OAuth callback server binds to IPv6, breaking WSL2 localhost forwarding

[billovfo]

Description

The OAuth callback server in packages/opencode/src/mcp/oauth-callback.ts:164
calls server.listen(port) without a host, which binds to :: (IPv6) on Linux.
WSL2's localhost forwarding cannot route to IPv6 dual-stack sockets, so OAuth
callbacks from the Windows browser never reach OpenCode.

Plugins

No response

OpenCode version

Latest

Steps to reproduce

server!.listen(currentPort, '0.0.0.0', () => {

All OAuth-based remote MCP servers on WSL2 (Notion, etc.).

Screenshot and/or share link

No response

Operating System

Windows 11 pro (WSL 2, Ubuntu)

Terminal

WSL Ubuntu Tmus

[mertcanvural]

I hit a similar WSL2 loopback bug once. Since your repro already pins binding to , I'd compare three things first: a plain manual diff of the callback host the Windows browser actually reaches, authproxy.dev if you want to watch the handoff live, or OAuth Redirect Doctor if you want the callback host, loopback listener, and provider redirect lined up. tbh WSL2 usually falls over when the browser can hit localhost but the OAuth listener is only sitting on IPv6.

[billovfo]

Thank you guys