Dev tools · alternatives · 2026

Bastion provides isolated Linux virtual machines designed for running background coding agents. It's built for developers who need to execute code in a contained environment without affecting their main system. The… Below are 24 products that do a similar job, ranked by how close each is in meaning and then by launch-day votes. Prices are shown for the 4 we have checked on their own sites, 3 of them free or with a free tier.

1. 1
   Harness by Autonomousfree tier, from $149/mo▲292

   Every coding agent, every machine, one command center.

   7d ago · autonomous.ai · its alternatives →

2. 2
   Sub-millisecond VM sandboxes using CoW memory forking▲311

   I wanted to see how fast an isolated code sandbox could start if I never had to boot a fresh VM. So instead of launching a new microVM per execution, I boot Firecracker once with Python and numpy already loaded, then snapshot the full VM state. Every execution after that creates a new KVM VM backed by a `MAP_PRIVATE` mapping of the snapshot memory, so Linux gives me copy-on-write pages automatically. That means each sandbox starts from an already-running Python process inside a real VM, runs the code, and exits. These are real KVM VMs, not containers: separate guest kernel, separate guest…

   Mar 2026 · github.com · its alternatives →

3. 3
   Clawk – Give coding agents a disposable Linux VM, not your laptop▲226

   Give coding agents a disposable Linux VM, not your laptop - clawkwork/clawk

   Jul 2026 · github.com · its alternatives →

4. 4
   Runtimefree tier, from $99/mo▲299

   Sandboxed coding agents for everyone on your team

   May 2026 · runtm.com · its alternatives →

5. 5
   Grass▲291

   Gives your coding agent a dedicated VM that's ready 24/7

   Apr 2026 · codeongrass.com · its alternatives →

6. 6
   Replicas▲239

   Hey HN! I'm Connor, creator of Replicas. I'm a heavy Codex/Claude Code user, and I wanted to hand off tasks to agents like I would to an engineer - kick something off before work, let it scaffold while I'm at lunch, even come back to a ready PR. The problem: existing alternatives use workspace VMs that are black boxes. I have no access to any of them - they can't run tests, read logs, or use tools like the Playwright MCP (which I use to verify agents actually fixed what they claim to fix). Replicas gives agents real cloud workspaces where they can: - Run your test suite and read the…

   Jun 2026 · replicas.dev · its alternatives →

7. 7
   Context Gateway▲220

   We built an open-source proxy that sits between coding agents (Claude Code, OpenClaw, etc.) and the LLM, compressing tool outputs before they enter the context window. Demo: https://www.youtube.com/watch?v=-vFZ6MPrwjw#t=9s. Motivation: Agents are terrible at managing context. A single file read or grep can dump thousands of tokens into the window, most of it noise. This isn't just expensive — it actively degrades quality. Long-context benchmarks consistently show steep accuracy drops as context grows (OpenAI's GPT-5.4 eval goes from 97.2% at 32k to 36.6% at 1M…

   Mar 2026 · github.com · its alternatives →

8. 8
   The Cloud for AI Agents▲128

   Spin up secure sandboxes in ~100 ms

   Nov 2025 · hopx.ai · its alternatives →

9. 9
   Drop – a rootless Linux sandbox with gVisor support▲193

   Drop: a rootless Linux sandbox for developers. It isolates coding agents and third-party packages while preserving your work environment.

   30d ago · droprun.sh · its alternatives →

10. 10
    Hosting 100 Linux dev environments on one VM using LXC▲16

    Open-source agent runtime — SSH-native isolation, eBPF egress policy, Kubernetes + LXC backends, GPU passthrough, MCP-native CLI - FootprintAI/Containarium

    Jan 2026 · github.com · its alternatives →

11. 11
    Run coding agents in microVM sandboxes instead of your host machine▲63

    Hi HN, we built SuperHQ, an open source app that runs AI coding agents in isolated microVM sandboxes instead of directly on your machine. Each agent gets its own VM with a full Debian environment. You mount your projects in, writes go to a tmpfs overlay so your host is never touched, and you get a diff view to accept or discard changes. API keys never enter the sandbox. We also just launched remote.superhq.ai which acts as a remote control for SuperHQ, allowing you to access your workspaces and agents from anywhere.

    Apr 2026 · github.com · its alternatives →

12. 12
    Confidential computing for high-assurance RISC-V embedded systems▲103

    Dear HN community! Looking forward to hearing your feedback on ACE (assured confidential execution), technology that implements VM-based trusted execution environment (TEE) for embedded RISC-V systems with focus on a formally verified and auditable firmware. We target high-assurance systems that can benefit from compartmentalization and hardware-backed isolation. The key ingredient called security monitor (firmware) is implemented in Rust. The formal specification is defined as annotations directly in code and gets translated to Coq using RefinedRust automation. ACE design is now part of the…

    2025 · github.com · its alternatives →

13. 13
    Vas-quod – A minimal Linux container runtime written in Rust▲110

    :aerial_tramway: Minimal linux container runtime. Contribute to flouthoc/vas-quod development by creating an account on GitHub.

    2020 · github.com · its alternatives →

14. 14
    relaydfree tier, from $5/mo▲101

    I kept missing when my Codex agents finished, so I built relayd — a mobile dashboard that sends push notifications and lets me continue agents from my phone. Free tier available. Would love feedback.

    Jan 2026 · relayd.dev · its alternatives →

15. 15
    Isolate – 2FA(OTP) SSH bastion host▲11

    Contribute to devopsprodigy/isolate development by creating an account on GitHub.

    2017 · github.com · its alternatives →

16. 16
    Eve – Managed OpenClaw for work▲72

    Eve is an AI agent harness that runs in an isolated Linux sandbox (2 vCPUs, 4GB RAM, 10GB disk) with a real filesystem, headless Chromium, code execution, and connectors to 1000+ services. You give it a task and it works in the background until it's done. I built this because I wanted OpenClaw without the self-hosting, pointed at actual day-to-day work. I’m thinking less personal assistant and more helpful colleague. Here’s a short demo video: https://www.loom.com/share/00d11bdbe804478e8817710f5f53ac61 The main interface is a web app where you can watch work happen in…

    Apr 2026 · eve.new · its alternatives →

17. 17
    Second State VM▲78

    High performance secure & portable Rust functions in Node.js

    2020 · secondstate.io · its alternatives →

18. 18LV
    Launch VM workloads securely and instantaneously, without VMs▲12

    Hello HN! We've been working on a new hypervisor https://kwarantine.xyz that can run strongly isolated containers. This is still a WIP, but we wanted to give the community an idea about our approach, its benefits, and various use cases it unlocks. Today, VMs are used to host containers, and make up for the lack of strong security as well as kernel isolation in containers. This work adds this missing security piece in containers. We plan on launching a free private beta soon. Meanwhile, we'd deeply appreciate any feedback, and happy to answer any questions here or on our slack…

    2021 · its alternatives →

19. 19AP
    A password system with no database, no sync, and nothing to breach▲14

    Hi HN, Bastion Enclave is an experiment in removing centralized trust from password management by eliminating server-side state entirely. Instead of storing an encrypted vault or syncing secrets through a backend, Bastion computes credentials deterministically on-the-fly using explicit cryptographic inputs. Given the same master entropy, service name, username, and version counter, the same password is reproduced across platforms. There is no account system, no database, and no persistent server storage — the server serves static code only. Password generation uses domain-separated salts and…

    Feb 2026 · bastion-enclave.vercel.app · its alternatives →

20. 20
    VM-curator – a TUI alternative to libvirt and virt-manager▲42

    I've long wanted to harness QEMU/KVM for my desktop virtual machines, but I'm befuddled by virt-manager's lack of support for working NVIDIA 3D acceleration, dogmatic embrace of ugly XML, and the puzzling UI decision of having to click what seems like 15 buttons to attach an ISO to a VM image. When I further learned that NVIDIA's broken 3D acceleration is the fault of libvirt as opposed to QEMU's virtio driver, I had an idea... Behold, vm-curator! A fast and friendly VM management TUI written in Rust. You can create, configure, organize, and manage VMs directly with QEMU. No libvert. No…

    Jan 2026 · github.com · its alternatives →

21. 21
    Bastions▲8

    Automated form testing and HTTPS monitoring made easy

    2018 · its alternatives →

22. 22
    Fully isolated honeypot SSH server using thrussh▲35

    🧸 fully isolated honeypot ssh server using thrussh - w4/pisshoff

    2023 · github.com · its alternatives →

23. 23
    Mantlecore▲15

    Managed cloud for open-source AI agents

    Jul 2026 · mantlecore.ai · its alternatives →

24. 24
    Sandockfrom $5/mo▲8

    Persistent Docker Workspaces for Coding Agents

    Apr 2026 · sandock.ai · its alternatives →

Ranked by how close each launch is in meaning, then by votes. Prices were read from each product’s own site when checked and can change. Refine with your own description →