# 2026-01-19 AI Work Log - **Substack Copy Plugin Development** - **Outcome**: Created `obsidian-substack-copy` (v0.1.0) and released to GitHub. - **Technical Decision**: Validated that Substack accepts local images if they are embedded as `data:image/png;base64,...` in the HTML clipboard data. Implemented logic to render Markdown to HTML using `MarkdownRenderer`, parse `img` tags, resolve local paths (handling Japanese characters), and inject Base64 data. - **Repository**: [goryugocast/obsidian-substack-copy](https://github.com/goryugocast/obsidian-substack-copy) - **ステータス**: Tested by user (Base64 OK). Ready for BRAT.