Dead letter mode — what to do when a command has no registered handler.
'error' (default): returns { ok: false, error }
'throw': throws the error
'ignore': returns { ok: true, value: undefined }
'buffer': queue the command (per action, FIFO) and replay it — in order —
the moment a handler for that action is register()-ed. Built for
lazy/async wiring where a command can be dispatched before its handler
exists (e.g. Astro/island hydration, code-split panels): the click isn't
lost, it fires when the handler arrives. The synchronous dispatch returns
{ ok: true, value: undefined } (the real handler runs later). query
never buffers (it must return a value) — it falls back to 'error'.
Bounded by bufferLimit (drop-oldest + dev warning on overflow).
function: called with the command, return value used as result
Dead letter mode — what to do when a command has no registered handler.
'error'(default): returns{ ok: false, error }'throw': throws the error'ignore': returns{ ok: true, value: undefined }'buffer': queue the command (per action, FIFO) and replay it — in order — the moment a handler for that action isregister()-ed. Built for lazy/async wiring where a command can be dispatched before its handler exists (e.g. Astro/island hydration, code-split panels): the click isn't lost, it fires when the handler arrives. The synchronous dispatch returns{ ok: true, value: undefined }(the real handler runs later).querynever buffers (it must return a value) — it falls back to'error'. Bounded bybufferLimit(drop-oldest + dev warning on overflow).