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A Preview not found response with a 404 status means the requested preview has been deleted or is being deleted. Check the lifecycle state of both the parent sandbox and the preview.

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Common causes

This error occurs when:
  • The parent sandbox was deleted manually
  • The parent sandbox expired because of its TTL
  • The preview’s TTL expired
  • An asynchronous deletion request placed the preview in the DELETING state

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Resolve the error

Create previews with createIfNotExists in TypeScript or create_if_not_exists in Python. When a preview is in the DELETING state, the platform waits for deletion to finish before recreating it. These methods safely reuse preview IDs and avoid a race with deletion. Also verify that the sandbox and preview are still active and were not removed by TTL expiration or manual cleanup.

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Prevent future errors

  • Handle 404 responses gracefully in your application
  • Poll the sandbox status periodically where appropriate
  • Configure sandbox TTL values that match your usage pattern
If the error continues after these checks, contact support.

Preview URLs

Learn how to create and use sandbox previews.

Sandbox overview

Review sandbox lifecycle and configuration.
Last modified on October 5, 2026