Bastion

What it does

Bastion deploys virtual computers for coding agents. It provides isolated Linux virtual machines (VMs) designed specifically for running background coding agents. Each agent runs in its own VM, giving it complete control over its development environment—from file systems to background processes—without runtime conflicts from other agents working in parallel. Environments are initialized using schema-validated JSON templates, and the system can be self-hosted on any Linux machine with KVM support, from a local workstation to cloud instances like AWS EC2.

Who it is for

Bastion is built for developers and teams who run multiple coding agents in the background and need isolation to prevent conflicts. It is particularly useful for those using AI-powered coding agents (e.g., OpenCode) that require a clean, reproducible environment for each task. The tool is also suited for developers who want to self-host their agent infrastructure rather than relying on a third-party cloud service.

Why it matters

Running multiple coding agents simultaneously often leads to runtime conflicts, such as dependency clashes or port collisions. Bastion solves this by giving each agent its own VM, ensuring complete isolation. This allows teams to scale their agent usage without worrying about environment pollution. Additionally, defining environments as JSON templates makes it easy to version-control and reproduce agent setups, improving reliability and collaboration.

Launch signal

Bastion was launched on Hacker News as a Show HN post titled "Show HN: Bastion – isolated Linux VMs for background coding agents." The project is open-source and available on GitHub. The website includes installation instructions via a curl command, documentation, and examples. The launch appears to be early-stage, with no disclosed funding or team information.

Brand and naming

The name "Bastion" evokes the idea of a fortified stronghold, which aligns well with the product's focus on isolation and security for coding agents. The branding is straightforward and technical, appealing to developers who value clarity. The tagline "Isolated Linux VMs for background coding agents" is descriptive and immediately communicates the core value proposition.