E2B vs Namespace
E2B is an agent sandbox API: each job gets a Firecracker microVM that starts fast and can pause and resume with its memory. Namespace is a build and dev platform: CI runners, build caches and Devboxes on Linux, macOS and Windows, which coding agents can also use.
The companies and products
E2B
E2B calls itself the AI agent cloud: an API that gives each agent session its own isolated Linux machine.
Every E2B sandbox is a Firecracker microVM that boots from a snapshot, so it starts fast and can be paused and resumed with its memory. You build custom sandboxes from templates based on a Docker image, and drive them from Python or JavaScript SDKs. It is built for teams that run many short code, data or agent jobs, and its runtime is open source.
- Isolation
- Firecracker microVM per sandbox
- Bring your own cloud
- Enterprise data plane in your AWS, GCP or Azure account
- Compliance
- SOC 2 Type II; HIPAA BAA on request
- Machine size
- 1 to 8 vCPU and 1 to 8 GiB RAM, CPU only
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
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. “16th cheapest of 367” means 15 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 | E2B: price rank | Namespace: price rank | boat: price rank |
|---|---|---|---|
| Software factory 100 at once · 4 vCPU / 8 GB · 2,200 sessions of 8 h a month E2B fits fully while a Namespace Devbox is a compromise because it is shut down after at most 24 hours; boat fits too, with no session cap and /dev/kvm. | 16th cheapest of 367 $4,143 a month | 39th of 367, with limits $3,495 a month | 3rd cheapest of 367 $634 a month |
| Always-on AI employees 50 machines 24/7 · 2 vCPU / 4 GB Both are a compromise for an assistant that never stops: E2B ends a session after 24 hours on Pro and a Namespace Devbox after at most 24 hours; boat has no session cap on paid plans. | 51st of 366, with limits $5,348 a month | 303rd of 366, with limits $6,645 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 E2B is built for this: short code runs that start fast, pause with their memory and wake on the next request, while Namespace is a compromise here. | 37th cheapest of 345 $421 a month | 247th of 345, with limits $250 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 E2B fits fully and can wake a paused sandbox on the next request, Namespace is a compromise, and boat ranks first with a bigger, faster machine and hosting built in. | 23rd cheapest of 361 $2,354 a month | 284th of 361, with limits $2,068 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 E2B ranks 2nd here: memory forks and a high start rate suit many short rollouts that branch from the same state. | 2nd cheapest of 360 $9,384 a month | 356th of 360, with limits $9,012 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 | 78th cheapest of 364 $1,975 a month | 282nd of 364, with limits $1,043 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 runners are Namespace's main product, with caches for Docker, Bazel and more; E2B is a compromise because it has no nested virtualization, and boat runs CI jobs on full VMs with /dev/kvm. | 337th of 377, with limits $1,429 a month | 80th cheapest of 377 $765 a month | 4th cheapest of 377 $86 a month |
| 24/7 dev boxes 1 machine 24/7 · 4 vCPU / 8 GB | 192nd of 368, with limits $358 a month | 126th of 368, with limits $168 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 E2B has a Linux desktop for computer use, while Namespace's screenshot and click API works on macOS Devboxes only; boat streams a 60fps Linux desktop you can embed. | 32nd cheapest of 369 $1,342 a month | 67th of 369, with limits $982 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 | 100th of 367, with limits $746 a month | 285th of 367, with limits $789 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 | 57th cheapest of 346 $554 a month | 259th of 346, with limits $332 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 | 227th of 338, with limits $9,223 a month | 226th of 338, with limits $9,012 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 | 11th cheapest of 360 $1,043 a month | 242nd of 360, with limits $339 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 Only Namespace fits: it runs macOS on Apple Silicon, while E2B and boat run Linux only. | Can't run it | 6th cheapest of 36 $1,205 a month | Can't run it |
Key features
| Feature | E2B | Namespace | boat |
|---|---|---|---|
| Isolation | Firecracker microVM with its own kernel | Linux Devboxes run from a container image on Namespace's own hardware; the docs do not say if each has its own kernel | Full VM with its own kernel on dedicated AMD Ryzen 9 9950X hosts |
| CPU speed (Node.js build-and-test, 4 vCPU / 8 GB) | 12.61 runs/s | 21.79 runs/s | 26.69 runs/s |
| How long a session can run | 1 hour on Hobby, 24 hours on Pro; pausing resets the clock | Devboxes stop after 4, 5 or 24 hours by plan, even while you work; 24 hours at most | No session cap on paid plans; you set the time to live |
| Pause and resume | Saves memory and disk; resumes in about 1 second with processes still running | Devboxes stop when idle and start again when you connect; compute instances can suspend with RAM kept | Disk saved every minute and on stop; resume boots the machine again |
| Fork | Fork a running sandbox with its memory, up to 20 copies per call | No fork | Fork a running sandbox with its disk |
| Docker and nested virtualization | Docker inside; nested virtualization not supported | Docker in Linux Devboxes; /dev/kvm on Linux compute instances | Docker, root, systemd and /dev/kvm on every machine |
| Desktop and computer use | Linux desktop for computer use | Screenshot and click API on macOS Devboxes only; VNC and RDP for compute instances | 60fps Linux desktop and Chromium, computer use and browser control, embeddable stream |
| Reaching the sandbox | HTTPS URL per port, public unless you turn on a token; no dedicated IP | HTTPS URLs that need a Namespace login; TCP through a CLI port-forward; no public IP | HTTPS URLs for up to 50 ports, token-protected; raw TCP; dedicated IPv4 or IPv6 |
| Outbound rules | Allow and deny lists by IP, CIDR or domain | Egress policies by domain: block, advisory or allow | Open internet, no provider-side allowlist |
| Keeping API keys out of the sandbox | Secrets injected into outbound HTTPS headers (private beta) | Egress rules inject a header from Namespace Vault, outside the workload | Credentials proxy for model providers and any HTTPS API; switch a credential to another account when credits run out |
| Coding agents | Templates and guides for many agents, run through the command API | Hosts Claude Managed Agents, Cursor and Devin sessions; an MCP server lets your agent create Devboxes | Seven agents preinstalled, driven from outside with a prompt, steer and events API |
| Operating systems | Linux only | Linux, macOS on Apple Silicon, and Windows on Team plans and up | Linux only; Wine for Windows apps |
| Regions | US by default; EU and APAC on Pro and above through support | Several regions, nearest by default; region-exclusive residency on Enterprise | EU only (Germany, Finland, France) |
| Self-hosting | Open-source runtime (Apache-2.0), plus your own cloud on Enterprise | No | No |
Every feature Battleships tracks (43)
| Feature | E2B | Namespace | boat |
|---|---|---|---|
| Full VM (own kernel) | Yes | Yes | Yes |
| Docker inside | Yes | Yes | Yes |
| Nested virtualization | No | Yes | Yes |
| Root | Yes | Yes | Yes |
| Systemd | Yes | Not published | Yes |
| Desktop GUI | Yes | Yes | Yes |
| Browser | Yes | No | Yes |
| Computer-use API | Yes | Yes | Yes |
| SSH | Yes | Yes | Yes |
| Persistent disk | Yes | Yes | Yes |
| Pause/resume | Yes | Yes | Yes |
| Automatic snapshots | Yes | Yes | Yes |
| Fork/clone | Yes | No | Yes |
| Live fork (no pause) | Yes | No | Yes |
| Memory fork | Yes | No | 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 | Yes | No |
| HTTPS preview URLs | Yes | Yes | Yes |
| Raw TCP inbound | No | Yes | 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 | Yes | Yes |
| Agent harness API | No | No | Yes |
| MCP server | Yes | Yes | No |
| GPU | No | No | No |
| Windows | No | Yes | No |
| Arm64 | No | Yes | No |
| Self-hosting | Yes | No | No |
| BYOC | Yes | No | No |
| Open source | Yes | No | No |
| Scoped API keys | Not published | Not published | Yes |
| Spend limits | Yes | Yes | Yes |
| Usage per sandbox (API) | No | No | Yes |
| Audit logs | Not published | Yes | No |
| SSO | No | Yes | No |
| SOC 2 | Yes | Yes | No |
| HIPAA | Yes | No | No |
| EU data residency | Yes | Yes | Yes |
| Zero data retention | Not published | Not published | Yes |
Performance
In the same StarSling hpc-sandbox-benchmarks run at 4 vCPU / 8 GB, boat did 26.69 Node.js build-and-test runs per second, Namespace did 21.79 and E2B did 12.61. So Namespace does about 1.7 times the CPU work of E2B, and boat about twice E2B and a fifth more than Namespace. A Namespace Devbox's vCPU count is a ceiling it can boost to, not a guaranteed share.
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).
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 | E2B, a month | Namespace, 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 | $202 · Pro | $50 · Devbox (pay as you go) | $20 · $20/mo |
| One agent that never stops 4 vCPU / 8 GB, 50 GB disk, running 24/7 all month | $368 · Pro · with limits | $176 · Devbox (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 | $2,773 · Pro | $2,198 · Devbox (pay as you go) | $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 | $1,395 · Pro+ (600 concurrent) | $1,214 · Devbox (pay as you go) | $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 | $2,797 · Pro++ (1,100 concurrent) | $3,237 · Devbox (pay as you go) | $2,000 · $2000/mo · with limits |
E2B: E2B bills per second for the vCPU and RAM you set, idle time included, until you pause or kill the sandbox. Pro costs $150 a month for higher limits with no usage credit, and more concurrency costs $500 a month per 500 slots.
Namespace: Namespace bills Devboxes in Devbox Minutes at $0.004 each, pay as you go on every plan; a 4 vCPU / 8 GB Devbox uses one a minute. Team and Business plan minutes cover runners and instances, not Devboxes, and stored files cost $0.20 per GB-month.
Namespace: Plans start at $20 a month and the whole fee is usage credit, spent per second while a sandbox runs. A stopped sandbox costs nothing and keeps its disk.
Limits in those scenarios
Time is the limit that bites on both: E2B Pro caps a session at 24 hours and a Namespace Devbox stops after at most 24, so neither fits the agent that never stops without restarts. On Namespace's Developer or Team plans even one 8-hour workday session hits the 4 or 5 hour limit, and E2B Pro includes only 20 GiB of disk, with no published price for more. For 1,000 short jobs at once both fit, though E2B queues bursts above 300 starts a minute; boat's start limits make that scenario a poor fit. Neither E2B nor Namespace publishes an egress price.
| Scenario | E2B | Namespace | 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 |
| 1,000 short jobs at once |
|
|
|
Which one should you use?
Use E2B when
you run many short jobs that pause between requests, need memory forks for rollouts, or want an open-source runtime in your own cloud.
- Memory pause and wake on request. For short jobs that sleep between requests, a paused E2B sandbox wakes on the next call in about a second, processes still running.
- Memory forks for branching work. For RL rollouts and parallel tries, E2B forks a running sandbox with its memory, up to 20 copies per call.
- Open source and your own cloud. For teams that want control of the stack, the runtime is Apache-2.0 and Enterprise can run it in your AWS, GCP or Azure.
Use Namespace when
you need macOS or Windows machines, faster GitHub Actions runners with build caches, or Devboxes for people that stop when idle.
- macOS and Windows. For agents that build iOS or Mac apps or test on Windows, Namespace runs macOS on Apple Silicon and Windows machines.
- CI runners and build caches. For faster GitHub Actions, Namespace is a drop-in runner with Docker, Bazel, Turborepo and Nix caching.
- Devboxes that stop when idle. For dev machines people share with agents, a Devbox stops after an idle timeout and starts again when you connect.
Where boat fits
If what you are really running is coding agents that work for hours on Linux, both E2B and Namespace stop them within a day. boat gives each agent a full VM with no session cap on paid plans, /dev/kvm, a faster CPU, and the agents and their keys built in.
No clock on the session
E2B ends a session after 24 hours on Pro, so your code must pause and resume it. A Namespace Devbox shuts down after 4, 5 or 24 hours even while it works. On boat's paid plans a sandbox runs as long as the work does.
A faster, fuller machine
boat did 26.69 runs per second against 12.61 on E2B and 21.79 on Namespace, so builds and tests wait less. E2B has no nested virtualization for Android emulators or VMs; every boat machine has /dev/kvm, Docker and systemd.
Agents and keys built in
On E2B you run agents through its command API, and on Namespace through a partner service or your own code. boat preinstalls seven agents you drive from outside, and its credentials proxy keeps real keys out of the sandbox.
Use boat when your agents work on Linux for hours or days: a full, faster VM with no session cap, Docker and /dev/kvm, a 60fps desktop, and coding agents you drive from outside. Compare it one to one: boat vs E2B and boat vs Namespace.
Questions people ask
Is E2B cheaper than Namespace?
Namespace costs less in four of the five scenarios we priced: one coding agent on workdays is $202 a month on E2B and $50 on Namespace, and 50 agents in parallel are $2,773 against $2,198. E2B is cheaper for 1,000 short jobs at once, at $2,797 against $3,237. boat comes to $20 and $317 a month for the first two.
Which is faster, E2B or Namespace?
On the same CPU benchmark at 4 vCPU / 8 GB, Namespace did 21.79 runs per second and E2B did 12.61, so Namespace is about 1.7 times as fast. boat did 26.69. This measures CPU work only, not start time.
Can E2B and Namespace run Docker?
Both run Docker inside. E2B does not support nested virtualization, so Android emulators and VMs will not start, while Namespace offers /dev/kvm on Linux compute instances. boat has Docker, systemd and /dev/kvm on every machine.
How long can a session run on E2B or Namespace?
E2B stops a sandbox after 1 hour on Hobby and 24 hours on Pro, though pausing resets the clock. A Namespace Devbox stops after 4, 5 or 24 hours by plan, even while you work, and 24 hours is the most support can set. boat has no session cap on paid plans.
Do E2B or Namespace run macOS or Windows?
Namespace does: macOS on Apple M4 Pro and M5 Max chips, and Windows on Team plans and up. E2B runs Linux only, and so does boat, with Wine for Windows apps.
Where do E2B, Namespace and boat run?
E2B runs in the US by default, with EU and APAC on Pro and above through support. Namespace runs in several regions and keeps a workload in one region only on Enterprise. boat runs only in the EU, in Germany, Finland and France.
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