CreateOS Sandbox vs Collimate
For RL post-training and tree search, Collimate is the better tool: it live-forks a running, warmed-up VM into copy-on-write children in milliseconds (vendor-stated), and forking is free. CreateOS Sandbox suits agent workspaces that must outlive Collimate's 24-hour Pro cap, and teams that want SDKs in TypeScript, Go, Rust, C# or Java. Both run on Firecracker.
Pricing at a Glance
CreateOS rates verified 17 October 2026. Collimate pricing as published on 17 October 2026. Rates billed per GB rather than per GiB, or as bundled sizes, are quoted as published rather than converted.
CreateOS Sandbox
Lower compute rate- Compute
- $0.0362 /vCPU-hr
- Memory
- $0.0116 /GiB-hr
Collimate
- Compute
- $0.0400 /vCPU-hr
- Memory
- See below
Collimate charges $0.040 per vCPU-hour and $0.012 per GB-hour of memory while running, plus $0.10 per GB-month for suspended snapshot storage, with spawn and fork free, as of 17 October 2026.
Where CreateOS Sandbox Fits Better
What CreateOS Sandbox brings to this matchup, with a plain note on where Collimate has the edge.
No session cap. Sandboxes run until you pause or destroy them; Collimate reaps sessions after 1 hour on Demo and 24 hours on Pro.
Slightly lower list rates: $0.03616363 per vCPU-hour and $0.01159025 per GiB-hour, against $0.040 per vCPU-hour and $0.012 per GB-hour.
Official SDKs in TypeScript, Go, Python, Rust, C# and Java (all but TypeScript pre-1.0); Collimate's Python SDK targets RL rollouts.
A choice of two managed regions, eu and us, set per sandbox.
Where Collimate is strong
Collimate makes live fork the core operation: a running sandbox splits into N copy-on-write children that keep process memory, at about 2.4 ms p50 (vendor-stated) and no charge, so expensive setup is paid once. Pinning the guest RNG seed gives deterministic replay for RL research.
Which to Pick
Pick CreateOS Sandbox if
- Agent workspaces stay up for days.
- Your orchestration is not written in Python.
- You need to choose between an EU and a US region.
Pick Collimate if
- You run GRPO-style rollouts or tree search from one warmed environment.
- You need to fork while the parent keeps running.
- You want to self-host the control plane on Kubernetes via Helm.
Head-to-Head Comparison
Every dimension side by side, checked on 17 October 2026 against each vendor's own docs and pricing pages. "Not published" means we could not find it on the vendor's pages, not that the feature is missing.
| Dimension | CreateOS Sandbox | Collimate |
|---|---|---|
| Isolation | Firecracker micro-VM with its own guest kernel | Firecracker microVM (KVM) |
| Pause and resume | Saves disk, memory and CPU state; vCPU billing stops while paused, memory and storage still bill | Suspend snapshots to disk, reclaims RAM and stops CPU/RAM billing; resume keeps memory |
| Fork | Fork a paused sandbox into many independent copies | Live fork of a running sandbox into N copy-on-write children with memory; free |
| Outbound network default | Open with no rules; deny-by-default once any host, IP, CIDR or wildcard rule exists, enforced on the host outside the VM | Default-deny allowlist per fork; pure code templates have no network |
| Inbound access | Closed by default; opt-in HTTPS URL | Not published |
| Concurrency | 1 / 5 / 20 / 30 by plan (Free to Enterprise); paused sandboxes count | Demo 2; Pro up to 100 (pricing page) or uncapped (limits doc); Enterprise unlimited |
| Session length | No cap; optional idle auto-pause from 60 s to 24 h, off by default | Demo 1 h, Pro 24 h, Enterprise unlimited; sandboxes past the cap are reaped |
| Billing | Per second: $0.03616363 per vCPU-hour, $0.01159025 per GiB-hour, storage $0.0001584 per GB-hour; no egress fees (50 GiB bandwidth budget per sandbox) | $0.040 per vCPU-hour, $0.012 per GB-hour; suspended $0.10 per GB-month |
| SDKs and interfaces | TypeScript, Go, Python, Rust, C#, Java (all but TypeScript pre-1.0), CLI, MCP, REST | REST API, Python SDK (collimate-rl), hosted MCP server |
| Self-host or BYOC | Enterprise only, onboarded by our team | Self-host control plane on Kubernetes via Helm; BYOC on Enterprise |
Common Questions
What happens to a Collimate sandbox at the session cap?
It is reaped: Demo sessions end at 1 hour and Pro at 24 hours, and Collimate advises suspending before the cap to keep state. CreateOS has no session cap; a sandbox runs until you pause or destroy it, or until an optional idle auto-pause triggers.
Can CreateOS fork a running sandbox like Collimate?
No. CreateOS forks from a paused sandbox: you pause it, then fork the saved snapshot into independent sandboxes while the source stays paused. Collimate forks a running sandbox and the parent keeps running, which suits RL fan-out better.
Does Collimate charge for forks?
No. Spawn and fork are free on Collimate; you pay $0.040 per vCPU-hour and $0.012 per GB-hour for children while they run. On CreateOS each child is a normal sandbox billed per second, and the paused source keeps billing memory and storage.
Is outbound traffic blocked by default on Collimate?
Collimate's docs describe per-fork egress as a default-deny allowlist by host, and pure code templates have no network at all. CreateOS starts open and becomes deny-by-default once you add a host, IP, CIDR or wildcard rule.
Sources
Checked 17 October 2026.
See CreateOS Sandbox for yourself
Book a demo, or explore the Sandbox and its pricing.