diff --git a/.changeset/new-icons-chew.md b/.changeset/new-icons-chew.md
new file mode 100644
index 0000000000..269b235443
--- /dev/null
+++ b/.changeset/new-icons-chew.md
@@ -0,0 +1,7 @@
+---
+"medusa-fulfillment-manual": patch
+"medusa-interfaces": patch
+"@medusajs/medusa": patch
+---
+
+Convert FulfillmentService to TypeScript
diff --git a/packages/medusa-fulfillment-manual/src/services/manual-fulfillment.js b/packages/medusa-fulfillment-manual/src/services/manual-fulfillment.js
index a03d5499e7..c0b5ddedc1 100644
--- a/packages/medusa-fulfillment-manual/src/services/manual-fulfillment.js
+++ b/packages/medusa-fulfillment-manual/src/services/manual-fulfillment.js
@@ -19,7 +19,7 @@ class ManualFulfillmentService extends FulfillmentService {
     ]
   }
 
-  validateFulfillmentData(data, cart) {
+  validateFulfillmentData(_, data, cart) {
     return data
   }
 
diff --git a/packages/medusa-interfaces/src/fulfillment-service.js b/packages/medusa-interfaces/src/fulfillment-service.js
index 4e56063a63..912480a0b0 100644
--- a/packages/medusa-interfaces/src/fulfillment-service.js
+++ b/packages/medusa-interfaces/src/fulfillment-service.js
@@ -24,7 +24,9 @@ class BaseFulfillmentService extends BaseService {
    * to create shipping options in Medusa that can be chosen between by the
    * customer.
    */
-  getFulfillmentOptions() {}
+  getFulfillmentOptions() {
+    throw Error("getFulfillmentOptions must be overridden by the child class")
+  }
 
   /**
    * Called before a shipping method is set on a cart to ensure that the data
@@ -32,12 +34,13 @@ class BaseFulfillmentService extends BaseService {
    * data about the shipment such as an id of a drop point. It is up to the
    * fulfillment provider to enforce that the correct data is being sent
    * through.
+   * @param {object} optionData - the data to validate
    * @param {object} data - the data to validate
-   * @param {object} cart - the cart to which the shipping method will be applied
+   * @param {object | undefined} cart - the cart to which the shipping method will be applied
    * @return {object} the data to populate `cart.shipping_methods.$.data` this
    *    is usually important for future actions like generating shipping labels
    */
-  validateFulfillmentData(data, cart) {
+  validateFulfillmentData(optionData, data, cart) {
     throw Error("validateFulfillmentData must be overridden by the child class")
   }
 
@@ -56,12 +59,16 @@ class BaseFulfillmentService extends BaseService {
   /**
    * Used to calculate a price for a given shipping option.
    */
-  calculatePrice(data, cart) {
+  calculatePrice(optionData, data, cart) {
     throw Error("calculatePrice must be overridden by the child class")
   }
 
-  createFulfillment() {
-    throw Error("createOrder must be overridden by the child class")
+  createFulfillment(data, items, order, fulfillment) {
+    throw Error("createFulfillment must be overridden by the child class")
+  }
+
+  cancelFulfillment(fulfillment) {
+    throw Error("cancelFulfillment must be overridden by the child class")
   }
 
   /**
@@ -94,6 +101,10 @@ class BaseFulfillmentService extends BaseService {
   getShipmentDocuments(data) {
     return []
   }
+
+  retrieveDocuments(fulfillmentData, documentType) { 
+    throw Error("retrieveDocuments must be overridden by the child class")
+  }
 }
 
 export default BaseFulfillmentService
diff --git a/packages/medusa/src/services/fulfillment-provider.js b/packages/medusa/src/services/fulfillment-provider.js
deleted file mode 100644
index cc6e5ffca4..0000000000
--- a/packages/medusa/src/services/fulfillment-provider.js
+++ /dev/null
@@ -1,108 +0,0 @@
-import { MedusaError } from "medusa-core-utils"
-
-/**
- * Helps retrive fulfillment providers
- */
-class FulfillmentProviderService {
-  constructor(container) {
-    /** @private {logger} */
-    this.container_ = container
-  }
-
-  async registerInstalledProviders(providers) {
-    const { manager, fulfillmentProviderRepository } = this.container_
-    const model = manager.getCustomRepository(fulfillmentProviderRepository)
-    await model.update({}, { is_installed: false })
-
-    for (const p of providers) {
-      const n = model.create({ id: p, is_installed: true })
-      await model.save(n)
-    }
-  }
-
-  async list() {
-    const { manager, fulfillmentProviderRepository } = this.container_
-    const fpRepo = manager.getCustomRepository(fulfillmentProviderRepository)
-
-    return await fpRepo.find({})
-  }
-
-  async listFulfillmentOptions(providers) {
-    const result = await Promise.all(
-      providers.map(async (p) => {
-        const provider = await this.retrieveProvider(p)
-        return {
-          provider_id: p,
-          options: await provider.getFulfillmentOptions(),
-        }
-      })
-    )
-
-    return result
-  }
-
-  /**
-   * @param {string} provider_id - the provider id
-   * @return {FulfillmentService} the payment fulfillment provider
-   */
-  retrieveProvider(provider_id) {
-    try {
-      return this.container_[`fp_${provider_id}`]
-    } catch (err) {
-      throw new MedusaError(
-        MedusaError.Types.NOT_FOUND,
-        `Could not find a fulfillment provider with id: ${provider_id}`
-      )
-    }
-  }
-
-  async createFulfillment(method, items, order, fulfillment) {
-    const provider = this.retrieveProvider(method.shipping_option.provider_id)
-    return provider.createFulfillment(method.data, items, order, fulfillment)
-  }
-
-  async canCalculate(option) {
-    const provider = this.retrieveProvider(option.provider_id)
-    return provider.canCalculate(option.data)
-  }
-
-  async validateFulfillmentData(option, data, cart) {
-    const provider = this.retrieveProvider(option.provider_id)
-    return provider.validateFulfillmentData(option.data, data, cart)
-  }
-
-  async cancelFulfillment(fulfillment) {
-    const provider = this.retrieveProvider(fulfillment.provider_id)
-    return provider.cancelFulfillment(fulfillment.data)
-  }
-
-  async calculatePrice(option, data, cart) {
-    const provider = this.retrieveProvider(option.provider_id)
-    return provider.calculatePrice(option.data, data, cart)
-  }
-
-  async validateOption(option) {
-    const provider = this.retrieveProvider(option.provider_id)
-    return provider.validateOption(option.data)
-  }
-
-  async createReturn(returnOrder) {
-    const option = returnOrder.shipping_method.shipping_option
-    const provider = this.retrieveProvider(option.provider_id)
-    return provider.createReturn(returnOrder)
-  }
-
-  /**
-   * Fetches documents from the fulfillment provider
-   * @param {string} providerId - the id of the provider
-   * @param {object} fulfillmentData - the data relating to the fulfillment
-   * @param {"invoice" | "label"} documentType - the typ of
-   *  document to fetch
-   */
-  async retrieveDocuments(providerId, fulfillmentData, documentType) {
-    const provider = this.retrieveProvider(providerId)
-    return provider.retrieveDocuments(fulfillmentData, documentType)
-  }
-}
-
-export default FulfillmentProviderService
diff --git a/packages/medusa/src/services/fulfillment-provider.ts b/packages/medusa/src/services/fulfillment-provider.ts
new file mode 100644
index 0000000000..e58181d921
--- /dev/null
+++ b/packages/medusa/src/services/fulfillment-provider.ts
@@ -0,0 +1,191 @@
+import { MedusaError } from "medusa-core-utils"
+import BaseFulfillmentService from "medusa-interfaces/dist/fulfillment-service"
+import { EntityManager } from "typeorm"
+import { TransactionBaseService } from "../interfaces"
+import {
+  Cart,
+  Fulfillment,
+  FulfillmentProvider,
+  LineItem,
+  Order,
+  Return,
+  ShippingMethod,
+  ShippingOption,
+} from "../models"
+import { FulfillmentProviderRepository } from "../repositories/fulfillment-provider"
+import { CreateFulfillmentOrder } from "../types/fulfillment"
+import {
+  CreateReturnType,
+  FulfillmentOptions,
+} from "../types/fulfillment-provider"
+import { MedusaContainer } from "../types/global"
+
+type FulfillmentProviderKey = `fp_${string}`
+
+type FulfillmentProviderContainer = MedusaContainer & {
+  fulfillmentProviderRepository: typeof FulfillmentProviderRepository
+  manager: EntityManager
+} & {
+  [key in `${FulfillmentProviderKey}`]: BaseFulfillmentService
+}
+
+/**
+ * Helps retrive fulfillment providers
+ */
+class FulfillmentProviderService extends TransactionBaseService {
+  protected manager_: EntityManager
+  protected transactionManager_: EntityManager | undefined
+
+  protected readonly container_: FulfillmentProviderContainer
+
+  protected readonly fulfillmentProviderRepository_: typeof FulfillmentProviderRepository
+
+  constructor(container: FulfillmentProviderContainer) {
+    super(container)
+
+    const { manager, fulfillmentProviderRepository } = container
+
+    this.container_ = container
+    this.manager_ = manager
+    this.fulfillmentProviderRepository_ = fulfillmentProviderRepository
+  }
+
+  async registerInstalledProviders(providers: string[]): Promise<void> {
+    return await this.atomicPhase_(async (manager) => {
+      const fulfillmentProviderRepo = manager.getCustomRepository(
+        this.fulfillmentProviderRepository_
+      )
+      await fulfillmentProviderRepo.update({}, { is_installed: false })
+
+      for (const p of providers) {
+        const n = fulfillmentProviderRepo.create({ id: p, is_installed: true })
+        await fulfillmentProviderRepo.save(n)
+      }
+    })
+  }
+
+  async list(): Promise<FulfillmentProvider[]> {
+    const fpRepo = this.manager_.getCustomRepository(
+      this.fulfillmentProviderRepository_
+    )
+
+    return await fpRepo.find({})
+  }
+
+  async listFulfillmentOptions(
+    providerIds: string[]
+  ): Promise<FulfillmentOptions[]> {
+    return await Promise.all(
+      providerIds.map(async (p) => {
+        const provider = await this.retrieveProvider(p)
+        return {
+          provider_id: p,
+          options:
+            (await provider.getFulfillmentOptions()) as unknown as Record<
+              string,
+              unknown
+            >[],
+        }
+      })
+    )
+  }
+
+  /**
+   * @param providerId - the provider id
+   * @return the payment fulfillment provider
+   */
+  retrieveProvider(providerId: string): BaseFulfillmentService {
+    try {
+      return this.container_[`fp_${providerId}`]
+    } catch (err) {
+      throw new MedusaError(
+        MedusaError.Types.NOT_FOUND,
+        `Could not find a fulfillment provider with id: ${providerId}`
+      )
+    }
+  }
+
+  async createFulfillment(
+    method: ShippingMethod,
+    items: LineItem[],
+    order: CreateFulfillmentOrder,
+    fulfillment: Omit<Fulfillment, "beforeInsert">
+  ): Promise<Record<string, unknown>> {
+    const provider = this.retrieveProvider(method.shipping_option.provider_id)
+    return provider.createFulfillment(
+      method.data,
+      items,
+      order,
+      fulfillment
+    ) as unknown as Record<string, unknown>
+  }
+
+  async canCalculate(option: ShippingOption): Promise<boolean> {
+    const provider = this.retrieveProvider(option.provider_id)
+    return provider.canCalculate(option.data) as unknown as boolean
+  }
+
+  async validateFulfillmentData(
+    option: ShippingOption,
+    data: Record<string, unknown>,
+    cart: Cart | Record<string, unknown>
+  ): Promise<Record<string, unknown>> {
+    const provider = this.retrieveProvider(option.provider_id)
+    return provider.validateFulfillmentData(
+      option.data,
+      data,
+      cart
+    ) as unknown as Record<string, unknown>
+  }
+
+  async cancelFulfillment(fulfillment: Fulfillment): Promise<Fulfillment> {
+    const provider = this.retrieveProvider(fulfillment.provider_id)
+    return provider.cancelFulfillment(
+      fulfillment.data
+    ) as unknown as Fulfillment
+  }
+
+  async calculatePrice(
+    option: ShippingOption,
+    data: Record<string, unknown>,
+    cart?: Order | Cart
+  ): Promise<number> {
+    const provider = this.retrieveProvider(option.provider_id)
+    return provider.calculatePrice(option.data, data, cart) as unknown as number
+  }
+
+  async validateOption(option: ShippingOption): Promise<boolean> {
+    const provider = this.retrieveProvider(option.provider_id)
+    return provider.validateOption(option.data) as unknown as boolean
+  }
+
+  async createReturn(
+    returnOrder: CreateReturnType
+  ): Promise<Record<string, unknown>> {
+    const option = returnOrder.shipping_method.shipping_option
+    const provider = this.retrieveProvider(option.provider_id)
+    return provider.createReturn(returnOrder) as unknown as Record<
+      string,
+      unknown
+    >
+  }
+
+  /**
+   * Fetches documents from the fulfillment provider
+   * @param providerId - the id of the provider
+   * @param fulfillmentData - the data relating to the fulfillment
+   * @param documentType - the typ of
+   * @returns document to fetch
+   */
+  // TODO: consider removal in favor of "getReturnDocuments" and "getShipmentDocuments"
+  async retrieveDocuments(
+    providerId: string,
+    fulfillmentData: Record<string, unknown>,
+    documentType: "invoice" | "label"
+  ): Promise<any> {
+    const provider = this.retrieveProvider(providerId)
+    return provider.retrieveDocuments(fulfillmentData, documentType)
+  }
+}
+
+export default FulfillmentProviderService
diff --git a/packages/medusa/src/services/shipping-option.ts b/packages/medusa/src/services/shipping-option.ts
index a11a68ae94..83dee51501 100644
--- a/packages/medusa/src/services/shipping-option.ts
+++ b/packages/medusa/src/services/shipping-option.ts
@@ -252,7 +252,7 @@ class ShippingOptionService extends TransactionBaseService {
    */
   async createShippingMethod(
     optionId: string,
-    data: object,
+    data: Record<string, unknown>,
     config: CreateShippingMethodDto
   ): Promise<ShippingMethod> {
     return await this.atomicPhase_(async (manager) => {
@@ -678,7 +678,7 @@ class ShippingOptionService extends TransactionBaseService {
    */
   async getPrice_(
     option: ShippingOption,
-    data: object,
+    data: Record<string, unknown>,
     cart: Cart | Order | undefined
   ): Promise<number> {
     if (option.price_type === "calculated") {
diff --git a/packages/medusa/src/types/fulfillment-provider.ts b/packages/medusa/src/types/fulfillment-provider.ts
new file mode 100644
index 0000000000..641bcba459
--- /dev/null
+++ b/packages/medusa/src/types/fulfillment-provider.ts
@@ -0,0 +1,8 @@
+import { Return } from "../models"
+
+export type FulfillmentOptions = {
+  provider_id: string
+  options: Record<string, unknown>[]
+}
+
+export type CreateReturnType = Omit<Return, "beforeInsert">