Read Receipts Group Chat Block for Ark UI

Everything. Each member's position is a typed record of the message they last read and the time they got there, and the chain after a send is three timeouts in this file. Nothing is sent, as the line under the composer says. To wire it for real, store a lastReadId and a timestamp per member, update them from your server's read events, and drop the timer; the markers, the "Seen by" text and the popover already read from that list.

By data. Each reader holds the id of the last message they read, and every message shows the readers whose id matches it, so people at the same message form one stack and a reader moves by changing the id. Only other members get markers; your own read position is never drawn, and the stack is hidden from assistive technology with a sentence in text instead: "Read up to here by Ana and Kofi."

The members who have read at least up to your newest message, in words: "Seen by Ana", "Seen by Ana and Kofi", "Seen by Ana, Kofi and Lena" or "Not seen yet". Pressing it opens each member with the typed time they read it, or "Not yet". It is a real button, so Enter and Space open it and Escape closes it.

Read receipts are reciprocal, as in most messengers. Off, the markers and the "Seen by" line disappear for you and the status line says "You won't see read times and others won't see yours." The positions are still tracked in the demo, so turning it back on shows where everyone is now.

The readers do not walk one by one: after you send, the three timeouts run at once and all three markers land together. The status line still says each name as it is applied.

The same single column: the switch keeps its place in the top bar with its label read by screen readers only, the markers stay under the bubbles and the popover opens over the log. The window keeps its height and only the log scrolls.