Which is better for a persistent agent environment?

Containarium. A box is a long-lived LXC container with real root, persistent disk, systemd, and a routable hostname with TLS — so an agent can install tools, keep caches warm across sessions, and host a service on the open internet.

Comparison

Containarium vs E2B

Q: What is the difference between Containarium and E2B?

Both give AI agents an isolated environment to run code. The main differences are how you drive them and what they run. Containarium gives each agent a persistent, full Linux box (an LXC container) driven by an MCP server and a CLI — any MCP-aware agent or a human can use it directly. E2B is an SDK-first code-execution sandbox you typically drive from your application code. Containarium leans toward long-lived agent boxes that can host services on a hostname; E2B leans toward running AI-generated code from within your app.

Q: Which is better for running AI-generated code snippets?

E2B is purpose-built for the code-interpreter pattern — your app generates code and runs it in a fresh sandbox via an SDK call. If that is your core loop, E2B fits it directly. Containarium can do this too, but its strength is giving an agent a long-lived box it works in over many sessions.

Q: Can I drive Containarium with Claude Code or Cursor?

Yes. Each Containarium box runs an MCP server over stdio, so any MCP-aware agent — Claude Code, Cursor, Cline, OpenCode, or your own — drives it directly, with no SDK glue code.

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.

Choose Containarium when…

You want a persistent box an agent lives in across many sessions.
You drive it from an MCP agent (Claude Code, Cursor, Cline) or a CLI — not by writing SDK glue.
The agent needs to host a service on a real HTTPS hostname.
You want to self-host on one VM and keep agent code in your perimeter.

Choose E2B when…

Your core loop is the code-interpreter pattern: app generates code → run it in a fresh sandbox.
You build primarily in Python/JS and want a first-class SDK.
You want short-lived, per-call execution rather than a long-lived box.
You're happy running on their hosted cloud as the default path.

Same goal — isolated code execution for agents. Different center of gravity: a box you live in vs a function you call.

Side-by-side

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 default timeout; runs capped at 1h Hobby / 24h Pro); paused sandboxes are kept indefinitely
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, audit log, $20 per seat per month, no usage bill	E2B cloud — hosted sandboxes

Comparison reflects each project's stated design as of 2026. Check the latest E2B docs for current specifics.

How you drive it: MCP & CLI vs an SDK

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.

A box you live in vs a function you call

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 5-minute default timeout, and a running sandbox capped at 24 hours on Pro). You can pause a sandbox to keep its state, but a paused sandbox isn't running anything. 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.

Self-hosting & data residency

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.

FAQ

What is the difference between Containarium and E2B?

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.

Are Containarium and E2B open source?

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.

Which is better for running AI-generated code snippets?

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.

Can I drive Containarium with Claude Code or Cursor?

Yes — each box runs an MCP server over stdio, so any MCP-aware agent drives it directly with no SDK glue code.