Comparison
Both give AI agents a place to run code safely. They differ in how you drive them and what they run: Containarium gives each agent a persistent full Linux box driven over MCP and a CLI; E2B is an SDK-first sandbox built for running AI-generated code from your application. Here's an honest side-by-side.
Same goal — isolated code execution for agents. Different center of gravity: a box you live in vs a function you call.
| Dimension | Containarium | E2B |
|---|---|---|
| Primary interface | MCP server + CLI — driven by any agent or a human, no glue code | SDK-first (Python / JS) — driven from your application code |
| Runtime | LXC container — a full Linux box with systemd & real networking | Firecracker microVM, tuned for fast code execution |
| Best for | A long-lived box an agent works in & hosts services from | Running AI-generated code / the code-interpreter pattern |
| Persistence | Long-lived; state & caches survive between sessions until you delete the box | Short-lived by default (≈5-min idle timeout; max 1h free / 24h Pro); pause & resume in beta |
| Networking | Built-in sentinel: routable hostname, TLS, and SSH routing | Exposed sandbox ports / URLs |
| Agent compatibility | Any MCP agent: Claude Code, Cursor, Cline, OpenCode, custom | Whatever you wire up through the SDK |
| Open source | Yes — Apache 2.0 (CLI, daemon, sentinel, in-box MCP) | Yes — open-source core, oriented around the hosted cloud |
| Self-hosting posture | First-class: one VM → many isolated boxes, your infra | Available; default path is their hosted cloud |
| Hosted option | Containarium Cloud — multi-tenant, SSO, audit log, hybrid pricing | E2B cloud — hosted sandboxes |
Comparison reflects each project's stated design as of 2026. Check the latest E2B docs for current specifics.
This is the biggest practical difference. With E2B you write code — you import the SDK and call into a sandbox from your Python or JS app. That's a great fit when your product is the app generating the code.
Containarium flips it: every box runs an MCP server, so an
agent like Claude Code or Cursor drives the box directly — no SDK, no glue. A human gets the
same surface through the containarium
CLI. You bring the agent; the box is already wired to be driven.
E2B's microVM model is optimized for spinning up a clean environment, running code, and tearing
it down — fast and stateless by default, with a short lifespan (a few minutes idle, capped at
24 hours) and pause/resume still in beta. Containarium's LXC box is the opposite center of
gravity: it's a persistent Linux environment with root,
a real filesystem, systemd,
and a routable hostname. The agent installs tools once, keeps caches warm, and can host the app
it just built on a public HTTPS URL.
Both projects are open source. The difference is posture: Containarium is built to run on a single VM you own as the primary path, so agent code, files, and build artifacts can stay entirely inside your network. If keeping the workload in your perimeter matters, that's the design Containarium optimizes for — with Containarium Cloud available when you'd rather not run ops.
Both give agents an isolated place to run code. Containarium gives each agent a persistent full Linux box driven by an MCP server and a CLI; E2B is an SDK-first code-execution sandbox you drive from your app. Containarium leans toward long-lived boxes that host services; E2B leans toward running AI-generated code per call.
Both have open-source cores under Apache 2.0. The difference is self-hosting posture: Containarium targets a single VM you own as the first-class path; E2B's open source is oriented around its hosted cloud.
E2B is purpose-built for that code-interpreter loop. Containarium can do it too, but shines when an agent needs a long-lived box it works in over many sessions.
Yes — each box runs an MCP server over stdio, so any MCP-aware agent drives it directly with no SDK glue code.
Start free on the hosted cloud, or self-host the open source on your own VM.
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