Cursor has published the source code of minisqlite, an implementation of the SQLite DBMS, recreated in the Rust language and successfully passing the official set of tests sqllogictest from the SQLite project. The project was prepared as part of an experiment that tested the performance of AI models GPT-5.5, Grok 4.5, Opus 4.8 and Fable 5 in recreating SQLite based only on the official 835-page manual, without access to the original code, the Internet, test suites and the SQLite executable file. The main idea of the experiment is to use a detailed specification as a prompt to create a complex product.
The published implementation is based on the results obtained using the Opus 4.8 AI model. Minisqlite includes about 200 thousand lines of Rust code that does not contain unsafe blocks in the library code. The library can open files created in native sqlite3 and write files that can be read in sqlite3. The implementation covers the SQL dialect from SQLite, transaction support, 90 built-in functions, a query planner, a query engine, and a storage engine compatible with disk format SQLite 3. Of the external dependencies, only the package elsa is involved, using which implemented page cache.