Amplify outputs could not be generated. [ZodError]

[anni1236012]

How did you install the Amplify CLI?

npm create amplify@latest

If applicable, what version of Node.js are you using?

20.9.0

Amplify CLI Version

^1.8.1

What operating system are you using?

Ubuntu

Did you make any manual changes to the cloud resources managed by Amplify? Please describe the changes made.

No manual changes made.

Describe the bug

I am using default AWS Amplify GEN2 todo schema template. Sandbox is created but it failed to generate amplify_outputs.json file.

Expected behavior

generate amplify_outputs.json file.

Reproduction steps

1. npx ampx sandbox --debug

Project Identifier

amplify diagnose --send-report

Learn more at https://docs.amplify.aws/cli/reference/diagnose/
⠋ Creating Zip
No Amplify backend project files detected within this folder.
✖ Creating Zip

Log output

npx ampx sandbox --debug

1:08:10 PM [deploy: CDK_TOOLKIT_I5001] 1:08:10 PM Total time: 103.2s {
  "duration": 103197
}
1:08:10 PM [Sandbox] Deployment successful
1:08:10 PM [Sandbox] Watching for file changes...
Amplify outputs could not be generated. [ZodError] [
  {
    "code": "invalid_key",
    "origin": "record",
    "issues": [
      {
        "expected": "object",
        "code": "invalid_type",
        "path": [],
        "message": "Invalid input: expected object, received string"
      }
    ],
    "path": [
      "AWS::Amplify::Platform"
    ],
    "message": "Invalid key in record"
  },
  {
    "code": "invalid_key",
    "origin": "record",
    "issues": [
      {
        "expected": "object",
        "code": "invalid_type",
        "path": [],
        "message": "Invalid input: expected object, received string"
      }
    ],
    "path": [
      "AWS::Amplify::GraphQL"
    ],
    "message": "Invalid key in record"
  },
  {
    "code": "invalid_key",
    "origin": "record",
    "issues": [
      {
        "expected": "object",
        "code": "invalid_type",
        "path": [],
        "message": "Invalid input: expected object, received string"
      }
    ],
    "path": [
      "AWS::Amplify::Auth"
    ],
    "message": "Invalid key in record"
  }
]

Additional information

package.json file

{
  "name": "iframe-comm",
  "version": "0.1.0",
  "private": true,
  "scripts": {
    "scan:templates": "tsx scripts/scan-templates.ts",
    "generate:versions": "tsx scripts/generate-versions.ts",
    "build:hmr": "NODE_ENV=development tsx scripts/build-iframe-esbuild.ts",
    "build:hmr:prod": "NODE_ENV=production tsx scripts/build-iframe-esbuild.ts",
    "dev": "yarn scan:templates && yarn generate:versions && yarn build:hmr && next dev --turbopack",
    "build": "yarn scan:templates && yarn generate:versions && yarn build:hmr:prod && next build --turbopack",
    "build:ci": "yarn test:ci && yarn build",
    "start": "next start",
    "lint": "eslint",
  },
  "dependencies": {
    "@babel/generator": "^7.28.3",
    "@babel/parser": "^7.28.4",
    "@babel/standalone": "^7.28.4",
    "@babel/traverse": "^7.28.4",
    "@babel/types": "^7.28.4",
    "@dnd-kit/core": "^6.3.1",
    "@dnd-kit/modifiers": "^9.0.0",
    "@dnd-kit/sortable": "^10.0.0",
    "@hookform/resolvers": "^5.2.2",
    "@radix-ui/react-accordion": "^1.2.12",
    "@radix-ui/react-alert-dialog": "^1.1.15",
    "@radix-ui/react-aspect-ratio": "^1.1.7",
    "@radix-ui/react-avatar": "^1.1.10",
    "@radix-ui/react-checkbox": "^1.3.3",
    "@radix-ui/react-collapsible": "^1.1.12",
    "@radix-ui/react-context-menu": "^2.2.16",
    "@radix-ui/react-dialog": "^1.1.15",
    "@radix-ui/react-dropdown-menu": "^2.1.16",
    "@radix-ui/react-hover-card": "^1.1.15",
    "@radix-ui/react-label": "^2.1.7",
    "@radix-ui/react-menubar": "^1.1.16",
    "@radix-ui/react-navigation-menu": "^1.2.14",
    "@radix-ui/react-popover": "^1.1.15",
    "@radix-ui/react-progress": "^1.1.7",
    "@radix-ui/react-radio-group": "^1.3.8",
    "@radix-ui/react-scroll-area": "^1.2.10",
    "@radix-ui/react-select": "^2.2.6",
    "@radix-ui/react-separator": "^1.1.7",
    "@radix-ui/react-slider": "^1.3.6",
    "@radix-ui/react-slot": "^1.2.3",
    "@radix-ui/react-switch": "^1.2.6",
    "@radix-ui/react-tabs": "^1.1.13",
    "@radix-ui/react-toast": "^1.2.15",
    "@radix-ui/react-toggle": "^1.1.10",
    "@radix-ui/react-toggle-group": "^1.1.11",
    "@radix-ui/react-tooltip": "^1.2.8",
    "@tabler/icons-react": "^3.29.0",
    "@tanstack/react-virtual": "^3.13.12",
    "@tsparticles/engine": "^3.9.1",
    "@tsparticles/react": "^3.0.0",
    "@tsparticles/slim": "^3.9.1",
    "@types/three": "^0.174.0",
    "aws-amplify": "^6.15.9",
    "class-variance-authority": "^0.7.1",
    "clsx": "^2.1.1",
    "cmdk": "^1.1.1",
    "cobe": "^0.6.5",
    "culori": "^4.0.2",
    "date-fns": "^4.1.0",
    "dotted-map": "^2.2.3",
    "embla-carousel-react": "^8.6.0",
    "esbuild-wasm": "0.20.2",
    "idb": "^8.0.3",
    "immer": "^10.1.3",
    "input-otp": "^1.4.2",
    "lucide-react": "^0.544.0",
    "motion": "^12.23.22",
    "next": "15.5.4",
    "next-themes": "^0.4.6",
    "react": "19.1.0",
    "react-colorful": "^5.6.1",
    "react-day-picker": "^9.11.0",
    "react-dom": "19.1.0",
    "react-hook-form": "^7.63.0",
    "react-resizable-panels": "^3.0.6",
    "react-syntax-highlighter": "^15.6.6",
    "recharts": "2.15.4",
    "simplex-noise": "^4.0.3",
    "sonner": "^2.0.7",
    "tailwind-merge": "^3.3.1",
    "tailwindcss-animate": "^1.0.7",
    "three": "^0.180.0",
    "tw-animate-css": "^1.4.0",
    "vaul": "^1.1.2",
    "zod": "^4.1.11",
    "zustand": "^5.0.8"
  },
  "devDependencies": {
    "@aws-amplify/backend": "^1.19.0",
    "@aws-amplify/backend-cli": "^1.8.1",
    "@babel/core": "^7.28.4",
    "@babel/preset-typescript": "^7.27.1",
    "@eslint/eslintrc": "^3",
    "@playwright/test": "^1.55.1",
    "@tailwindcss/postcss": "^4",
    "@testing-library/jest-dom": "^6.9.1",
    "@testing-library/react": "^16.3.0",
    "@testing-library/user-event": "^14.6.1",
    "@types/babel__core": "^7.20.5",
    "@types/babel__generator": "^7.27.0",
    "@types/babel__traverse": "^7.28.0",
    "@types/culori": "^4.0.1",
    "@types/node": "^20",
    "@types/react": "^19",
    "@types/react-dom": "^19",
    "@types/react-syntax-highlighter": "^15.5.13",
    "@vitest/ui": "2.1.8",
    "aws-cdk-lib": "^2.216.0",
    "babel-plugin-react-compiler": "^1.0.0",
    "constructs": "^10.4.4",
    "esbuild": "^0.25.12",
    "eslint": "^9",
    "eslint-config-next": "15.5.4",
    "glob": "^11.0.3",
    "happy-dom": "^19.0.2",
    "javascript-obfuscator": "^4.1.1",
    "playwright": "^1.55.1",
    "sharp": "^0.34.4",
    "tailwindcss": "^4",
    "terser": "^5.44.0",
    "tsx": "^4.21.0",
    "typescript": "^5.9.3",
    "vitest": "2.1.8"
  }
}

Before submitting, please confirm:

• I have done my best to include a minimal, self-contained set of instructions for consistently reproducing the issue.
• I have removed any sensitive information from my code snippets and submission.

[pahud]

Hi @anni1236012,

Thank you for reporting this issue! I've identified the root cause of your problem.

Root Cause: Your project has Zod v4.1.11 installed ("zod": "^4.1.11" in your package.json), but Amplify Backend packages require Zod v3.25.17. Zod v4 introduced breaking changes in how z.record() validates keys, which causes the amplify_outputs.json generation to fail.

This is the same issue reported and resolved in aws-amplify/amplify-backend#2994.

Solution: Downgrade Zod to version 3 by adding an override to your package.json:

For npm:

{
  "overrides": {
    "zod": "3.25.17"
  }
}

For yarn:

{
  "resolutions": {
    "zod": "3.25.17"
  }
}

After adding the override:

1. Delete your node_modules folder and lock file
2. Run npm install (or yarn install)
3. Run npx ampx sandbox again

The amplify_outputs.json file should now generate successfully.

Let me know if it works for you.

[anni1236012]

I was using yarn package manager to install. I deleted node_modules and installed with npm and it worked. Yarn did not work.