# What changed in https-proxy-agent

> 7 changes in https-proxy-agent 8 to 9 from its official release notes, upgrade guides and advisories: 2 breaking, 3 new APIs and options. Each one cited. Sources checked 2026-10-18. HTML: https://unstale.sh/npm/https-proxy-agent/

To see which of these apply to a repository, run `npx @unstale/cli init` in it.

## https-proxy-agent 9

### Breaking changes

- The minimum supported Node.js version is now 20. (9.0.0) — [release notes](https://github.com/TooTallNate/proxy-agents/releases/tag/https-proxy-agent%409.0.0)

### New APIs and options

- HttpsProxyAgent and HttpProxyAgent accept negotiate: true to use the kerberos package for automatic Negotiate/SPNEGO proxy authentication. (9.1.0) — [release notes](https://github.com/TooTallNate/proxy-agents/releases/tag/https-proxy-agent%409.1.0)
- HttpsProxyAgent and HttpProxyAgent accept an optional async onProxyAuth callback, invoked on a 407 response to return headers for retrying the request. (9.1.0) — [release notes](https://github.com/TooTallNate/proxy-agents/releases/tag/https-proxy-agent%409.1.0)
- All proxy agents emit a proxy event on the request after the proxy connection is established, with the proxy URL and socket for debugging and logging. (9.1.0) — [release notes](https://github.com/TooTallNate/proxy-agents/releases/tag/https-proxy-agent%409.1.0)

### Behavior and default changes

- Package exports were simplified to remove an unnecessary restriction on imports. (9.0.0) — [release notes](https://github.com/TooTallNate/proxy-agents/releases/tag/https-proxy-agent%409.0.0)

### Fixes and other changes

- Defers socket.resume() via setImmediate() so HTTP client machinery can attach data listeners before data starts flowing, fixing a socket event race condition. (9.1.0) — [release notes](https://github.com/TooTallNate/proxy-agents/releases/tag/https-proxy-agent%409.1.0)

## https-proxy-agent 8

### Breaking changes

- Packages now use type: module and compile to ESM output instead of CommonJS, which affects how developers load them. (8.0.0) — [release notes](https://github.com/TooTallNate/proxy-agents/releases/tag/https-proxy-agent%408.0.0)