sqlite-statelisted

# SQLite State Use this skill when a recurring job must remember what it already did - which items it has alerted on, the last cursor it processed - so it does not re-notify or re-scrape on the next tick. One stdlib SQLite file gives durable, file-locked state with no server and no extra dependency. ## When to invoke - User says: "don't alert the same thing twice", "dedup across runs", "remember the last id", "resume where it left off". - Code in the conversation is a cron/scheduled script that currently re-processes everything each run. ## When NOT to invoke - State is tiny and ephemeral within a single run - a plain set/dict is enough. - Multiple machines must share state concurrently; reach for a real server DB instead of a single file. ## Concrete example User input: ```text My news scraper re-sends the same headlines every hour. Make it only send new ones. ``` Output: ```python from state import filter_new, mark_seen db = "news.db" fresh = filter_new(db, [a["url"] for a in articles]) # only unseen URLs for url in fresh: send_alert(url) mark_seen(db, *fresh) # remember them for next run ``` ## Pattern to apply 1. Key each item by something stable and unique (URL, id, content hash), not by array position. 2. Use `filter_new` to decide what to act on, then `mark_seen` only after the action succeeds. 3. Store progress as a named cursor (`set_cursor`/`get_cursor`) so a resumable scraper restarts mid-stream. 4. Enable WAL mo