> The SQLite database file format is also stable. All releases of SQLite version 3 can read and write database files created by the very first SQLite 3 release (version 3.0.0) going back to 2004-06-18. This is "backwards compatibility". The developers promise to maintain backwards compatibility of the database file format for all future releases of SQLite 3. "Forwards compatibility" means that older releases of SQLite can also read and write databases created by newer releases. SQLite is usually, but not completely forwards compatible.
And yet, "The json1 extension uses the sqlite3_value_subtype() and sqlite3_result_subtype() interfaces that were introduced with SQLite version 3.9.0 (2015-10-14) The json1 extension will not work in earlier versions of SQLite."
This just means you can't use the json1 extension with an old version of the library. But anything you write using it, will still be readable with an older version.
Of course, if you do something like creating an index using a json1 expression, that will cause issues if you try to use the database with an older version.
> The SQLite database file format is also stable. All releases of SQLite version 3 can read and write database files created by the very first SQLite 3 release (version 3.0.0) going back to 2004-06-18. This is "backwards compatibility". The developers promise to maintain backwards compatibility of the database file format for all future releases of SQLite 3. "Forwards compatibility" means that older releases of SQLite can also read and write databases created by newer releases. SQLite is usually, but not completely forwards compatible.