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OpenTofu

OpenTofu Registry: Providers, Modules & Contributing

opentofu registry

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If you are developing infrastructure as code (IaC), you must have some experience with OpenTofu. This open-source IaC tool is a fork of Terraform that the Linux Foundation manages. OpenTofu continues the spirit of open IaC tooling. It has the same syntax and capabilities as Terraform but can operate without the licensing strings.

OpenTofu allows teams to define and manage infrastructure using declarative configuration files. With a familiar HashiCorp Configuration Language (HCL) syntax, it integrates with various providers like AWS, Azure, and others. However, what truly scales this ecosystem is the OpenTofu Registry.

In this blog, we will explore the OpenTofu Registry in detail as we cover the following topics:

  • Understand the purpose of using the OpenTofu Registry 
  • Explore how it powers modular IaC with reusable providers and modules
  • Learn how OpenTofu uses modules and providers efficiently
  • Explore the technical IaC flow using a detailed architecture diagram
  • Step-by-step usage of registry modules and provider configurations
  • How to contribute and publish your modules to the registry

What is the OpenTofu Registry?

The OpenTofu Registry is a public catalog where users can find, reuse, and share modules and providers for OpenTofu infrastructure code. It simplifies discovering community-supported components that act as reusable building blocks. You can reuse the same modules and version them as you like. You can also submit new providers and modules yourself!

How does IaC work with OpenTofu?

Infrastructure as Code means describing your cloud infrastructure using configuration files instead of point-and-click UIs. You define what you want, not how to do it. OpenTofu takes those configurations and looks at the current state to determine the differences before applying them.

Let’s understand how the OpenTofu registry works with the IaC ecosystem:

  • Configuration files: Everything starts with a set of .tf configuration files written by the user. These files declare infrastructure resources and compute instances to define which modules and providers are needed.
  • OpenTofu engine: The OpenTofu CLI takes these files and performs two primary operations. The plan operation shows what will change in the infrastructure. The apply option provisions or updates resources based on the plan.
  • OpenTofu registry: This is the core Dependency Hub. The registry plays a critical role by acting as a centralized source for providers (Plugins that abstract the APIs) and modules (Reusable pieces of infrastructure logic).

When OpenTofu runs, it pulls the required versions of providers and modules directly from the OpenTofu Registry. This maintains consistency across version-controlled IaC components and reduces logic duplication.

  • State management: OpenTofu also interacts with a state file to track the infrastructure deployed. This current state is stored and regularly updated as OpenTofu runs apply.
  • Cloud infrastructure execution: Finally, with all dependencies resolved and plans in place, OpenTofu communicates with the respective cloud providers, such as AWS or Google Cloud, to spin up or modify the infrastructure.

Why do you need the OpenTofu registry?

The OpenTofu Registry is a trusted source of reusable building blocks. It ensures that the same infrastructure logic can be shared and reused across multiple projects and teams. It decouples the development of IaC logic from its execution using modular and testable infrastructure practices.

The OpenTofu Registry steps in when OpenTofu needs to resolve modules (reusable code blocks like a VPC setup) or providers (cloud service APIs like AWS or Azure). Instead of building everything from scratch, you pull trusted components directly from the Registry. 

Here is what the OpenTofu Registry does:

  • Distributes modules and providers from verified and community sources
  • Manages versions of those components with semantic tagging
  • Helps discover reusable IaC components through search
  • Acts as a source of truth for module definitions used across environments

The OpenTofu Registry might look similar to the JavaScript package manager (npm), but its purpose is entirely different. It simplifies collaboration and enforces best practices in reusable IaC design.

How is the OpenTofu registry different from the Terraform registry?

The Terraform Registry is managed by HashiCorp, offering official, partner, and community modules. It supports both public and private modules, with advanced features tied to Terraform’s commercial offerings.

The OpenTofu Registry is a community-driven platform under the Linux Foundation. It offers a public registry and has recently introduced a user-friendly UI to facilitate module and provider discovery. 

OpenTofu 1.10 added support for distributing modules and providers via OCI registries, enhancing flexibility for organizations with existing container registry infrastructure.

Both registries are technically compatible with the same module format.

How to use OpenTofu Registry

To use OpenTofu Registry well, you need to follow simple steps. 

  • Learn the discovery and reference workflows. Understand how modules and providers are located and declared so you can choose the right approach for each use case.
  • Pin every dependency. Specify fixed versions, or use pessimistic version constraints, for all modules and providers to avoid surprises when you reapply your code.
  • Choose trusted, well-documented modules. Search the registry for vetted modules that already solve your problem, prioritizing those with clear examples and usage instructions.
  • Standardize across environments. Re-use the same modules in dev, staging, and production to keep your infrastructure clean, predictable, and easy to manage.

We will cover all of the details next. Let’s walk through the essential parts:

1. Accessing OpenTofu Registry using UI

First, visit the official OpenTofu Registry site. Go to https://search.opentofu.org/ in your browser. Once the page loads, you will see a clean search interface like the one below.

opentofu registry search

On the homepage, a search bar prominently displays where you can search for specific modules or providers.

Below the search bar, there are sections showcasing featured modules and providers. Enter the name or keyword related to the module or provider you’re interested in into the search bar. 

As you type, suggestions may appear to assist your search. 

The search results will display a list of matching modules or providers. Each entry includes the name, a brief description, and the latest version. 

Click on the desired module or provider to view more details.

The module or provider detail page summarizes its function. You can also review examples of implementing it in your OpenTofu configurations. The OpenTofu registry UI also lists all available versions so that you can select the one suitable for your project.

The OpenTofu Registry UI is clean and fast to access. Even though it’s in beta mode, it’s handy for developers when managing dozens of resources.

2. Accessing the OpenTofu Registry using CLI

To access the OpenTofu Registry through the CLI, ensure you have OpenTofu installed on your system. If not, download and install it from the official site.

Once installed, open your terminal and move to your project directory. You should already have a .tf file where you declare providers or modules. 

Inside that file, declare a provider or module from the registry like this:

provider "aws" {
  region = "us-east-1"
}

module "vpc" {
  source  = "registry.opentofu.org/my-org/vpc/aws"
  version = "1.0.0"
}

You must run the following command from your CLI that connects you with the OpenTofu Registry. It fetches the module and provider source code automatically. 

You don’t need to download anything manually.

tofu init

OpenTofu CLI reads your .tf file and finds what needs to be pulled. Then it uses the registry URL behind the scenes to get the latest version. Once done, it shows a message that the modules and providers were installed. 

This is how you access the OpenTofu Registry through the CLI. Efficient and straightforward, isn’t it?

3. Searching for providers and modules

Use the web UI to find the “providers” option at the top and click on it.

searching for opentofu providers

Clicking the Providers tab takes you to a list of all available providers in the registry. Providers are plugins that allow OpenTofu to manage external APIs like AWS, Azure, or Google Cloud. This page shows each provider’s name, latest version, and basic description. It’s helpful for developers who want to integrate cloud services into their infrastructure setup.

Next, click the “Modules” option from the web UI to search for any required module.

The modules tab shows reusable configuration blocks created by the community or teams. Modules help you group resources like a full VPC setup or database configuration. Each module in the list shows a name, version, and usage description.

You can use these modules to save time and avoid writing repeated OpenTofu code across your projects.

4. Using providers from the registry in the OpenTofu project

Let’s say you want to create resources in AWS using OpenTofu. To do that, you need to use the AWS provider. A provider is like a connector that helps OpenTofu talk to a specific platform. OpenTofu won’t know how to create anything on AWS or anywhere else without a provider.

Create a new folder for your project where you will write your infrastructure code. You’ll add a new file called main.tf in this folder. This file will define what provider you want to use. 

Add the AWS provider block in the file:

provider "aws" {
  region = "us-east-1"
}
resource "aws_s3_bucket" "my_bucket" {
  bucket = "my-first-tofu-bucket-123"
  acl    = "private"
}

This tells OpenTofu that you want to use AWS and create resources in the us-east-1 region. The word provider is a keyword that signals OpenTofu to pull in the AWS plugin. 

The file tells OpenTofu to create a new S3 bucket with your specified name. The resource is a block that defines what to build. "aws_s3_bucket" is the type, and "my_bucket" is the name you give for reference. 

Once your main.tf is ready, you save the file and run this command.

tofu apply

This command connects your machine to the OpenTofu Registry. It checks what provider is used in your config and downloads it automatically. You’ll see a message that the AWS provider was installed. Now, OpenTofu will call AWS using the provider and create the S3 bucket for you.

That’s it. You just used a provider from the OpenTofu Registry. You didn’t need to download anything manually. The provider was pulled automatically from the registry based on your config. The same pattern works for all other providers!

5. Using modules from the registry in the OpenTofu project

Modules are reusable chunks of OpenTofu code that you can plug into your project. Instead of writing long configurations from scratch, you can just call a module and pass a few values.

Let’s say you want to use a VPC module for AWS. First, create a new folder for your project and a main.tf file inside it

In that file, you’ll define a module block like this:

module "vpc" {
  source  = "terraform-aws-modules/vpc/aws"
  version = "5.1.0"

  name = "my-vpc"
  cidr = "10.0.0.0/16"

  azs             = ["us-east-1a", "us-east-1b", "us-east-1c"]
  private_subnets = ["10.0.1.0/24", "10.0.2.0/24", "10.0.3.0/24"]
  public_subnets  = ["10.0.101.0/24", "10.0.102.0/24", "10.0.103.0/24"]

  enable_nat_gateway = true
  single_nat_gateway = true
}

This tells OpenTofu to pull a VPC module from the registry. The source field shows the path to the module. The version ensures consistency by locking the module version. The rest are input values that the module needs to build your VPC.

Now save the file and run this command:

tofu init

This connects to the OpenTofu Registry and downloads the module locally. Once it’s ready, run:

tofu apply

OpenTofu will now call the module and create your VPC with all subnets. You didn’t have to define all the resources line by line. The module took care of it.

6. Managing dependencies in OpenTofu projects

Dependencies tell OpenTofu which resource should be created first. Some resources depend on others. For example, a subnet must be created after the VPC. OpenTofu figures out these relationships automatically, but sometimes you need to guide it.

Let’s say you are creating a security group that needs a VPC ID. That means your security group depends on the VPC. Here’s how you can handle that:

resource "aws_vpc" "main" {
  cidr_block = "10.0.0.0/16"
}

resource "aws_security_group" "web_sg" {
  name        = "web-sg"
  description = "Allow web traffic"
  vpc_id      = aws_vpc.main.id

  ingress {
    from_port   = 80
    to_port     = 80
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"]
  }
}

In this config, the security group uses aws_vpc.main.id. OpenTofu sees this and knows the VPC must be created before the security group. That’s an automatic dependency. Sometimes you want to make the order clear without using any values. 

You can use depends_on like this:

resource "aws_instance" "web_server" {
  ami           = "ami-123456"
  instance_type = "t2.micro"

  depends_on = [aws_security_group.web_sg]
}

This forces OpenTofu to create the security group before the instance. It’s useful when there’s no direct value reference but still a logical dependency.

When you run the tofu plan, OpenTofu will show the dependency tree. You can review the order before applying changes. Always define dependencies clearly to avoid resource creation errors.

7. Advanced features of OpenTofu Registry

Once you’re comfortable using modules and providers, you can explore advanced features that help you scale and manage infrastructure better.

  • Searchable Registry UI – The OpenTofu Registry offers a user-friendly interface that allows users to search for and view documentation for providers and modules. This centralized hub enhances the developer experience by providing quick access to relevant information.
  • Comprehensive catalog of providers and modules – The registry hosts a wide array of modules and providers, covering major cloud platforms, third-party services, and community contributions, supporting diverse infrastructure needs. 
  • Metadata management – When you publish a module or provider, the OpenTofu Registry does much behind-the-scenes work for you. It automatically handles version numbers, checks if everything is valid, and builds the docs based on your code. This means you don’t have to tag or format things manually. So when others use your module, they get clean docs with correct versions and a setup that works.
  • Support for private registries – Organizations can set up private registries for modules or providers that must be kept private. OpenTofu supports several third-party projects implementing the Terraform registry API, allowing private registries that are compatible with OpenTofu to be hosted.
  • Provider and module publishing – You can publish your providers and modules to share with the community or your team. This is useful when you build custom logic that is not found in existing modules. Publishing involves submitting your provider or module to the OpenTofu Registry, making it discoverable and reusable by others.
  • Module composition – Modules can include other modules, a practice known as composition. This approach allows you to build larger infrastructure setups using nested, reusable parts. Composing modules creates more organized and maintainable configurations.
  • Versioned documentation – Each provider and module in the registry comes with its versioned documentation. This ensures that users can refer to the appropriate documentation corresponding to their specific version, facilitating accurate implementation and reducing potential errors.

These features let you write safer and reusable configurations. They also help you manage large codebases and prevent accidental errors. Use them to make your OpenTofu workflows production-ready.

How to contribute to the OpenTofu Registry

The Registry is open to module and provider submissions. The process is simple and helps developers worldwide reuse their work. Below is how to get started step by step.

Step 1. Configure your module or provider

First, prepare your module or provider. Make sure the code is clean and includes a proper README. The README should explain what the module does and what inputs it takes, as well as give one or two usage examples. Without this, others won’t understand how to use it. Also, include examples in an /examples folder to show different use cases.

Step 2. Push your code to a public GitHub repository

Next, push your module to a public GitHub repository. OpenTofu follows its own naming and structure rules. For consistency, follow this format when naming your repo:

For modules: opentofu-<NAMESPACE>-<NAME>

For providers: opentofu-provider-<NAME>

Replace <NAMESPACE> with your GitHub username or organization name, and <NAME> with the actual name of your module or provider. This structure helps the registry correctly detect and verify your project.

To see how to publish your provider, check out this page.

Step 3. Connect your repository to the OpenTofu Registry

Now, go to the official OpenTofu Registry site. From the top-right corner, log in using your GitHub account. Once logged in, go to the “Publish” section. You’ll find a simple form where you can connect your GitHub repo, similar to this:

Connect your repository to the OpenTofu Registry

Step 4. Monitor feedback and update your code

After publishing, you can keep updating your code. The registry automatically detects new Git tags in your GitHub repo, like v1.0.0 or v1.1.0. Each tag becomes a versioned release on the registry. This versioning makes it easier for users to pick the right release for their use case, whether it’s a stable build or something more cutting-edge.

Finally, monitor feedback and open issues. If people are using your module or provider, they may have questions or suggestions. Actively maintaining your contribution makes it reliable and trusted within the community. The OpenTofu ecosystem depends on community-driven modules and providers, so staying involved is a big plus.

Contributing helps grow the OpenTofu ecosystem. It also showcases your expertise in open infrastructure tooling and lets you support a fully open-source IaC community. 

Why use OpenTofu with Spacelift?

Spacelift is an infrastructure orchestration platform that supports both OpenTofu and Terraform, as well as other tools such as Pulumi, CloudFormation, Terragrunt, Ansible, and Kubernetes. Spacelift offers a variety of features that map easily to your OpenTofu and Terraform workflow.

Spacelift stacks enable you to plug in the VCS repository containing your Terraform and OpenTofu configuration files and do a GitOps workflow for them. 

spacelift stacks opentofu

At the stack level, you can add a variety of other components that will influence this GitOps workflow, such as:

  • Policies – Control the kind of resources engineers can create, their parameters, the number of approvals you need for runs, where to send notifications, and more.
  • Stack dependencies –  Build dependencies between your configurations, and even share outputs between them. There are no constraints on creating dependencies between multiple tools or the number of dependencies you can have.
  • Cloud integrations – Dynamic credentials for major cloud providers (AWS, Microsoft Azure, Google Cloud).
  • Contexts – Shareable containers for your environment variables, mounted files, and lifecycle hooks.
  • Drift detection – Easily detect infrastructure drift and optionally remediate it.
  • Resources view – Enhanced observability of all resources deployed with your Spacelift account.

If you need help migrating from Terraform to OpenTofu or are looking for an infrastructure management platform that supports the top flavors of infrastructure as code, configuration management, and container orchestration, don’t hesitate to contact Spacelift.

As a founding partner of the initiative, Spacelift offers the native and commercial support you need to ensure your OpenTofu success. Learn more about OpenTofu Commercial Support & Services.

Key points

By now, you’ve explored the OpenTofu Registry and how it fits into real-world infrastructure such as code workflows. You’ve learned how to search, use, and manage providers and modules, and contribute your own. Whether setting up cloud resources or organizing reusable components, the registry gives you a central place to start and scale.

As OpenTofu grows, its registry will become even more critical for teams building modern infrastructure. Properly using it can save time, reduce errors, and improve how infrastructure is shared and reused. Start small, experiment with examples, and gradually build your reusable modules. OpenTofu’s registry is simple, open, and built to help developers confidently move fast.

If you want to improve your OpenTofu workflow, Spacelift can help. Create a free account today or schedule a demo with one of our engineers.

OpenTofu commercial support

Spacelift offers native and commercial support to ensure your OpenTofu success. If you need a reliable partner to run your critical workloads with OpenTofu, accelerate your migration, provide support coverage, or train your team – we are here to help.

Learn more