diff --git a/.changeset/silly-clouds-kneel.md b/.changeset/silly-clouds-kneel.md
new file mode 100644
index 0000000000000..6a3ef0cd21b16
--- /dev/null
+++ b/.changeset/silly-clouds-kneel.md
@@ -0,0 +1,7 @@
+---
+"@medusajs/link-modules": patch
+"@medusajs/modules-sdk": patch
+"@medusajs/core-flows": patch
+---
+
+feat(core-flows,link-modules,modules-sdk): add cart <> promotion link as source of truth
diff --git a/integration-tests/modules/__tests__/cart/store/add-promotions-to-cart.spec.ts b/integration-tests/modules/__tests__/cart/store/add-promotions-to-cart.spec.ts
index 3a05145574789..22229b272d5ea 100644
--- a/integration-tests/modules/__tests__/cart/store/add-promotions-to-cart.spec.ts
+++ b/integration-tests/modules/__tests__/cart/store/add-promotions-to-cart.spec.ts
@@ -1,4 +1,9 @@
-import { ModuleRegistrationName } from "@medusajs/modules-sdk"
+import {
+  LinkModuleUtils,
+  ModuleRegistrationName,
+  Modules,
+  RemoteLink,
+} from "@medusajs/modules-sdk"
 import { ICartModuleService, IPromotionModuleService } from "@medusajs/types"
 import { PromotionType } from "@medusajs/utils"
 import path from "path"
@@ -18,6 +23,7 @@ describe("Store Carts API: Add promotions to cart", () => {
   let shutdownServer
   let cartModuleService: ICartModuleService
   let promotionModuleService: IPromotionModuleService
+  let remoteLinkService: RemoteLink
 
   beforeAll(async () => {
     const cwd = path.resolve(path.join(__dirname, "..", "..", ".."))
@@ -28,6 +34,7 @@ describe("Store Carts API: Add promotions to cart", () => {
     promotionModuleService = appContainer.resolve(
       ModuleRegistrationName.PROMOTION
     )
+    remoteLinkService = appContainer.resolve(LinkModuleUtils.REMOTE_LINK)
   })
 
   afterAll(async () => {
@@ -119,6 +126,11 @@ describe("Store Carts API: Add promotions to cart", () => {
           },
         ])
 
+      await remoteLinkService.create({
+        [Modules.CART]: { cart_id: cart.id },
+        [Modules.PROMOTION]: { promotion_id: appliedPromotion.id },
+      })
+
       const api = useApi() as any
 
       const created = await api.post(`/store/carts/${cart.id}/promotions`, {
@@ -247,6 +259,11 @@ describe("Store Carts API: Add promotions to cart", () => {
         ]
       )
 
+      await remoteLinkService.create({
+        [Modules.CART]: { cart_id: cart.id },
+        [Modules.PROMOTION]: { promotion_id: appliedPromotion.id },
+      })
+
       const [adjustment] = await cartModuleService.addShippingMethodAdjustments(
         cart.id,
         [
diff --git a/integration-tests/modules/__tests__/cart/store/carts.spec.ts b/integration-tests/modules/__tests__/cart/store/carts.spec.ts
index f77d89341eb82..ac8acc091d855 100644
--- a/integration-tests/modules/__tests__/cart/store/carts.spec.ts
+++ b/integration-tests/modules/__tests__/cart/store/carts.spec.ts
@@ -1,4 +1,9 @@
-import { ModuleRegistrationName } from "@medusajs/modules-sdk"
+import {
+  LinkModuleUtils,
+  ModuleRegistrationName,
+  Modules,
+  RemoteLink,
+} from "@medusajs/modules-sdk"
 import {
   ICartModuleService,
   ICustomerModuleService,
@@ -31,7 +36,7 @@ describe("Store Carts API", () => {
   let customerModule: ICustomerModuleService
   let productModule: IProductModuleService
   let pricingModule: IPricingModuleService
-  let remoteLink
+  let remoteLink: RemoteLink
   let promotionModule: IPromotionModuleService
 
   let defaultRegion
@@ -47,7 +52,7 @@ describe("Store Carts API", () => {
     customerModule = appContainer.resolve(ModuleRegistrationName.CUSTOMER)
     productModule = appContainer.resolve(ModuleRegistrationName.PRODUCT)
     pricingModule = appContainer.resolve(ModuleRegistrationName.PRICING)
-    remoteLink = appContainer.resolve("remoteLink")
+    remoteLink = appContainer.resolve(LinkModuleUtils.REMOTE_LINK)
     promotionModule = appContainer.resolve(ModuleRegistrationName.PROMOTION)
   })
 
@@ -351,6 +356,11 @@ describe("Store Carts API", () => {
         },
       ])
 
+      await remoteLink.create({
+        [Modules.CART]: { cart_id: cart.id },
+        [Modules.PROMOTION]: { promotion_id: appliedPromotion.id },
+      })
+
       const api = useApi() as any
 
       // Should remove earlier adjustments from other promocodes
@@ -629,6 +639,11 @@ describe("Store Carts API", () => {
         },
       ])
 
+      await remoteLink.create({
+        [Modules.CART]: { cart_id: cart.id },
+        [Modules.PROMOTION]: { promotion_id: appliedPromotion.id },
+      })
+
       const api = useApi() as any
       const response = await api.post(`/store/carts/${cart.id}/line-items`, {
         variant_id: product.variants[0].id,
diff --git a/integration-tests/modules/__tests__/cart/store/remove-promotions-from-cart.spec.ts b/integration-tests/modules/__tests__/cart/store/remove-promotions-from-cart.spec.ts
index 286d113160272..fc7dedf925d45 100644
--- a/integration-tests/modules/__tests__/cart/store/remove-promotions-from-cart.spec.ts
+++ b/integration-tests/modules/__tests__/cart/store/remove-promotions-from-cart.spec.ts
@@ -1,4 +1,9 @@
-import { ModuleRegistrationName } from "@medusajs/modules-sdk"
+import {
+  LinkModuleUtils,
+  ModuleRegistrationName,
+  Modules,
+  RemoteLink,
+} from "@medusajs/modules-sdk"
 import { ICartModuleService, IPromotionModuleService } from "@medusajs/types"
 import { PromotionType } from "@medusajs/utils"
 import path from "path"
@@ -18,6 +23,7 @@ describe("Store Carts API: Remove promotions from cart", () => {
   let shutdownServer
   let cartModuleService: ICartModuleService
   let promotionModuleService: IPromotionModuleService
+  let remoteLinkService: RemoteLink
 
   beforeAll(async () => {
     const cwd = path.resolve(path.join(__dirname, "..", "..", ".."))
@@ -25,6 +31,7 @@ describe("Store Carts API: Remove promotions from cart", () => {
     shutdownServer = await startBootstrapApp({ cwd, env })
     appContainer = getContainer()
     cartModuleService = appContainer.resolve(ModuleRegistrationName.CART)
+    remoteLinkService = appContainer.resolve(LinkModuleUtils.REMOTE_LINK)
     promotionModuleService = appContainer.resolve(
       ModuleRegistrationName.PROMOTION
     )
@@ -129,6 +136,17 @@ describe("Store Carts API: Remove promotions from cart", () => {
           },
         ])
 
+      await remoteLinkService.create([
+        {
+          [Modules.CART]: { cart_id: cart.id },
+          [Modules.PROMOTION]: { promotion_id: appliedPromotion.id },
+        },
+        {
+          [Modules.CART]: { cart_id: cart.id },
+          [Modules.PROMOTION]: { promotion_id: appliedPromotionToRemove.id },
+        },
+      ])
+
       const api = useApi() as any
 
       const response = await api.delete(`/store/carts/${cart.id}/promotions`, {
@@ -263,6 +281,17 @@ describe("Store Carts API: Remove promotions from cart", () => {
         },
       ])
 
+      await remoteLinkService.create([
+        {
+          [Modules.CART]: { cart_id: cart.id },
+          [Modules.PROMOTION]: { promotion_id: appliedPromotion.id },
+        },
+        {
+          [Modules.CART]: { cart_id: cart.id },
+          [Modules.PROMOTION]: { promotion_id: appliedPromotionToRemove.id },
+        },
+      ])
+
       const api = useApi() as any
 
       const response = await api.delete(`/store/carts/${cart.id}/promotions`, {
diff --git a/packages/core-flows/src/definition/cart/steps/get-actions-to-compute-from-promotions.ts b/packages/core-flows/src/definition/cart/steps/get-actions-to-compute-from-promotions.ts
index 1efbd492f894d..b1eebded3e7fd 100644
--- a/packages/core-flows/src/definition/cart/steps/get-actions-to-compute-from-promotions.ts
+++ b/packages/core-flows/src/definition/cart/steps/get-actions-to-compute-from-promotions.ts
@@ -1,15 +1,9 @@
-import { ModuleRegistrationName } from "@medusajs/modules-sdk"
+import { LinkModuleUtils, ModuleRegistrationName } from "@medusajs/modules-sdk"
 import { CartDTO, IPromotionModuleService } from "@medusajs/types"
-import { PromotionActions, deduplicate, isString } from "@medusajs/utils"
 import { StepResponse, createStep } from "@medusajs/workflows-sdk"
 
 interface StepInput {
   cart: CartDTO
-  promoCodes?: string[]
-  action:
-    | PromotionActions.ADD
-    | PromotionActions.REMOVE
-    | PromotionActions.REPLACE
 }
 
 export const getActionsToComputeFromPromotionsStepId =
@@ -17,46 +11,26 @@ export const getActionsToComputeFromPromotionsStepId =
 export const getActionsToComputeFromPromotionsStep = createStep(
   getActionsToComputeFromPromotionsStepId,
   async (data: StepInput, { container }) => {
-    const promotionModuleService: IPromotionModuleService = container.resolve(
+    const { cart } = data
+    const remoteQuery = container.resolve(LinkModuleUtils.REMOTE_QUERY)
+    const promotionService = container.resolve<IPromotionModuleService>(
       ModuleRegistrationName.PROMOTION
     )
 
-    const { action = PromotionActions.ADD, promoCodes, cart } = data
+    const existingCartPromotionLinks = await remoteQuery({
+      cart_promotion: {
+        __args: { cart_id: [cart.id] },
+        fields: ["id", "cart_id", "promotion_id", "deleted_at"],
+      },
+    })
 
-    if (!Array.isArray(promoCodes)) {
-      return new StepResponse([])
-    }
-
-    const appliedItemPromoCodes = cart.items
-      ?.map((item) => item.adjustments?.map((adjustment) => adjustment.code))
-      .flat(1)
-      .filter(isString) as string[]
-
-    const appliedShippingMethodPromoCodes = cart.shipping_methods
-      ?.map((shippingMethod) =>
-        shippingMethod.adjustments?.map((adjustment) => adjustment.code)
-      )
-      .flat(1)
-      .filter(isString) as string[]
-
-    let promotionCodesToApply = deduplicate([
-      ...promoCodes,
-      ...appliedItemPromoCodes,
-      ...appliedShippingMethodPromoCodes,
-    ])
-
-    if (action === PromotionActions.REMOVE) {
-      promotionCodesToApply = promotionCodesToApply.filter(
-        (code) => !promoCodes.includes(code)
-      )
-    }
-
-    if (action === PromotionActions.REPLACE) {
-      promotionCodesToApply = promoCodes
-    }
+    const existingPromotions = await promotionService.list(
+      { id: existingCartPromotionLinks.map((l) => l.promotion_id) },
+      { take: null, select: ["code"] }
+    )
 
-    const actionsToCompute = await promotionModuleService.computeActions(
-      promotionCodesToApply,
+    const actionsToCompute = await promotionService.computeActions(
+      existingPromotions.map((p) => p.code!),
       cart as any
     )
 
diff --git a/packages/core-flows/src/definition/cart/steps/index.ts b/packages/core-flows/src/definition/cart/steps/index.ts
index c14bd9664327c..68df836551e35 100644
--- a/packages/core-flows/src/definition/cart/steps/index.ts
+++ b/packages/core-flows/src/definition/cart/steps/index.ts
@@ -12,5 +12,6 @@ export * from "./prepare-adjustments-from-promotion-actions"
 export * from "./remove-line-item-adjustments"
 export * from "./remove-shipping-method-adjustments"
 export * from "./retrieve-cart"
+export * from "./update-cart-promotions"
 export * from "./update-carts"
 export * from "./validate-variants-existence"
diff --git a/packages/core-flows/src/definition/cart/steps/update-cart-promotions.ts b/packages/core-flows/src/definition/cart/steps/update-cart-promotions.ts
new file mode 100644
index 0000000000000..6411646098107
--- /dev/null
+++ b/packages/core-flows/src/definition/cart/steps/update-cart-promotions.ts
@@ -0,0 +1,107 @@
+import {
+  LinkModuleUtils,
+  ModuleRegistrationName,
+  Modules,
+} from "@medusajs/modules-sdk"
+import { IPromotionModuleService } from "@medusajs/types"
+import { PromotionActions } from "@medusajs/utils"
+import { StepResponse, createStep } from "@medusajs/workflows-sdk"
+
+interface StepInput {
+  id: string
+  promo_codes?: string[]
+  action?:
+    | PromotionActions.ADD
+    | PromotionActions.REMOVE
+    | PromotionActions.REPLACE
+}
+
+export const updateCartPromotionsStepId = "update-cart-promotions"
+export const updateCartPromotionsStep = createStep(
+  updateCartPromotionsStepId,
+  async (data: StepInput, { container }) => {
+    const { promo_codes = [], id, action = PromotionActions.ADD } = data
+
+    const remoteLink = container.resolve(LinkModuleUtils.REMOTE_LINK)
+    const remoteQuery = container.resolve(LinkModuleUtils.REMOTE_QUERY)
+    const promotionService = container.resolve<IPromotionModuleService>(
+      ModuleRegistrationName.PROMOTION
+    )
+
+    const existingCartPromotionLinks = await remoteQuery({
+      cart_promotion: {
+        __args: { cart_id: [id] },
+        fields: ["cart_id", "promotion_id"],
+      },
+    })
+
+    const promotionLinkMap = new Map<string, any>(
+      existingCartPromotionLinks.map((link) => [link.promotion_id, link])
+    )
+
+    const promotions = await promotionService.list(
+      { code: promo_codes },
+      { select: ["id"] }
+    )
+
+    const linksToCreate: any[] = []
+    const linksToDismiss: any[] = []
+
+    for (const promotion of promotions) {
+      const linkObject = {
+        [Modules.CART]: { cart_id: id },
+        [Modules.PROMOTION]: { promotion_id: promotion.id },
+      }
+
+      if ([PromotionActions.ADD, PromotionActions.REPLACE].includes(action)) {
+        linksToCreate.push(linkObject)
+      }
+
+      if (action === PromotionActions.REMOVE) {
+        const link = promotionLinkMap.get(promotion.id)
+
+        if (link) {
+          linksToDismiss.push(linkObject)
+        }
+      }
+    }
+
+    if (action === PromotionActions.REPLACE) {
+      for (const link of existingCartPromotionLinks) {
+        linksToDismiss.push({
+          [Modules.CART]: { cart_id: link.cart_id },
+          [Modules.PROMOTION]: { promotion_id: link.promotion_id },
+        })
+      }
+    }
+
+    const linksToDismissPromise = linksToDismiss.length
+      ? remoteLink.dismiss(linksToDismiss)
+      : []
+
+    const linksToCreatePromise = linksToCreate.length
+      ? remoteLink.create(linksToCreate)
+      : []
+
+    const [_, createdLinks] = await Promise.all([
+      linksToDismissPromise,
+      linksToCreatePromise,
+    ])
+
+    return new StepResponse(null, {
+      createdLinkIds: createdLinks.map((link) => link.id),
+      dismissedLinks: linksToDismiss,
+    })
+  },
+  async (revertData, { container }) => {
+    const remoteLink = container.resolve(LinkModuleUtils.REMOTE_LINK)
+
+    if (revertData?.dismissedLinks?.length) {
+      await remoteLink.create(revertData.dismissedLinks)
+    }
+
+    if (revertData?.createdLinkIds?.length) {
+      await remoteLink.delete(revertData.createdLinkIds)
+    }
+  }
+)
diff --git a/packages/core-flows/src/definition/cart/workflows/add-to-cart.ts b/packages/core-flows/src/definition/cart/workflows/add-to-cart.ts
index 36faf12b13974..fd9e379149dd0 100644
--- a/packages/core-flows/src/definition/cart/workflows/add-to-cart.ts
+++ b/packages/core-flows/src/definition/cart/workflows/add-to-cart.ts
@@ -19,7 +19,6 @@ import { prepareLineItemData } from "../utils/prepare-line-item-data"
 // TODO: The AddToCartWorkflow are missing the following steps:
 // - Confirm inventory exists (inventory module)
 // - Refresh/delete shipping methods (fulfillment module)
-// - Create line item adjustments (promotion module)
 // - Update payment sessions (payment module)
 
 export const addToCartWorkflowId = "add-to-cart"
diff --git a/packages/core-flows/src/definition/cart/workflows/update-cart-promotions.ts b/packages/core-flows/src/definition/cart/workflows/update-cart-promotions.ts
index e83ec25c84949..78022217c95b0 100644
--- a/packages/core-flows/src/definition/cart/workflows/update-cart-promotions.ts
+++ b/packages/core-flows/src/definition/cart/workflows/update-cart-promotions.ts
@@ -12,6 +12,7 @@ import {
   removeLineItemAdjustmentsStep,
   removeShippingMethodAdjustmentsStep,
   retrieveCartStep,
+  updateCartPromotionsStep,
 } from "../steps"
 
 type WorkflowInput = {
@@ -39,11 +40,15 @@ export const updateCartPromotionsWorkflow = createWorkflow(
       },
     }
 
+    updateCartPromotionsStep({
+      id: input.cartId,
+      promo_codes: input.promoCodes,
+      action: input.action || PromotionActions.ADD,
+    })
+
     const cart = retrieveCartStep(retrieveCartInput)
     const actions = getActionsToComputeFromPromotionsStep({
       cart,
-      promoCodes: input.promoCodes,
-      action: input.action || PromotionActions.ADD,
     })
 
     const {
diff --git a/packages/core-flows/tsconfig.json b/packages/core-flows/tsconfig.json
index d27e01678bb73..e01f3f8b52a0c 100644
--- a/packages/core-flows/tsconfig.json
+++ b/packages/core-flows/tsconfig.json
@@ -9,7 +9,7 @@
     "moduleResolution": "node",
     "emitDecoratorMetadata": true,
     "experimentalDecorators": true,
-    "sourceMap": true,
+    "sourceMap": false,
     "noImplicitReturns": true,
     "strictNullChecks": true,
     "strictFunctionTypes": true,
diff --git a/packages/link-modules/src/definitions/cart-promotion.ts b/packages/link-modules/src/definitions/cart-promotion.ts
new file mode 100644
index 0000000000000..c14221cda0163
--- /dev/null
+++ b/packages/link-modules/src/definitions/cart-promotion.ts
@@ -0,0 +1,55 @@
+import { Modules } from "@medusajs/modules-sdk"
+import { ModuleJoinerConfig } from "@medusajs/types"
+import { LINKS } from "../links"
+
+export const CartPromotion: ModuleJoinerConfig = {
+  serviceName: LINKS.CartPromotion,
+  isLink: true,
+  databaseConfig: {
+    tableName: "cart_promotion",
+    idPrefix: "cartpromo",
+  },
+  alias: [
+    {
+      name: ["cart_promotion", "cart_promotions"],
+      args: {
+        entity: "LinkCartPromotion",
+      },
+    },
+  ],
+  primaryKeys: ["id", "cart_id", "promotion_id"],
+  relationships: [
+    {
+      serviceName: Modules.CART,
+      primaryKey: "id",
+      foreignKey: "cart_id",
+      alias: "cart",
+    },
+    {
+      serviceName: Modules.PROMOTION,
+      primaryKey: "id",
+      foreignKey: "promotion_id",
+      alias: "promotion",
+    },
+  ],
+  extends: [
+    {
+      serviceName: Modules.CART,
+      relationship: {
+        serviceName: LINKS.CartPromotion,
+        primaryKey: "cart_id",
+        foreignKey: "id",
+        alias: "cart_link",
+      },
+    },
+    {
+      serviceName: Modules.PROMOTION,
+      relationship: {
+        serviceName: LINKS.CartPromotion,
+        primaryKey: "promotion_id",
+        foreignKey: "id",
+        alias: "promotion_link",
+      },
+    },
+  ],
+}
diff --git a/packages/link-modules/src/definitions/index.ts b/packages/link-modules/src/definitions/index.ts
index aeb2f0dc1fc93..be6247d3619a7 100644
--- a/packages/link-modules/src/definitions/index.ts
+++ b/packages/link-modules/src/definitions/index.ts
@@ -1,5 +1,6 @@
 export * from "./cart-customer"
 export * from "./cart-payment-collection"
+export * from "./cart-promotion"
 export * from "./cart-region"
 export * from "./cart-sales-channel"
 export * from "./inventory-level-stock-location"
diff --git a/packages/link-modules/src/links.ts b/packages/link-modules/src/links.ts
index 5ea25bab21c5c..00716128bed1a 100644
--- a/packages/link-modules/src/links.ts
+++ b/packages/link-modules/src/links.ts
@@ -20,6 +20,12 @@ export const LINKS = {
     Modules.PAYMENT,
     "payment_collection_id"
   ),
+  CartPromotion: composeLinkName(
+    Modules.CART,
+    "cart_id",
+    Modules.PROMOTION,
+    "promotion_id"
+  ),
 
   // Internal services
   ProductShippingProfile: composeLinkName(
diff --git a/packages/modules-sdk/src/definitions.ts b/packages/modules-sdk/src/definitions.ts
index 86436a2c65ee0..8881451fa1dd3 100644
--- a/packages/modules-sdk/src/definitions.ts
+++ b/packages/modules-sdk/src/definitions.ts
@@ -6,6 +6,11 @@ import {
 
 import { upperCaseFirst } from "@medusajs/utils"
 
+export enum LinkModuleUtils {
+  REMOTE_QUERY = "remoteQuery",
+  REMOTE_LINK = "remoteLink",
+}
+
 export enum Modules {
   AUTH = "auth",
   CACHE = "cacheService",