Migrating from E2B

mitos.e2b is a one-way migration bridge for teams leaving E2B’s cloud for a SELF-HOSTED sandbox runtime: regulated, air-gapped, or on-prem environments where agent code, data, and credentials must not run on someone else’s infrastructure. The promise is “change one import”:

# before
from e2b_code_interpreter import Sandbox
# after
from mitos.e2b import Sandbox

The shim presents E2B’s Sandbox surface over the standalone Mitos sandbox-server REST API (no Kubernetes required). It is an adapter over the native DirectSandbox surface, not a re-implementation, and it has no dependency on the e2b package. E2B’s per-operation vocabulary is roughly 70% aligned with ours, so most scripts run unchanged.

Why self-host

• Your agents’ code, data, and credentials run on infrastructure you control.
• Air-gapped and regulated deployments: no egress to a third-party cloud.
• The same snapshot-fork engine, exec, files, and code-interpreter surface you get from the native SDK, behind E2B’s method names.

Quickstart

Point the shim at a sandbox-server you run (for example the local mock engine, mitos dev up, or a real KVM deployment):

from mitos.e2b import Sandbox

sandbox = Sandbox.create("python", base_url="http://localhost:8080")

# run a shell command
result = sandbox.commands.run("echo hello")
print(result.stdout, result.exit_code)

# files
sandbox.files.write("/tmp/data.json", "{}")
print(sandbox.files.read("/tmp/data.json"))
sandbox.files.make_dir("/tmp/out")          # E2B make_dir -> mitos mkdir

# code interpreter with rich MIME results
execution = sandbox.run_code("import matplotlib; 1 + 1")
print(execution.text)
for r in execution.results:
    print(r.data.keys())                     # image/png, text/html, ...

# live TTL extension and teardown
sandbox.set_timeout(300)
sandbox.kill()

Auth resolves exactly like mitos.create: pass api_key= / base_url= explicitly, or set MITOS_API_KEY / MITOS_BASE_URL. The standalone server is tokenless and ignores the key; the hosted front door verifies the same header with no code change.

Reconnect and list

sandbox = Sandbox.create("python", base_url="http://localhost:8080")
again = Sandbox.connect(sandbox.sandbox_id, base_url="http://localhost:8080")

for info in Sandbox.list(base_url="http://localhost:8080"):
    print(info.sandbox_id)

connect reattaches to a running sandbox by id; an unknown id raises the typed NotFoundError.

Support table

Every E2B method the shim exposes, what it maps to, and whether it works today against the standalone sandbox-server.

“needs a guest agent” means the op runs end-to-end only against a real guest over vsock (a KVM deployment, or mitos dev up with the engine). The bare mock-engine sandbox-server answers the create / connect / list / kill / set_timeout lifecycle but cannot run exec / files / run_code, which is why the test suite proves those against a fake target and runs them end-to-end in the KVM CI job.

The one vocabulary rename

E2B’s files.make_dir(path) maps to Mitos files.mkdir(path). The shim exposes make_dir so your E2B script does not change; under the hood it calls mkdir.

get_host returns a signed preview URL

sandbox.get_host(port) returns a signed, expiring preview URL for a sandbox port, served by the per-sandbox preview reverse proxy:

url = sandbox.get_host(3000)   # https://<sandbox-id>.preview.<domain>/?token=...

The server mints the URL (the signing secret stays server-side) and the token expires (Daytona style), so treat the URL value as a credential. The URL resolves once the preview proxy is deployed and routing to the sandbox; the proxy is not part of the default install yet, so a server that does not expose it raises a typed AgentRunError from the call rather than fabricating a URL that would not resolve.

What you gain beyond E2B parity

The underlying DirectSandbox (reachable via sandbox.sandbox) exposes Mitos superpowers E2B does not: fork(n) for branching / parallel runs at fork(2) speeds, pause / resume, and an interactive pty. The shim keeps your E2B script working; reach for the native handle when you want those.