Namespace vs Modal VM Sandboxes
Namespace is a build platform: CI runners, caches and Devboxes on Linux, macOS and Windows that stop after 4 to 24 hours. Modal VM Sandboxes are Linux VMs with their own kernel that you create from code, run for up to 24 hours and then throw away.
The companies and products
Namespace
Namespace is a dev platform for fast builds, tests and coding environments: CI runners, build caches and Devboxes, on its own hardware.
Most of Namespace is CI: a faster drop-in for GitHub Actions runners, with Docker, Bazel, Turborepo and Nix caching. Its Devboxes are remote Linux and macOS machines with persistent storage, made for people and AI coding agents, and they also host sessions for Claude Managed Agents, Cursor Cloud Agents and Devin. It is a different kind of product from boat, so this page compares the part where they overlap: a machine an agent works on.
- Products
- GitHub Actions runners, Docker, Bazel, Turborepo and Nix caching, Devboxes, and a compute API
- Hardware
- Its own hardware in its own racks: AMD EPYC for Linux and Windows, Apple M4 Pro or M5 Max for macOS
- Linux Devboxes
- Run from a container image you choose and include Docker; the docs do not say whether each one has its own kernel
- Funding
- Announced a $42M Series B
- Compliance
- Trust center lists SOC 2 Type II
Modal VM Sandboxes
Modal is a serverless cloud for AI work, and VM Sandboxes are the version of its sandboxes that run in a virtual machine with their own Linux kernel.
You create a VM Sandbox from Python, TypeScript or Go code with runtime="vm", run commands in it, and terminate it when the job is done. Modal built the runtime on the Rust-based Cloud Hypervisor, so Docker, FUSE, systemd and nested cgroups work, with the same API, images and prices as its gVisor sandboxes. It became generally available on 1 October 2026 and suits teams that want many short-lived agent machines next to Modal's inference and training.
- Funding
- Over $466M raised
- Generally available
- 1 October 2026; early customers launched over 20 million VMs before that
- Session length
- Default 5 minutes, maximum 24 hours
- Compliance
- SOC 2 on every plan; HIPAA on Enterprise
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. “80th cheapest of 377” means 79 of the other 376 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 | Namespace: price rank | Modal VM Sandboxes: price rank | boat: price rank |
|---|---|---|---|
| Software factory 100 at once · 4 vCPU / 8 GB · 2,200 sessions of 8 h a month Both are a compromise for a software factory because each machine ends within 24 hours; boat ranks 3rd here with a VM that keeps its disk and has no session cap on paid plans. | 39th of 367, with limits $3,495 a month | 84th of 367, with limits $759 a month | 3rd cheapest of 367 $634 a month |
| Always-on AI employees 50 machines 24/7 · 2 vCPU / 4 GB An agent that never stops is cut off on both: a Namespace Devbox and a Modal VM Sandbox each end within 24 hours, while boat has no session cap on paid plans. | 303rd of 366, with limits $6,645 a month | Can't run it | 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 | 247th of 345, with limits $250 a month | Can't run it | 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 | 284th of 361, with limits $2,068 a month | Can't run it | 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 Modal is built for huge bursts of short sandboxes, so it does better than Namespace for rollouts, and boat's start limits queue the largest bursts. | 356th of 360, with limits $9,012 a month | 171st of 360, with limits $16,322 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 | 282nd of 364, with limits $1,043 a month | Can't run it | 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 runners are Namespace's main product, with caches for Docker, Bazel and more, so it fits where Modal VM Sandboxes are a compromise; boat also fits, with Docker and /dev/kvm on every machine. | 80th cheapest of 377 $765 a month | 188th of 377, with limits $1,064 a month | 4th cheapest of 377 $86 a month |
| 24/7 dev boxes 1 machine 24/7 · 4 vCPU / 8 GB | 126th of 368, with limits $168 a month | Can't run it | 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 Namespace's screenshot and click API works on macOS Devboxes only and Modal has no desktop at all; boat streams a 60fps Linux desktop with Chromium. | 67th of 369, with limits $982 a month | Can't run it | 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 | 285th of 367, with limits $789 a month | Can't run it | 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 | 259th of 346, with limits $332 a month | Can't run it | 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 | 226th of 338, with limits $9,012 a month | Can't run it | 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 Both are a compromise for many parallel attack machines; boat ranks 2nd here, with forks of a running sandbox and open internet on every plan. | 242nd of 360, with limits $339 a month | 294th of 360, with limits $642 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 None of the three fits: Namespace and boat are CPU only, and Modal's GPUs need its gVisor sandboxes, not the VM runtime. | 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 Only Namespace fits: it runs macOS on Apple Silicon, and neither Modal VM Sandboxes nor boat have macOS. | 6th cheapest of 36 $1,205 a month | Can't run it | Can't run it |
Key features
| Feature | Namespace | Modal VM Sandboxes | boat |
|---|---|---|---|
| Isolation | Linux Devboxes run from a container image on Namespace's own hardware; the docs do not say if each has its own kernel | VM with its own Linux kernel on Cloud Hypervisor | Full VM with its own kernel on dedicated AMD Ryzen 9 9950X hosts |
| CPU speed (Node.js build-and-test, 4 vCPU / 8 GB) | 21.79 runs/s | 15.54 runs/s | 26.69 runs/s |
| Docker and nested virtualization | Docker in Linux Devboxes; /dev/kvm on Linux compute instances | Docker and systemd (start dockerd yourself); /dev/kvm on Team and Enterprise only, on request | Docker, root, systemd and /dev/kvm on every machine |
| Longest session | Devboxes stop after 4, 5 or 24 hours by plan, raisable to 24 at most | 24 hours (default 5 minutes) | No session cap on paid plans |
| Files after a stop | A stopped Devbox keeps its storage, billed at $0.20 per GB-month used | No paused state; only Volumes and filesystem snapshots keep files | Disk saved every minute and on stop; a stopped sandbox costs nothing |
| Idle stop and wake | Devboxes stop after an idle timeout and start again when you connect | No wake on connect; you create a new sandbox | Machines run until you stop them |
| Fork and snapshots | No fork; compute instances can suspend and resume with RAM kept | Filesystem snapshots boot many new sandboxes; memory snapshots in alpha | Fork a running sandbox with its disk; resume reboots from disk |
| Desktop and computer use | Screenshot and click API on macOS Devboxes only; VNC and RDP for compute instances | Not offered; an example shows how to set up Xvfb and VNC yourself | 60fps Linux desktop, Chromium, computer use and browser control |
| Coding agents | Hosts Claude Managed Agents, Cursor and Devin sessions; an MCP server lets your agent create Devboxes | Examples only; you install the agent harness yourself | Claude Code, Codex, OpenCode and more preinstalled, with a prompt, steer and events API |
| Keeping keys out of the sandbox | Egress rules inject a header from Namespace Vault, outside the workload | Secrets are environment variables, or you run your own proxy in a sidecar | AI credentials proxy for model providers and any HTTPS API you register |
| Reaching the sandbox | HTTPS URLs that need a Namespace login; TCP through a CLI port-forward; no public IP | Encrypted and raw TCP tunnels, connect tokens, inbound IP allowlist | HTTPS URLs for up to 50 ports, token-protected, plus raw TCP |
| Outbound network rules | Block, advisory or allow by domain, per Devbox blueprint, runner or instance | Block all, IP-range allowlist, domain allowlist (beta) | Open internet, no provider-side allowlist |
| Operating systems | Linux, macOS on Apple Silicon, and Windows on Team plans and up | Linux only | Linux only; Wine for Windows apps |
| Regions | Several regions; keeping a workload inside one region needs Enterprise | US, EU and Asia-Pacific; pinning a region costs 1.15x to 1.75x | EU only: Germany, Finland, France, with EU data residency |
Every feature Battleships tracks (43)
| Feature | Namespace | Modal VM Sandboxes | boat |
|---|---|---|---|
| Full VM (own kernel) | Yes | Yes | Yes |
| Docker inside | Yes | Yes | Yes |
| Nested virtualization | Yes | Yes | Yes |
| Root | Yes | Yes | Yes |
| Systemd | Not published | Yes | Yes |
| Desktop GUI | Yes | No | Yes |
| Browser | No | No | Yes |
| Computer-use API | Yes | No | Yes |
| SSH | Yes | Yes | Yes |
| Persistent disk | Yes | Yes | Yes |
| Pause/resume | Yes | No | Yes |
| Automatic snapshots | Yes | No | Yes |
| Fork/clone | No | Yes | Yes |
| Live fork (no pause) | No | Yes | Yes |
| Memory fork | No | Yes | No |
| Custom image (Docker or snapshot) | Yes | Yes | Yes |
| ≥24 h sessions | Yes | Yes | Yes |
| Idle auto-stop | Yes | Yes | No |
| Wake on request | Yes | No | No |
| HTTPS preview URLs | Yes | Yes | Yes |
| Raw TCP inbound | Yes | Yes | Yes |
| Public IPv4 | No | No | No |
| Egress allowlist | Yes | Yes | No |
| Secret proxy | Yes | No | Yes |
| Secret proxy for any API | Yes | No | Yes |
| Preinstalled agents | Yes | No | Yes |
| Agent harness API | No | No | Yes |
| MCP server | Yes | No | No |
| GPU | No | No | No |
| Windows | Yes | No | No |
| Arm64 | Yes | No | No |
| Self-hosting | No | No | No |
| BYOC | No | No | No |
| Open source | No | No | No |
| Scoped API keys | Not published | Not published | Yes |
| Spend limits | Yes | Not published | Yes |
| Usage per sandbox (API) | No | Not published | Yes |
| Audit logs | Yes | Yes | No |
| SSO | Yes | Yes | No |
| SOC 2 | Yes | Yes | No |
| HIPAA | No | Yes | No |
| EU data residency | Yes | Yes | Yes |
| Zero data retention | Not published | Not published | Yes |
Performance
In StarSling's public run of 29 September 2026, at 4 vCPU / 8 GB, boat did 26.69 Node.js build-and-test runs per second, Namespace 21.79 and Modal's VM runtime 15.54. So Namespace did about 1.4 times the CPU work of Modal VM Sandboxes, and boat about 1.2 times Namespace and 1.7 times Modal. This measures CPU speed only, not start time.
Node.js build-and-test loop at 4 vCPU / 8 GB, higher is better. Measured with the open hpc-sandbox-benchmarks suite. Namespace measured on: Linux compute instance (unit-minutes, PAYG/overage $0.0015). Modal VM Sandboxes measured on: VM Sandbox, request = size.
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 | Namespace, a month | Modal VM Sandboxes, 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 | $50 · Devbox (pay as you go) | $15 · Starter · with limits | $20 · $20/mo |
| One agent that never stops 4 vCPU / 8 GB, 50 GB disk, running 24/7 all month | $176 · Devbox (pay as you go) · with limits | $178 · Starter · 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 | $2,198 · Devbox (pay as you go) | $2,229 · Starter · 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 | $1,214 · Devbox (pay as you go) | $792 · Team | $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 | $3,237 · Devbox (pay as you go) | $3,193 · Team · with limits | $2,000 · $2000/mo · with limits |
Namespace: Devboxes are billed in Devbox Minutes at $0.004 each, pay as you go on every plan: a 4 vCPU / 8 GB Devbox uses one a minute. The minutes in the Team ($100) and Business ($250) plans cover runners and instances, not Devboxes, and stored files cost $0.20 per GB-month.
Modal VM Sandboxes: Modal bills by the second for the higher of the CPU and memory you request or what you use, until the sandbox ends. Starter is free with $30 of monthly credit, Team is $250 a month with $100 of credit, and egress above the free allowance costs $0.04 per GiB.
Modal VM Sandboxes: You pick a monthly plan from $20, and all of it becomes usage credit spent per second on running sandboxes. A stopped sandbox costs nothing and keeps its disk.
Limits in those scenarios
Time is the limit that bites on both: the agent that never stops comes to $176 a month on Namespace and $178 on Modal, and neither fits, because each machine ends within 24 hours. On Modal, the workday and 50-agent scenarios also lose installed packages between sessions unless files live in a Volume, and the 1,000-job burst runs on shared vCPUs. Namespace fits the burst and the fleet but does not publish an egress price or a Devbox concurrency limit; boat's start limits queue the 1,000-job burst.
| Scenario | Namespace | Modal VM Sandboxes | boat |
|---|---|---|---|
| One coding agent, workdays |
|
| 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 | None that bite |
| 1,000 short jobs at once |
|
|
|
Which one should you use?
Use Namespace when
you need macOS or Windows machines, faster GitHub Actions runners with build caches, or Devboxes for people that stop when idle and wake on connect.
- macOS and Windows. Useful if your agents build iOS or Mac apps or test on Windows: Namespace runs macOS on Apple Silicon and Windows machines.
- CI runners and build caches. Useful if you want faster GitHub Actions: Namespace is a drop-in runner with Docker, Bazel, Turborepo and Nix caching.
- Devboxes that sleep and wake. Useful for people's dev machines: a Devbox stops when idle, keeps its storage and starts again when you connect.
Use Modal VM Sandboxes when
you run large bursts of short jobs that finish within a day, need regions outside Europe, or already run your models on Modal.
- Huge bursts of short jobs. Useful for evals and rollouts that finish fast: Modal runs 5,000 containers at once on Team and bills by the second.
- Snapshots that fan out. Useful when one prepared machine should become many: a filesystem snapshot boots any number of new sandboxes.
- Next to your models. Useful if you already serve or train models on Modal: sandboxes, GPUs and models sit on one account and one bill.
Where boat fits
If what you are really running is agents that work for hours or days on Linux, both Namespace and Modal VM Sandboxes cut the machine off within 24 hours. boat gives each agent a full VM that keeps its disk, has no session cap on paid plans and comes with a desktop and coding agents built in.
No clock on the session
A Namespace Devbox is shut down after 4, 5 or 24 hours even while it works, and a Modal VM Sandbox ends within 24 hours. Your code has to notice, snapshot or restart, and resume the task every day.
A disk that survives the stop
On Modal everything outside a Volume or snapshot is gone when the sandbox ends, so packages reset. Namespace keeps Devbox storage but bills it per GB-month. boat saves the disk every minute and a stopped sandbox costs nothing.
Desktop and agents ready to go
Namespace's computer-use API works on macOS Devboxes only and Modal has no desktop, so a Linux browser agent means installing VNC yourself. boat ships a 60fps desktop, Chromium and coding agents you drive from outside.
Use boat when your agents work on Linux for hours or days: a full, faster VM with no session cap on paid plans, a disk that survives free stops, Docker and /dev/kvm, a 60fps desktop and coding agents you drive from outside. Compare it one to one: boat vs Namespace and boat vs Modal VM Sandboxes.
Questions people ask
Is Namespace cheaper than Modal VM Sandboxes?
It depends on the job. For one coding agent on workdays Modal comes to $15 a month and Namespace $50, but Modal's files reset between days unless you use a Volume. For sandboxes for your users Modal is $792 against $1,214, and for 50 parallel agents they are close at $2,198 on Namespace against $2,229 on Modal.
Which is faster, Namespace or Modal VM Sandboxes?
On the same CPU test at 4 vCPU / 8 GB, Namespace did 21.79 runs per second and Modal's VM runtime 15.54, about 1.4 times the CPU work. boat did 26.69 in the same run.
Can Namespace and Modal VM Sandboxes run Docker?
Yes. Namespace's Linux Devboxes include Docker, and Modal VM Sandboxes run Docker once you start dockerd as the entrypoint. For /dev/kvm, Namespace offers it on Linux compute instances and Modal on Team and Enterprise after you ask support; boat has Docker and /dev/kvm on every machine.
How long can a session run on each?
A Namespace Devbox runs up to 4 hours on Developer, 5 on Team and 24 on Business, even while you work. A Modal VM Sandbox defaults to 5 minutes and runs 24 hours at most. boat has no session cap on paid plans.
Does either run macOS or GPUs?
Namespace runs macOS on Apple Silicon and Windows on Team plans and up, while Modal VM Sandboxes and boat run Linux only. None of the three has GPUs on these machines; Modal's GPUs need its gVisor sandboxes.
Is boat SOC 2 compliant?
SOC 2 is in progress. We're open about where we stand: live status at status.ascii.dev and our data retention policy at docs.boat.dev/data-retention.
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