E2B, Daytona, and box are the products teams actually evaluate when they need somewhere for an agent to run untrusted code. Zeish (zei.sh) is in that market. It is an orchestrator for isolated machines: hardware-isolated MicroVMs on bare metal, with snapshot, clone, and branch as first-class APIs. The VMM is an implementation detail.
The four products do not isolate the same way, and they do not clone the same way. That is the whole comparison.
Side by side
| Capability | Zeish | E2B | Daytona | box |
|---|---|---|---|---|
| Isolation | Hardware-isolated machine, own kernel | Firecracker MicroVM, own kernel | Containers (Docker / Sysbox), shared kernel | Persistent Ubuntu VM |
| Runtime | Pluggable MicroVM (VMM-agnostic) | Firecracker | Docker Engine + Sysbox | Full Ubuntu machine |
| Clone model | Copy-on-write clone from snapshot | Resume snapshot; pause keeps memory | Workspace snapshot / fork | Disk-level fork from snapshot |
| Ready time | Snapshot boot and copy-on-write clones | ~150ms from snapshot | ~90ms claimed after warm pool | Seconds; not in the sub-500ms class |
| Persistence | Snapshots, volumes, clones | Pause/resume, templates, session caps | Long-lived workspaces, volumes | Stop snapshots the disk; no session cap |
| Access | REST, CLI, SDK, MCP | Python and TypeScript SDKs | SDK, SSH, persistent IDE-style workspace | SSH/SCP, CLI, HTTP API, desktop |
| Best fit | Eval farms, untrusted tool use, git-like fan-out | Ephemeral code execution as an agent tool | Persistent coding-agent workstations | Always-on Ubuntu boxes with SSH |
Zeish vs E2B
E2B is the closest product. Both give the agent a Linux machine with its own kernel, boot from snapshots in well under a second, and treat the sandbox as something you exec into, not as a Kubernetes pod. E2B’s public architecture is Firecracker. Zeish’s contract is the machine: snapshot, clone, destroy. The hypervisor underneath can change.
The split is the clone loop. E2B is built as an SDK for ephemeral code execution: create a sandbox, run commands, pause if you want the memory image kept, destroy. Pause/resume of live guest memory is a real strength. Session length is capped (up to 24 hours on paid plans). The SDK is Python and TypeScript, and it is the default many agent frameworks already know.
Zeish is built as an orchestrator for fleets of clones. You warm one sandbox, snapshot it, then fork N copy-on-write children for evals, retries, or parallel prompt trials. Parent pages stay shared; each fork pays for its writes. That is closer to git branch than to “start another interpreter.” The same flow is on the TypeScript SDK, CLI, REST API, and MCP. Volumes, networks, and secrets are control-plane objects, not something you rebuild inside every session. See git-like branching for VM states.
Pick E2B if you want the most adopted code-execution SDK and pause/resume of a live process. Pick Zeish if the workload is “prepare once, clone many” on isolated machines.
Zeish vs Daytona
Daytona is a persistent workspace product. The pitch is a fast, long-lived environment for coding agents: SSH, GPU options, snapshots, an SDK aimed at your app’s users. Independent fingerprinting in 2026 has shown production sandboxes as Docker + Sysbox on a shared host kernel. Daytona can optionally talk about Kata or stronger runtimes; the default boundary is still a container.
That is a different security claim. A shared kernel is fine for a trusted engineering workstation. It is the wrong boundary for multi-tenant untrusted agent code. Zeish gives each sandbox its own guest kernel in a hardware-isolated machine. The longer argument is in agent sandboxing: why containers aren't enough.
Daytona wins if the sandbox is the developer workstation: days-long sessions, GPU, an IDE-shaped workspace. Zeish wins if the sandbox is a disposable, clonable machine you fan out for evals and tool execution.
Zeish vs box
box, from ASCII, is a persistent Ubuntu VM with SSH, SCP, Docker inside the guest, a dedicated IPv6 or IPv4, and a 60fps desktop. Disk-level fork from a snapshot is first class. Regions are EU-only today. box’s own comparison is clear: it is an always-on machine, not a sub-500ms microVM pool. Process-level fork of running memory is listed for E2B, not for box.
That product is a personal or factory Linux box you SSH into. Zeish is a control plane. You do not live in the VM. You create, snapshot, clone, and destroy over API, CLI, SDK, or MCP, with copy-on-write clones in tens of milliseconds. Previews, tunnels, volumes, and short-lived data-plane credentials are part of the same model.
Pick box if you want SSH, a desktop, Docker-in-the-guest, and long-running Ubuntu in the EU. Pick Zeish if you need isolated machines and git-like clone fan-out.
When to pick each
- E2B for ephemeral code execution as an agent tool, with a mature Python / TypeScript SDK and pause/resume of live memory.
- Daytona for persistent coding-agent workspaces, GPU, and an IDE-shaped environment, if a container boundary is acceptable.
- box for SSH-able Ubuntu VMs with disk fork, desktop, and Docker-in-guest, especially in the EU.
- Zeish for hardware-isolated machines plus git-like snapshot and clone of agent environments.
Run the clone loop
Create from a template, wait until running, snapshot, clone. That is the product. Start with the getting started guide, then estimate fan-out on the pricing calculator.