# Terraform Stacks

Comprehensive guide for working with HashiCorp Terraform Stacks.

- Repository: https://github.com/hashicorp/agent-skills (911 stars)
- Category: DevOps
- License: MPL-2.0
- Last updated: 2026-10-28
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add hashicorp/agent-skills --skill terraform-stacks -g -a claude-code -y`
Codex: `npx skills add hashicorp/agent-skills --skill terraform-stacks -g -a codex -y`
Cursor: `npx skills add hashicorp/agent-skills --skill terraform-stacks -g -a cursor -y`
Gemini CLI: `npx skills add hashicorp/agent-skills --skill terraform-stacks -g -a gemini-cli -y`
Claude Code plugin marketplace: `/plugin marketplace add hashicorp/agent-skills`

## Description

Comprehensive guide for working with HashiCorp Terraform Stacks. Use when creating, modifying, or validating Terraform Stack configurations (.tfcomponent.hcl, .tfdeploy.hcl files), working with stack components and deployments from local modules, public registry, or private registry sources, managing multi-region or multi-environment infrastructure, or troubleshooting Terraform Stacks syntax and structure.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# Terraform Stacks

Terraform Stacks simplify infrastructure provisioning and management at scale by providing a configuration layer above traditional Terraform modules. Stacks enable declarative orchestration of multiple components across environments, regions, and cloud accounts.

## Core Concepts

**Stack**: A complete unit of infrastructure composed of components and deployments that can be managed together.

**Component**: An abstraction around a Terraform module that defines infrastructure pieces. Each component specifies a source module, inputs, and providers.

**Deployment**: An instance of all components in a stack with specific input values. Use deployments for different environments (dev/staging/prod), regions, or cloud accounts.

**Stack Language**: A separate HCL-based language (not regular Terraform HCL) with distinct blocks and file extensions.

## File Structure

Terraform Stacks use specific file extensions:

- **Component configuration**: `.tfcomponent.hcl`
- **Deployment configuration**: `.tfdeploy.hcl`
- **Provider lock file**: `.terraform.lock.hcl` (generated by CLI)

All configuration files must be at the root level of the Stack repository. HCP Terraform processes all files in dependency order.

### Recommended File Organization

```
my-stack/
├── .terraform-version               # The required Terraform version for this Stack
├── variables.tfcomponent.hcl        # Variable declarations
├── providers.tfcomponent.hcl        # Provider configurations
├── components.tfcomponent.hcl       # Component definitions
├── outputs.tfcomponent.hcl          # Stack outputs
├── deployments.tfdeploy.hcl         # Deployment definitions
├── .terraform.lock.hcl              # Provider lock file (generated)
└── modules/                         # Local modules (optional - only if using local modules)
    ├── s3/
    └── compute/
```

The rest: https://github.com/hashicorp/agent-skills/blob/HEAD/plugins/terraform/skills/terraform-stacks/SKILL.md