---
title: JavaScript SDK 4.0.0-pre.0
summary: null
url: >-
  https://www.fastly.com/documentation/reference/changes/2026/08/javascript-sdk-4.0.0-pre.0
---

## Added

- Upgrade StarlingMonkey - ([6687326](https://github.com/fastly/js-compute-runtime/commit/6687326eb8d3eb6184fd1d27471c626a55719df3))

#### Bug Fixes

- Correct error handling in SimpleCache::getOrSet (#1540) - ([fededa3](https://github.com/fastly/js-compute-runtime/commit/fededa35e89bebcc62e4c1d15a217523d16b0c53))
- StarlingMonkey patches (#1514) - ([56ec489](https://github.com/fastly/js-compute-runtime/commit/56ec48929fcff3c619b9e66f95749de9d5a74212))
- memory safety issues in convertBodyInit (#1504) - ([989bce6](https://github.com/fastly/js-compute-runtime/commit/989bce6dcbb1d7d63964a427c470dca189f10f8e))
- starlingmonkey update already fixed urlsearchparams memory issue (#1549) - ([0871652](https://github.com/fastly/js-compute-runtime/commit/0871652326fab41190675ad24fd6adfd55ff4281))