What is Semaphore UI used for?

Semaphore UI is a web UI and API for running Ansible, Terraform, OpenTofu, Terragrunt, PowerShell and Bash from a shared, access-controlled place, with scheduling and notifications. It is a good fit for giving teams a shared UI for Ansible, scheduling infrastructure automation runs and replacing ad hoc deploys from terminals.

Is Semaphore UI open source?

Yes. Semaphore UI is open source under the MIT licence. Its source code is on GitHub at semaphoreui/semaphore and is written mainly in Go.

Is Semaphore UI free?

Yes. Semaphore UI is open source, so the software itself is free to use. Paid plans are also available, starting at $490 per year.

Can I self-host Semaphore UI?

Yes. Semaphore UI can be self-hosted on your own server or infrastructure.

What is Semaphore UI an alternative to?

Semaphore UI is an open-source alternative to HCP Terraform, Spacelift, env0 and Scalr. Other open-source alternatives to HCP Terraform include Atlantis, Burrito and OpenTofu.

Is Semaphore UI actively maintained?

Yes. The most recent commit to Semaphore UI was on 2 October 2026, and the latest release is v2.19.12, published on 30 August 2026. The project has 14k stars on GitHub.

Semaphore UI: open-source alternative to HCP Terraform

About Semaphore UI

Semaphore UI is a web interface for managing DevOps tooling when running commands from a terminal no longer scales. It lets teams run Ansible playbooks, Terraform and OpenTofu code, and Bash and PowerShell scripts from a shared place with controlled access and notifications about failed tasks.

Work is organized into projects, with reusable task templates that can be run on demand or on a schedule. Inventories describe the target hosts, and variable groups hold environment variables and secrets for tasks to use. An API allows automation, and a Postman collection plus documentation are provided. Its repository topics place it in the same space as AWX and Jenkins.

Semaphore is written in Go and licensed under MIT. The most common installation method is Docker, but it is also available as a Snap, as Debian or RPM packages, as a plain binary, or as a pre-built virtual machine from marketplaces such as AWS, DigitalOcean and Vultr. An online demo is available for trying it out.

Key features

Run Ansible playbooks from a web UI
Terraform, OpenTofu and Terragrunt support
Bash and PowerShell script execution
Reusable task templates and schedules
Inventories and secret variable groups
Failure notifications and access control
API for automation

Good fit for

→Giving teams a shared UI for Ansible
→Scheduling infrastructure automation runs
→Replacing ad hoc deploys from terminals

Built with: Go; Docker
Tags: ansible; terraform; opentofu; devops; automation; ci-cd; infrastructure; self-hosted; go

Semaphore UI: questions and answers

What is Semaphore UI used for?: Semaphore UI is a web UI and API for running Ansible, Terraform, OpenTofu, Terragrunt, PowerShell and Bash from a shared, access-controlled place, with scheduling and notifications. It is a good fit for giving teams a shared UI for Ansible, scheduling infrastructure automation runs and replacing ad hoc deploys from terminals.
Is Semaphore UI open source?: Yes. Semaphore UI is open source under the MIT licence. Its source code is on GitHub at semaphoreui/semaphore and is written mainly in Go.
Is Semaphore UI free?: Yes. Semaphore UI is open source, so the software itself is free to use. Paid plans are also available, starting at $490 per year.
Can I self-host Semaphore UI?: Yes. Semaphore UI can be self-hosted on your own server or infrastructure.
What is Semaphore UI an alternative to?: Semaphore UI is an open-source alternative to HCP Terraform, Spacelift, env0 and Scalr. Other open-source alternatives to HCP Terraform include Atlantis, Burrito and OpenTofu.
Is Semaphore UI actively maintained?: Yes. The most recent commit to Semaphore UI was on 2 October 2026, and the latest release is v2.19.12, published on 30 August 2026. The project has 14k stars on GitHub.