Bastion

What it does

Bastion is a self-hosted platform that runs coding agents inside isolated Linux virtual machines. Each agent gets its own VM with a dedicated filesystem and environment, orchestrated across physical servers. Users define agent environments using JSON templates that specify dependencies, credentials, working directories, and initialization steps. Agents can be deployed on demand, accessed via SSH, tmux, or OpenCode, and run asynchronously in the background.

Who it is for

Developers and teams running autonomous coding agents who need isolation between different agent instances and control over resource allocation. Organizations that want agents to execute in restricted environments without access to the host system. Teams already running on-premises infrastructure or cloud servers with KVM support and preferring not to use managed services.

Pricing

The site does not show prices.

How it stands out

Bastion emphasizes isolation: each agent runs in a full VM rather than a container, preventing agents from interfering with each other or the host system. The JSON template approach eliminates manual provisioning, allowing environment definitions to be version-controlled and reproduced consistently. Self-hosting removes vendor lock-in and keeps agent execution on customer infrastructure. The platform supports scaling agents across clusters of physical servers while keeping setup lightweight enough for local workstations.

What a founder should check

First, verify actual adoption and retention among users running coding agents at scale. Bastion targets a growing but still-emerging market of autonomous coding tools; confirm there is sufficient demand for self-hosted isolation versus managed cloud alternatives offered by LLM providers and agent frameworks.

Second, assess switching costs. Once users define their agent environments in Bastion's JSON schema and integrate it into their deployment pipeline, what prevents them from migrating to a simpler container-based solution or a managed platform? Evaluate whether the isolation value proposition is strong enough to justify operational overhead.

Third, examine the competitive moat. Docker containers with network policies, Kubernetes with resource limits, and sandboxing mechanisms already solve some isolation problems. Determine whether Bastion's VM-level isolation is a must-have feature or a nice-to-have that users would accept trade-offs to avoid managing additional infrastructure.