[jhedlund]

Summary

Threads in Buzz have no name anyone can set. This adds shared, editable thread titles as a client-only convention on NIP-AR channel artifacts (#7791, #7919). The relay needs no changes.

Convention (buzz_sdk::thread_title, so the CLI and desktop write byte-identical artifacts):

Tag	Value
kind	45010
type	buzz.thread-title
d	UUIDv5(fixed namespace, "buzz.thread-title:" + lowercase root id): one title per thread. The type is folded into the name, so a future type change gets fresh ids (NIP-AR never reuses a deleted d).
h	the channel
root	the thread root event
title	the title, also copied into content for readers that ignore tags

Renaming is a normal artifact update from the current head. Clearing is op=delete, and setting a title after a clear is restore. Authorization is NIP-AR's: anyone who can post a kind:9 in the channel, agents included, can title a thread.

CLI: buzz threads title set|clear|get|list. Writes plan create/update/delete/restore from the current head and re-read on a head conflict. set --if-unset leaves an existing or cleared title alone.

Agent auto-titling (buzz-acp): when a human's new top-level channel message mentions agents, the first-mentioned agent is asked to title the thread with --if-unset, the way chat apps name a new conversation. Replies, edits, DMs and agent-authored roots never trigger it, and later mentions never rename a thread.

Desktop (through Tauri commands, since artifact queries are HTTP-only on the relay):

• The thread panel header shows the title with an inline editor: pencil on hover, Enter saves, Escape cancels, blank clears. Edits carry the revision they started from, so a concurrent rename is reported ("someone else changed this thread's title") instead of overwritten.
• The title sits on its own line under the author of a thread root in the channel, and clicking it opens the thread. It appears before anyone replies.
• Inbox rows show the title under "Mentioned in #channel", and the detail header reads "Title · #channel".
• Titles are looked up per root by their derived d, up to 100 roots per query. Lookups made in the same tick share one query. A returned title only counts when its d matches its root. There's no global title list, so lookups stay exact however many titles a community has.
• Artifact events in the open channel refresh titles live.

Not in this PR:

• Search. The title is in content, but desktop search hardcodes [9, 40002, 45001, 45003], and the FTS allowlist (fresh installs, nip_rs_search_allowlist.sql) leaves search_tsv NULL for kind 45010. Enabling it means widening the allowlist, which rewrites a generated column on populated relays, plus mapping hits back to root. I'd rather a maintainer decides that separately.
• A cross-channel Threads list. Kept apart because it overlaps feat(read-state): followed threads, follow intents and a threads view #8264, but I am putting mine in Draft so it's a visible PR next.
• Mobile. Titles don't show on mobile yet.

Open question: buzz.* is the reserved artifact type namespace. I used buzz.thread-title because this is meant to become a Buzz convention. If you'd rather it start outside the namespace, it's a one-constant change.

Related issue

Partially closes #6739 (title plumbing). Related: #8264 (relay threads view; its /me/threads rows carry the channel_id + root_id a title is keyed by), #6067, #5254 (thread search in forums).

Testing

• SDK (thread_title.rs): head selection follows the prev chain rather than timestamps. Also covers the write-plan lifecycle, revisions passing relay validation, ignoring other artifact types, title normalization, root filters naming each derived d, and that only compare-and-set losses are retryable.
• CLI: --if-unset skips live and cleared titles but not untitled threads.
• buzz-acp: the first-mentioned agent is asked to title a new thread, and an unknown profile ahead of it doesn't block that. Replies, agent authors, DMs and unmentioned agents never auto-title.
• Desktop unit (threadTitles.test.mjs): same-tick lookups share one fetch, invalid ids are skipped, a failed batch rejects every lookup in it. Also covers revision handling on writes, draft trimming and clearing, and UTF-8 byte bounds.
• Desktop e2e (thread-titles.spec.ts): name a thread from its header, then clear it. A title another user sets appears before anyone replies.
• cargo fmt and cargo clippy (0 warnings) are clean. Desktop typecheck, file-size checks and biome on changed files pass.
• Tests, run on Windows on the feat/threads-view tip (which includes this commit): desktop Tauri 3254 passed; desktop unit 161/161; buzz-cli 500 passed; buzz-sdk and the other crates pass; buzz-acp 1046 passed. Five buzz-acp tests in acp.rs/relay (idle/keepalive, blocked recovery, two steer-capture tests) hang or fail the same way on plain main on this machine, because they drive sh/sleep child processes.

I've run this daily against my own relay since early October, with agents auto-titling threads.

[github-actions]

🔐 Codex Security Review

Status: review required for the current range.

The current range is 9e8c9fc04daf20259cd259dcaec89109587cc7f5...5ce84f6520f02743a89600be9625265714490e29.
A new review must complete for this exact range. When manual authorization
is required, a user with write access must comment exactly
@buzz-security-review 5ce84f6520f02743a89600be9625265714490e29 to authorize a new review.
Any previous review applies only to its recorded range.