# Terraform 1 5

> Apply Terraform 1.5 language, CLI, state, testing, migration, and behaviour changes. Load for Terraform work targeting 1.5 or later when the model's knowledge may predate the 2023-06-12 release.

- Skill: `cedws/terraform-1-5` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add cedws/terraform-1-5`
- Raw SKILL.md: https://api.skillmd.com/api/skills/cedws/terraform-1-5/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-1-5

---


# Terraform 1.5

This overview applies when the project's target Terraform version is at least 1.5.

## Configuration and validation

- Top-level `check` blocks can continuously validate infrastructure independently of resource lifecycle operations. Each contains one or more `assert` blocks and may contain a scoped data source; failed checks warn without halting the operation.
- Configuration-driven `import` blocks make adoption of existing resources visible in plans. Terraform 1.5 requires a literal string for `id`; expression support arrives in Terraform 1.6.
- `terraform plan -generate-config-out=PATH` can generate initial resource configuration for import targets that have no resource block. Generated configuration requires review before apply.

```hcl
import {
  to = aws_s3_bucket.logs
  id = "company-logs"
}
```

## Functions and operations

- `plantimestamp()` returns a stable timestamp selected during planning, unlike `timestamp()`, whose result is determined during apply.
- `strcontains(string, substring)` tests whether a string contains a substring.
- Local apply operations periodically persist state snapshots and attempt another snapshot after an interrupt, reducing the potential loss window during an aborted apply.

## Compatibility

- Terraform 1.5 is the final minor series supporting macOS 10.13 and 10.14 and legacy Windows versions older than Windows 10 or Windows Server 2016.