channels/
├── fake/             # FakeMessagePlatform — implemented (test channel)
├── qq/               # Reserved — QQ
├── weixin/           # Reserved — WeChat (微信公众号/小程序/企业微信)
├── shangwutong/      # Reserved — 商务通
├── douyin/           # Reserved — 抖音
└── xiaohongshu/      # Reserved — 小红书

Current status

fake — Fully implemented. A programmable fake message platform for automated end-to-end integration testing. See fake/README.md.
qq/weixin/shangwutong/douyin/xiaohongshu — Reserved only. No code implemented. These platforms require real API credentials and per-platform provider implementations. The directories are pre-created so future extensions have a stable path convention.

GoChat backend channel providers

Each channel's backend provider lives in backend/internal/channel/provider/. The fake channel's provider is at backend/internal/channel/provider/fake.go.