diff --git a/apps/studio/src/server/modules/folder/__tests__/folder.router.test.ts b/apps/studio/src/server/modules/folder/__tests__/folder.router.test.ts
new file mode 100644
index 000000000..54796eff0
--- /dev/null
+++ b/apps/studio/src/server/modules/folder/__tests__/folder.router.test.ts
@@ -0,0 +1,218 @@
+import { TRPCError } from "@trpc/server"
+import {
+  applyAuthedSession,
+  applySession,
+  createMockRequest,
+} from "tests/integration/helpers/iron-session"
+import {
+  setupFolder,
+  setupPageResource,
+  setupSite,
+} from "tests/integration/helpers/seed"
+
+import { createCallerFactory } from "~/server/trpc"
+import { db } from "../../database"
+import { folderRouter } from "../folder.router"
+
+const createCaller = createCallerFactory(folderRouter)
+
+describe("folder.router", () => {
+  let caller: ReturnType<typeof createCaller>
+  let unauthedCaller: ReturnType<typeof createCaller>
+
+  beforeAll(async () => {
+    const session = await applyAuthedSession()
+    caller = createCaller(createMockRequest(session))
+    const unauthedSession = applySession()
+    unauthedCaller = createCaller(createMockRequest(unauthedSession))
+  })
+
+  describe("create", () => {
+    it("should throw 401 if not logged in", async () => {
+      // Act
+      const result = unauthedCaller.create({
+        folderTitle: "test folder",
+        siteId: 1,
+        permalink: "test-folder",
+      })
+
+      // Assert
+      await expect(result).rejects.toThrowError(
+        new TRPCError({ code: "UNAUTHORIZED" }),
+      )
+    })
+
+    it("should throw 409 if permalink already exists", async () => {
+      // Arrange
+      const duplicatePermalink = "duplicate-permalink"
+      const { site } = await setupFolder({ permalink: duplicatePermalink })
+
+      // Act
+      const result = caller.create({
+        folderTitle: "test folder",
+        siteId: site.id,
+        permalink: duplicatePermalink,
+      })
+
+      // Assert
+      await expect(result).rejects.toThrowError(
+        new TRPCError({
+          code: "CONFLICT",
+          message: "A resource with the same permalink already exists",
+        }),
+      )
+    })
+
+    it("should throw 404 if `siteId` does not exist", async () => {
+      // Arrange
+      const invalidSiteId = 999
+      const { site } = await setupSite()
+      expect(site.id).not.toEqual(invalidSiteId)
+
+      // Act
+      const result = caller.create({
+        folderTitle: "test folder",
+        siteId: invalidSiteId,
+        permalink: "test-folder",
+      })
+
+      // Assert
+      await expect(result).rejects.toThrowError(
+        new TRPCError({
+          code: "NOT_FOUND",
+          message: "Site does not exist",
+        }),
+      )
+    })
+
+    it("should throw 404 if `parentFolderId` does not exist", async () => {
+      // Arrange
+      const { site } = await setupSite()
+
+      // Act
+      const result = caller.create({
+        folderTitle: "test folder",
+        siteId: site.id,
+        permalink: "test-folder",
+        parentFolderId: 999,
+      })
+
+      // Assert
+      await expect(result).rejects.toThrowError(
+        new TRPCError({
+          code: "NOT_FOUND",
+          message: "Parent folder does not exist",
+        }),
+      )
+    })
+
+    it("should throw 400 if `parentFolderId` is not a folder", async () => {
+      // Arrange
+      const { site, page } = await setupPageResource({
+        resourceType: "Page",
+      })
+
+      // Act
+      const result = caller.create({
+        folderTitle: "test folder",
+        siteId: site.id,
+        permalink: "test-folder",
+        parentFolderId: Number(page.id),
+      })
+
+      // Assert
+      await expect(result).rejects.toThrowError(
+        new TRPCError({
+          code: "BAD_REQUEST",
+          message: "Resource ID does not point to a folder",
+        }),
+      )
+    })
+
+    it("should create a folder even with duplicate permalink if `siteId` is different", async () => {
+      // Arrange
+      const duplicatePermalink = "duplicate-permalink"
+      const { site: _firstSite } = await setupFolder({
+        permalink: duplicatePermalink,
+      })
+      const { site: secondSite } = await setupSite()
+
+      // Act
+      const result = await caller.create({
+        folderTitle: "test folder",
+        siteId: secondSite.id,
+        permalink: duplicatePermalink,
+      })
+
+      // Assert
+      const actualFolder = await getFolderWithPermalink({
+        siteId: secondSite.id,
+        permalink: duplicatePermalink,
+      })
+      expect(result).toEqual({ folderId: actualFolder.id })
+    })
+
+    it("should create a folder", async () => {
+      // Arrange
+      const permalinkToUse = "test-folder-999"
+      const { site } = await setupSite()
+      // Act
+      const result = await caller.create({
+        folderTitle: "test folder 999",
+        siteId: site.id,
+        permalink: permalinkToUse,
+      })
+
+      // Assert
+      const actualFolder = await getFolderWithPermalink({
+        permalink: permalinkToUse,
+        siteId: site.id,
+      })
+      expect(result).toEqual({ folderId: actualFolder.id })
+    })
+
+    it("should create a nested folder if `parentFolderId` is provided", async () => {
+      // Arrange
+      const permalinkToUse = "test-folder-777"
+      const { folder: parentFolder, site } = await setupFolder()
+
+      // Act
+      const result = await caller.create({
+        folderTitle: "test folder",
+        siteId: site.id,
+        permalink: permalinkToUse,
+        parentFolderId: Number(parentFolder.id),
+      })
+
+      // Assert
+      const actualFolder = await getFolderWithPermalink({
+        permalink: permalinkToUse,
+        siteId: site.id,
+      })
+      expect(actualFolder.parentId).toEqual(parentFolder.id)
+      expect(result).toEqual({ folderId: actualFolder.id })
+    })
+
+    // TODO: Add tests when permissions are implemented
+    it.skip("should throw 403 if user does not have write access to the site", async () => {})
+
+    it.skip("should throw 403 if user does not have write access to the parent folder", async () => {})
+  })
+})
+
+// Test util functions
+const getFolderWithPermalink = ({
+  siteId,
+  permalink,
+}: {
+  siteId: number
+  permalink: string
+}) => {
+  return db
+    .selectFrom("Resource")
+    .where("type", "=", "Folder")
+    .where("siteId", "=", siteId)
+    .where("permalink", "=", permalink)
+    .selectAll()
+    .executeTakeFirstOrThrow()
+}