feat(desktop): show each agent's role in the @-mention selector

desktop/playwright.config.ts

@@ -58,6 +58,7 @@ export default defineConfig({
         "**/composer-link-shortcut.spec.ts",
         "**/composer-tooltip-dismiss.spec.ts",
         "**/mentions.spec.ts",
+        "**/mention-descriptions-screenshots.spec.ts",
         "**/team-mentions.spec.ts",
         "**/persistent-agent-audience.spec.ts",
         "**/relay-reconnect.spec.ts",

desktop/src-tauri/src/models.rs

@@ -48,6 +48,10 @@ pub struct UserProfileSummaryInfo {
     #[serde(default)]
     pub name: Option<String>,
     pub avatar_url: Option<String>,
+    /// Kind-0 `about` field — one-line role/description surfaced in the
+    /// @-mention selector for agents.
+    #[serde(default)]
+    pub about: Option<String>,
     pub nip05_handle: Option<String>,
     pub owner_pubkey: Option<String>,
     #[serde(default)]
@@ -65,6 +69,10 @@ pub struct UserSearchResultInfo {
     pub pubkey: String,
     pub display_name: Option<String>,
     pub avatar_url: Option<String>,
+    /// Kind-0 `about` field — one-line role/description surfaced in the
+    /// @-mention selector for agents.
+    #[serde(default)]
+    pub about: Option<String>,
     pub nip05_handle: Option<String>,
     pub owner_pubkey: Option<String>,
     #[serde(default)]

desktop/src-tauri/src/nostr_convert.rs

@@ -341,6 +341,7 @@ pub fn users_batch_from_events(
                 .map(str::to_string),
             name: v.get("name").and_then(Value::as_str).map(str::to_string),
             avatar_url: v.get("picture").and_then(Value::as_str).map(str::to_string),
+            about: v.get("about").and_then(Value::as_str).map(str::to_string),
             nip05_handle: v.get("nip05").and_then(Value::as_str).map(str::to_string),
             is_agent: owner_pubkey.is_some(),
             owner_pubkey,
@@ -835,6 +836,28 @@ mod tests {
         );
     }
 
+    #[test]
+    fn users_batch_carries_about_when_present() {
+        let with_about = ev(
+            0,
+            r#"{"display_name":"Bumble","about":"Researcher — deep dives & sourcing"}"#,
+            vec![],
+        );
+        let without_about = ev(0, r#"{"display_name":"Fizz"}"#, vec![]);
+        let pk_with = with_about.pubkey.to_hex();
+        let pk_without = without_about.pubkey.to_hex();
+
+        let resp = users_batch_from_events(
+            &[with_about, without_about],
+            &[pk_with.clone(), pk_without.clone()],
+        );
+        assert_eq!(
+            resp.profiles[&pk_with].about.as_deref(),
+            Some("Researcher — deep dives & sourcing")
+        );
+        assert_eq!(resp.profiles[&pk_without].about, None);
+    }
+
     #[test]
     fn user_notes_builds_cursor_from_last() {
         let e1 = ev(1, "first", vec![]);

desktop/src-tauri/src/nostr_convert/user_search.rs

@@ -19,6 +19,7 @@ pub fn user_search_result_from_event(ev: &Event) -> UserSearchResultInfo {
             .or_else(|| v.get("name").and_then(Value::as_str))
             .map(str::to_string),
         avatar_url: v.get("picture").and_then(Value::as_str).map(str::to_string),
+        about: v.get("about").and_then(Value::as_str).map(str::to_string),
         nip05_handle: v.get("nip05").and_then(Value::as_str).map(str::to_string),
         is_agent: owner_pubkey.is_some(),
         owner_pubkey,
@@ -238,6 +239,18 @@ mod tests {
         assert_eq!(r.users[1].display_name.as_deref(), Some("B"));
     }
 
+    #[test]
+    fn user_search_result_carries_about_when_present() {
+        let with_about = ev(0, r#"{"name":"honey","about":"Writer bee"}"#, vec![]);
+        let without_about = ev(0, r#"{"name":"fizz"}"#, vec![]);
+
+        assert_eq!(
+            user_search_result_from_event(&with_about).about.as_deref(),
+            Some("Writer bee")
+        );
+        assert_eq!(user_search_result_from_event(&without_about).about, None);
+    }
+
     #[test]
     fn user_search_result_marks_valid_nip_oa_profile_as_agent() {
         let event = oa_profile_event(r#"{"display_name":"Mira"}"#);

desktop/src/features/messages/lib/mentionCandidates.ts

@@ -21,6 +21,10 @@ export type MentionCandidate = {
   role?: ChannelRole | null;
   personaName?: string | null;
   secondaryLabel?: string | null;
+  /** Kind-0 `about` when already resolved at candidate-build time (e.g. from
+   * a user-search result). `undefined` means "unknown — resolve from the
+   * profile lookup at suggestion-mapping time"; `null` means "known absent". */
+  description?: string | null;
   ownerPubkey?: string | null;
   isAgent: boolean;
   isManagedAgent?: boolean;

desktop/src/features/messages/lib/mentionSuggestionMapping.test.mjs

@@ -0,0 +1,88 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+
+import { mapMentionCandidateToSuggestion } from "./mentionSuggestionMapping.ts";
+
+const AGENT_PUBKEY = "a".repeat(64);
+
+function agentCandidate(overrides = {}) {
+  return {
+    kind: "identity",
+    pubkey: AGENT_PUBKEY,
+    isAgent: true,
+    isMember: true,
+    ...overrides,
+  };
+}
+
+function profileSummary(about) {
+  return {
+    displayName: "Bumble",
+    name: null,
+    avatarUrl: null,
+    about,
+    nip05Handle: null,
+    ownerPubkey: null,
+    isAgent: true,
+  };
+}
+
+test("agent description comes from the candidate when resolved at build time", () => {
+  const suggestion = mapMentionCandidateToSuggestion({
+    candidate: agentCandidate({ description: "Researcher — deep dives" }),
+    label: "Bumble",
+    profiles: { [AGENT_PUBKEY]: profileSummary("stale profile about") },
+  });
+
+  assert.equal(suggestion.description, "Researcher — deep dives");
+});
+
+test("agent description falls back to the profile lookup's about", () => {
+  const suggestion = mapMentionCandidateToSuggestion({
+    candidate: agentCandidate(),
+    label: "Bumble",
+    profiles: { [AGENT_PUBKEY]: profileSummary("Researcher — deep dives") },
+  });
+
+  assert.equal(suggestion.description, "Researcher — deep dives");
+});
+
+test("agent description is null when about is missing everywhere", () => {
+  const suggestion = mapMentionCandidateToSuggestion({
+    candidate: agentCandidate(),
+    label: "Bumble",
+    profiles: { [AGENT_PUBKEY]: profileSummary(null) },
+  });
+
+  assert.equal(suggestion.description, null);
+});
+
+test("non-agent suggestions never carry a description", () => {
+  const suggestion = mapMentionCandidateToSuggestion({
+    candidate: agentCandidate({ isAgent: false }),
+    label: "Alice",
+    profiles: { [AGENT_PUBKEY]: profileSummary("A human bio") },
+  });
+
+  assert.equal(suggestion.description, null);
+});
+
+test("multi-line about collapses to a single trimmed line", () => {
+  const suggestion = mapMentionCandidateToSuggestion({
+    candidate: agentCandidate({
+      description: "  Writer bee.\nDrafts docs\n\tand posts.  ",
+    }),
+    label: "Honey",
+  });
+
+  assert.equal(suggestion.description, "Writer bee. Drafts docs and posts.");
+});
+
+test("whitespace-only about degrades to null (name-only row)", () => {
+  const suggestion = mapMentionCandidateToSuggestion({
+    candidate: agentCandidate({ description: "   \n  " }),
+    label: "Fizz",
+  });
+
+  assert.equal(suggestion.description, null);
+});

desktop/src/features/messages/lib/mentionSuggestionMapping.ts

@@ -15,6 +15,7 @@ export type MentionSuggestionCandidate = {
   isAgent: boolean;
   isMember: boolean;
   role?: ChannelRole | null;
+  description?: string | null;
   ownerPubkey?: string | null;
 };
 
@@ -38,6 +39,18 @@ export function mapMentionCandidateToSuggestion(opts: {
     ? formatOwnerLabel(candidate.ownerPubkey, currentPubkey, ownerProfiles)
     : null;
 
+  // Agent role line: prefer an `about` resolved at candidate-build time
+  // (search results), else fall back to the profile lookup like avatarUrl.
+  // Collapsed to a single line — the selector is a quick picker, not a
+  // profile card.
+  const rawDescription = candidate.isAgent
+    ? (candidate.description ??
+      (candidate.pubkey
+        ? profiles?.[normalizePubkey(candidate.pubkey)]?.about
+        : null))
+    : null;
+  const description = rawDescription?.replace(/\s+/g, " ").trim() || null;
+
   return {
     pubkey: candidate.pubkey,
     personaId: candidate.personaId ?? undefined,
@@ -58,5 +71,6 @@ export function mapMentionCandidateToSuggestion(opts: {
       candidate.isMember === false,
     ownerLabel,
     role: !candidate.isAgent && candidate.role === "admin" ? "admin" : null,
+    description,
   };
 }

desktop/src/features/messages/lib/useMentions.ts

@@ -282,6 +282,9 @@ export function useMentions(
         role: current.role ?? candidate.role ?? null,
         secondaryLabel:
           current.secondaryLabel ?? candidate.secondaryLabel ?? null,
+        // `??` (not `?? null`) so both-undefined stays undefined — that is
+        // the "still unknown, resolve from the profile lookup" signal.
+        description: current.description ?? candidate.description,
         ownerPubkey:
           current.ownerPubkey ??
           candidate.ownerPubkey ??
@@ -379,6 +382,7 @@ export function useMentions(
             relayAgentNamesByPubkey.has(pubkey),
           personaName: personaNameByPubkey.get(pubkey) ?? null,
           secondaryLabel: formatSearchUserSecondaryLabel(user),
+          description: user.about ?? null,
           ownerPubkey: user.ownerPubkey ?? null,
           isGlobalSearchResult: true,
           isManagedAgent: managedAgentNamesByPubkey.has(pubkey),
@@ -457,6 +461,40 @@ export function useMentions(
     enabled: ownerPubkeys.length > 0,
   });
 
+  // Agent candidates whose kind-0 `about` is not already known — neither
+  // resolved at candidate-build time (search results) nor present in the
+  // caller's profile lookup. Batch-resolve them so the selector can show a
+  // role line even for agents who haven't authored anything in the loaded
+  // timeline. The per-pubkey entry cache behind useUsersBatchQuery keeps
+  // repeat lookups off the network.
+  const agentProfilePubkeys = React.useMemo(
+    () => [
+      ...new Set(
+        mentionCandidates
+          .filter(
+            (candidate) =>
+              candidate.isAgent &&
+              candidate.pubkey &&
+              candidate.description === undefined &&
+              !profiles?.[candidate.pubkey],
+          )
+          .map((candidate) => candidate.pubkey as string),
+      ),
+    ],
+    [mentionCandidates, profiles],
+  );
+  const agentProfilesQuery = useUsersBatchQuery(agentProfilePubkeys, {
+    enabled: agentProfilePubkeys.length > 0,
+  });
+  const mentionProfiles = React.useMemo<UserProfileLookup | undefined>(() => {
+    const agentProfiles = agentProfilesQuery.data?.profiles;
+    if (!agentProfiles || Object.keys(agentProfiles).length === 0) {
+      return profiles;
+    }
+    // Caller-provided profiles win on conflict.
+    return { ...agentProfiles, ...profiles };
+  }, [agentProfilesQuery.data?.profiles, profiles]);
+
   const searchableNames = React.useMemo<string[]>(() => {
     const names: string[] = [];
     const seen = new Set<string>();
@@ -551,17 +589,17 @@ export function useMentions(
           channelType: options?.channelType,
           currentPubkey,
           ownerProfiles: ownerProfilesQuery.data?.profiles,
-          profiles,
+          profiles: mentionProfiles,
         }),
       );
   }, [
     activePersonaIds,
     currentPubkey,
     mentionCandidatesWithTeams,
+    mentionProfiles,
     mentionQuery,
     options?.channelType,
     ownerProfilesQuery.data?.profiles,
-    profiles,
   ]);
 
   const fetchMoreSuggestions = React.useCallback(() => {
@@ -930,7 +968,7 @@ export function useMentions(
             channelType: options?.channelType,
             currentPubkey,
             ownerProfiles: ownerProfilesQuery.data?.profiles,
-            profiles,
+            profiles: mentionProfiles,
           });
           if (flushed?.type === "match") {
             flushedMentionStartIndexRef.current = flushed.startIndex;
@@ -960,10 +998,10 @@ export function useMentions(
       currentPubkey,
       isMentionOpen,
       mentionCandidatesWithTeams,
+      mentionProfiles,
       mentionSelectedIndex,
       options?.channelType,
       ownerProfilesQuery.data?.profiles,
-      profiles,
       suggestions,
     ],
   );

desktop/src/features/messages/ui/MentionAutocomplete.tsx

@@ -25,6 +25,8 @@ export type MentionSuggestion = {
   notInChannel?: boolean;
   ownerLabel?: string | null;
   role?: string | null;
+  /** One-line agent role/description from the kind-0 `about` field. */
+  description?: string | null;
 };
 
 type MentionAutocompleteProps = {
@@ -163,13 +165,23 @@ export const MentionAutocomplete = React.memo(function MentionAutocomplete({
                         team · {suggestion.teamMembers?.length ?? 0} agents
                       </span>
                     ) : suggestion.isAgent ? (
-                      <span className="inline-flex shrink-0 items-center gap-1">
+                      <span className="inline-flex min-w-0 items-center gap-1">
                         <Bot
                           aria-hidden="true"
-                          className="h-3.5 w-3.5"
+                          className="h-3.5 w-3.5 shrink-0"
                           data-testid="mention-agent-icon"
                         />
-                        {agentLabel}
+                        {suggestion.description ? (
+                          <span
+                            className="min-w-0 truncate"
+                            data-testid="mention-agent-description"
+                            title={suggestion.description}
+                          >
+                            {suggestion.description}
+                          </span>
+                        ) : (
+                          agentLabel
+                        )}
                       </span>
                     ) : suggestion.role ? (
                       <Badge

desktop/src/features/profile/lib/identity.ts

@@ -39,6 +39,7 @@ export function profileLookupsEqual(
       prev.displayName !== next.displayName ||
       prev.name !== next.name ||
       prev.avatarUrl !== next.avatarUrl ||
+      prev.about !== next.about ||
       prev.nip05Handle !== next.nip05Handle ||
       prev.ownerPubkey !== next.ownerPubkey ||
       prev.isAgent !== next.isAgent
@@ -80,6 +81,7 @@ export function mergeCurrentProfileIntoLookup(
       // lookup already resolved so mention aliases survive the merge.
       name: profiles?.[normalizePubkey(currentProfile.pubkey)]?.name ?? null,
       avatarUrl: currentProfile.avatarUrl,
+      about: profiles?.[normalizePubkey(currentProfile.pubkey)]?.about ?? null,
       nip05Handle: currentProfile.nip05Handle,
       isAgent: profiles?.[normalizePubkey(currentProfile.pubkey)]?.isAgent,
       ownerPubkey: