The server drops a page's own chord.* attributes and writes chord.host and the principal hook's result itself; tests
for the hook returning nothing, the NOOP adapter and calls over a link.
The four telemetry gaps (rows on commits, chord.host, microsecond times, a read-only store) and: pages record and
send span batches over their link to the server's ingest object (checked, capped, rate-limited, stamped browser and
with the link's principal); workers send theirs too, so the server is the store's only writer; principalAttributes
lets an app choose what a span records about its principal. The tutorial shows a real page's click traced to the
worker, with the trace viewer.
A call arriving while an attempt activates waits for its outcome (bounded by readyTimeout) instead of failing
not_ready while its client sees live. Fates start in the reverse of the order objects went live, so a pure
dependent of a swapping provider swaps instead of parking.
defineMessages with typed t, t.message/t.render for messages as data, the Translations registry with fallbacks and
conflicts, a locale preference per principal with the device as default and a live switch, useMessages and
scope.messages, formatTime/formatNumber. The tutorial gains a chapter on languages.
self.query(table, q, limit) runs before the object goes live and again in the commit step of every commit that
touched the table, publishing only the diff; a reload swaps the object. The tutorial and 59-chat use it.
