# What changed in http-proxy-agent

> 7 changes in http-proxy-agent 8 to 9 from its official release notes, upgrade guides and advisories: 2 breaking, 4 new APIs and options. Each one cited. Sources checked 2026-10-18. HTML: https://unstale.sh/npm/http-proxy-agent/

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

## http-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/http-proxy-agent%409.0.0)

### New APIs and options

- Adds the negotiate: true option to use the kerberos package for automatic Negotiate/SPNEGO proxy authentication. (9.1.0) — [release notes](https://github.com/TooTallNate/proxy-agents/releases/tag/http-proxy-agent%409.1.0)
- Adds an optional async callback to HttpProxyAgent options; when a proxy responds with 407, it receives the response and auth scheme and returns headers for retrying the request. (9.1.0) — [release notes](https://github.com/TooTallNate/proxy-agents/releases/tag/http-proxy-agent%409.1.0)
- After the proxy connection is established, the request emits a proxy event with the proxy URL string and socket, useful for debugging and logging which proxy was used. (9.1.0) — [release notes](https://github.com/TooTallNate/proxy-agents/releases/tag/http-proxy-agent%409.1.0)
- Emits a proxyConnect event on both the request and agent instance when the socket connects to the proxy server. (9.1.0) — [release notes](https://github.com/TooTallNate/proxy-agents/releases/tag/http-proxy-agent%409.1.0)

### Behavior and default changes

- The package exports no longer impose the unnecessary imports restriction. (9.0.0) — [release notes](https://github.com/TooTallNate/proxy-agents/releases/tag/http-proxy-agent%409.0.0)

## http-proxy-agent 8

### Breaking changes

- All packages now use type: module and compile to ESM output instead of CommonJS. (8.0.0) — [release notes](https://github.com/TooTallNate/proxy-agents/releases/tag/http-proxy-agent%408.0.0)