I Reverse Engineered a Closed-Format App. Everything Was in SQLite.

Short summary

Developer reverse-engineered Youdao Cloud Note after finding no export feature, discovering all 2,285 notes stored in plain SQLite databases with unencrypted metadata. The JSON block schema was converted to Markdown via a 200-line parser. Open-source Python migration script and Claude Code Skill now enable automated extraction to Obsidian.

• •Closed-format app stored all user data in unencrypted SQLite databases with documented schema
• •Reverse-engineered JSON block structure and built Markdown converter in 200 lines of code
• •Released open-source Python script and Claude Code Skill for automated data extraction

Generated with AI, which can make mistakes.