Or install as standalone binary

Varlock

add declarative schema to your .env files using @env-spec decorator comments

• 🛡️ validation, coercion, type safety w/ IntelliSense
• 🔏 protection for sensitive config values (log redaction, leak prevention)
• 🌐 flexible multi-environment management
• 💫 composition of values, functions, load from external sources

Your .env.schema is a declarative schema of your environment variables that lives within version control, so it will never be out of sync.

# @defaultSensitive=false @defaultRequired=infer @currentEnv=$APP_ENV
# ---
# our environment flag, will control automatic loading of `.env.xxx` files
# @type=enum(development, preview, production, test
APP_ENV=development # default value, can override

# API port
# @type=port @example=3000
API_PORT=

# API url including _expansion_ referencing another env var
# @required @type=url
API_URL=http://localhost:${API_PORT}

# API key with validation, securely fetched from 1Password
# @required @sensitive @type=string(startsWith=sk-)
OPENAI_API_KEY=exec('op read "op://api-prod/openai/api-key"')

# Non-secret value, included directly
# @type=url
SOME_SERVICE_API_URL=https://api.someservice.com

Installation

You can get started with varlock by installing the CLI:

# Run the installation wizard, which will install as a dependency in a JavaScript project
npx varlock init

# Or install as standalone binary
brew install dmno-dev/tap/varlock # via homebrew
curl -sSfL https://varlock.dev/install.sh | sh -s # via cURL

# Or use the official Docker image
docker pull ghcr.io/dmno-dev/varlock:latest

See the full installation docs or the Docker guide for more information.

Workflow

Validate your .env.schema and pretty print your environment variables with:

varlock load

If you need to pass resolved env vars into another process, you can run:

varlock run -- python script.py

Or you can integrate more deeply with one of our integrations to enable security guardrails, like log redaction and leak prevention.

@env-spec

Varlock is built on top of @env-spec, a new DSL for attaching a schema and additional functionality to .env files using JSDoc style comments. The @env-spec package contains a parser and info about the spec itself.

• @env-spec docs
• @env-spec RFC

Published Packages

Package	Published listing page
varlock
@varlock/nextjs-integration
@varlock/vite-integration
@env-spec/parser
@env-spec VSCode extension	VSCode Marketplace, Open VSX Registry
varlock Docker image	GitHub Container Registry

MCP Servers

MCP Server	Link	URL
Varlock Docs (HTTP)	Installation	https://docs.mcp.varlock.dev/mcp
Varlock Docs (SSE)	Installation	https://docs.mcp.varlock.dev/sse

Development & Contribution

See CONTRIBUTING.md for more information.