Mitos vs E2B
Mitos forks a running agent into a fleet, so you can run many at once from one warm machine. E2B runs each agent in a fresh sandbox and does not fork a live one.
Both run agents in Apache-2.0 Firecracker microVMs, so isolation and license tie. The difference is the fleet: Mitos forks one running machine into many warm copies; E2B builds each from scratch, and closed the live-fork request as out of scope.
Mitos vs E2B, capability by capability
Capabilities from each project's public docs as of June 2026, not a head-to-head benchmark. Numbers move; the source of truth is each project's own repo and docs.
| Capability | Mitos | E2B |
|---|---|---|
| Fork a running VM (memory + processes) | ✓ memory + processes | ✗ fresh sandbox |
| Published marginal cost per fork | ✓ ~3 MiB / fork | ✗ |
| microVM isolation (own kernel) | ✓ Firecracker microVM, KVM | ✓ Firecracker |
| Open source license | ✓ Apache 2.0 | ✓ Apache 2.0 |
| Fully managed cloud | ✓ yes | ✓ |
What sets Mitos apart
Run many at once
Mitos forks the running VM into many daughters that share memory copy-on-write, so each starts warm and you pay only for what changes, about 3 MiB at fork time. E2B builds a fresh sandbox per agent, so each one rebuilds its state from scratch.
Same isolation, same license
Both run each sandbox as a Firecracker microVM with its own kernel, and both ship under Apache 2.0, so the isolation boundary and the no-lock-in promise are a tie. The live fork of a running machine into a fleet is the real difference.
Built for the fleet
Fanning one agent into many is what Mitos is built around, managed and open. E2B users have asked for a live fork, and the request was closed as out of scope, pointing instead to snapshots that pause and resume a single sandbox.
Why teams pick Mitos over E2B
- Fork one warm machine into many, instead of rebuilding each agent from scratch.
- A live copy-on-write fork: daughters start warm, and you pay about 3 MiB for what changes.
- The same Apache-2.0 microVM isolation, plus the live fork E2B closed as out of scope.
Mitos vs E2B, in brief
Can E2B fork a running sandbox?
No. E2B creates fresh microVM sandboxes; it does not copy a running one into many. Mitos is built around that live fork, so a warmed agent becomes a fleet in milliseconds.
Are Mitos and E2B both open source?
Yes, both Apache 2.0. Mitos adds the live fork and a published per-fork memory cost, and the managed service runs the same engine you can self-host.
Is the isolation different?
No. Both run each sandbox as a Firecracker microVM with its own kernel. Isolation is a tie; the fork into a fleet is not.