`MarmotOutboundDao.addMembersToChatRoom` stages every member with `proposeAdd` and issues a single `commit()`. Both callers that know their membership up front now use it: `SelectChatRoomTypeViewModel.inviteMembers` at room creation, and `DkgRitualViewModel.inviteAdmins` for the #admins room. Inviting one at a time created an epoch per member, and each of those commits raced the previous member's welcome. MarmotInboundManager refuses future-epoch messages outright, on both wire formats, with no queue and no replay -- so the member who lost that race was silently stuck an epoch behind while the caller saw a successful invite. Deriving isOneMemberInitialGroupCreation narrowed that window; this removes it. No member ever has to process a commit for an epoch they were not yet in, so there is no longer a race to lose. One commit yields one welcome: `buildWelcome` emits an EncryptedGroupSecrets per added member and each joiner finds its own entry by key package reference. The blob is shared, delivery stays per peer, because each welcome event is tagged with that peer's key package. ## Why this needed no schema change Batching at creation time means the single commit happens while the group is still only its creator, which takes the immediate-welcome branch: nothing is broadcast and MarmotCommitResult is never written. The bookkeeping that assumes one peer per commit is simply not on this path. So the batch is taken only when `members().size == 1`, and anything else falls back to inviting sequentially -- correct, if not ideal. Batching into an established group would take the deferred branch, where `peerKeyPackageEventId` is singular and the ack-triggered delivery in DatabaseNostrRepository expects one welcome; making that work needs a list there and a fan-out on acknowledgement. Nothing currently adds several members to an established group, so that is left outstanding and documented rather than speculatively built. The group state is persisted after `commit()` and before any welcome goes out, so a crash between them leaves the group at the epoch the welcomes describe rather than one behind it. ## Reporting Members with no published key package still cannot be added -- a Marmot invite needs one -- and are now returned alongside any that failed to receive their welcome, rather than the two being conflated. Both still only reach the log; the coordinator is not yet told. docs/marmot-membership.md is updated in the same change: batching moves from outstanding work to described behaviour, with the schema constraint that shapes it and the remaining fan-out work recorded. The note about sequential invites is narrowed to where they still happen. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
mantra docs
Notes on the parts of this app whose behaviour is not recoverable by reading the code alone — where the reasoning lives in a protocol, a failure mode that is silent, or a decision that looked arbitrary and was not.
| document | covers |
|---|---|
| shared-key-ceremony.md | ChillDKG over NIP-17: the rounds, the approval gates, the chat transcript, participant ordering |
| shared-key-derivation.md | deriving further keys from the group's threshold key with FROST tweaks — why not BIP32, why no chain code, and the one rule that must not be broken |
| marmot-membership.md | how members join an MLS group, and the epoch race that makes a missing member look like a successful invite |
Start with the ceremony if you are new to this area; the other two both assume it.