Cool! I was looking for a simple key-value alternative for SQLite3 and was going to use redislite[1]. But this is perfect, I think it has the potential to replace SQLite3.
SQLite4 is being designed as a key-value alternative to SQLite3[1]. SQLite3 and SQLite4 are meant for different use-cases and are expected to co-exist. Unfortunately, SQLite4 hasn't yet been released, but wanted to let you know that the SQLite developers are actively working on addressing the need for an embedded key-value store with SQLite4.
[1] https://sqlite.org/src4/doc/trunk/www/design.wiki