dotenv Sync & Validator
Keep your local .env files in sync with their .env.example / .env.template
templates — right inside the editor. The extension continuously compares every
template against its matching .env file and flags any key that a teammate
added to the template but that you're still missing locally. One action fills
them in.
No more "works on my machine" because someone forgot to add STRIPE_SECRET_KEY
to their .env.
Features
Live validation
Every key defined in a template but absent from the corresponding .env file is
underlined as a diagnostic in the editor and listed in the Problems panel.
Validation runs automatically as you type or save — no command needed.
# .env.example
DATABASE_URL= # ok, present in .env
STRIPE_SECRET_KEY= # missing from .env -> flagged
SENTRY_DSN= # missing from .env -> flagged
One-action Quick Fix
Put the cursor on a flagged key and open the Code Actions menu
(Ctrl + . on Windows/Linux, Cmd + . on macOS):
- Sync missing key(s) to .env — appends the key under the cursor.
- Sync all N missing keys to .env — appends every missing key at once.
You can also use the sync button that appears in the editor title bar while a
template file is open.
Keys are appended with empty values (KEY=), so your secrets are never
overwritten and nothing is copied out of the template. If the .env file
doesn't exist yet, it is created for you.
Template matching
The extension pairs templates to env files by stripping the template suffix:
| Template |
Local file |
.env.example |
.env |
.env.template |
.env |
.env.production.example |
.env.production |
Commands
Available from the Command Palette (Ctrl/Cmd + Shift + P):
| Command |
Description |
| dotenv Sync: Sync all missing keys to .env |
Sync every missing key for the active template. |
| dotenv Sync: Re-validate .env files |
Force a re-scan of the workspace. |
Extension Settings
| Setting |
Default |
Description |
dotenvSyncValidator.enable |
true |
Enable/disable validation. |
dotenvSyncValidator.diagnosticSeverity |
Warning |
Severity for missing keys (Error, Warning, Information, Hint). |
How it works
The extension watches all .env* files in your workspace. When a template or an
env file changes, it re-parses both, computes the set difference of their keys,
and updates the diagnostics. Only key names are ever read from your files —
values are never inspected, logged, or transmitted.
Try it in this repo
The samples/ folder ships a template and a partly-filled .env.
Press F5 to launch the Extension Development Host, open
samples/.env.example, and try the Quick Fix. See
samples/README.md for the full walkthrough.
Development
This project uses Bun and oxlint.
bun install
bun run check-types # tsc --noEmit
bun run lint # oxlint
bun run test # vscode-test (headless integration tests)
bun run package # production bundle via esbuild
License
MIT © ActiveClientMods
