Tick-based activity session tracking. No start/stop calls — report elapsed time as it happens, and stints (bounded periods of activity) assemble themselves.

# on every activity ping (a reader's progress tick, a player's
# watch-time beat, a practice timer):
Stint.track(user_id, "manga:mangadex/one-piece", 30)

If the owner's latest stint on that item ended within the gap window (default 5 minutes), the tick extends it — ended_at moves to now, seconds accumulates. A longer silence means the next tick opens a new stint. That inference is the whole point: session ends are unobservable in real apps (tabs close, phones lock, processes die), while periodic ticks are easy and reliable. A "session" stops being an API anyone can forget to call and becomes an emergent fact of the data.

Each stint carries second-resolution started_at / ended_at, so the data distinguishes one two-hour binge from six three-minute peeks — not just "N minutes in hour H".

Setup

config :stint, repo: MyApp.Repo

And a migration:

def up, do: Stint.Migration.up()
def down, do: Stint.Migration.down()

Identity

owner_id and item are opaque strings — a user UUID, a device id, "manga:source/slug", "habit:guitar" — the library never interprets them.

Options

• :gap — seconds of silence that split stints (default 300, configurable app-wide via config :stint, default_gap: n)
• :at — the tick's timestamp (default DateTime.utc_now/0)
• :meta — map shallow-merged into the stint's meta on every tick (last write wins per key)

Timezone-aware day queries take :utc_offset in seconds (e.g. a UTC+2 user is utc_offset: 7200).