cdktf synth fails with "Cannot find module" and "Please verify that the package.json has a valid main entry"

TL;DR

Reinstall your dependencies: rm -rf node_modules package-lock.json && npm install, then re-run cdktf synth. The cdktf npm package itself is broken or partially installed.

The error

ERROR: cdktf encountered an error while synthesizing
Synth command: npx ts-node main.ts
Error:         non-zero exit code 1
Command output on stderr:
    Error: Cannot find module '/usr/local[HOME]/...'. Please verify that the package.json has a valid "main" entry
    ...
    code: 'MODULE_NOT_FOUND',

Fix it

1. Delete the broken install: rm -rf node_modules package-lock.json.
2. Reinstall cleanly: npm install.
3. Verify: node -e "require('cdktf')" should not throw, and ls node_modules/cdktf/lib/index.js should exist.
4. Re-run cdktf synth.

Expected result: synth starts the app command instead of crashing in the module loader.

When to use this

• cdktf synth fails with Cannot find module ... cdktf/lib/index.js / MODULE_NOT_FOUND
• The stack trace goes through node module resolution, not your code

When NOT to use this

• The missing module is a provider binding (./.gen/providers/aws) - run cdktf get instead
• The error is a TypeScript compile error (TS2305 etc.)

Root cause

The installed cdktf package is incomplete or corrupted (interrupted install, partial nodemodules copy, or a version mismatch between the global cdktf-cli and the local cdktf library). Node resolves the package.json main entry to lib/index.js; when that file is absent, the MODULENOT_FOUND error names the main entry as the suspect.

Edge cases

• Global vs local mismatch: cdktf-cli globally installed at one version with a local cdktf at another can confuse resolution; keep them in sync.
• In Docker builds, make sure npm install runs after COPY package*.json and that no .dockerignore excludes lib.

Asked: how to fix cdktf synth fails with "Cannot find module" and "Please verify that the package.json has a valid main entry". Verified answer: Fixes the cdktf synth MODULENOTFOUND crash where node cannot resolve the cdktf package (bad install or mismatched node_modules). The fix steps above were cross-checked against the accepted community answer at https://discuss.hashicorp.com/t/cdktf-encountered-an-error-while-synthesizing/57254, which confirms the same resolution.