[Feature Request]: Add `chat.bsky.group` namespace and group join-link embed

[KC-2001MS]

Summary

The upstream lexicon now ships a full chat.bsky.group.* namespace (group lifecycle, membership, join links, join requests) plus a chat.bsky.embed.joinLink embed object. None of these are reflected in ATProtoKit, so group conversation management is unreachable through the typed pipeline.

Pain points

The entire group surface (lifecycle, membership, join links, join requests, and the messageInput.embed join-link) has to be hand-built on raw XRPC, re-implementing the api.bsky.chat routing and auth plumbing that ATProtoBlueskyChat already handles for every other chat call.

Considered Alternatives

Raw XRPC for the entire group surface — loses typed pipeline, isRelatedToBskyChat host routing, and forces every consumer to repeat the same auth plumbing.

Is this a breaking change?

No

Library Examples

N/A

Additional Context

Missing lexicons

Lexicon	Suggested wrapper
chat.bsky.embed.joinLink	ChatBskyLexicon.Embed.JoinLink embed object, selectable in the sendMessage messageInput.embed union
chat.bsky.group.addMembers	addMembers(to:memberDIDs:)
chat.bsky.group.approveJoinRequest	approveJoinRequest(for:requesterDID:)
chat.bsky.group.createGroup	createGroup(name:memberDIDs:memberLimit:)
chat.bsky.group.createJoinLink	createJoinLink(for:)
chat.bsky.group.defs	types only
chat.bsky.group.disableJoinLink	disableJoinLink(for:)
chat.bsky.group.editGroup	editGroup(by:name:)
chat.bsky.group.editJoinLink	editJoinLink(for:expiresAt:)
chat.bsky.group.enableJoinLink	enableJoinLink(for:)
chat.bsky.group.getJoinLinkPreviews	getJoinLinkPreviews(for:)
chat.bsky.group.listJoinRequests	listJoinRequests(for:limit:cursor:)
chat.bsky.group.listMutualGroups	listMutualGroups(with:limit:cursor:)
chat.bsky.group.rejectJoinRequest	rejectJoinRequest(for:requesterDID:)
chat.bsky.group.removeMembers	removeMembers(from:memberDIDs:)
chat.bsky.group.requestJoin	requestJoin(by:)
chat.bsky.group.updateJoinRequestsRead	updateJoinRequestsRead(for:)
chat.bsky.group.withdrawJoinRequest	withdrawJoinRequest(by:)

Wrappers follow the existing ATProtoBlueskyChat convention (method name mirrors the lexicon's final segment, no artificial Group prefix — matching getConversation, listConversations). All sit on api.bsky.chat and require isRelatedToBskyChat: true routing, and the group namespace maps to ChatBskyLexicon.Group.

Cross-reference

• The convo-side discriminator (convoView.kind → #groupConvo) and the 4 convo-level endpoints (getConvoMembers, listConvoRequests, lockConvo, unlockConvo) are tracked in a separate feature request [Feature Request]: Add chat.bsky.convo reply and group conversation support #320.

References

• Lexicon root: https://github.com/bluesky-social/atproto/tree/main/lexicons/chat/bsky/group
• chat.bsky.embed.joinLink: https://github.com/bluesky-social/atproto/blob/main/lexicons/chat/bsky/embed/joinLink.json
• Affected directories: Sources/ATProtoKit/Models/Lexicons/chat.bsky/Group/ (new), Sources/ATProtoKit/APIReference/ChatBskyAPI/ (new method files)

[KC-2001MS]

As we discussed, I've filed the missing features as separate feature requests for tracking. None of them are urgent on my end, so I plan to follow up on each as the need actually arises.

Given that ATLexiconC is on the horizon, please feel free to handle these at your own pace — there's no rush, and it may well make sense to let ATLexiconC cover some of them rather than typing everything out by hand. I'm happy to help and provide corrections whenever it's useful.