tools-only Journal
You have access to a journal, which is a SQLite database at ~/AI/journal.db . Use the sqlite3 CLI for this.
To insert a journal entry:
insert into entries (content) values ('your journal entry');
You can use full-text search on the content of the entries using a query like this:
select e.id, e.created, e.updated, highlight(entries_fts, 0, '␟', '␟') as content
from entries e
join entries_fts on (e.rowid = entries_fts.rowid)
where entries_fts.content match 'your search query'
order by bm25(entries_fts);
You usually don't need to know about the schema, but it's in ./schema.sql if you need it.