diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 7095250..9547831 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -31,11 +31,8 @@ jobs:
       - name: Linting
         run: npm run lint
 
-      - name: Run server tests
-        run: npm run test:server
-
       - name: Install Playwright dependencies
         run: npx playwright install --with-deps chromium
 
-      - name: Run Playwright end-to-end tests
-        run: npm run test:frontend
+      - name: Run tests
+        run: npm run test
diff --git a/README.md b/README.md
index a0cda29..ab16fd9 100644
--- a/README.md
+++ b/README.md
@@ -4,11 +4,14 @@ This is a template project for CS4530, Software Engineering at Northeastern.
 
 ## Vite+Express Full-stack React Application
 
-This project has two parts:
-
-1.  A minimal Express transcript API for a very simple transcript server
-2.  A Vite frontend with code that calls that server (this lives in the
-    `./frontend` directory)
+This project has three parts, which together form an
+[npm workspaces](https://docs.npmjs.com/cli/v8/using-npm/workspaces) project.
+
+1.  A minimal Express transcript API for a very simple transcript server (in
+    the `./server` directory)
+2.  A Vite frontend with code that calls that server (in the `./frontend`
+    directory)
+3.  Shared Zod validation and type definitions (in the `./shared` directory)
 
 The way this project runs in "production mode" versus "development mode" is
 very different.
diff --git a/frontend/package.json b/frontend/package.json
new file mode 100644
index 0000000..7a25cef
--- /dev/null
+++ b/frontend/package.json
@@ -0,0 +1,32 @@
+{
+  "name": "@cs4530-workspaces/frontend",
+  "version": "1.0.0",
+  "description": "CS4530 Template",
+  "type": "module",
+  "scripts": {
+    "check": "tsc",
+    "lint": "eslint .",
+    "prettier": "prettier --ignore-path ../.gitignore --check .",
+    "prettier:fix": "prettier --ignore-path ../.gitignore --write .",
+    "test": "playwright test",
+    "dev": "vite",
+    "build": "tsc -b && vite build",
+    "playwright": "playwright test --ui"
+  },
+  "author": "Rob Simmons",
+  "dependencies": {
+    "@cs4530-workspaces/shared": "^1.0.0",
+    "express": "^5.2.1",
+    "react": "^19.2.3",
+    "react-dom": "^19.2.3",
+    "zod": "^4.3.6"
+  },
+  "devDependencies": {
+    "@playwright/test": "^1.58.1",
+    "@types/react": "^19.2.13",
+    "@types/react-dom": "^19.2.3",
+    "@vitejs/plugin-react": "^6.0.1",
+    "vite": "^8.0.0",
+    "vitest": "^4.0.18"
+  }
+}
diff --git a/playwright.config.mjs b/frontend/playwright.config.mjs
similarity index 90%
rename from playwright.config.mjs
rename to frontend/playwright.config.mjs
index fc1d6bf..3b0e608 100644
--- a/playwright.config.mjs
+++ b/frontend/playwright.config.mjs
@@ -3,7 +3,7 @@ import { defineConfig, devices } from "@playwright/test";
 /* global process */ // TODO: is there a better way to avoid making ESLint angry?
 export default defineConfig({
   // Where the tests live, relative to this file
-  testDir: "./frontend/tests/e2e",
+  testDir: "./tests/e2e",
 
   // Fail the build on CI if you accidentally left test.only in the source code.
   forbidOnly: !!process.env.CI,
@@ -31,13 +31,15 @@ export default defineConfig({
   webServer: [
     {
       name: "Frontend",
-      command: "npm run dev:frontend",
+      cwd: "..",
+      command: "npm run dev -w=frontend",
       reuseExistingServer: !process.env.CI,
       url: "http://localhost:5173",
     },
     {
       name: "Server",
-      command: "npm run dev:server",
+      cwd: "..",
+      command: "npm run dev -w=server",
       reuseExistingServer: !process.env.CI,
       url: "http://localhost:3000",
     },
diff --git a/frontend/src/service.ts b/frontend/src/service.ts
index 822a736..c935b37 100644
--- a/frontend/src/service.ts
+++ b/frontend/src/service.ts
@@ -1,4 +1,13 @@
 import { z } from "zod";
+import {
+  zAddGradeResponse,
+  zAddStudentResponse,
+  zError,
+  zGetTranscriptResponse,
+  type AddGradeResponse,
+  type AddStudentResponse,
+  type GetTranscriptResponse,
+} from "@cs4530-workspaces/shared";
 
 export class ServiceError extends Error {
   constructor(message: string) {
@@ -6,9 +15,6 @@ export class ServiceError extends Error {
   }
 }
 
-const zError = z.object({ error: z.string() });
-
-const zAddStudentResponse = z.object({ studentID: z.int() });
 /**
  * Validate inputs and call the `addStudent` api
  *
@@ -20,7 +26,7 @@ const zAddStudentResponse = z.object({ studentID: z.int() });
 export async function addStudent(
   password: string,
   studentName: string,
-): Promise<z.infer<typeof zAddStudentResponse>> {
+): Promise<AddStudentResponse> {
   if (studentName === "") throw new ServiceError("Student name must be non-empty");
 
   const response = await fetch("/api/addStudent", {
@@ -36,7 +42,6 @@ export async function addStudent(
   return data;
 }
 
-const zAddGradeResponse = z.object({ success: z.literal(true) });
 /**
  * Validate inputs and call the `addGrade` api
  *
@@ -52,7 +57,7 @@ export async function addGrade(
   studentIDStr: string,
   courseName: string,
   courseGradeStr: string,
-): Promise<z.infer<typeof zAddGradeResponse>> {
+): Promise<AddGradeResponse> {
   const studentID = parseInt(studentIDStr);
   if (isNaN(studentID) || `${studentID}` !== studentIDStr || studentID < 0) {
     throw new ServiceError("Student ID is invalid");
@@ -87,17 +92,6 @@ export async function addGrade(
   return data;
 }
 
-const zGetTranscriptResponse = z.union([
-  z.object({ success: z.literal(false) }),
-  z.object({
-    success: z.literal(true),
-    transcript: z.object({
-      student: z.object({ studentID: z.int(), studentName: z.string() }),
-      grades: z.array(z.object({ course: z.string(), grade: z.number() })),
-    }),
-  }),
-]);
-
 /**
  * Validate inputs and call the `getTranscript` API
  *
@@ -109,7 +103,7 @@ const zGetTranscriptResponse = z.union([
 export async function getTranscript(
   password: string,
   studentIDStr: string,
-): Promise<z.infer<typeof zGetTranscriptResponse>> {
+): Promise<GetTranscriptResponse> {
   const studentID = parseInt(studentIDStr);
   if (isNaN(studentID) || `${studentID}` !== studentIDStr || studentID < 0) {
     throw new ServiceError("Student ID is invalid");
diff --git a/frontend/vite.config.mjs b/frontend/vite.config.mjs
index 8e407dc..bd95efd 100644
--- a/frontend/vite.config.mjs
+++ b/frontend/vite.config.mjs
@@ -1,9 +1,15 @@
 import { defineConfig } from "vitest/config";
 import react from "@vitejs/plugin-react";
 
+// Must match the port the server creates
+const DEV_BACKEND_PORT = 3000;
+
+// https://vite.dev/config/
 export default defineConfig({
   plugins: [react()],
   server: {
-    proxy: { "/api": `http://localhost:3000` },
+    proxy: {
+      "/api": `http://localhost:${DEV_BACKEND_PORT}`,
+    },
   },
 });
diff --git a/package-lock.json b/package-lock.json
index 122afcb..662d107 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,13 +1,26 @@
 {
-  "name": "cs4530-fullstack",
+  "name": "cs4530-workspaces",
   "version": "1.0.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
-      "name": "cs4530-fullstack",
+      "name": "cs4530-workspaces",
+      "version": "1.0.0",
+      "workspaces": [
+        "frontend",
+        "server",
+        "shared"
+      ],
+      "devDependencies": {
+        "concurrently": "^9.2.1"
+      }
+    },
+    "frontend": {
+      "name": "@cs4530-workspaces/frontend",
       "version": "1.0.0",
       "dependencies": {
+        "@cs4530-workspaces/shared": "^1.0.0",
         "express": "^5.2.1",
         "react": "^19.2.3",
         "react-dom": "^19.2.3",
@@ -15,28 +28,11 @@
       },
       "devDependencies": {
         "@playwright/test": "^1.58.1",
-        "@types/express": "^5.0.6",
-        "@types/react": "^19.2.9",
+        "@types/react": "^19.2.13",
         "@types/react-dom": "^19.2.3",
-        "@types/supertest": "^7.2.0",
         "@vitejs/plugin-react": "^6.0.1",
-        "@vitest/coverage-v8": "^4.0.18",
-        "concurrently": "^9.2.1",
-        "eslint": "^9.39.2",
-        "eslint-config-prettier": "^10.1.8",
-        "eslint-import-resolver-typescript": "^4.4.4",
-        "eslint-plugin-import": "^2.32.0",
-        "eslint-plugin-prettier": "^5.5.4",
-        "eslint-plugin-react-hooks": "^7.0.1",
-        "eslint-plugin-react-refresh": "^0.5.0",
-        "npm-run-all2": "^8.0.4",
-        "playwright": "^1.58.1",
-        "prettier": "^3.7.4",
-        "supertest": "^7.2.2",
-        "typescript": "^6.0.2",
-        "typescript-eslint": "^8.57.3",
         "vite": "^8.0.0",
-        "vitest": "^4.0.17"
+        "vitest": "^4.0.18"
       }
     },
     "node_modules/@babel/code-frame": {
@@ -297,6 +293,18 @@
         "node": ">=18"
       }
     },
+    "node_modules/@cs4530-workspaces/frontend": {
+      "resolved": "frontend",
+      "link": true
+    },
+    "node_modules/@cs4530-workspaces/server": {
+      "resolved": "server",
+      "link": true
+    },
+    "node_modules/@cs4530-workspaces/shared": {
+      "resolved": "shared",
+      "link": true
+    },
     "node_modules/@emnapi/core": {
       "version": "1.10.0",
       "resolved": "https://registry.npmjs.org/@emnapi/core/-/core-1.10.0.tgz",
@@ -1792,7 +1800,6 @@
       "integrity": "sha512-38C0/Ddb7HcRG0Z4/DUem8x57d2p9jYgp18mkaYswEOQBGsI1CG4f/hjm0ZCeaJfWhSZ4k7jgs29V1Zom7Ki9A==",
       "dev": true,
       "license": "MIT",
-      "peer": true,
       "dependencies": {
         "@bcoe/v8-coverage": "^1.0.2",
         "@vitest/utils": "4.1.5",
@@ -4609,16 +4616,6 @@
       "dev": true,
       "license": "MIT"
     },
-    "node_modules/json-parse-even-better-errors": {
-      "version": "4.0.0",
-      "resolved": "https://registry.npmjs.org/json-parse-even-better-errors/-/json-parse-even-better-errors-4.0.0.tgz",
-      "integrity": "sha512-lR4MXjGNgkJc7tkQ97kb2nuEMnNCyU//XYVH0MKTGcXEiSudQ5MKGKen3C5QubYy0vmq+JGitUg92uuywGEwIA==",
-      "dev": true,
-      "license": "MIT",
-      "engines": {
-        "node": "^18.17.0 || >=20.5.0"
-      }
-    },
     "node_modules/json-schema-traverse": {
       "version": "0.4.1",
       "resolved": "https://registry.npmjs.org/json-schema-traverse/-/json-schema-traverse-0.4.1.tgz",
@@ -5033,15 +5030,6 @@
         "node": ">= 0.8"
       }
     },
-    "node_modules/memorystream": {
-      "version": "0.3.1",
-      "resolved": "https://registry.npmjs.org/memorystream/-/memorystream-0.3.1.tgz",
-      "integrity": "sha512-S3UwM3yj5mtUSEfP41UZmt/0SCoVYUcU1rkXv+BQ5Ig8ndL4sPoJNBUJERafdPb5jjHJGuMgytgKvKIf58XNBw==",
-      "dev": true,
-      "engines": {
-        "node": ">= 0.10.0"
-      }
-    },
     "node_modules/merge-descriptors": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/merge-descriptors/-/merge-descriptors-2.0.0.tgz",
@@ -5208,82 +5196,6 @@
       "dev": true,
       "license": "MIT"
     },
-    "node_modules/npm-normalize-package-bin": {
-      "version": "4.0.0",
-      "resolved": "https://registry.npmjs.org/npm-normalize-package-bin/-/npm-normalize-package-bin-4.0.0.tgz",
-      "integrity": "sha512-TZKxPvItzai9kN9H/TkmCtx/ZN/hvr3vUycjlfmH0ootY9yFBzNOpiXAdIn1Iteqsvk4lQn6B5PTrt+n6h8k/w==",
-      "dev": true,
-      "license": "ISC",
-      "engines": {
-        "node": "^18.17.0 || >=20.5.0"
-      }
-    },
-    "node_modules/npm-run-all2": {
-      "version": "8.0.4",
-      "resolved": "https://registry.npmjs.org/npm-run-all2/-/npm-run-all2-8.0.4.tgz",
-      "integrity": "sha512-wdbB5My48XKp2ZfJUlhnLVihzeuA1hgBnqB2J9ahV77wLS+/YAJAlN8I+X3DIFIPZ3m5L7nplmlbhNiFDmXRDA==",
-      "dev": true,
-      "license": "MIT",
-      "dependencies": {
-        "ansi-styles": "^6.2.1",
-        "cross-spawn": "^7.0.6",
-        "memorystream": "^0.3.1",
-        "picomatch": "^4.0.2",
-        "pidtree": "^0.6.0",
-        "read-package-json-fast": "^4.0.0",
-        "shell-quote": "^1.7.3",
-        "which": "^5.0.0"
-      },
-      "bin": {
-        "npm-run-all": "bin/npm-run-all/index.js",
-        "npm-run-all2": "bin/npm-run-all/index.js",
-        "run-p": "bin/run-p/index.js",
-        "run-s": "bin/run-s/index.js"
-      },
-      "engines": {
-        "node": "^20.5.0 || >=22.0.0",
-        "npm": ">= 10"
-      }
-    },
-    "node_modules/npm-run-all2/node_modules/ansi-styles": {
-      "version": "6.2.3",
-      "resolved": "https://registry.npmjs.org/ansi-styles/-/ansi-styles-6.2.3.tgz",
-      "integrity": "sha512-4Dj6M28JB+oAH8kFkTLUo+a2jwOFkuqb3yucU0CANcRRUbxS0cP0nZYCGjcc3BNXwRIsUVmDGgzawme7zvJHvg==",
-      "dev": true,
-      "license": "MIT",
-      "engines": {
-        "node": ">=12"
-      },
-      "funding": {
-        "url": "https://github.com/chalk/ansi-styles?sponsor=1"
-      }
-    },
-    "node_modules/npm-run-all2/node_modules/isexe": {
-      "version": "3.1.5",
-      "resolved": "https://registry.npmjs.org/isexe/-/isexe-3.1.5.tgz",
-      "integrity": "sha512-6B3tLtFqtQS4ekarvLVMZ+X+VlvQekbe4taUkf/rhVO3d/h0M2rfARm/pXLcPEsjjMsFgrFgSrhQIxcSVrBz8w==",
-      "dev": true,
-      "license": "BlueOak-1.0.0",
-      "engines": {
-        "node": ">=18"
-      }
-    },
-    "node_modules/npm-run-all2/node_modules/which": {
-      "version": "5.0.0",
-      "resolved": "https://registry.npmjs.org/which/-/which-5.0.0.tgz",
-      "integrity": "sha512-JEdGzHwwkrbWoGOlIHqQ5gtprKGOenpDHpxE9zVR1bWbOtYRyPPHMe9FaP6x61CmNaTThSkb0DAJte5jD+DmzQ==",
-      "dev": true,
-      "license": "ISC",
-      "dependencies": {
-        "isexe": "^3.1.1"
-      },
-      "bin": {
-        "node-which": "bin/which.js"
-      },
-      "engines": {
-        "node": "^18.17.0 || >=20.5.0"
-      }
-    },
     "node_modules/object-inspect": {
       "version": "1.13.4",
       "resolved": "https://registry.npmjs.org/object-inspect/-/object-inspect-1.13.4.tgz",
@@ -5575,6 +5487,7 @@
       "integrity": "sha512-QP88BAKvMam/3NxH6vj2o21R6MjxZUAd6nlwAS/pnGvN9IVLocLHxGYIzFhg6fUQ+5th6P4dv4eW9jX3DSIj7A==",
       "dev": true,
       "license": "MIT",
+      "peer": true,
       "engines": {
         "node": ">=12"
       },
@@ -5582,19 +5495,6 @@
         "url": "https://github.com/sponsors/jonschlinkert"
       }
     },
-    "node_modules/pidtree": {
-      "version": "0.6.0",
-      "resolved": "https://registry.npmjs.org/pidtree/-/pidtree-0.6.0.tgz",
-      "integrity": "sha512-eG2dWTVw5bzqGRztnHExczNxt5VGsE6OwTeCG3fdUf9KBsZzO3R5OIIIzWR+iZA0NtZ+RDVdaoE2dK1cn6jH4g==",
-      "dev": true,
-      "license": "MIT",
-      "bin": {
-        "pidtree": "bin/pidtree.js"
-      },
-      "engines": {
-        "node": ">=0.10"
-      }
-    },
     "node_modules/playwright": {
       "version": "1.59.1",
       "resolved": "https://registry.npmjs.org/playwright/-/playwright-1.59.1.tgz",
@@ -5790,20 +5690,6 @@
         "react": "^19.2.5"
       }
     },
-    "node_modules/read-package-json-fast": {
-      "version": "4.0.0",
-      "resolved": "https://registry.npmjs.org/read-package-json-fast/-/read-package-json-fast-4.0.0.tgz",
-      "integrity": "sha512-qpt8EwugBWDw2cgE2W+/3oxC+KTez2uSVR8JU9Q36TXPAGCaozfQUs59v4j4GFpWTaw0i6hAZSvOmu1J0uOEUg==",
-      "dev": true,
-      "license": "ISC",
-      "dependencies": {
-        "json-parse-even-better-errors": "^4.0.0",
-        "npm-normalize-package-bin": "^4.0.0"
-      },
-      "engines": {
-        "node": "^18.17.0 || >=20.5.0"
-      }
-    },
     "node_modules/reflect.getprototypeof": {
       "version": "1.0.10",
       "resolved": "https://registry.npmjs.org/reflect.getprototypeof/-/reflect.getprototypeof-1.0.10.tgz",
@@ -6983,7 +6869,6 @@
       "integrity": "sha512-9Xx1v3/ih3m9hN+SbfkUyy0JAs72ap3r7joc87XL6jwF0jGg6mFBvQ1SrwaX+h8BlkX6Hz9shdd1uo6AF+ZGpg==",
       "dev": true,
       "license": "MIT",
-      "peer": true,
       "dependencies": {
         "@vitest/expect": "4.1.5",
         "@vitest/mocker": "4.1.5",
@@ -7305,6 +7190,42 @@
       "peerDependencies": {
         "zod": "^3.25.0 || ^4.0.0"
       }
+    },
+    "server": {
+      "name": "@cs4530-workspaces/server",
+      "version": "1.0.0",
+      "dependencies": {
+        "express": "^5.2.1",
+        "zod": "^4.3.6"
+      },
+      "devDependencies": {
+        "@cs4530-workspaces/shared": "^1.0.0",
+        "@types/express": "^5.0.6",
+        "@types/supertest": "^7.2.0",
+        "@vitest/coverage-v8": "^4.0.18",
+        "supertest": "^7.2.2",
+        "vitest": "^4.0.18"
+      }
+    },
+    "shared": {
+      "name": "@cs4530-workspaces/shared",
+      "version": "1.0.0",
+      "dependencies": {
+        "zod": "^4.3.6"
+      },
+      "devDependencies": {
+        "eslint": "^9.39.2",
+        "eslint-config-prettier": "^10.1.8",
+        "eslint-import-resolver-typescript": "^4.4.4",
+        "eslint-plugin-import": "^2.32.0",
+        "eslint-plugin-prettier": "^5.5.4",
+        "eslint-plugin-react-hooks": "^7.0.1",
+        "eslint-plugin-react-refresh": "^0.5.0",
+        "prettier": "^3.7.4",
+        "typescript": "^6.0.2",
+        "typescript-eslint": "^8.50.0",
+        "vitest": "^4.0.17"
+      }
     }
   }
 }
diff --git a/package.json b/package.json
index 7b1c761..c134957 100644
--- a/package.json
+++ b/package.json
@@ -1,56 +1,25 @@
 {
-  "name": "cs4530-fullstack",
+  "name": "cs4530-workspaces",
   "version": "1.0.0",
   "description": "CS4530 Template",
-  "type": "module",
+  "author": "Rob Simmons",
+  "workspaces": [
+    "frontend",
+    "server",
+    "shared"
+  ],
   "scripts": {
-    "check": "npm-run-all check:*",
-    "check:frontend": "tsc -p frontend/tsconfig.json",
-    "check:server": "tsc",
+    "check": "npm run check --workspaces",
     "lint": "eslint .",
-    "lint:fix": "eslint . --fix",
     "prettier": "prettier --check .",
     "prettier:fix": "prettier --write .",
-    "test": "npm-run-all test:*",
-    "test:frontend": "playwright test",
-    "test:server": "vitest run --coverage",
-    "dev": "concurrently -n frontend,server -c blue,green \"npm run dev:frontend\" \"npm run dev:server\"",
-    "dev:frontend": "vite frontend",
-    "dev:server": "node --watch ./src/server.ts",
-    "build": "tsc -p frontend/tsconfig.json --noEmit && vite build frontend",
-    "start": "MODE=production node ./src/server.ts",
-    "playwright": "playwright test --ui"
+    "test": "npm run test --workspaces",
+    "dev": "concurrently -n frontend,server -c blue,green \"npm run dev -w=frontend\" \"npm run dev -w=server\"",
+    "build": "npm run build -w=frontend",
+    "start": "npm start -w=server",
+    "playwright": "npm run playwright -w=frontend"
   },
-  "author": "Rob Simmons",
   "devDependencies": {
-    "@playwright/test": "^1.58.1",
-    "@types/express": "^5.0.6",
-    "@types/react": "^19.2.9",
-    "@types/react-dom": "^19.2.3",
-    "@types/supertest": "^7.2.0",
-    "@vitejs/plugin-react": "^6.0.1",
-    "@vitest/coverage-v8": "^4.0.18",
-    "concurrently": "^9.2.1",
-    "eslint": "^9.39.2",
-    "eslint-config-prettier": "^10.1.8",
-    "eslint-import-resolver-typescript": "^4.4.4",
-    "eslint-plugin-import": "^2.32.0",
-    "eslint-plugin-prettier": "^5.5.4",
-    "eslint-plugin-react-hooks": "^7.0.1",
-    "eslint-plugin-react-refresh": "^0.5.0",
-    "npm-run-all2": "^8.0.4",
-    "playwright": "^1.58.1",
-    "prettier": "^3.7.4",
-    "supertest": "^7.2.2",
-    "typescript": "^6.0.2",
-    "typescript-eslint": "^8.57.3",
-    "vite": "^8.0.0",
-    "vitest": "^4.0.17"
-  },
-  "dependencies": {
-    "express": "^5.2.1",
-    "react": "^19.2.3",
-    "react-dom": "^19.2.3",
-    "zod": "^4.3.6"
+    "concurrently": "^9.2.1"
   }
 }
diff --git a/server/package.json b/server/package.json
new file mode 100644
index 0000000..b101452
--- /dev/null
+++ b/server/package.json
@@ -0,0 +1,26 @@
+{
+  "name": "@cs4530-workspaces/server",
+  "version": "1.0.0",
+  "type": "module",
+  "scripts": {
+    "check": "tsc",
+    "lint": "eslint .",
+    "prettier": "prettier --ignore-path ../.gitignore --check . ",
+    "prettier:fix": "prettier --ignore-path ../.gitignore --write .",
+    "test": "vitest run --coverage",
+    "dev": "node --watch ./src/server.ts",
+    "start": "MODE=production node ./src/server.ts"
+  },
+  "devDependencies": {
+    "@cs4530-workspaces/shared": "^1.0.0",
+    "@types/express": "^5.0.6",
+    "@types/supertest": "^7.2.0",
+    "@vitest/coverage-v8": "^4.0.18",
+    "supertest": "^7.2.2",
+    "vitest": "^4.0.18"
+  },
+  "dependencies": {
+    "express": "^5.2.1",
+    "zod": "^4.3.6"
+  }
+}
diff --git a/src/api.spec.ts b/server/src/api.spec.ts
similarity index 100%
rename from src/api.spec.ts
rename to server/src/api.spec.ts
diff --git a/src/app.ts b/server/src/app.ts
similarity index 97%
rename from src/app.ts
rename to server/src/app.ts
index 4c610ad..5057f91 100644
--- a/src/app.ts
+++ b/server/src/app.ts
@@ -2,7 +2,7 @@ import express from "express";
 import { z } from "zod";
 import { checkPassword } from "./auth.service.ts";
 import { TranscriptDB } from "./transcript.service.ts";
-import type { Transcript } from "./types.ts";
+import type { Transcript } from "@cs4530-workspaces/shared";
 
 export const app = express();
 app.use(express.json());
diff --git a/src/auth.service.ts b/server/src/auth.service.ts
similarity index 100%
rename from src/auth.service.ts
rename to server/src/auth.service.ts
diff --git a/src/server.ts b/server/src/server.ts
similarity index 88%
rename from src/server.ts
rename to server/src/server.ts
index 6de0f7b..b4f6fde 100644
--- a/src/server.ts
+++ b/server/src/server.ts
@@ -17,9 +17,9 @@ import express from "express";
 //    matter what you do.
 if (process.env.MODE === "production") {
   // In production mode, we want to serve the frontend code from Express
-  app.use(express.static(path.join(import.meta.dirname, "../frontend/dist")));
+  app.use(express.static(path.join(import.meta.dirname, "../../frontend/dist")));
   app.get(/(.*)/, (req, res) =>
-    res.sendFile(path.join(import.meta.dirname, "../frontend/dist/index.html")),
+    res.sendFile(path.join(import.meta.dirname, "../../frontend/dist/index.html")),
   );
 } else {
   app.get("/", (req, res) => {
diff --git a/src/transcript.service.spec.ts b/server/src/transcript.service.spec.ts
similarity index 100%
rename from src/transcript.service.spec.ts
rename to server/src/transcript.service.spec.ts
diff --git a/src/transcript.service.ts b/server/src/transcript.service.ts
similarity index 95%
rename from src/transcript.service.ts
rename to server/src/transcript.service.ts
index 55ec386..da0d5d2 100644
--- a/src/transcript.service.ts
+++ b/server/src/transcript.service.ts
@@ -1,4 +1,9 @@
-import { type StudentID, type Student, type Course, type Transcript } from "./types.ts";
+import {
+  type StudentID,
+  type Student,
+  type Course,
+  type Transcript,
+} from "@cs4530-workspaces/shared";
 
 export class TranscriptDB {
   /**
diff --git a/tsconfig.json b/server/tsconfig.json
similarity index 83%
rename from tsconfig.json
rename to server/tsconfig.json
index c788434..2b9db53 100644
--- a/tsconfig.json
+++ b/server/tsconfig.json
@@ -15,7 +15,5 @@
     /* Linting */
     "noFallthroughCasesInSwitch": true,
     "noImplicitReturns": true
-  },
-  "include": ["./**/*.ts"],
-  "exclude": ["./node_modules", "./client", "./frontend"]
+  }
 }
diff --git a/shared/package.json b/shared/package.json
new file mode 100644
index 0000000..bc7f0ec
--- /dev/null
+++ b/shared/package.json
@@ -0,0 +1,29 @@
+{
+  "name": "@cs4530-workspaces/shared",
+  "version": "1.0.0",
+  "type": "module",
+  "main": "shared.ts",
+  "scripts": {
+    "check": "tsc",
+    "lint": "eslint .",
+    "prettier": "prettier --ignore-path ../.gitignore --check .",
+    "prettier:fix": "prettier --ignore-path ../.gitignore --write .",
+    "test": "vitest run"
+  },
+  "devDependencies": {
+    "eslint": "^9.39.2",
+    "eslint-config-prettier": "^10.1.8",
+    "eslint-import-resolver-typescript": "^4.4.4",
+    "eslint-plugin-import": "^2.32.0",
+    "eslint-plugin-prettier": "^5.5.4",
+    "eslint-plugin-react-hooks": "^7.0.1",
+    "eslint-plugin-react-refresh": "^0.5.0",
+    "prettier": "^3.7.4",
+    "typescript": "^6.0.2",
+    "typescript-eslint": "^8.50.0",
+    "vitest": "^4.0.17"
+  },
+  "dependencies": {
+    "zod": "^4.3.6"
+  }
+}
diff --git a/shared/shared.spec.ts b/shared/shared.spec.ts
new file mode 100644
index 0000000..50afa7e
--- /dev/null
+++ b/shared/shared.spec.ts
@@ -0,0 +1,37 @@
+import { describe, expect, it } from "vitest";
+import { zTranscript } from "./shared.ts";
+
+describe("the Transcript validator", () => {
+  it("forbids omission of the grades element", () => {
+    const response = zTranscript.safeParse({
+      student: { studentID: 4, studentName: "Naomi" },
+    });
+    expect(response.success).toBe(false);
+  });
+
+  it("forbids omission of the student element", () => {
+    const response = zTranscript.safeParse({
+      grades: [],
+    });
+    expect(response.success).toBe(false);
+  });
+
+  it("accepts transcripts with no grades", () => {
+    const response = zTranscript.safeParse({
+      student: { studentID: 4, studentName: "Naomi" },
+      grades: [],
+    });
+    expect(response.success).toBe(true);
+  });
+
+  it("accepts transcripts with duplicate grades", () => {
+    const response = zTranscript.safeParse({
+      student: { studentID: 4, studentName: "Naomi" },
+      grades: [
+        { course: "Math", grade: 4 },
+        { course: "Math", grade: 3 },
+      ],
+    });
+    expect(response.success).toBe(true);
+  });
+});
diff --git a/shared/shared.ts b/shared/shared.ts
new file mode 100644
index 0000000..a717c57
--- /dev/null
+++ b/shared/shared.ts
@@ -0,0 +1,41 @@
+import { z } from "zod";
+
+/** Validator for error responses from the API*/
+export const zError = z.object({ error: z.string() });
+
+/** Validator for non-error POST `/api/addStudent` responses */
+export const zAddStudentResponse = z.object({ studentID: z.int() });
+/** Response type for POST /api/addStudent */
+export type AddStudentResponse = z.infer<typeof zAddStudentResponse>;
+
+/** Validator for POST `/api/addGrade` responses */
+export const zAddGradeResponse = z.object({ success: z.literal(true) });
+/** Response type for POST `/api/addGrade` */
+export type AddGradeResponse = z.infer<typeof zAddGradeResponse>;
+
+/** Validator for student records */
+export const zStudent = z.object({ studentID: z.int(), studentName: z.string() });
+export type Student = z.infer<typeof zStudent>;
+
+/** Validator for individual course grade records */
+export const zCourseGrade = z.object({ course: z.string(), grade: z.number() });
+export type CourseGrade = z.infer<typeof zCourseGrade>;
+
+/** Validator for transcripts */
+export const zTranscript = z.object({ student: zStudent, grades: z.array(zCourseGrade) });
+/** Type of student transcripts */
+export type Transcript = z.infer<typeof zTranscript>;
+
+/** Validator for POST `/api/getTranscript` responses */
+export const zGetTranscriptResponse = z.union([
+  z.object({ success: z.literal(false) }),
+  z.object({ success: z.literal(true), transcript: zTranscript }),
+]);
+/** Response type for POST `/api/zGetTranscript` */
+export type GetTranscriptResponse = z.infer<typeof zGetTranscriptResponse>;
+
+// Aliases for simple types
+
+export type Course = string;
+export type StudentID = number;
+export type StudentName = string;
diff --git a/shared/tsconfig.json b/shared/tsconfig.json
new file mode 100644
index 0000000..2b9db53
--- /dev/null
+++ b/shared/tsconfig.json
@@ -0,0 +1,19 @@
+/* Visit https://www.typescriptlang.org/tsconfig/ to learn about this file */
+{
+  "compilerOptions": {
+    /* Basic configuration */
+    "lib": ["ES2024"],
+    "module": "node18",
+    "skipLibCheck": true,
+    "noEmit": true,
+
+    /* Support the use of type stripping in Node */
+    "allowImportingTsExtensions": true,
+    "erasableSyntaxOnly": true,
+    "verbatimModuleSyntax": true,
+
+    /* Linting */
+    "noFallthroughCasesInSwitch": true,
+    "noImplicitReturns": true
+  }
+}
diff --git a/src/types.ts b/src/types.ts
deleted file mode 100644
index b2b9f26..0000000
--- a/src/types.ts
+++ /dev/null
@@ -1,8 +0,0 @@
-// types.ts - types for the transcript service
-
-export type Course = string;
-export type StudentID = number;
-export type StudentName = string;
-export type Student = { studentID: StudentID; studentName: StudentName };
-export type CourseGrade = { course: Course; grade: number };
-export type Transcript = { student: Student; grades: CourseGrade[] };
diff --git a/vitest.config.mjs b/vitest.config.mjs
deleted file mode 100644
index 0aaff1a..0000000
--- a/vitest.config.mjs
+++ /dev/null
@@ -1,7 +0,0 @@
-import { defineConfig } from "vitest/config";
-
-export default defineConfig({
-  test: {
-    exclude: ["**/node_modules/**", "**/.git/**", "./{client,frontend}/**"],
-  },
-});