kosa8 vs E2B

01The short verdict

Choose E2B if

• you want a managed sandbox cloud with five regions and BYOC on AWS, GCP or Azure [2] [4];
• you need a SOC 2 Type II report and a pen test report today [1];
• you want the integrations E2B documents for many agent frameworks and tools [13];
• you need up to 1,100 concurrent sandboxes on Pro [15].

Choose kosa8 if

• sandboxes must run on developers' laptops (Mac, Linux or Windows through WSL2) as well as servers [18];
• you need an air-gapped site with a signed offline licence [18];
• you want API keys added by an egress broker so the sandbox never holds them [26];
• you want a hash-chained audit log anyone can verify, and an organization-wide freeze [22] [24].

02E2B and kosa8, feature by feature

Bracketed numbers point to the sources. "Not documented" means the vendor's own pages did not say on 2026-11-14; it does not mean the feature is missing.

03Where E2B is stronger

• Compliance paperwork. E2B has a SOC 2 Type II report and a pen test report [1]; kosa8 has neither yet [26].
• Managed regions and BYOC. Five regions across GCP and AWS, and BYOC on three clouds [2] [4]. kosa8 Cloud has two regions, and its BYOC joins KVM Linux servers you run [18].
• Ecosystem and scale. Many documented integrations [13] and up to 1,100 concurrent sandboxes on Pro [15]; kosa8 Cloud defaults to 20 [20].
• Network rules on a running sandbox. E2B changes egress rules live [8]; kosa8 fixes them at create, and kosa8 Cloud has no egress setting yet [21] [22].

04Where kosa8 is different

• Local first. kosa8 runs on a Mac, Linux or Windows (WSL2) laptop, not only on Linux servers [18].
• Rewind. kosa8 keeps a list of checkpoints and puts the machine back to any of them [19].
• Keys stay out, and the log can be checked. An egress broker adds keys on the way out; the hash-chained audit log verifies with one command [24] [26].
• Freeze. One call on kosa8 Cloud refuses new work, sleeps every sandbox and can suspend every key [22].

05Moving from E2B to kosa8

E2B's quickstart creates a sandbox, runs a shell line and kills it [13] [6]. kosa8 Cloud has the same shape.

E2B, from its docs:

from e2b import Sandbox

sandbox = Sandbox.create()  # Needs E2B_API_KEY environment variable
result = sandbox.commands.run('echo "Hello from E2B Sandbox!"')
print(result.stdout)
sandbox.kill()

The same on kosa8 Cloud (Python, pip install kosa8):

from kosa8 import Kosa8Cloud

cloud = Kosa8Cloud()  # reads KOSA8_API_KEY
box = cloud.sandboxes.create(template="python", sleep_after_s=600)
r = box.exec(["python3", "-c", "print('hello')"])
print(r.exit_code, r.stdout)
box.delete()

• E2B_API_KEY becomes KOSA8_API_KEY.
• commands.run('a shell line') becomes exec(['sh', '-c', 'a shell line']); result.stdout stays r.stdout.
• sandbox.kill() becomes box.delete(); pause() becomes box.sleep() [19].
• sandbox.fork() becomes POST /v1/sandboxes/{id}/fork with n up to 100, or kosa8 fork locally [19].
• E2B's allowOut list maps to --egress-allow on a local sandbox [21].
• Each kosa8 Cloud exec runs in a fresh container on the sandbox's disk: files under /workspace persist between commands, background processes do not. A buffered exec stops at 90 seconds; send stream: true for longer commands [19].
• Templates today are base (Alpine), python (Python 3.12) and node (Node.js 22) [19].
• An organization runs up to 20 sandboxes at once on kosa8 Cloud unless you ask for more [20].

06Questions

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