> ## Documentation Index > Fetch the complete documentation index at: https://docs.ghostable.dev/llms.txt > Use this file to discover all available pages before exploring further. # Validation Rules > Validation rules define the expected shape of environment variables before they are pushed or deployed. Validation rules apply to project environments, not isolated local files. ## How Validation Works Ghostable validation rules live alongside your local project metadata: ```yaml Example theme={null} .ghostable/ ghostable.yaml schema.yaml schemas/ production.yaml staging.yaml ``` * `.ghostable/schema.yaml` defines global rules. * `.ghostable/schemas/.yaml` overrides or extends rules for a specific environment. Validation runs locally. The client loads your schema files and compares them against the variables being worked on. Plaintext values do not need to be uploaded for validation to happen. ## Why Teams Use It Validation catches drift before a push, export, or deployment turns into a production issue. Common checks include: * required keys, * allowed values, * string length limits, * URLs, emails, and other format rules, * environment-specific overrides. ## Desktop vs CLI * **Desktop** uses the linked project folder to read schema files, edit them in the built-in Rules Editor, and run validation against project environments. * **CLI** reads the same schema files and exposes command-driven validation for scripts and CI. Both clients rely on the same `.ghostable` files, so the rules stay consistent across tools. ## Continue with Your Client Use the project Validation view to inspect schema coverage, edit rules, and run checks. Use terminal validation for local checks and CI gates.