E2B 2.61 adds idempotency keys for sandbox creation
Updated E2B
Summary
JavaScript and Python sandbox creation gain explicit idempotency keys, alongside revised control-plane retry rules from 2.60.
- Tool
- E2B
- Category
- Agent infra
- Date
- Pricing
- Not stated in the sources we cited.
E2B published SDK 2.61.0 on October 26, 2026, for JavaScript and Python. The two SDK announcements describe the same capability and are covered together here.
Give creation requests a stable identity
Sandbox.create accepts idempotencyKey in JavaScript and idempotency_key in Python. The SDK sends that value as the Idempotency-Key header. The documented format is 1–255 lowercase ASCII letters, digits or hyphens.
This gives application code an explicit request identity when creating a sandbox. The release notes do not specify a retention period or all server-side replay rules, so this should not be presented as an unlimited duplicate-prevention guarantee.
Retry behavior also changed
The preceding 2.60 release follows the control plane's Should-Retry response header. An explicit false prevents retry; without that header, selected transient HTTP statuses qualify. Post-send network errors are no longer automatically retried, while connection failures still can be.
For agent infrastructure, the useful upgrade question is how creation identity and retry handling fit together, not whether every failed request can safely be repeated.
See the e2b hub.
More from E2B
E2B 2.62.0 adds streaming file writes and optional output retention
E2BJavaScript and Python SDKs can stream byte chunks into files and stop retaining command output in memory.
Category: Agent infra
Pricing: Not stated
E2B CLI 2.23.0 changes template listing and selection
E2BTemplate lists become paginated, and delete, publish and unpublish commands now require an explicit template argument.
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E2B 2.56.0 requires Node 22.19+ and drops request cap
E2BE2B 2.56.0, released October 13, 2026, requires Node.js 22.19.0+, moves to undici 8 and removes the SDK in-flight request cap and its env vars.
Category: Agent infra
Pricing: Open source
Questions
What is E2B?
The GitHub repository describes E2B as an open-source, secure environment with real-world tools for enterprise-grade agents. The documentation describes a sandbox as a Linux VM created on demand for your agent.
Is E2B open source?
The GitHub API reports the e2b-dev/E2B repository license as Apache-2.0. Pricing for hosted use is not stated in the cited sources.
What changed in e2b 2.56.0?
The release notes say it requires Node.js 22.19.0 or newer, uses undici 8 and removes the SDK-level in-flight request cap.
Filed on Agent Radar. Claims in this note are limited to the sources above.