}';
 
@@ -79,7 +83,8 @@ const buildPriceSelectionStrategyTemplate = (name: string): string => {
 
 const buildTaxCalcStrategyTemplate = (name: string): string => {
   return `
-  class ${name}TaxCalculationStrategy {
+  import { AbstractTaxCalculationStrategy } from "../../../../interfaces/tax-calculation-strategy"
+  class ${name}TaxCalculationStrategy extends AbstractTaxCalculationStrategy {
     calculate(items, taxLines, calculationContext) {
       throw new Error("Method not implemented.")
     }
diff --git a/packages/medusa/src/loaders/helpers/plugins.ts b/packages/medusa/src/loaders/helpers/plugins.ts
index 1d2c70a33e..ccd83bbb74 100644
--- a/packages/medusa/src/loaders/helpers/plugins.ts
+++ b/packages/medusa/src/loaders/helpers/plugins.ts
@@ -1,13 +1,10 @@
-import { Lifetime, LifetimeType, aliasTo, asFunction } from "awilix"
-import { FulfillmentService } from "medusa-interfaces"
+import { aliasTo, asFunction, Lifetime, LifetimeType } from "awilix"
 import {
   AbstractFulfillmentService,
   AbstractPaymentProcessor,
-  AbstractPaymentService,
-  isPaymentProcessor,
-  isPaymentService,
 } from "../../interfaces"
 import { ClassConstructor, MedusaContainer } from "../../types/global"
+import { PaymentService } from "medusa-interfaces"
 
 type Context = {
   container: MedusaContainer
@@ -15,44 +12,16 @@ type Context = {
   registrationName: string
 }
 
-export function registerPaymentServiceFromClass(
-  klass: ClassConstructor<AbstractPaymentService> & {
-    LIFE_TIME?: LifetimeType
-  },
-  context: Context
-): void {
-  if (!isPaymentService(klass.prototype)) {
-    return
-  }
-
-  const { container, pluginDetails, registrationName } = context
-
-  container.registerAdd(
-    "paymentProviders",
-    asFunction((cradle) => new klass(cradle, pluginDetails.options), {
-      lifetime: klass.LIFE_TIME || Lifetime.SINGLETON,
-    })
-  )
-
-  container.register({
-    [registrationName]: asFunction(
-      (cradle) => new klass(cradle, pluginDetails.options),
-      {
-        lifetime: klass.LIFE_TIME || Lifetime.SINGLETON,
-      }
-    ),
-    [`pp_${(klass as unknown as typeof AbstractPaymentService).identifier}`]:
-      aliasTo(registrationName),
-  })
-}
-
 export function registerPaymentProcessorFromClass(
   klass: ClassConstructor<AbstractPaymentProcessor> & {
     LIFE_TIME?: LifetimeType
   },
   context: Context
 ): void {
-  if (!isPaymentProcessor(klass.prototype)) {
+  if (
+    !AbstractPaymentProcessor.isPaymentProcessor(klass.prototype) &&
+    !PaymentService.isPaymentService(klass.prototype)
+  ) {
     return
   }
 
@@ -83,7 +52,7 @@ export function registerAbstractFulfillmentServiceFromClass(
   },
   context: Context
 ): void {
-  if (!(klass.prototype instanceof AbstractFulfillmentService)) {
+  if (!AbstractFulfillmentService.isFulfillmentService(klass.prototype)) {
     return
   }
 
@@ -108,34 +77,3 @@ export function registerAbstractFulfillmentServiceFromClass(
     }`]: aliasTo(registrationName),
   })
 }
-
-export function registerFulfillmentServiceFromClass(
-  klass: ClassConstructor<typeof FulfillmentService> & {
-    LIFE_TIME?: LifetimeType
-  },
-  context: Context
-): void {
-  if (!(klass.prototype instanceof FulfillmentService)) {
-    return
-  }
-
-  const { container, pluginDetails, registrationName } = context
-
-  container.registerAdd(
-    "fulfillmentProviders",
-    asFunction((cradle) => new klass(cradle, pluginDetails.options), {
-      lifetime: klass.LIFE_TIME || Lifetime.SINGLETON,
-    })
-  )
-
-  container.register({
-    [registrationName]: asFunction(
-      (cradle) => new klass(cradle, pluginDetails.options),
-      {
-        lifetime: klass.LIFE_TIME || Lifetime.SINGLETON,
-      }
-    ),
-    [`fp_${(klass as unknown as typeof FulfillmentService).identifier}`]:
-      aliasTo(registrationName),
-  })
-}
diff --git a/packages/medusa/src/loaders/plugins.ts b/packages/medusa/src/loaders/plugins.ts
index 47fbeb172f..1e21f1f8cb 100644
--- a/packages/medusa/src/loaders/plugins.ts
+++ b/packages/medusa/src/loaders/plugins.ts
@@ -1,4 +1,8 @@
-import { promiseAll, SearchUtils, upperCaseFirst } from "@medusajs/utils"
+import {
+  AbstractSearchService,
+  promiseAll,
+  upperCaseFirst,
+} from "@medusajs/utils"
 import { aliasTo, asFunction, asValue, Lifetime } from "awilix"
 import { Express } from "express"
 import fs from "fs"
@@ -6,19 +10,19 @@ import { sync as existsSync } from "fs-exists-cached"
 import glob from "glob"
 import _ from "lodash"
 import { createRequireFromPath } from "medusa-core-utils"
-import { FileService, OauthService } from "medusa-interfaces"
+import { OauthService } from "medusa-interfaces"
 import { trackInstallation } from "medusa-telemetry"
 import { EOL } from "os"
 import path from "path"
 import { EntitySchema } from "typeorm"
 import {
+  AbstractBatchJobStrategy,
+  AbstractCartCompletionStrategy,
+  AbstractFileService,
+  AbstractNotificationService,
+  AbstractPriceSelectionStrategy,
+  AbstractTaxCalculationStrategy,
   AbstractTaxService,
-  isBatchJobStrategy,
-  isCartCompletionStrategy,
-  isFileService,
-  isNotificationService,
-  isPriceSelectionStrategy,
-  isTaxCalculationStrategy,
 } from "../interfaces"
 import { MiddlewareService } from "../services"
 import {
@@ -35,9 +39,7 @@ import { getModelExtensionsMap } from "./helpers/get-model-extension-map"
 import ScheduledJobsLoader from "./helpers/jobs"
 import {
   registerAbstractFulfillmentServiceFromClass,
-  registerFulfillmentServiceFromClass,
   registerPaymentProcessorFromClass,
-  registerPaymentServiceFromClass,
 } from "./helpers/plugins"
 import { RoutesLoader } from "./helpers/routing"
 import { SubscriberLoader } from "./helpers/subscribers"
@@ -230,7 +232,9 @@ export function registerStrategies(
     const module = require(file).default
 
     switch (true) {
-      case isTaxCalculationStrategy(module.prototype): {
+      case AbstractTaxCalculationStrategy.isTaxCalculationStrategy(
+        module.prototype
+      ): {
         if (!("taxCalculationStrategy" in registeredServices)) {
           container.register({
             taxCalculationStrategy: asFunction(
@@ -246,7 +250,9 @@ export function registerStrategies(
         break
       }
 
-      case isCartCompletionStrategy(module.prototype): {
+      case AbstractCartCompletionStrategy.isCartCompletionStrategy(
+        module.prototype
+      ): {
         if (!("cartCompletionStrategy" in registeredServices)) {
           container.register({
             cartCompletionStrategy: asFunction(
@@ -262,7 +268,7 @@ export function registerStrategies(
         break
       }
 
-      case isBatchJobStrategy(module.prototype): {
+      case AbstractBatchJobStrategy.isBatchJobStrategy(module.prototype): {
         container.registerAdd(
           "batchJobStrategies",
           asFunction((cradle) => new module(cradle, pluginDetails.options))
@@ -279,7 +285,9 @@ export function registerStrategies(
         break
       }
 
-      case isPriceSelectionStrategy(module.prototype): {
+      case AbstractPriceSelectionStrategy.isPriceSelectionStrategy(
+        module.prototype
+      ): {
         if (!("priceSelectionStrategy" in registeredServices)) {
           container.register({
             priceSelectionStrategy: asFunction(
@@ -441,8 +449,7 @@ async function registerApi(
 }
 
 /**
- * Registers a service at the right location in our container. If the service is
- * a BaseService instance it will be available directly from the container.
+ * Registers a service at the right location in our container.
  * PaymentService instances are added to the paymentProviders array in the
  * container. Names are camelCase formatted and namespaced by the folder i.e:
  * services/example-payments -> examplePaymentsService
@@ -464,13 +471,10 @@ export async function registerServices(
 
       const context = { container, pluginDetails, registrationName: name }
 
-      registerPaymentServiceFromClass(loaded, context)
       registerPaymentProcessorFromClass(loaded, context)
-
-      registerFulfillmentServiceFromClass(loaded, context)
       registerAbstractFulfillmentServiceFromClass(loaded, context)
 
-      if (loaded.prototype instanceof OauthService) {
+      if (OauthService.isOauthService(loaded.prototype)) {
         const appDetails = loaded.getAppDetails(pluginDetails.options)
 
         const oauthService =
@@ -486,7 +490,9 @@ export async function registerServices(
             }
           ),
         })
-      } else if (isNotificationService(loaded.prototype)) {
+      } else if (
+        AbstractNotificationService.isNotificationService(loaded.prototype)
+      ) {
         container.registerAdd(
           "notificationProviders",
           asFunction((cradle) => new loaded(cradle, pluginDetails.options), {
@@ -505,10 +511,7 @@ export async function registerServices(
           ),
           [`noti_${loaded.identifier}`]: aliasTo(name),
         })
-      } else if (
-        loaded.prototype instanceof FileService ||
-        isFileService(loaded.prototype)
-      ) {
+      } else if (AbstractFileService.isFileService(loaded.prototype)) {
         // Add the service directly to the container in order to make simple
         // resolution if we already know which file storage provider we need to use
         container.register({
@@ -520,7 +523,7 @@ export async function registerServices(
           ),
           [`fileService`]: aliasTo(name),
         })
-      } else if (SearchUtils.isSearchService(loaded.prototype)) {
+      } else if (AbstractSearchService.isSearchService(loaded.prototype)) {
         // Add the service directly to the container in order to make simple
         // resolution if we already know which search provider we need to use
         container.register({
@@ -534,7 +537,7 @@ export async function registerServices(
         })
 
         container.register(isSearchEngineInstalledResolutionKey, asValue(true))
-      } else if (loaded.prototype instanceof AbstractTaxService) {
+      } else if (AbstractTaxService.isTaxService(loaded.prototype)) {
         container.registerAdd(
           "taxProviders",
           asFunction((cradle) => new loaded(cradle, pluginDetails.options), {
diff --git a/packages/medusa/src/loaders/strategies.ts b/packages/medusa/src/loaders/strategies.ts
index 22808c3444..ad2551cc66 100644
--- a/packages/medusa/src/loaders/strategies.ts
+++ b/packages/medusa/src/loaders/strategies.ts
@@ -3,9 +3,9 @@ import path from "path"
 import { aliasTo, asFunction } from "awilix"
 
 import formatRegistrationName from "../utils/format-registration-name"
-import { isBatchJobStrategy } from "../interfaces"
 import { MedusaContainer } from "../types/global"
 import { isDefined } from "medusa-core-utils"
+import { AbstractBatchJobStrategy } from "../interfaces"
 
 type LoaderOptions = {
   container: MedusaContainer
@@ -49,7 +49,7 @@ export default ({ container, configModule, isTest }: LoaderOptions): void => {
     const loaded = require(fn).default
     const name = formatRegistrationName(fn)
 
-    if (isBatchJobStrategy(loaded.prototype)) {
+    if (AbstractBatchJobStrategy.isBatchJobStrategy(loaded.prototype)) {
       container.registerAdd(
         "batchJobStrategies",
         asFunction((cradle) => new loaded(cradle, configModule))
diff --git a/packages/medusa/src/services/system-tax.ts b/packages/medusa/src/services/system-tax.ts
index 855ca52aee..ce9532d90d 100644
--- a/packages/medusa/src/services/system-tax.ts
+++ b/packages/medusa/src/services/system-tax.ts
@@ -10,7 +10,7 @@ class SystemTaxService extends AbstractTaxService {
   static identifier = "system"
 
   constructor() {
-    super()
+    super({})
   }
 
   async getTaxLines(
diff --git a/packages/utils/src/search/abstract-service.ts b/packages/utils/src/search/abstract-service.ts
index 0a265f7166..0ab9628f32 100644
--- a/packages/utils/src/search/abstract-service.ts
+++ b/packages/utils/src/search/abstract-service.ts
@@ -3,6 +3,12 @@ import { SearchTypes } from "@medusajs/types"
 export abstract class AbstractSearchService
   implements SearchTypes.ISearchService
 {
+  static _isSearchService = true
+
+  static isSearchService(obj) {
+    return obj?.constructor?._isSearchService
+  }
+
   abstract readonly isDefault
   protected readonly options_: Record<string, unknown>
 
diff --git a/packages/utils/src/search/index.ts b/packages/utils/src/search/index.ts
index 1ff2fc7601..f2526b1380 100644
--- a/packages/utils/src/search/index.ts
+++ b/packages/utils/src/search/index.ts
@@ -1,6 +1,4 @@
 export * from "./abstract-service"
-export * from "./is-search-service"
 export * from "./search-relations"
 export * from "./index-types"
 export * from "./variant-keys"
-
diff --git a/packages/utils/src/search/is-search-service.ts b/packages/utils/src/search/is-search-service.ts
deleted file mode 100644
index 39fc298152..0000000000
--- a/packages/utils/src/search/is-search-service.ts
+++ /dev/null
@@ -1,5 +0,0 @@
-import { AbstractSearchService } from "./abstract-service"
-
-export function isSearchService(obj: unknown): boolean {
-  return obj instanceof AbstractSearchService
-}