PlugWiki

terraform-style-guide Skill for Claude: Write Terraform to HashiCorp Style

Makes Claude write and review Terraform code to HashiCorp's style guide, with set file layout, naming, variable rules and security practices.

Installs
12.8K
on skills.sh
Stars
911
on GitHub
Files
1
besides SKILL.md
Updated
Oct 2026
last repo commit

terraform-style-guide is a skill from HashiCorp's agent-skills repository. When you ask Claude to write, review or generate Terraform configuration, it follows a generation order (providers, data sources, resources, outputs), a six-file layout, naming rules, version pinning and a review checklist. Security rules sit in a second file in the folder, SECURITY.md, which SKILL.md points to.

The skill bundles no scripts. It tells Claude to run terraform fmt -recursive and terraform validate before committing and names tflint, checkov and tfsec as extra tools, so Claude may run those in your project. You need Terraform installed for that part.

Good for

  • Engineers writing new Terraform who want HashiCorp-style layout and names from the start
  • Reviewers checking a pull request against a written checklist
  • Platform teams that want generated infrastructure code to use variables, tags and pinned versions
  • Anyone adding encryption and secret handling rules to generated Terraform

Install terraform-style-guide

Claude Code

  1. 1

    Copy this prompt.

    Install the terraform-style-guide skill in Claude Code. Run this command:

npx skills add hashicorp/agent-skills/plugins/terraform/skills/terraform-style-guide

Then check that it loaded and tell me how to use it.
  2. 2

    Paste it into Claude Code. It shows the change and asks before running it.

Requires Node.js.

The skill folder has two files, SKILL.md and SECURITY.md, and SKILL.md points to SECURITY.md, so install the whole folder. The plugin route installs all 16 skills in HashiCorp's terraform plugin. Its manifest points to a skills folder and lists no hooks or MCP servers.

From the project README. Source.

What's in the skill

When it loads

Generate Terraform HCL code following HashiCorp's official style conventions and best practices. Use when writing, reviewing, or generating Terraform configurations.

Sections in SKILL.md

  1. Code Generation Strategy
  2. File Organization
  3. Example Structure
  4. Code Formatting
  5. Indentation and Alignment
  6. Block Organization
  7. Naming Conventions
  8. Variables
  9. Outputs
  10. Dynamic Resource Creation
  11. Prefer for_each over count
  12. count for Conditional Creation
  13. Security Best Practices
  14. Version Pinning
  15. Provider Configuration
  16. Version Control

Key facts

Author
HashiCorp
Repository
hashicorp/agent-skills
Installs on skills.sh
12,830 as of 2026-11-02
GitHub stars
911 for the whole repo, 2026-11-02
License
MPL-2.0 (repo metadata)
Last commit to the repo
2026-10-28
Files
2 files: SKILL.md and SECURITY.md
Author source
HashiCorp, per the terraform plugin manifest (plugin.json)
Plugin
Part of the terraform plugin in hashicorp/agent-skills, which has 16 skills
Reference
HashiCorp Terraform Style Guide

What it includes

  • Providers and version constraints first, then data sources, resources, outputs

    Five steps in order: provider configuration, data sources, resources in dependency order, outputs for key attributes, and variables for every configurable value.

    Try: “Write Terraform for an AWS VPC with private subnets, using the HashiCorp style.”

    Code generation strategy

  • terraform.tf, providers.tf, main.tf, variables.tf, outputs.tf, locals.tf

    A table of what each file holds. Variables and outputs are in alphabetical order.

    File organization

  • Two-space indent, aligned equals, lowercase names with underscores

    Meta-arguments come first, then arguments, then blocks, with lifecycle last. Resource names are singular, descriptive nouns, and main is the default when only one instance exists.

    Formatting and naming

  • Every variable needs a type and description; every output needs a description

    Shows validation blocks and marks passwords and similar values sensitive.

    Variables and outputs

  • Use for_each for multiple resources, count only for on/off creation

    Shows a named for_each set against a count loop, and count = condition ? 1 : 0 for optional resources.

    for_each over count

  • required_version, provider version constraints, default_tags, aliases

    Says to use the latest major provider version and latest minor Terraform version unless a lock file or module requires otherwise.

    Version pinning and providers

  • Encryption, private networking, least privilege, no hardcoded secrets

    Adds a secure S3 bucket example and a priority order for secrets: native secrets manager first, then write-only attributes with ephemeral resources, then regular resources as a last resort. Ephemeral resources need Terraform 1.11.0 or newer.

    Read · SECURITY.md

  • terraform fmt -recursive, terraform validate, tflint, checkov, tfsec

    Says to run fmt and validate before committing and lists tflint, checkov and tfsec as additional tools.

    Runs code · Validation tools

  • Ten checkbox items from formatting to no hardcoded credentials

    A closing checklist Claude can run against a configuration.

    Code review checklist

From the official docs

Permissions

Low risk

Claude writes Terraform and may run terraform fmt and validate in your project. Keep your files in git and read the plan before any apply.

What it can do

  • Read your data
  • Create and change things
  • Delete things
  • Read-only mode

Watch out for

  • It runs Terraform commands in your project

    SKILL.md has Claude run terraform fmt -recursive across your folders. Use version control so you can review any changes it makes. github.com

  • Generated infrastructure code can create real resources

    The skill only writes code. Anything you apply to a cloud account is created by Terraform, so read the plan first. github.com

Technical details
Scopes

  • Claude writes and edits .tf files in your project

  • SKILL.md tells Claude to run terraform fmt -recursive and terraform validate before committing

  • Names tflint, checkov and tfsec as additional tools

Questions

What does the terraform-style-guide skill do?

It makes Claude write and review Terraform HCL to HashiCorp's style conventions, including file layout, naming, variables, version pinning and security practices.

How do I install it in Claude Code, the Claude app or Codex?

Use the install box at the top of this page. It covers the single skill and HashiCorp's terraform plugin. Install the whole folder, because SKILL.md points to SECURITY.md.

Does it need Terraform or an API key?

SKILL.md names no API key. It tells Claude to run terraform fmt and terraform validate, so Terraform must be installed for those steps.

Is it safe?

The skill bundles no scripts and only tells Claude to run formatting and validation commands. Claude writes Terraform that can create real cloud resources when you apply it, so review the plan before any apply.

Should I install the single skill or the terraform plugin?

The single skill covers style only. The plugin installs all 16 skills in HashiCorp's terraform plugin, which covers more tasks. Its manifest lists a skills folder and no hooks or MCP servers.

Does it write secrets into Terraform?

No, it tells Claude not to. SKILL.md says never to commit state files or sensitive .tfvars and to avoid hardcoded credentials, and SECURITY.md prefers a secrets manager or ephemeral resources.

Information

updated Nov 2, 2026

Repository
hashicorp/agent-skills
Folder
plugins/terraform/skills/terraform-style-guide

hashicorp/agent-skillsskills.sh

Sources

Docs, issue trackers and discussions this page is built from.

Show all 4
  1. hashicorp/agent-skills README · github.com
  2. terraform plugin.json · github.com
  3. terraform-style-guide SKILL.md · github.com
  4. terraform-style-guide SECURITY.md · github.com

Updated Nov 2, 2026.