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OpenAI

E2B

Checked 09/15/2026View original
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For the complete documentation index, see llms.txt. Markdown versions of documentation pages are available by appending .md to the page URL.

See the application-managed and webhook-managed examples in the OpenAI Cookbook.

Choose a provisioning mode:

  • Application-managed: Your application creates and connects the E2B sandbox directly.
  • Webhook-managed: Deploy a handler that starts or reconnects sandboxes from OpenAI webhooks.

See Sandbox lifecycle to compare the two modes.

Before you begin

Set E2B_API_KEY and use OPENAI_API_KEY for application requests. Set OPENAI_EXECUTOR_API_KEY to an environment key, and pass only that key into the sandbox as CODEX_API_KEY.

Webhook-managed

Implement a controller that verifies OpenAI webhooks and provisions a separate E2B worker for each session. Follow Deploy and connect a handler for credentials, endpoint registration, and signature verification.

Persist the session-to-sandbox mapping. On a connection request, resume a paused worker or replace a deleted one. Pausing preserves its files; replacement does not. Set running timeouts for the controller and workers, and remove the OpenAI webhook when you stop using the controller.

Application-managed

Use the E2B SDK or API from your application to manage the sandbox:

  1. Create a self-hosted session and save its environment ID.
  2. Create an isolated E2B sandbox with the session's working directory and install the Codex CLI inside it.
  3. Start the executor in the sandbox using the environment ID and environment key.
  4. Use Run and continue sessions to send input and check the turn's outcome.
  5. Delete the session and stop the E2B sandbox when finished.

Configure the sandbox lifetime separately from the timeout for the executor command. A command with no timeout does not keep an expired sandbox running.

References