# Introduction to isolated-vm in TypeScript

DevFeed: [Introduction to isolated-vm in TypeScript](<https://devfeed.tech/articles/introduction-to-isolated-vm-in-typescript-35885.md>)

Original publisher: [Read original article](<https://temporal.io/blog/intro-to-isolated-vm>)

Author: Valeri Karpov

Published: 2021-09-22T07:00:00Z

Content type: article

Language: en

Sources: [Temporal Blog](<https://devfeed.tech/sources/temporal-blog.md>)

Topics: [TypeScript](<https://devfeed.tech/topics/typescript.md>), [V8](<https://devfeed.tech/topics/v8.md>), [SDKs](<https://devfeed.tech/topics/sdks.md>)

Tags: [how-to](<https://devfeed.tech/tags/how-to.md>), [sdk](<https://devfeed.tech/tags/sdk.md>), [typescript](<https://devfeed.tech/tags/typescript.md>), [v8](<https://devfeed.tech/tags/v8.md>), [workflows](<https://devfeed.tech/tags/workflows.md>)

## AI overview

This article explains how Temporal's TypeScript SDK uses V8 isolates to keep Workflows deterministic. It describes event-history replay, isolation of Workflow memory, and the restriction of non-deterministic operations such as file-system access and random-number generation.

## Source excerpt

Temporal's TypeScript SDK makes heavy use of V8 isolates to ensure your Workflows are deterministic.