Docker Cloud Sandboxes vs OpenAI Containers
Docker Cloud Sandboxes gives each coding agent its own microVM with Docker inside, for up to 24 hours, started from the same sbx CLI you use on your laptop. OpenAI Containers are a tool inside OpenAI's model API: the model runs Python or shell commands in a box without sudo that expires after 20 minutes without use.
The companies and products
Docker Cloud Sandboxes
Docker Cloud Sandboxes runs Docker's sbx coding-agent microVMs on Docker-managed compute instead of your laptop.
Each sandbox is a microVM with its own Linux kernel and its own Docker Engine, started from the same sbx CLI you use locally, with Claude Code, Codex and other agents ready to run. You can move a sandbox from your laptop to the cloud and back, publish HTTPS ports and SSH in. It launched on September 24, 2026, is billed pay-as-you-go on a personal Docker account, and is built for developers who want their local agent sandboxes to keep going off their machine.
- Launched
- September 24, 2026
- Session length
- 1 hour by default, extendable to 24 hours from creation
- Default quota
- 10 concurrent and 50 stored sandboxes per account
- Regions
- Not published
OpenAI Containers
OpenAI Containers are the sandboxes OpenAI runs for its own model tools: Code Interpreter, Hosted Shell and the Agents API's hosted sandbox.
This is a different kind of product from boat: a tool inside OpenAI's model API, not a machine you rent. You create a container through the API or let a Responses call make one, and the model runs Python or shell commands in it on a fixed Debian 12 image without sudo, until it expires after 20 minutes without use. It is built for apps that already call OpenAI models and want them to run code, read files and make charts without running any servers.
Which use cases each one fits
For each use case, Battleships prices every sandbox provider on the same workload and sorts them from the cheapest monthly bill up. “280th cheapest of 367” means 279 of the other 366 providers run that workload, with every feature it needs, for less. “With limits” means the provider runs it but misses something, so it is listed after every full match. Open a use case for its whole ranking and what each provider misses.
| Use case and its workload | Docker Cloud Sandboxes: price rank | OpenAI Containers: price rank | boat: price rank |
|---|---|---|---|
| Software factory 100 at once · 4 vCPU / 8 GB · 2,200 sessions of 8 h a month A software factory needs agents that run for days and by the dozen; Docker stops each sandbox at 24 hours and runs 10 at once, and OpenAI containers have no Docker or persistent disk. | 280th of 367, with limits $4,928 a month | 356th of 367, with limits $17,371 a month | 3rd cheapest of 367 $634 a month |
| Always-on AI employees 50 machines 24/7 · 2 vCPU / 4 GB An assistant that lives on its machine all month fits neither: Docker ends a session 24 hours after creation, and an OpenAI container is deleted after 20 idle minutes. | 276th of 366, with limits $5,110 a month | 341st of 366, with limits $13,140 a month | 5th cheapest of 366 $657 a month |
| Code interpreter bursts 100 at once · 1 vCPU / 2 GB · 200,000 sessions of 1 min a month Short code runs are where both fit best; Docker's small sandboxes billed by the second rank ahead of both OpenAI and boat here, while OpenAI's runs live inside the model call itself. | 119th of 345, with limits $233 a month | 194th of 345, with limits $6,000 a month | 186th of 345, with limits $2,000 a month |
| Sandboxes for your users 300 at once · 2 vCPU / 4 GB · 30,000 sessions of 23 min a month Serving your own users needs many sandboxes and a way in; Docker allows 10 at once by default, and OpenAI containers accept no inbound connections. | 136th of 361, with limits $1,628 a month | 361st of 361, with limits $3,780 a month | Cheapest of 361 $209 a month |
| RL rollouts 1,000 at once · 2 vCPU / 4 GB · 1,000,000 sessions of 3 min a month | 114th of 360, with limits $7,000 a month | 191st of 360, with limits $30,000 a month | 34th of 360, with limits $2,000 a month |
| Agent evals 250 at once · 4 vCPU / 8 GB · 15,000 sessions of 20 min a month | 167th of 364, with limits $1,400 a month | 360th of 364, with limits $5,760 a month | 10th cheapest of 364 $200 a month |
| CI runners 40 at once · 8 vCPU / 16 GB · 6,000 sessions of 12 min a month CI needs Docker, root and open internet; Docker has all three, OpenAI documents no Docker or root, and boat adds /dev/kvm for Android and VM builds. | 172nd of 377, with limits $672 a month | 345th of 377, with limits $1,728 a month | 4th cheapest of 377 $86 a month |
| 24/7 dev boxes 1 machine 24/7 · 4 vCPU / 8 GB A dev box you keep all month needs no session cap and a disk that stays; Docker gives the disk but caps sessions at 24 hours, OpenAI gives neither. | 127th of 368, with limits $204 a month | 362nd of 368, with limits $1,051 a month | 18th cheapest of 368 $26 a month |
| Computer-use agents 50 at once · 4 vCPU / 8 GB · 20,000 sessions of 15 min a month OpenAI's Agents API has a hosted browser for computer use and Docker's sandboxes are terminal only; boat streams a full 60fps desktop with Chromium. | 268th of 369, with limits $1,400 a month | 351st of 369, with limits $5,280 a month | 6th cheapest of 369 $200 a month |
| Browser-use agents 50 at once · 2 vCPU / 4 GB · 30,000 sessions of 10 min a month Docker ships no browser in the sandbox, OpenAI's hosted browser is driven by its own Codex harness, and boat runs Chromium you can drive with any agent. | 277th of 367, with limits $700 a month | 328th of 367, with limits $1,440 a month | 7th cheapest of 367 $200 a month |
| Scraping & bots (startup scale) 50 at once · 1 vCPU / 2 GB · 100,000 sessions of 3 min a month | 262nd of 346, with limits $350 a month | 328th of 346, with limits $1,755 a month | 6th cheapest of 346 $90 a month |
| Mass scraping & bots (undetectable) 1,000 at once · 1 vCPU / 2 GB · 3,000,000 sessions of 2 min a month | 190th of 338, with limits $7,000 a month | 311th of 338, with limits $35,100 a month | 71st of 338, with limits $1,800 a month |
| Parallel red teaming 200 at once · 2 vCPU / 4 GB · 5,000 sessions of 30 min a month | 248th of 360, with limits $350 a month | 308th of 360, with limits $870 a month | 2nd cheapest of 360 $200 a month |
| GPU eval jobs 10 at once · 8 vCPU / 32 GB · 500 sessions of 30 min a month | Can't run it | Can't run it | Can't run it |
| macOS agents 5 at once · 4 vCPU / 8 GB · 1,000 sessions of 20 min a month | Can't run it | Can't run it | Can't run it |
Key features
| Feature | Docker Cloud Sandboxes | OpenAI Containers | boat |
|---|---|---|---|
| What it is | A microVM you start, stop and SSH into from the sbx CLI | A sandbox tool the model uses inside OpenAI's API | A cloud VM you create, keep, stop and reach from outside |
| Isolation | MicroVM with its own Linux kernel and Docker Engine; hypervisor not named | A fully sandboxed virtual machine; hypervisor not named | Full VM with its own kernel on dedicated AMD Ryzen 9 9950X hosts |
| Root and Docker inside | Its own Docker Engine; agent runs as a non-root user with sudo | Commands do not run with sudo; no Docker documented | Root, systemd and Docker on every machine |
| Nested virtualization | Not documented | Not documented | Yes, /dev/kvm for Android emulators and VMs |
| Machine size | 1 vCPU / 2 GiB up to 16 vCPU / 32 GiB, amd64 or arm64 by account | 1, 4, 16 or 64 GB of memory; vCPU not published | 4 vCPU / 8 GB by default, up to 16 vCPU / 32 GB |
| Session length | 1 hour by default, at most 24 hours from creation | Expires after 20 minutes without use; Agents API sandboxes after an hour without activity | No cap on paid plans; you set the time to live |
| Files after the session | Stop keeps memory and files; stopped snapshots are deleted after 7 days of non-use | Data is discarded when the container expires | Disk saved every minute and on stop; a stopped sandbox costs nothing and comes back |
| Fork | Snapshot a running sandbox with disk or disk and memory, restore it as a new one | No fork | Fork a running sandbox with its disk |
| Sandboxes at once | 10 by default; no published way to raise it | Not published | 100 on the $20 plan, up to 2,000 on higher plans |
| Inbound access | Public HTTPS URL per published port and SSH | None; you reach the container only through the API | SSH, HTTPS URLs for up to 50 ports, raw TCP |
| Outbound internet | Allow and deny rules by host, with allow-all, balanced and deny-all presets | Code Interpreter and Hosted Shell: off until an admin sets an org allowlist | Open internet, no provider-side allowlist |
| Keeping API keys out of the sandbox | Cloud proxy sets the auth header; the sandbox sees a placeholder | domain_secrets: a sidecar adds the real header for approved domains | Credentials proxy for model providers and any HTTPS API; switch a credential to another account when credits run out |
| Coding agents | Claude Code, Codex, Copilot, OpenCode and more, attached to from the sbx CLI | Agents API (beta) drives a managed Codex harness with steering and events | Seven agents preinstalled, with a prompt, steer and events API to drive them from outside |
| Desktop and computer use | Terminal sessions only | Hosted browser for the Agents API computer_use tool | 60fps Linux desktop with Chromium and computer use |
Every feature Battleships tracks (43)
| Feature | Docker Cloud Sandboxes | OpenAI Containers | boat |
|---|---|---|---|
| Full VM (own kernel) | Yes | Yes | Yes |
| Docker inside | Yes | No | Yes |
| Nested virtualization | No | No | Yes |
| Root | Yes | No | Yes |
| Systemd | Not published | Not published | Yes |
| Desktop GUI | No | Yes | Yes |
| Browser | No | Yes | Yes |
| Computer-use API | No | Yes | Yes |
| SSH | Yes | No | Yes |
| Persistent disk | Yes | No | Yes |
| Pause/resume | Yes | No | Yes |
| Automatic snapshots | Yes | No | Yes |
| Fork/clone | Yes | No | Yes |
| Live fork (no pause) | Yes | No | Yes |
| Memory fork | Yes | No | No |
| Custom image (Docker or snapshot) | Yes | No | Yes |
| ≥24 h sessions | Yes | Yes | Yes |
| Idle auto-stop | No | Yes | No |
| Wake on request | Not published | No | No |
| HTTPS preview URLs | Yes | No | Yes |
| Raw TCP inbound | Not published | No | Yes |
| Public IPv4 | No | No | No |
| Egress allowlist | Yes | Yes | No |
| Secret proxy | Yes | Yes | Yes |
| Secret proxy for any API | Yes | Yes | Yes |
| Preinstalled agents | Yes | No | Yes |
| Agent harness API | No | Yes | Yes |
| MCP server | Yes | No | No |
| GPU | No | No | No |
| Windows | No | No | No |
| Arm64 | Yes | No | No |
| Self-hosting | No | Yes | No |
| BYOC | No | No | No |
| Open source | No | No | No |
| Scoped API keys | Not published | Not published | Yes |
| Spend limits | Not published | Not published | Yes |
| Usage per sandbox (API) | No | No | Yes |
| Audit logs | Not published | Not published | No |
| SSO | Yes | Yes | No |
| SOC 2 | No | Yes | No |
| HIPAA | No | Yes | No |
| EU data residency | No | Yes | Yes |
| Zero data retention | Not published | Not published | Yes |
Performance
There is no comparable measurement for either one. Docker Cloud Sandboxes launched in September 2026 and is not in the hpc-sandbox-benchmarks runs, and OpenAI does not publish the vCPU behind each container size. boat did 26.69 runs per second on the same Node.js build-and-test benchmark at 4 vCPU / 8 GB.
Node.js build-and-test loop at 4 vCPU / 8 GB, higher is better. Measured with the open hpc-sandbox-benchmarks suite. Docker Cloud Sandboxes and OpenAI Containers have no published run in this suite yet, so there is no like-for-like number to compare.
Pricing in five scenarios
Each bill is priced from the providers' public price lists by the open Battleships engine, with the cheapest plan that runs the scenario.
| Scenario | Docker Cloud Sandboxes, a month | OpenAI Containers, a month | boat, a month |
|---|---|---|---|
| One coding agent, workdays 4 vCPU / 8 GB, 50 GB disk, 8 hours a day, 22 days a month, files kept between days | $49 · Docker Agentic Platform (pay-as-you-go) | $228 · API pay as you go · with limits | $20 · $20/mo |
| One agent that never stops 4 vCPU / 8 GB, 50 GB disk, running 24/7 all month | $204 · Docker Agentic Platform (pay-as-you-go) · with limits | $1,051 · API pay as you go · with limits | $26 · $20/mo |
| 50 agents in parallel 50 machines of 4 vCPU / 8 GB at once, 8-hour sessions, 1,100 sessions a month, Docker inside | $2,464 · Docker Agentic Platform (pay-as-you-go) · with limits | $11,405 · API pay as you go · with limits | $317 · $20/mo × 3 seats |
| Sandboxes for your users 2 vCPU / 4 GB, 30,000 sessions of 10 minutes a month, up to 300 at once | $700 · Docker Agentic Platform (pay-as-you-go) · with limits | $1,620 · API pay as you go · with limits | $200 · $100/mo × 2 seats |
| 1,000 short jobs at once 2 vCPU / 4 GB, 1,000 at once, 3 minutes each, 200,000 jobs a month | $1,400 · Docker Agentic Platform (pay-as-you-go) · with limits | $6,000 · API pay as you go · with limits | $2,000 · $2000/mo · with limits |
Docker Cloud Sandboxes: Docker bills per second for the size you pick, from $0.07 an hour for 1 vCPU / 2 GiB to $1.12 an hour for 16 vCPU / 32 GiB, with no monthly fee. A stopped sandbox costs nothing, and model calls are billed by your model provider.
OpenAI Containers: OpenAI bills each container session by the minute for the memory size you pick, with a 5-minute minimum, and model tokens are billed on top. The scenarios use the 16 GB size for 8 GB needs and the 4 GB size for 4 GB needs, since vCPU is not published.
OpenAI Containers: Plans start at $20 a month, and the whole fee is usage credit spent per second on running sandboxes. A stopped sandbox costs nothing and keeps its disk.
Limits in those scenarios
Docker fits one coding agent on workdays, but its 24-hour session cap rules out an agent that never stops, and its default of 10 sandboxes at once rules out 50 agents, 300 user sandboxes and a 1,000-job burst. OpenAI Containers fit none of the five scenarios: no persistent disk, no Docker, no internet until an admin sets an allowlist, and no published vCPU or concurrency limit. On boat the 1,000-job burst is limited by starts per minute, so even the $2,000 plan queues those starts.
| Scenario | Docker Cloud Sandboxes | OpenAI Containers | boat |
|---|---|---|---|
| One coding agent, workdays | None that bite |
| None that bite |
| One agent that never stops |
|
| None that bite |
| 50 agents in parallel |
|
| None that bite |
| Sandboxes for your users |
|
| None that bite |
| 1,000 short jobs at once |
|
|
|
Which one should you use?
Use Docker Cloud Sandboxes when
you already run agents in sbx on your laptop and want a few of them to keep going in the cloud for up to a day, with Docker inside and memory kept across stops.
- A real machine with Docker inside. For coding agents that build and test: each sandbox has its own kernel, its own Docker Engine, sudo and SSH.
- Stop and fork with memory. For agents that pause between steps: a stopped sandbox comes back with memory and processes, and can be forked.
- The same sandbox on your laptop. If you already run sbx locally, the cloud is the same microVM and CLI, and you can move work between them.
Use OpenAI Containers when
your app already calls OpenAI models and the model only needs to run short pieces of code or shell commands on files you give it.
- Built into the model call. If your app already calls OpenAI models, one tool line in a request gives the model a place to run code.
- Locked-down network by default. If code must only reach chosen hosts, Code Interpreter and Hosted Shell have no outbound access until an admin allows domains.
- US or EU processing and your own compute. Code Interpreter can process data in the US or Europe, and the Agents API can drive a sandbox you host.
Where boat fits
If your agents run for days, by the dozen, or need a screen, look at boat. Docker caps each session at 24 hours and 10 at once, and OpenAI's containers expire after 20 idle minutes with no Docker or root. boat gives each agent a full VM with no session cap on paid plans.
Runs as long as the work
A multi-day agent on Docker must be stopped and resumed by your code before 24 hours. On OpenAI it must touch the container every 20 minutes or lose everything. boat has no session cap and saves the disk every minute.
A whole machine, screen included
Docker gives a terminal with no /dev/kvm, and OpenAI gives no sudo or Docker. boat has root, systemd, Docker, /dev/kvm for Android emulators and a 60fps desktop with Chromium, so one machine covers builds, tests and clicking through a UI.
Drive agents inside from outside
On Docker you attach to an agent's terminal and parse its text; on OpenAI the Agents API drives only its own Codex harness. boat preinstalls seven agents and drives any of them through one prompt, steer and events API.
Use boat when your agents run for days or by the dozen, need root, Docker, Android emulators or a desktop, or have to be driven from your own app through an API. Compare it one to one: boat vs Docker Cloud Sandboxes and boat vs OpenAI Containers.
Questions people ask
Is Docker Cloud Sandboxes cheaper than OpenAI Containers?
For one coding agent on workdays, Docker comes to $49 a month against $228 on OpenAI, and OpenAI also bills model tokens on top. boat comes to $20 a month for the same 4 vCPU / 8 GB machine.
Which is faster?
Neither has a public CPU measurement: Docker's cloud sandboxes are too new for the benchmark, and OpenAI does not publish the vCPU behind its containers. boat did 26.69 runs per second on the hpc-sandbox-benchmarks Node.js test at 4 vCPU / 8 GB.
Can OpenAI Containers run Docker?
No Docker support is documented, and hosted shell commands do not run with sudo. Docker Cloud Sandboxes give each sandbox its own Docker Engine, and boat gives root, systemd, Docker and /dev/kvm.
How long can a sandbox run on each?
A Docker cloud sandbox runs 1 hour by default and at most 24 hours from creation. An OpenAI container expires after 20 minutes without use, and its data is discarded. boat has no session cap on paid plans.
Can I open a web app running inside the sandbox?
On Docker, yes: each published port gets a public HTTPS URL, and you can SSH in. OpenAI containers have no ports, URLs or SSH. boat gives HTTPS URLs for up to 50 ports, raw TCP and SSH.
Can I use OpenAI models with Docker Cloud Sandboxes or boat?
Yes. Both run Codex inside the sandbox, and both keep your real API key outside it with a credentials proxy. On boat the proxy also covers any HTTPS API.
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