---
description: >-
  Learn commands that help validate, format, and upgrade code written in the
  OpenTofu Configuration Language.
---

# Writing and Modifying OpenTofu Code

The [OpenTofu language](/docs/language) is OpenTofu's primary
user interface, and all of OpenTofu's workflows rely on configurations written
in the OpenTofu language.

OpenTofu CLI includes several commands to make OpenTofu code more convenient
to work with. Integrating these commands into your editing workflow can
potentially save you time and effort.

- [The `tofu console` command](/docs/cli/commands/console) starts an
  interactive shell for evaluating OpenTofu
  [expressions](/docs/language/expressions), which can be a faster way
  to verify that a particular resource argument results in the value you expect.

- [The `tofu fmt` command](/docs/cli/commands/fmt) rewrites OpenTofu
  configuration files to a canonical format and style, so you don't have to
  waste time making minor adjustments for readability and consistency. It works
  well as a pre-commit hook in your version control system.

- [The `tofu validate` command](/docs/cli/commands/validate) validates the
  syntax and arguments of the OpenTofu configuration files in a directory,
  including argument and attribute names and types for resources and modules.
  The `plan` and `apply` commands automatically validate a configuration before
  performing any other work, so `validate` isn't a crucial part of the core
  workflow, but it can be very useful as a pre-commit hook or as part of a
  continuous integration pipeline.
