Nymchat's group chat feature was the first fully functioning NIP-17 group chat that didn't expose metadata related to group membership.
It was then upgraded to support roles and moderation within the group chats, also a first.
It has now been upgraded further, patching a few bugs and allowing the ephemeral keys to be encrypted at rest when using the "encrypted identity" feature (setting a password or passkey or face/touch ID lock on the app). And the group chat owner can now decide to allow backfilling of chat messages for new members who join.
If you're unfamiliar, Nymchat's group chat feature uses a different ephemeral key for every sent message, with the next planned key advertised inside the encrypted rumor. To an outside observer, there is no possible way to correlate group membership.
There is no shared key for the group that could be compromised and leak all previous chat history. There is no re-keying of the entire group if a user gets kicked or leaves. Nymchat's group chat is a very streamlined and privacy-focused group chat implementation, which should probably be spun off into its own "protocol" or NIP or just how NIP-17 should be for groups tbh.
https://nymchat.app
Luxas
npub16j…733sv
2026-08-17 02:33:05 UTC
Author Public Key
npub16jdfqgazrkapk0yrqm9rdxlnys7ck39c7zmdzxtxqlmmpxg04r0sd733svPublished at
2026-08-17 02:33:05 UTCEvent JSON
{
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"pubkey": "d49a9023a21dba1b3c8306ca369bf3243d8b44b8f0b6d1196607f7b0990fa8df",
"created_at": 1786933985,
"kind": 1,
"tags": [
[
"client",
"Yakihonne",
"31990:20986fb83e775d96d188ca5c9df10ce6d613e0eb7e5768a0f0b12b37cdac21b3:1700732875747"
]
],
"content": "Nymchat's group chat feature was the first fully functioning NIP-17 group chat that didn't expose metadata related to group membership. \n\nIt was then upgraded to support roles and moderation within the group chats, also a first.\n\nIt has now been upgraded further, patching a few bugs and allowing the ephemeral keys to be encrypted at rest when using the \"encrypted identity\" feature (setting a password or passkey or face/touch ID lock on the app). And the group chat owner can now decide to allow backfilling of chat messages for new members who join.\n\nIf you're unfamiliar, Nymchat's group chat feature uses a different ephemeral key for every sent message, with the next planned key advertised inside the encrypted rumor. To an outside observer, there is no possible way to correlate group membership.\n\nThere is no shared key for the group that could be compromised and leak all previous chat history. There is no re-keying of the entire group if a user gets kicked or leaves. Nymchat's group chat is a very streamlined and privacy-focused group chat implementation, which should probably be spun off into its own \"protocol\" or NIP or just how NIP-17 should be for groups tbh. \n\nhttps://nymchat.app",
"sig": "85222ade4b74a3782aad77356339833503b813cc7d2105527688da899e9616c61be4871d5f86c392b2974e1cbd5506027ebfb82755c816ab0eeff3050f434841"
}