MoQT track + MLS epoch inspector.
Watch a group form. Watch a member join. See the epoch tick. Every state mutation is signed.
Subscribe to closing/audio at priority 1, closing/video at priority 4.
Each MoQT track namespace fans out via the us-west-1 relay. Object headers carry (group_id, object_id, priority) so a congested relay drops video B-frames first while audio objects remain in-order. SUBSCRIBE_OK returns the latest group id so a late joiner catches up without a renegotiation.
Anatomy — operational specs
TreeKEM group state. Rekeys on every membership change.
The closing call's group g_92c1 starts at epoch 46 with 4 members. Add(notary) commits to epoch 47; Remove(notary) commits to epoch 48 at session end. Every epoch carries a fresh sender_data_secret, exporter_secret, and confirmation tag — RFC 9420 §8.5 forward secrecy holds.
Anatomy — operational specs
INVITE / 200 OK / ACK across five endpoints.
The dialog id (Call-ID + tags) anchors every subsequent SDP renegotiation. When the PSTN-dialed agent's codec changes, a re-INVITE on the same dialog updates the SFU without disturbing the MLS group. BYE on hangup closes the dialog and triggers the recording seal.
Anatomy — operational specs
Frame-by-frame BLAKE3 root. The recording IS the receipt.
Audio objects (OPUS, 20ms frames) and video objects (AV1, ~33ms keyframe cadence) are folded into a streaming BLAKE3 hasher in their MoQT delivery order. The 32-byte root commits to 26,130 objects. Anyone with the recording can re-derive the root and compare — there's no separate "chain of custody" log.
Anatomy — operational specs
PSTN bridge + RTCP feedback into the same MoQT track.
OpenSIPS 3.5 acts as a B2BUA: it terminates the PSTN leg, transcodes G.711μ → OPUS, and publishes onto closing/audio so MLS group members see one unified stream. Inbound CDRs are stamped into the receipt log; RTCP receiver reports flow back at 250 ms intervals so PLI loss stays under 0.07%.
Anatomy — operational specs
CommunicationOS, in one line
transport, made inspectable.
Click anything. The same primitives that compose the rest of the Transaction Science family — receipts, joules, signed transport — show up here too. The family is one system.