Atlantis v0.46.0 is here, and it brings a feature that OpenTofu users have been waiting for: native .tofu file support that makes Atlantis work with OpenTofu projects as smoothly as it always has with Terraform. If you have been migrating from Terraform to OpenTofu — or running both side by side — this release removes the last major friction point in your pull request workflow.
What is Atlantis? It is a self-hosted tool that automates Terraform and OpenTofu workflows through pull requests. You open a PR, Atlantis runs terraform plan (or tofu plan), posts the output as a comment on your PR, and then waits for approval before running apply. Think of it as a CI/CD pipeline specifically for infrastructure-as-code — one that lives inside your Git workflow instead of requiring a separate dashboard.
Who uses it? Platform engineering teams, DevOps groups, and anyone managing cloud infrastructure through Terraform or OpenTofu. If your team reviews infrastructure changes the same way you review application code — through pull requests — Atlantis is the tool that makes that workflow actually work.
Why care about v0.46.0? Because OpenTofu support just got real. Atlantis now natively detects .tofu and .tofu.json files, automatically includes them in project discovery and autoplan, and even reads workspace configuration from them. No more configuring workarounds. No more pretending your OpenTofu project is actually a Terraform project. Atlantis finally speaks both languages fluently.
What’s New in Atlantis v0.46.0
OpenTofu .tofu/.tofu.json Version Auto-Detection
This is the headline feature of v0.46.0. Atlantis now automatically detects OpenTofu projects by recognizing .tofu and .tofu.json files — not just .tf files. This means OpenTofu projects are picked up by default autoplan and project discovery without any special configuration.
Why this matters: OpenTofu has been gaining serious traction as the open-source fork of Terraform, especially after HashiCorp’s license change in 2023. But until now, Atlantis users running OpenTofu had to rely on workarounds — naming their files .tf even when they were using OpenTofu, or manually configuring project discovery to find .tofu files. That friction is gone.
# Before v0.46.0: Atlantis only found .tf files
# You had to manually configure discovery for .tofu projects
# After v0.46.0: Atlantis auto-detects .tofu and .tofu.json
# No extra config needed — just create your OpenTofu project
# and Atlantis finds it automaticallyIf your team has been holding off on OpenTofu because Atlantis did not fully support it, this is the release that removes that excuse.
Workspace Detection for .tofu/.tofu.json and Shared Project Indicators
Building on the .tofu file detection, v0.46.0 also adds Terraform Cloud/Enterprise workspace configuration detection from .tf.json, .tofu, and .tofu.json projects. This means Atlantis can now read your remote workspace settings directly from OpenTofu project files.
Why this matters: If you are using Terraform Cloud or Terraform Enterprise workspaces alongside Atlantis, the tool can now discover your workspace configuration the same way it always did for .tf files — but extended to cover the full OpenTofu file ecosystem. Plus, new shared project indicators make it easier to reason about which projects share state or configuration.
# Atlantis now detects workspace config from these file types:
# .tf.json
# .tofu
# .tofu.json
#
# No changes to your config files needed — Atlantis reads
# the 'terraform' block workspace settings automaticallyExpanded E2E Test Coverage
v0.46.0 activates expanded test fixtures from the atlantis-tests repository, covering a significantly broader range of real-world scenarios: multi-project targeting, autodiscovery, configured JSON projects, custom workflow environment behavior, and long-output status contexts.
Why this matters: You might not think test coverage is exciting — but it is what prevents the next bug from landing in your production Atlantis deployment. The expanded fixtures mean that edge cases in multi-project setups, JSON-based configurations, and custom workflows are now being exercised in CI before they ship. Fewer surprises for you when you upgrade.
Safer Plan and Apply Behavior
v0.46.0 ships three important fixes that make the plan and apply workflow more reliable in production:
- Stale plan validation — Atlantis now validates the current head and base plan state before applying, preventing scenarios where a plan is executed against an outdated branch state. PR #6605
- Lock preservation during cleanup — The
on_applylocks are now preserved during plan cleanup, preventing a race condition where concurrent operations could interfere with each other. PR #6606 - Policy checks fix — The
/api/planendpoint no longer panics whenATLANTIS_ENABLE_POLICY_CHECKS=trueis set, while per-project/api/applybehavior is preserved. PR #6484
If you have ever had Atlantis apply a plan against the wrong branch state, the stale plan validation fix alone is worth the upgrade.
Project Health and Community
Atlantis v0.46.0 also brings improvements to how the project tracks its own health:
- Top-ranking issues — Maintainers can now see open issues ranked by community thumbs-up reactions, giving a clearer signal for prioritization. Tracked in issue #6608.
- Go coverage reporting — Atlantis now uploads Go coverage data to GitHub Code Quality, making test coverage visible and trackable.
- Call for adopters — The project is actively seeking organizations to share sanitized setup examples at runatlantis/examples.
The maintainers are also looking ahead at flag lifecycle improvements — a clearer path for introducing, documenting, deprecating, and eventually removing server flags. If you have ever been bitten by a deprecated Atlantis flag disappearing without warning, that work should be on your radar.
Should You Upgrade?
If you use OpenTofu with Atlantis, yes — upgrade today. The .tofu file auto-detection removes real friction from your daily workflow. If you use Terraform exclusively, the plan/apply safety fixes (stale state validation, lock preservation, policy check panic fix) make this a solid maintenance upgrade with no urgency.
The full changelog covers 3 new features, 3 bug fixes, and a handful of CI and test improvements. It is a focused release that does exactly what it says on the tin.
Atlantis v0.46.0: OpenTofu support that finally feels first-class.
