# Terraform 1 6

> Apply Terraform 1.6 language, CLI, state, testing, migration, and behaviour changes. Load for Terraform work targeting 1.6 or later when the model's knowledge may predate the 2023-10-04 release.

- Skill: `cedws/terraform-1-6` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add cedws/terraform-1-6`
- Raw SKILL.md: https://api.skillmd.com/api/skills/cedws/terraform-1-6/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: DevOps & Infra
- Author: cedws (https://skillmd.com/u/cedws)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/cedws/terraform-1-6

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# Terraform 1.6

This overview applies when the project's target Terraform version is at least 1.6.

## Testing

- `terraform test` is generally available. Tests live in `.tftest.hcl` files as ordered `run` blocks that execute plans and optional applies, then evaluate assertions against plan and state values.
- Test runs can pass outputs from earlier runs into later runs. Test cleanup destroys infrastructure in reverse run order.

## Import and planning

- An `import` block's `id` accepts an expression when it resolves to a string known at plan time.
- HCP Terraform and Terraform Enterprise remote plans can be saved with `-out`, inspected with `terraform show`, and applied from the saved plan file.
- Refined unknown values can carry facts such as non-nullness or collection length ranges, allowing more expressions to produce known plan results.

## S3 backend migration

- Assume-role settings move into an `assume_role` block.
- Service endpoint overrides move into an `endpoints` block.
- `shared_credentials_files` replaces `shared_credentials_file`, and `use_path_style` replaces `force_path_style`.
- Standard `AWS_ENDPOINT_URL_*` variables replace the older Terraform-specific endpoint environment variables.

## Compatibility

- Terraform 1.6 requires macOS 10.15 or later and Windows 10 or Windows Server 2016 or later.