E2B

Infrastructure

medium confidence

e2b.dev ↗ · Status: active confirmed · Founded 2023

E2B provides open-source Firecracker-microVM sandboxes for AI agents. It is offered as a hosted API, as BYOC, and since September 2026 as a self-hostable single-node package (E2B Embed). In 2026 it became a supported sandbox provider in the OpenAI Agents SDK and published integrations for Devin Outposts and Cursor Self-Hosted Machines. Vendor case studies show it used for RL rollouts (Paper Instruments) and large-scale evals (Arena).

Key facts

Headquarters

San Francisco, USAconfirmed cite

Headcount band

11-50reported cite

Total raised

$32Mreported cite

Last round

Series A, $21M, July 2025 (announced 2025-07-28)confirmed cite

SOC 2

Type IIreported cite

What they sell

infraconfirmed cite

Open source

yesconfirmed cite

Deployment

managed-hosted cloud API (US, EU, APAC regions), BYOC in customer AWS/GCP/Azure VPC, and self-hosted via open-source E2B Embed (Apache-2.0, single machine; Docker Compose, Terraform, Kubernetes); private cloud listed as in developmentconfirmed cite

What's new

14 sourced updates · last 6 months

1 Oct 2026customer Arena case study: up to 600,000 E2B sandboxes per day
Arena is the Berkeley Sky Computing Lab model-evaluation platform behind WebDev Arena, which E2B profiled earlier under the LMArena name. It runs WebDev, Code Arena and Agent Arena evaluations on E2B: up to 600k sandboxes a day, up from 300-400k. E2B provisioned thousands of extra concurrent sandboxes within 24 hours ahead of Arena's June 2026 Agent Mode launch. Vendor-published.
Why it matters: A large public model-evaluation platform depends on E2B, which is a scale signal for eval and benchmark workloads (self-claimed).
30 Sep 2026open-source E2B Embed: open-source (Apache-2.0) single-machine self-hosted E2B
Packages the E2B stack to run on a single machine inside a customer's environment, using Docker Compose, Terraform (GCP/AWS) or Kubernetes. No E2B account or license key is needed, and one setting exports metrics, traces and logs over OpenTelemetry. The changelog lists Embed from 2026-09-14, and the launch post is dated 2026-09-30.
Why it matters: Gives regulated buyers a deployment that stays inside their own environment, and lets labs self-host with no vendor dependency. It runs on one machine only; scaling across machines uses BYOC.
10 Sep 2026product Guide: build an agent workbench on OpenAI's Agents API with E2B
A reference architecture in which OpenAI provides the model, harness and session lifecycle and E2B provides per-chat Firecracker sandboxes, with pause and fork implemented through snapshots.
Why it matters: Strengthens E2B's position inside the OpenAI agent stack.
7 Sep 2026product Workspaces, Cursor Self-Hosted Machines templates, and an NVIDIA NeMo Gym integration guide
Workspaces bring projects and access management together in one place. New cursor-agents dispatcher and worker templates run Cursor Self-Hosted Machines on E2B. Guides were published for Agno, NVIDIA NeMo Gym and Muse Code.
Why it matters: The NeMo Gym guide connects E2B to an open RL environment framework. The Cursor templates come from E2B and are not a confirmed Cursor partnership.
3 Sep 2026customer Paper Instruments case study: thousands of concurrent RL rollouts on E2B
Paper Instruments trains models for consulting, finance, investment banking and law work. It runs thousands of concurrent RL rollouts (GRPO/CISPO) on E2B and snapshots both filesystem and memory of running servers to start faster. Vendor-reported: up to 3x faster tool execution than other sandbox providers it evaluated.
Why it matters: The first named, vendor-published case study of E2B used directly as RL training infrastructure. The performance figure is self-claimed.
24 Aug 2026product Bring Your Own Proxy (SOCKS5 egress) and sandbox list filters
The network.egressProxy option sends all outbound TCP traffic through a customer SOCKS5 proxy. Sandbox.list gains order, startedAfter and template filters, and snapshot-management CLI commands were added.
Why it matters: Gives network-control options that enterprise security reviews look for.
17 Aug 2026product Workload identity tokens in the SDKs and a Rust-based Python HTTP transport
Sandbox.create takes an `iam` option for short-lived workload identity tokens. Python SDK 2.38.0 adopts the Rust-based pyqwest transport. Sandbox placement errors now return machine-readable codes.
Why it matters: Improves credential hygiene for agents that call cloud APIs.
3 Aug 2026product Legacy access tokens disabled; Fedora, Alpine, Arch and NixOS template base images
Access tokens were disabled as of 2026-08-01, and non-Debian base images were added for templates. API-key validation moved server-side on 2026-08-31.
Why it matters: A breaking authentication change for older integrations. Wider OS coverage helps people building environments.
21 Jul 2026product E2B publishes a guide to running Devin Outposts sessions on E2B microVMs
In 'Use E2B as the Execution Layer For Devin Outposts', each Devin session runs on an E2B microVM inside the customer's cloud boundary. CPU, RAM and disk are configurable, and snapshots allow pause and resume. The post does not mention Cognition or a formal partnership.
Why it matters: Gives teams that run Devin a BYOC execution option. It is an integration guide published by E2B, not a confirmed Cognition partnership.
21 Jul 2026product Sandbox forking and snapshot name filters released
A running sandbox can now be forked into one or more clones from its exact in-memory state, and listSnapshots accepts a name filter. A CLI command, `e2b sandbox fork`, followed on 2026-09-21.
Why it matters: Forking a running environment helps RL rollouts and branching agent search.
12 Jun 2026customer Rogo case study: Claude Managed Agents for orchestration plus E2B for code execution
Rogo, a financial-services AI company, pairs Anthropic's Claude Managed Agents with E2B sandboxes. The case study cites 10,000-15,000 concurrent sandboxes. Vendor-published, so self-claimed.
Why it matters: Shows E2B as the execution layer next to Anthropic's managed-agent product in a financial-services deployment. This is a customer's stack choice, not a direct E2B-Anthropic contract.
10 Jun 2026partnership E2B sandboxes available through Stripe Projects (developer preview partner)
E2B joined the Stripe Projects developer preview as a partner, implementing the Agentic Provisioning Protocol. Agents can provision and authenticate sandboxes with `stripe projects add e2b`, with no signup flow or manual API-key step.
Why it matters: Agents can get compute without a human in the loop, which simplifies automated pipelines.
8 Jun 2026customer StackAI case study: replaced its in-house sandbox infrastructure with E2B
StackAI, a no-code enterprise agent-workflow platform, replaced its homegrown code-execution sandbox with E2B. Co-founder Tony Rosinol is quoted saying the old system had taken up 5-6 platform engineers. Vendor-published, so self-claimed.
Why it matters: A vendor-published signal of adoption by enterprise agent platforms that handle sensitive data.
30 Apr 2026other E2B says its sandboxes are not affected by the Copy Fail Linux kernel bug (CVE-2026-31431)
E2B says each sandbox runs in its own Firecracker microVM with its own kernel, and that its minimal custom kernels do not compile in the vulnerable algif_aead module. This is the vendor's own security claim.
Why it matters: Security teams get a concrete comparison of microVM isolation against shared-kernel containers for running untrusted agent or RL code.

Founding team

Vasek (Vaclav) Mlejnsky

Co-founder & CEO

Czech founder. Studied at Charles University's Faculty of Mathematics and Physics (Matfyz), focusing on computer vision. Built iPhone games with Tomas Valenta in secondary school, and the two built several developer tools before E2B.

Profile ↗

Tomas Valenta

Co-founder & CTO

Czech founder. Studied at Charles University's Faculty of Mathematics and Physics (Matfyz), focusing on computer vision. Built iPhone games and later developer tools with Mlejnsky before co-founding E2B.

Profile ↗

What practitioners should know

For researchers

E2B has not authored any benchmarks or papers. It is infrastructure that other teams' evals and RL runs depend on: Hugging Face's Open R1 replication, Arena's WebDev, Code and Agent Arena evaluations, and Paper Instruments' RL rollouts. All of these come from vendor case studies.
Memory and filesystem snapshots and live-sandbox forking (2026-07-21; CLI fork 2026-09-21) let you pre-warm running servers and branch trajectories from an exact in-memory state.
An NVIDIA NeMo Gym integration guide was added in September 2026 (changelog).
The E2B for Research program offers academic and nonprofit teams a one-time $20k in credits for evals, RL rollouts and code-gen benchmarks. Acceptance is not guaranteed.
The core stack is open source under Apache-2.0: the E2B SDK repo (~14.2k stars), the Runtime (~1.7k) and E2B Embed for single-node self-hosting.

For program managers

Frontier-lab ties are integrations, not disclosed contracts. E2B is a supported sandbox provider in the OpenAI Agents SDK (2026-04, Python only) and published an OpenAI Agents API workbench guide (2026-09). Rogo's vendor case study pairs E2B with Anthropic's Claude Managed Agents (2026-06).
Coding-agent ties are E2B-published integration guides and templates for Devin Outposts (2026-07) and Cursor Self-Hosted Machines (2026-09). Neither is confirmed by Cognition or Cursor.
Scale signals, all self-claimed: 1B+ sandbox starts, 100k+ teams, signups from 94 of the Fortune 100 (careers page), and Arena running up to 600k sandboxes a day.
No new funding round was found after the July 2025 $21M Series A led by Insight Partners. The official total is $32M.

For data ops

Deployment options: managed cloud (US/EU/APAC), BYOC (AWS/GCP/Azure; data plane in the customer VPC), self-hosted E2B Embed (single machine), and private cloud (in development).
Breaking changes: legacy access tokens were disabled on 2026-08-01 and API-key validation moved server-side (2026-08-31). 'Team' was renamed to 'project' in the CLI and SDKs (2026-07-27). Workspaces arrived in September 2026, along with public prj_ project IDs (2026-09-28).
Security and network controls added in 2026: workload identity tokens, wildcard domain transform rules, SOCKS5 bring-your-own-proxy egress, and OpenTelemetry export from Embed.
The homepage states 'E2B Cloud is SOC 2 Type II compliant'. This is a vendor-only claim and has not been independently verified.
MCP is available through the Docker MCP Catalog partnership. The SDKs automatically retry HTTP 429 responses with exponential backoff (changelog 2026-09-14).

Products

E2B Cloud (Sandbox SDK / API) ↗

Managed Firecracker microVM sandboxes for AI agents. Regions: US, EU, APAC. Python/JS SDKs and CLI. The homepage lists 'parallel environments for reinforcement learning, evaluations, and benchmarks' as a use case.

E2B BYOC ↗

E2B runs the control plane and the data plane sits in the customer's VPC on AWS, GCP or Azure. Sandbox traffic does not pass through E2B Cloud.

E2B Private Cloud (in development) ↗

Control plane and data plane both inside the customer boundary, for air-gapped or sovereign networks. Listed as in development and seeking design partners.

E2B Embed ↗

Apache-2.0, single-machine self-hosted package of the E2B stack (Docker Compose, Terraform on GCP/AWS, Kubernetes). No account or license key required. Exports OpenTelemetry.launched Sep 2026

E2B Runtime (open source) ↗

Go runtime behind every E2B stack: Cloud, Enterprise and self-hosted (~1.7k GitHub stars).

Code Interpreter SDK ↗

Python and JS/TS SDK for running AI-generated code (~2.4k stars).

E2B Desktop ↗

Graphical virtual-desktop sandbox for computer-use agents (~1.5k stars).

MCP in E2B Sandbox (with Docker MCP Catalog) ↗

Gives sandboxes access to 200+ MCP tools from Docker's MCP Catalog.launched 23 Oct 2025

E2B for Research program ↗

One-time $20,000 in usage credits plus Pro tier for first-time academic or nonprofit research teams. Eligible uses include agent evals, RL rollouts and code-generation benchmarks. Capacity is limited, and no launch date is published.

Fragments ↗

Open-source Next.js template for AI-generated apps (~6.4k stars).

Surf ↗

Open-source computer-use agent demo on E2B Desktop (~0.9k stars).

Scale & velocity

Current headcount

11-50 (LinkedIn company size band; ~37 employees listed on LinkedIn as of 2026-06-07)reported cite

Headcount growth

unknown

Open roles

unknown cite

Other locations

Prague, Czech Republicreported cite

Distributed / remote

yesestimated cite

Research depth

Has researchers

noestimated cite

Researcher count

unknown

Backgrounds

unknown

Papers / benchmarks

unknown

Capital

Total raised

~$32M (official Series A blog states $32M total)reported cite

Last round

Series A, $21M, July 2025 (announced 2025-07-28)confirmed cite

Investors

Insight Partners (Series A lead), Decibel (seed lead), Sunflower Capital, Kaya / Kaya VC, Scott Johnston (former Docker CEO, angel)confirmed cite

Valuation

unknown

Revenue signals

unknown revenue. Self-claimed usage signals: 1B+ sandbox starts, 100k+ teams have run a sandbox, signups from 94 of the Fortune 100 (careers page, 2026-10); Arena case study cites up to 600k sandboxes/day. No revenue figure independently verified.reported cite

Security & compliance

SOC 2

claimed-unverified (homepage states 'E2B Cloud is SOC 2 Type II compliant'; trust center also claims it)reported cite

Other certifications

ISO 27001 (claimed-unverified), HIPAA (claimed-unverified), GDPR (claimed-unverified)reported cite

Security page

https://trust.e2b.dev/confirmed cite

Product

What they sell

infraconfirmed cite

Open source

yesconfirmed cite

License

Apache-2.0confirmed cite

Deployment model

Maturity

GAconfirmed cite

Notable customers

Perplexity self-claimed Hugging Face self-claimed Groq self-claimed Manus self-claimed Lindy self-claimed Genspark self-claimed Anything self-claimed Arena (LMArena) self-claimed Paper Instruments self-claimed Rogo self-claimed StackAI self-claimed cite

Buyer analysis

Best fit: Teams that need secure, isolated, snapshot-able runtimes for LLM-generated code, coding agents, massively parallel RL rollouts or eval harnesses, including deployments inside their own environment via BYOC or E2B Embed.

How we verified this

2026-10-05 refresh: I opened every source URL in the draft. All 15 news dates fall inside the 2026-04-01 to 2026-10-05 window and match their sources: OpenAI Agents SDK 04-15, Copy Fail 04-30, StackAI 06-08, Stripe Projects 06-10, Rogo 06-12, Devin Outposts and forking 07-21, changelog items 08-03 to 09-21, workbench 09-10, Embed 09-30 (changelog 09-14), Paper Instruments 09-03, Arena 10-01. The main corrections were to framing. The Devin Outposts post and the Cursor templates are E2B-published integration guides with no partner confirmation, so I stopped presenting them as partnerships and removed Devin from the customer list. The Arena case study does not say 'formerly LMArena', so I describe the link instead of asserting a rebrand. The OpenAI SDK integration is Python only. Founder backgrounds were trimmed to what CzechCrunch supports, removing the unsourced Devbook, Foundry and 'without finishing' claims. Both CzechCrunch portrait URLs return real single-person JPEG portraits labelled with the right names, so I kept them. Gumloop and Athena were dropped from customers because no current vendor page lists them. I added the Private Cloud (in development) offering and the E2B for Research $20k credits program. E2B's updates index, the sitemap and a Bing query showed no new funding, acquisition or status change. The WebSearch budget was exhausted, so wider press coverage could not be checked; that is the remaining gap. Customer, scale and SOC 2 claims are all vendor self-claims.

Related vendors

Sources

e2b.dev/ · 2026-10-05, Homepage: RL/evals/benchmarks use case, deployment options, SOC 2 Type II claim, no customer logos
e2b.dev/enterprise · 2026-10-05, BYOC, Private Cloud (in development), self-hosted Embed
e2b.dev/careers · 2026-10-05, Self-claimed usage metrics; roles linked to an external job board
docs.e2b.dev/changelog · 2026-10-05, Changelog entries 2026-07-21 to 2026-09-28
e2b.dev/resources/product.md · 2026-10-05, Product post index with dates
e2b.dev/resources/updates.md · 2026-10-05, Company updates index: no funding post after the July 2025 Series A
e2b.dev/sitemap.md · 2026-10-05, Sitemap used to look for missed posts and programs
e2b.dev/research.md · 2026-10-05, E2B for Research program, $20k credits
e2b.dev/resources/introducing-e2b-embed · 2026-10-05, E2B Embed launch, 2026-09-30
e2b.dev/resources/devin-outposts · 2026-10-05, Devin Outposts integration guide, 2026-07-21 (no Cognition mention)
e2b.dev/resources/e2b-is-now-in-agents-sdk · 2026-10-05, OpenAI Agents SDK integration, 2026-04-15, Python only
e2b.dev/resources/e2b-sandboxes-are-now-available-through-stripe-project · 2026-10-05, Stripe Projects developer preview, 2026-06-10
e2b.dev/resources/build-an-agent-workbench-on-openais-agents-api · 2026-10-05, OpenAI Agents API workbench guide, 2026-09-10
e2b.dev/resources/not-affected-by-copy-fail-heres-why · 2026-10-05, CVE-2026-31431 post, 2026-04-30
e2b.dev/resources/docker-e2b-partner-to-introduce-mcp-support-in-e2b-san · 2026-10-05, Docker MCP Catalog partnership, 2025-10-23
e2b.dev/customers · 2026-10-05, Current case-study list
e2b.dev/customers/paperinstruments.md · 2026-10-05, RL rollouts case study, 2026-09-03
e2b.dev/customers/arena.md · 2026-10-05, Arena case study, 2026-10-01
e2b.dev/customers/rogo.md · 2026-10-05, Rogo with Claude Managed Agents, 2026-06-12
e2b.dev/customers/stackai.md · 2026-10-05, StackAI case study, 2026-06-08
github.com/e2b-dev · 2026-10-05, Repo list and star counts
e2b.dev/blog/series-a · 2026-10-05, Series A ($21M, $32M total); CEO Vasek Mlejnsky, CTO Tomas; customers named
cc.cz/cc25/e2b/ · 2026-10-05, CzechCrunch CC25 profile with individual founder portraits
cc.cz/na-stredni-vyvijeli-hry-pro-iphone-ted-zari-s-umelou-inteligenci-c · 2026-10-05, CzechCrunch 2025-07-28: founder backgrounds (Matfyz, computer vision, iPhone games)
api.github.com/users/mlejva · 2026-10-05, Vasek Mlejnsky, company e2b, X handle mlejva
api.github.com/users/ValentaTomas · 2026-10-05, Tomas Valenta, 'Building @e2b-dev', X handle co_valenta
github.com/e2b-dev/E2B · 2026-06-07, OSS repo - Apache-2.0, 12.5k stars, latest release e2b@2.28.0 Jun 6 2026
trust.e2b.dev/ · 2026-06-07, Trust center landing
trust.e2b.dev/controls · 2026-06-07, Compliance frameworks - SOC 2 Type II, ISO 27001, HIPAA, GDPR, pen testing
www.linkedin.com/company/e2b-dev · 2026-06-07, LinkedIn company page (public snippet) - size band 11-50, ~37 employees, HQ SF, Prague office
www.insightpartners.com/ideas/e2b-raises-a-21m-series-a-to-offer-cloud-f · 2026-06-07, Insight Partners Series A writeup
www.prnewswire.com/news-releases/e2b-raises-a-21m-series-a-to-offer-clou · 2026-06-07, PR Newswire Series A release
venturebeat.com/ai/how-e2b-became-essential-to-88-of-fortune-100-compani · 2026-06-07, VentureBeat coverage - Fortune 100 adoption, $21M
tracxn.com/d/companies/e2b/__U7C82j6Wk3VH-rgW0n4LFnUqqq-LuBw6rnIcnLGz2yU · 2026-06-07, Tracxn - founding 2023, funding rounds, ~$35M total
www.crunchbase.com/organization/e2b-1c91 · 2026-06-07, Crunchbase - seed Oct 2024 $11.5M led by Decibel, founding 2023
www.glassdoor.com/Jobs/E2B-Jobs-E10750951.htm · 2026-06-07, Open roles count (~13)

Last updated 2026-10-05 · Every quantitative field carries a source and a confidence tag. Fields we could not source publicly are marked unknown, never estimated. See the methodology.