diff --git a/crates/sprout-db/src/lib.rs b/crates/sprout-db/src/lib.rs
index d39922c812..bd1864e34f 100644
--- a/crates/sprout-db/src/lib.rs
+++ b/crates/sprout-db/src/lib.rs
@@ -697,6 +697,15 @@ impl Db {
         user::get_user(&self.pool, pubkey).await
     }
 
+    /// Search users by display name, NIP-05 handle, or pubkey prefix.
+    pub async fn search_users(
+        &self,
+        query: &str,
+        limit: u32,
+    ) -> Result<Vec<user::UserSearchProfile>> {
+        user::search_users(&self.pool, query, limit).await
+    }
+
     /// Update a user's display_name, avatar_url, about, and/or nip05_handle.
     pub async fn update_user_profile(
         &self,
diff --git a/crates/sprout-db/src/user.rs b/crates/sprout-db/src/user.rs
index d29498ef92..527eeb6065 100644
--- a/crates/sprout-db/src/user.rs
+++ b/crates/sprout-db/src/user.rs
@@ -19,6 +19,19 @@ pub struct UserProfile {
     pub nip05_handle: Option<String>,
 }
 
+/// Lightweight user record returned from search.
+#[derive(Debug, Clone)]
+pub struct UserSearchProfile {
+    /// Raw 32-byte compressed public key.
+    pub pubkey: Vec<u8>,
+    /// Human-readable display name chosen by the user.
+    pub display_name: Option<String>,
+    /// URL of the user's avatar image.
+    pub avatar_url: Option<String>,
+    /// NIP-05 identifier (user@domain).
+    pub nip05_handle: Option<String>,
+}
+
 /// Ensure a user record exists for the given pubkey (upsert).
 /// Creates with minimal fields if not present; no-op if already exists.
 pub async fn ensure_user(pool: &MySqlPool, pubkey: &[u8]) -> Result<()> {
@@ -167,6 +180,70 @@ pub async fn get_user_by_nip05(
     ))
 }
 
+/// Search users by display name, NIP-05 handle, or pubkey prefix.
+///
+/// Empty queries return an empty vec and do not hit the database.
+pub async fn search_users(
+    pool: &MySqlPool,
+    query: &str,
+    limit: u32,
+) -> Result<Vec<UserSearchProfile>> {
+    let normalized = query.trim().to_lowercase();
+    if normalized.is_empty() {
+        return Ok(Vec::new());
+    }
+
+    let contains_pattern = format!("%{normalized}%");
+    let prefix_pattern = format!("{normalized}%");
+    let limit = limit.clamp(1, 50) as i64;
+
+    let rows = sqlx::query_as::<_, (Vec<u8>, Option<String>, Option<String>, Option<String>)>(
+        r#"
+        SELECT pubkey, display_name, avatar_url, nip05_handle
+        FROM users
+        WHERE LOWER(COALESCE(display_name, '')) LIKE ?
+           OR LOWER(COALESCE(nip05_handle, '')) LIKE ?
+           OR LOWER(HEX(pubkey)) LIKE ?
+        ORDER BY
+            CASE
+                WHEN LOWER(COALESCE(display_name, '')) = ? THEN 0
+                WHEN LOWER(COALESCE(nip05_handle, '')) = ? THEN 1
+                WHEN LOWER(HEX(pubkey)) = ? THEN 2
+                WHEN LOWER(COALESCE(display_name, '')) LIKE ? THEN 3
+                WHEN LOWER(COALESCE(nip05_handle, '')) LIKE ? THEN 4
+                WHEN LOWER(HEX(pubkey)) LIKE ? THEN 5
+                ELSE 6
+            END,
+            COALESCE(NULLIF(display_name, ''), NULLIF(nip05_handle, ''), LOWER(HEX(pubkey)))
+        LIMIT ?
+        "#,
+    )
+    .bind(&contains_pattern)
+    .bind(&contains_pattern)
+    .bind(&contains_pattern)
+    .bind(&normalized)
+    .bind(&normalized)
+    .bind(&normalized)
+    .bind(&prefix_pattern)
+    .bind(&prefix_pattern)
+    .bind(&prefix_pattern)
+    .bind(limit)
+    .fetch_all(pool)
+    .await?;
+
+    Ok(rows
+        .into_iter()
+        .map(
+            |(pubkey, display_name, avatar_url, nip05_handle)| UserSearchProfile {
+                pubkey,
+                display_name,
+                avatar_url,
+                nip05_handle,
+            },
+        )
+        .collect())
+}
+
 /// Set the owner pubkey for an agent user.
 /// The owner pubkey must already exist in the users table (FK constraint).
 /// Returns an error if the agent pubkey is not found (rows_affected == 0).
diff --git a/crates/sprout-relay/src/api/mod.rs b/crates/sprout-relay/src/api/mod.rs
index 22f60586a4..242fd5aee4 100644
--- a/crates/sprout-relay/src/api/mod.rs
+++ b/crates/sprout-relay/src/api/mod.rs
@@ -70,7 +70,8 @@ pub use presence::{presence_handler, set_presence_handler};
 pub use reactions::{add_reaction_handler, list_reactions_handler, remove_reaction_handler};
 pub use search::search_handler;
 pub use users::{
-    get_profile, get_user_profile, get_users_batch, put_channel_add_policy, update_profile,
+    get_profile, get_user_profile, get_users_batch, put_channel_add_policy, search_users,
+    update_profile,
 };
 pub use workflows::{
     create_workflow, delete_workflow, get_workflow, list_channel_workflows, list_workflow_runs,
diff --git a/crates/sprout-relay/src/api/users.rs b/crates/sprout-relay/src/api/users.rs
index 8c48a7ca07..bbfc3079a5 100644
--- a/crates/sprout-relay/src/api/users.rs
+++ b/crates/sprout-relay/src/api/users.rs
@@ -5,11 +5,12 @@
 //!   PUT /api/users/me/profile      — update own profile (display_name, avatar_url, about, nip05_handle)
 //!   GET /api/users/{pubkey}/profile — get any user's profile by pubkey hex
 //!   POST /api/users/batch          — resolve display names for multiple pubkeys
+//!   GET /api/users/search          — search users by display name, NIP-05, or pubkey
 
 use std::sync::Arc;
 
 use axum::{
-    extract::{Json as ExtractJson, Path, State},
+    extract::{Json as ExtractJson, Path, Query, State},
     http::{HeaderMap, StatusCode},
     response::Json,
 };
@@ -173,6 +174,15 @@ pub struct BatchProfilesRequest {
     pub pubkeys: Vec<String>,
 }
 
+/// Query string for user search.
+#[derive(Debug, Deserialize)]
+pub struct SearchUsersQuery {
+    /// Case-insensitive search query.
+    pub q: String,
+    /// Maximum number of results to return.
+    pub limit: Option<u32>,
+}
+
 /// `POST /api/users/batch` — resolve profile summaries for multiple pubkeys.
 pub async fn get_users_batch(
     State(state): State<Arc<AppState>>,
@@ -256,6 +266,38 @@ pub async fn get_users_batch(
     })))
 }
 
+/// `GET /api/users/search` — search users by display name, NIP-05, or pubkey prefix.
+pub async fn search_users(
+    State(state): State<Arc<AppState>>,
+    headers: HeaderMap,
+    Query(query): Query<SearchUsersQuery>,
+) -> Result<Json<serde_json::Value>, (StatusCode, Json<serde_json::Value>)> {
+    let ctx = extract_auth_context(&headers, &state).await?;
+    sprout_auth::require_scope(&ctx.scopes, sprout_auth::Scope::UsersRead).map_err(scope_error)?;
+
+    let q = query.q.trim();
+    if q.is_empty() {
+        return Ok(Json(serde_json::json!({ "users": [] })));
+    }
+
+    let results = state
+        .db
+        .search_users(q, query.limit.unwrap_or(8))
+        .await
+        .map_err(|e| internal_error(&format!("db error: {e}")))?;
+
+    Ok(Json(serde_json::json!({
+        "users": results.into_iter().map(|user| {
+            serde_json::json!({
+                "pubkey": nostr_hex::encode(&user.pubkey),
+                "display_name": user.display_name,
+                "avatar_url": user.avatar_url,
+                "nip05_handle": user.nip05_handle,
+            })
+        }).collect::<Vec<_>>(),
+    })))
+}
+
 /// Request body for updating channel add policy.
 #[derive(Debug, Deserialize)]
 pub struct UpdateChannelAddPolicyBody {
diff --git a/crates/sprout-relay/src/router.rs b/crates/sprout-relay/src/router.rs
index 93d8a2928e..79956af1a2 100644
--- a/crates/sprout-relay/src/router.rs
+++ b/crates/sprout-relay/src/router.rs
@@ -161,6 +161,7 @@ pub fn build_router(state: Arc<AppState>) -> Router {
             "/api/users/me/channel-add-policy",
             put(api::put_channel_add_policy),
         )
+        .route("/api/users/search", get(api::search_users))
         .route("/api/users/{pubkey}/profile", get(api::get_user_profile))
         .route("/api/users/batch", post(api::get_users_batch))
         // Feed route
diff --git a/desktop/src-tauri/src/commands/profile.rs b/desktop/src-tauri/src/commands/profile.rs
index 04b76c287c..bf677e4a3a 100644
--- a/desktop/src-tauri/src/commands/profile.rs
+++ b/desktop/src-tauri/src/commands/profile.rs
@@ -7,8 +7,8 @@ use tauri::State;
 use crate::{
     app_state::AppState,
     models::{
-        GetUsersBatchBody, ProfileInfo, SetPresenceBody, SetPresenceResponse, UpdateProfileBody,
-        UsersBatchResponse,
+        GetUsersBatchBody, ProfileInfo, SearchUsersResponse, SetPresenceBody, SetPresenceResponse,
+        UpdateProfileBody, UsersBatchResponse,
     },
     relay::{build_authed_request, send_empty_request, send_json_request},
 };
@@ -82,6 +82,25 @@ pub async fn get_users_batch(
     send_json_request(request).await
 }
 
+#[tauri::command]
+pub async fn search_users(
+    query: String,
+    limit: Option<u32>,
+    state: State<'_, AppState>,
+) -> Result<SearchUsersResponse, String> {
+    let limit = limit.unwrap_or(8);
+    let limit_param = limit.to_string();
+    let request = build_authed_request(
+        &state.http_client,
+        Method::GET,
+        "/api/users/search",
+        &state,
+    )?
+    .query(&[("q", query.as_str()), ("limit", limit_param.as_str())]);
+
+    send_json_request(request).await
+}
+
 #[tauri::command]
 pub async fn get_presence(
     pubkeys: Vec<String>,
diff --git a/desktop/src-tauri/src/lib.rs b/desktop/src-tauri/src/lib.rs
index 5f2af6ae03..a55b015e0c 100644
--- a/desktop/src-tauri/src/lib.rs
+++ b/desktop/src-tauri/src/lib.rs
@@ -27,6 +27,7 @@ pub fn run() {
             update_profile,
             get_user_profile,
             get_users_batch,
+            search_users,
             get_presence,
             set_presence,
             get_relay_ws_url,
diff --git a/desktop/src-tauri/src/models.rs b/desktop/src-tauri/src/models.rs
index 9fc8da5ead..21094f1869 100644
--- a/desktop/src-tauri/src/models.rs
+++ b/desktop/src-tauri/src/models.rs
@@ -32,6 +32,19 @@ pub struct UsersBatchResponse {
     pub missing: Vec<String>,
 }
 
+#[derive(Serialize, Deserialize)]
+pub struct UserSearchResultInfo {
+    pub pubkey: String,
+    pub display_name: Option<String>,
+    pub avatar_url: Option<String>,
+    pub nip05_handle: Option<String>,
+}
+
+#[derive(Serialize, Deserialize)]
+pub struct SearchUsersResponse {
+    pub users: Vec<UserSearchResultInfo>,
+}
+
 #[derive(Serialize, Deserialize)]
 pub struct SetPresenceResponse {
     pub status: PresenceStatus,
diff --git a/desktop/src/features/channels/ui/ChannelManagementSheet.tsx b/desktop/src/features/channels/ui/ChannelManagementSheet.tsx
index ce2402236c..2137aa372b 100644
--- a/desktop/src/features/channels/ui/ChannelManagementSheet.tsx
+++ b/desktop/src/features/channels/ui/ChannelManagementSheet.tsx
@@ -10,7 +10,6 @@ import {
   MessageSquare,
   Shield,
   User,
-  UserPlus,
   Users,
 } from "lucide-react";
 import * as React from "react";
@@ -43,6 +42,7 @@ import {
   SheetTitle,
 } from "@/shared/ui/sheet";
 import { Textarea } from "@/shared/ui/textarea";
+import { ChannelMemberInviteCard } from "./ChannelMemberInviteCard";
 
 type ChannelManagementSheetProps = {
   channel: Channel | null;
@@ -52,13 +52,6 @@ type ChannelManagementSheetProps = {
   open: boolean;
 };
 
-const roleOptions: Array<Exclude<ChannelMember["role"], "owner">> = [
-  "member",
-  "admin",
-  "guest",
-  "bot",
-];
-
 const roleOrder: Record<ChannelMember["role"], number> = {
   owner: 0,
   admin: 1,
@@ -197,9 +190,6 @@ export function ChannelManagementSheet({
   const [descriptionDraft, setDescriptionDraft] = React.useState("");
   const [topicDraft, setTopicDraft] = React.useState("");
   const [purposeDraft, setPurposeDraft] = React.useState("");
-  const [invitePubkeys, setInvitePubkeys] = React.useState("");
-  const [inviteRole, setInviteRole] =
-    React.useState<Exclude<ChannelMember["role"], "owner">>("member");
 
   // Sync drafts from server only when the sheet opens or the channel changes —
   // not on every background refetch, which would clobber in-flight edits.
@@ -232,11 +222,6 @@ export function ChannelManagementSheet({
 
   const resolvedChannel = detail ?? channel;
 
-  const parsedInvitePubkeys = invitePubkeys
-    .split(/[\s,]+/)
-    .map((value) => value.trim())
-    .filter((value) => value.length > 0);
-
   return (
     <Sheet onOpenChange={onOpenChange} open={open}>
       <SheetContent
@@ -499,92 +484,17 @@ export function ChannelManagementSheet({
             title="Members"
           >
             {canManageChannel && resolvedChannel.channelType !== "dm" ? (
-              <form
-                className="space-y-3 rounded-2xl border border-border/80 bg-muted/20 p-4"
-                onSubmit={(event) => {
-                  event.preventDefault();
-                  void addMembersMutation
-                    .mutateAsync({
-                      pubkeys: parsedInvitePubkeys,
-                      role: inviteRole,
-                    })
-                    .then((result) => {
-                      if (result.errors.length === 0) {
-                        setInvitePubkeys("");
-                      }
-                    });
-                }}
-              >
-                <div className="flex items-center gap-2 text-sm font-medium">
-                  <UserPlus className="h-4 w-4" />
-                  Invite members
-                </div>
-                <Textarea
-                  className="min-h-24"
-                  data-testid="channel-management-add-pubkeys"
-                  disabled={addMembersMutation.isPending}
-                  onChange={(event) => setInvitePubkeys(event.target.value)}
-                  placeholder="Paste one or more pubkeys, separated by spaces, commas, or new lines."
-                  value={invitePubkeys}
-                />
-                <div className="flex flex-wrap items-center gap-3">
-                  <label
-                    className="flex items-center gap-2 text-sm text-muted-foreground"
-                    htmlFor="channel-member-role"
-                  >
-                    Role
-                  </label>
-                  <select
-                    className="h-9 rounded-md border border-input bg-background px-3 text-sm"
-                    data-testid="channel-management-add-role"
-                    disabled={addMembersMutation.isPending}
-                    id="channel-member-role"
-                    onChange={(event) =>
-                      setInviteRole(
-                        event.target.value as Exclude<
-                          ChannelMember["role"],
-                          "owner"
-                        >,
-                      )
-                    }
-                    value={inviteRole}
-                  >
-                    {roleOptions.map((role) => (
-                      <option key={role} value={role}>
-                        {role}
-                      </option>
-                    ))}
-                  </select>
-                  <Button
-                    data-testid="channel-management-add-members"
-                    disabled={
-                      addMembersMutation.isPending ||
-                      parsedInvitePubkeys.length === 0
-                    }
-                    size="sm"
-                    type="submit"
-                  >
-                    {addMembersMutation.isPending
-                      ? "Inviting..."
-                      : "Add members"}
-                  </Button>
-                </div>
-                {addMembersMutation.error instanceof Error ? (
-                  <p className="text-sm text-destructive">
-                    {addMembersMutation.error.message}
-                  </p>
-                ) : null}
-                {addMembersMutation.data &&
-                addMembersMutation.data.errors.length > 0 ? (
-                  <div className="space-y-1 text-sm text-destructive">
-                    {addMembersMutation.data.errors.map((error) => (
-                      <p key={`${error.pubkey}-${error.error}`}>
-                        {formatPubkey(error.pubkey)}: {error.error}
-                      </p>
-                    ))}
-                  </div>
-                ) : null}
-              </form>
+              <ChannelMemberInviteCard
+                existingMembers={members}
+                isPending={addMembersMutation.isPending}
+                onSubmit={(input) => addMembersMutation.mutateAsync(input)}
+                open={open}
+                requestErrorMessage={
+                  addMembersMutation.error instanceof Error
+                    ? addMembersMutation.error.message
+                    : null
+                }
+              />
             ) : null}
 
             <div className="space-y-2" data-testid="channel-members-list">
diff --git a/desktop/src/features/channels/ui/ChannelMemberInviteCard.tsx b/desktop/src/features/channels/ui/ChannelMemberInviteCard.tsx
new file mode 100644
index 0000000000..1f7e691b80
--- /dev/null
+++ b/desktop/src/features/channels/ui/ChannelMemberInviteCard.tsx
@@ -0,0 +1,298 @@
+import { Search, UserPlus, X } from "lucide-react";
+import * as React from "react";
+
+import { useUserSearchQuery } from "@/features/profile/hooks";
+import type {
+  AddChannelMembersResult,
+  ChannelMember,
+  UserSearchResult,
+} from "@/shared/api/types";
+import { Button } from "@/shared/ui/button";
+import { Input } from "@/shared/ui/input";
+import { Textarea } from "@/shared/ui/textarea";
+
+function formatPubkey(pubkey: string) {
+  return `${pubkey.slice(0, 8)}…${pubkey.slice(-4)}`;
+}
+
+function formatSearchUserName(user: UserSearchResult) {
+  return (
+    user.displayName?.trim() ||
+    user.nip05Handle?.trim() ||
+    formatPubkey(user.pubkey)
+  );
+}
+
+function formatSearchUserSecondary(user: UserSearchResult) {
+  const displayName = user.displayName?.trim();
+  const nip05Handle = user.nip05Handle?.trim();
+
+  if (displayName && nip05Handle) {
+    return nip05Handle;
+  }
+
+  return formatPubkey(user.pubkey);
+}
+
+export function ChannelMemberInviteCard({
+  existingMembers,
+  isPending,
+  onSubmit,
+  open,
+  requestErrorMessage,
+}: {
+  existingMembers: ChannelMember[];
+  isPending: boolean;
+  onSubmit: (input: {
+    pubkeys: string[];
+    role: Exclude<ChannelMember["role"], "owner">;
+  }) => Promise<AddChannelMembersResult>;
+  open: boolean;
+  requestErrorMessage?: string | null;
+}) {
+  const [invitePubkeys, setInvitePubkeys] = React.useState("");
+  const [inviteQuery, setInviteQuery] = React.useState("");
+  const [selectedInvitees, setSelectedInvitees] = React.useState<
+    UserSearchResult[]
+  >([]);
+  const [inviteRole, setInviteRole] =
+    React.useState<Exclude<ChannelMember["role"], "owner">>("member");
+  const [submissionErrors, setSubmissionErrors] = React.useState<
+    AddChannelMembersResult["errors"]
+  >([]);
+
+  const deferredInviteQuery = React.useDeferredValue(inviteQuery.trim());
+  const selectedInviteePubkeys = React.useMemo(
+    () =>
+      new Set(selectedInvitees.map((invitee) => invitee.pubkey.toLowerCase())),
+    [selectedInvitees],
+  );
+  const memberPubkeys = React.useMemo(
+    () => new Set(existingMembers.map((member) => member.pubkey.toLowerCase())),
+    [existingMembers],
+  );
+  const userSearchQuery = useUserSearchQuery(deferredInviteQuery, {
+    enabled: open && deferredInviteQuery.length > 0,
+    limit: 8,
+  });
+  const inviteSearchResults = React.useMemo(
+    () =>
+      (userSearchQuery.data ?? []).filter(
+        (user) =>
+          !memberPubkeys.has(user.pubkey.toLowerCase()) &&
+          !selectedInviteePubkeys.has(user.pubkey.toLowerCase()),
+      ),
+    [memberPubkeys, selectedInviteePubkeys, userSearchQuery.data],
+  );
+
+  React.useEffect(() => {
+    if (!open) {
+      setInvitePubkeys("");
+      setInviteQuery("");
+      setSelectedInvitees([]);
+      setSubmissionErrors([]);
+    }
+  }, [open]);
+
+  const parsedInvitePubkeys = invitePubkeys
+    .split(/[\s,]+/)
+    .map((value) => value.trim())
+    .filter((value) => value.length > 0);
+  const inviteTargets = [
+    ...new Set([
+      ...selectedInvitees.map((invitee) => invitee.pubkey),
+      ...parsedInvitePubkeys,
+    ]),
+  ];
+
+  return (
+    <form
+      className="space-y-3 rounded-2xl border border-border/80 bg-muted/20 p-4"
+      onSubmit={(event) => {
+        event.preventDefault();
+        void onSubmit({
+          pubkeys: inviteTargets,
+          role: inviteRole,
+        }).then((result) => {
+          const addedPubkeys = new Set(
+            result.added.map((pubkey) => pubkey.toLowerCase()),
+          );
+          setSelectedInvitees((current) =>
+            current.filter(
+              (invitee) => !addedPubkeys.has(invitee.pubkey.toLowerCase()),
+            ),
+          );
+          setInvitePubkeys(
+            parsedInvitePubkeys
+              .filter((pubkey) => !addedPubkeys.has(pubkey.toLowerCase()))
+              .join("\n"),
+          );
+          setInviteQuery("");
+          setSubmissionErrors(result.errors);
+        });
+      }}
+    >
+      <div className="flex items-center gap-2 text-sm font-medium">
+        <UserPlus className="h-4 w-4" />
+        Add members
+      </div>
+      <div className="space-y-2">
+        <label
+          className="text-sm font-medium"
+          htmlFor="channel-management-search-users"
+        >
+          Search people
+        </label>
+        <div className="rounded-xl border border-border/80 bg-background">
+          <div className="flex items-center gap-2 px-3 py-2">
+            <Search className="h-4 w-4 text-muted-foreground" />
+            <Input
+              className="h-auto border-0 px-0 py-0 shadow-none focus-visible:ring-0"
+              data-testid="channel-management-search-users"
+              disabled={isPending}
+              id="channel-management-search-users"
+              onChange={(event) => setInviteQuery(event.target.value)}
+              placeholder="Search by name, NIP-05, or pubkey."
+              value={inviteQuery}
+            />
+          </div>
+          {selectedInvitees.length > 0 ? (
+            <div className="flex flex-wrap gap-2 border-t border-border/70 px-3 py-2">
+              {selectedInvitees.map((invitee) => (
+                <div
+                  className="inline-flex items-center gap-2 rounded-full border border-border/80 bg-muted/60 px-3 py-1 text-xs"
+                  data-testid={`selected-invitee-${invitee.pubkey}`}
+                  key={invitee.pubkey}
+                >
+                  <span className="font-medium">
+                    {formatSearchUserName(invitee)}
+                  </span>
+                  <button
+                    aria-label={`Remove ${formatSearchUserName(invitee)}`}
+                    className="text-muted-foreground transition-colors hover:text-foreground"
+                    onClick={() => {
+                      setSelectedInvitees((current) =>
+                        current.filter(
+                          (candidate) => candidate.pubkey !== invitee.pubkey,
+                        ),
+                      );
+                    }}
+                    type="button"
+                  >
+                    <X className="h-3.5 w-3.5" />
+                  </button>
+                </div>
+              ))}
+            </div>
+          ) : null}
+          {deferredInviteQuery.length > 0 ? (
+            <div className="border-t border-border/70 px-2 py-2">
+              {userSearchQuery.isLoading ? (
+                <p className="px-2 py-1 text-sm text-muted-foreground">
+                  Searching…
+                </p>
+              ) : inviteSearchResults.length > 0 ? (
+                <div className="space-y-1">
+                  {inviteSearchResults.map((result) => (
+                    <button
+                      className="flex w-full items-center justify-between rounded-lg px-3 py-2 text-left transition-colors hover:bg-accent hover:text-accent-foreground"
+                      data-testid={`channel-user-search-result-${result.pubkey}`}
+                      key={result.pubkey}
+                      onClick={() => {
+                        setSelectedInvitees((current) => [...current, result]);
+                        setInviteQuery("");
+                      }}
+                      type="button"
+                    >
+                      <div className="min-w-0">
+                        <p className="truncate text-sm font-medium">
+                          {formatSearchUserName(result)}
+                        </p>
+                        <p className="truncate text-xs text-muted-foreground">
+                          {formatSearchUserSecondary(result)}
+                        </p>
+                      </div>
+                      <span className="text-xs text-muted-foreground">Add</span>
+                    </button>
+                  ))}
+                </div>
+              ) : (
+                <p className="px-2 py-1 text-sm text-muted-foreground">
+                  No matching users.
+                </p>
+              )}
+            </div>
+          ) : null}
+        </div>
+        {userSearchQuery.error instanceof Error ? (
+          <p className="text-sm text-destructive">
+            {userSearchQuery.error.message}
+          </p>
+        ) : null}
+      </div>
+      <div className="space-y-1.5">
+        <label
+          className="text-sm font-medium"
+          htmlFor="channel-management-add-pubkeys"
+        >
+          Paste pubkeys
+        </label>
+        <Textarea
+          className="min-h-24"
+          data-testid="channel-management-add-pubkeys"
+          disabled={isPending}
+          id="channel-management-add-pubkeys"
+          onChange={(event) => setInvitePubkeys(event.target.value)}
+          placeholder="Optional: paste one or more pubkeys, separated by spaces, commas, or new lines."
+          value={invitePubkeys}
+        />
+      </div>
+      <div className="flex flex-wrap items-center gap-3">
+        <label
+          className="flex items-center gap-2 text-sm text-muted-foreground"
+          htmlFor="channel-member-role"
+        >
+          Role
+        </label>
+        <select
+          className="h-9 rounded-md border border-input bg-background px-3 text-sm"
+          data-testid="channel-management-add-role"
+          disabled={isPending}
+          id="channel-member-role"
+          onChange={(event) =>
+            setInviteRole(
+              event.target.value as Exclude<ChannelMember["role"], "owner">,
+            )
+          }
+          value={inviteRole}
+        >
+          {["member", "admin", "guest", "bot"].map((role) => (
+            <option key={role} value={role}>
+              {role}
+            </option>
+          ))}
+        </select>
+        <Button
+          data-testid="channel-management-add-members"
+          disabled={isPending || inviteTargets.length === 0}
+          size="sm"
+          type="submit"
+        >
+          {isPending ? "Adding..." : "Add members"}
+        </Button>
+      </div>
+      {requestErrorMessage ? (
+        <p className="text-sm text-destructive">{requestErrorMessage}</p>
+      ) : null}
+      {submissionErrors.length > 0 ? (
+        <div className="space-y-1 text-sm text-destructive">
+          {submissionErrors.map((error) => (
+            <p key={`${error.pubkey}-${error.error}`}>
+              {formatPubkey(error.pubkey)}: {error.error}
+            </p>
+          ))}
+        </div>
+      ) : null}
+    </form>
+  );
+}
diff --git a/desktop/src/features/messages/ui/MessageComposer.tsx b/desktop/src/features/messages/ui/MessageComposer.tsx
index 2e680c853d..39d2d31980 100644
--- a/desktop/src/features/messages/ui/MessageComposer.tsx
+++ b/desktop/src/features/messages/ui/MessageComposer.tsx
@@ -1,4 +1,3 @@
-import { Paperclip, SendHorizontal } from "lucide-react";
 import * as React from "react";
 
 import { useManagedAgentsQuery } from "@/features/agents/hooks";
@@ -10,11 +9,11 @@ import {
 } from "@/shared/api/tauri";
 import { Button } from "@/shared/ui/button";
 import { Textarea } from "@/shared/ui/textarea";
-import { ComposerEmojiPicker } from "./ComposerEmojiPicker";
 import {
   MentionAutocomplete,
   type MentionSuggestion,
 } from "./MentionAutocomplete";
+import { MessageComposerToolbar } from "./MessageComposerToolbar";
 
 type MessageComposerProps = {
   channelId?: string | null;
@@ -223,6 +222,47 @@ export function MessageComposer({
     [content],
   );
 
+  const openMentionPicker = React.useCallback(() => {
+    const textarea = textareaRef.current;
+    if (!textarea) {
+      return;
+    }
+
+    const cursorPosition = textarea.selectionStart ?? content.length;
+    const existingMention = detectMentionQuery(content, cursorPosition);
+    if (existingMention) {
+      pendingSelectionRef.current = cursorPosition;
+      setMentionStartIndex(existingMention.startIndex);
+      setMentionQuery(existingMention.query);
+      setMentionSelectedIndex(0);
+      textarea.focus();
+      return;
+    }
+
+    const { end, start } = draftSelectionRef.current;
+    const nextStart = Math.min(start, content.length);
+    const nextEnd = Math.min(end, content.length);
+    const previousCharacter = content.slice(0, nextStart).slice(-1);
+    const prefix =
+      nextStart > 0 && previousCharacter && !/\s/.test(previousCharacter)
+        ? " @"
+        : "@";
+    const nextContent = `${content.slice(0, nextStart)}${prefix}${content.slice(nextEnd)}`;
+    const mentionIndex = nextStart + (prefix.startsWith(" ") ? 1 : 0);
+    const nextCursor = mentionIndex + 1;
+
+    draftSelectionRef.current = {
+      end: nextCursor,
+      start: nextCursor,
+    };
+    pendingSelectionRef.current = nextCursor;
+    setContent(nextContent);
+    setIsEmojiPickerOpen(false);
+    setMentionStartIndex(mentionIndex);
+    setMentionQuery("");
+    setMentionSelectedIndex(0);
+  }, [content]);
+
   const onUploaded = React.useCallback((descriptor: BlobDescriptor) => {
     const markdown = `\n![image](${descriptor.url})\n`;
     setContent((prev) => prev + markdown);
@@ -582,50 +622,25 @@ export function MessageComposer({
             value={content}
           />
 
-          <div className="mt-4 flex flex-wrap items-center justify-between gap-3">
-            <div className="flex items-center gap-2">
-              <Button
-                disabled={disabled || isUploading}
-                onClick={() => {
-                  void handlePaperclip();
-                }}
-                size="icon"
-                title="Attach image"
-                type="button"
-                variant="ghost"
-              >
-                {isUploading ? (
-                  <span className="h-4 w-4 animate-spin rounded-full border-2 border-current border-t-transparent" />
-                ) : (
-                  <Paperclip className="h-4 w-4" />
-                )}
-              </Button>
-              <ComposerEmojiPicker
-                disabled={disabled}
-                onEmojiSelect={insertEmoji}
-                onOpenChange={setIsEmojiPickerOpen}
-                onTriggerMouseDown={() => {
-                  updateDraftSelection(textareaRef.current);
-                }}
-                open={isEmojiPickerOpen}
-              />
-            </div>
-
-            <Button
-              className="gap-2"
-              data-testid="send-message"
-              disabled={
-                disabled ||
-                isSending ||
-                (content.trim().length === 0 && pendingImeta.length === 0)
-              }
-              title="Send (Enter)"
-              type="submit"
-            >
-              <SendHorizontal className="h-4 w-4" />
-              {isSending ? "Sending" : "Send"}
-            </Button>
-          </div>
+          <MessageComposerToolbar
+            composerDisabled={disabled}
+            isEmojiPickerOpen={isEmojiPickerOpen}
+            isSending={isSending}
+            isUploading={isUploading}
+            onCaptureSelection={() => {
+              updateDraftSelection(textareaRef.current);
+            }}
+            onEmojiPickerOpenChange={setIsEmojiPickerOpen}
+            onEmojiSelect={insertEmoji}
+            onOpenMentionPicker={openMentionPicker}
+            onPaperclip={() => {
+              void handlePaperclip();
+            }}
+            sendDisabled={
+              disabled ||
+              (content.trim().length === 0 && pendingImeta.length === 0)
+            }
+          />
         </form>
       </div>
     </footer>
diff --git a/desktop/src/features/messages/ui/MessageComposerToolbar.tsx b/desktop/src/features/messages/ui/MessageComposerToolbar.tsx
new file mode 100644
index 0000000000..915413debf
--- /dev/null
+++ b/desktop/src/features/messages/ui/MessageComposerToolbar.tsx
@@ -0,0 +1,79 @@
+import { AtSign, Paperclip, SendHorizontal } from "lucide-react";
+
+import { Button } from "@/shared/ui/button";
+import { ComposerEmojiPicker } from "./ComposerEmojiPicker";
+
+export function MessageComposerToolbar({
+  composerDisabled,
+  isEmojiPickerOpen,
+  isSending,
+  isUploading,
+  onCaptureSelection,
+  onEmojiPickerOpenChange,
+  onEmojiSelect,
+  onOpenMentionPicker,
+  onPaperclip,
+  sendDisabled,
+}: {
+  composerDisabled: boolean;
+  isEmojiPickerOpen: boolean;
+  isSending: boolean;
+  isUploading: boolean;
+  onCaptureSelection: () => void;
+  onEmojiPickerOpenChange: (open: boolean) => void;
+  onEmojiSelect: (emoji: string) => void;
+  onOpenMentionPicker: () => void;
+  onPaperclip: () => void;
+  sendDisabled: boolean;
+}) {
+  return (
+    <div className="mt-4 flex flex-wrap items-center justify-between gap-3">
+      <div className="flex items-center gap-2">
+        <Button
+          data-testid="message-insert-mention"
+          disabled={composerDisabled}
+          onClick={onOpenMentionPicker}
+          onMouseDown={onCaptureSelection}
+          size="icon"
+          title="Mention someone"
+          type="button"
+          variant="ghost"
+        >
+          <AtSign className="h-4 w-4" />
+        </Button>
+        <Button
+          disabled={composerDisabled || isUploading}
+          onClick={onPaperclip}
+          size="icon"
+          title="Attach image"
+          type="button"
+          variant="ghost"
+        >
+          {isUploading ? (
+            <span className="h-4 w-4 animate-spin rounded-full border-2 border-current border-t-transparent" />
+          ) : (
+            <Paperclip className="h-4 w-4" />
+          )}
+        </Button>
+        <ComposerEmojiPicker
+          disabled={composerDisabled}
+          onEmojiSelect={onEmojiSelect}
+          onOpenChange={onEmojiPickerOpenChange}
+          onTriggerMouseDown={onCaptureSelection}
+          open={isEmojiPickerOpen}
+        />
+      </div>
+
+      <Button
+        className="gap-2"
+        data-testid="send-message"
+        disabled={sendDisabled || isSending}
+        title="Send (Enter)"
+        type="submit"
+      >
+        <SendHorizontal className="h-4 w-4" />
+        {isSending ? "Sending" : "Send"}
+      </Button>
+    </div>
+  );
+}
diff --git a/desktop/src/features/messages/ui/MessageRow.tsx b/desktop/src/features/messages/ui/MessageRow.tsx
index d700b5e1f1..cfed645a5f 100644
--- a/desktop/src/features/messages/ui/MessageRow.tsx
+++ b/desktop/src/features/messages/ui/MessageRow.tsx
@@ -115,14 +115,14 @@ export function MessageRow({
       {message.depth > 0 ? (
         <div
           aria-hidden
-          className="absolute bottom-2 left-3 top-2 rounded-full border-l border-border/70"
+          className="absolute bottom-1.5 left-3 top-1.5 rounded-full border-l border-border/70"
           style={{ left: `${Math.max(indentPx - 14, 12)}px` }}
         />
       ) : null}
 
       <article
         className={cn(
-          "group/message flex gap-3 rounded-2xl px-2 py-1.5 transition-colors",
+          "group/message flex gap-2.5 rounded-2xl px-2 py-1 transition-colors",
           message.highlighted ? "bg-primary/10 ring-1 ring-primary/30" : "",
           activeReplyTargetId === message.id
             ? "bg-muted/60 ring-1 ring-border"
@@ -140,7 +140,7 @@ export function MessageRow({
               {message.avatarUrl && !hasAvatarError ? (
                 <img
                   alt={`${message.author} avatar`}
-                  className="h-9 w-9 rounded-xl object-cover shadow-sm"
+                  className="h-8 w-8 rounded-lg object-cover shadow-sm"
                   data-testid="message-avatar-image"
                   onError={() => {
                     setHasAvatarError(true);
@@ -151,7 +151,7 @@ export function MessageRow({
               ) : (
                 <div
                   className={cn(
-                    "flex h-9 w-9 items-center justify-center rounded-xl text-xs font-semibold shadow-sm",
+                    "flex h-8 w-8 items-center justify-center rounded-lg text-[11px] font-semibold shadow-sm",
                     message.accent
                       ? "bg-primary text-primary-foreground"
                       : "bg-secondary text-secondary-foreground",
@@ -166,7 +166,7 @@ export function MessageRow({
         ) : message.avatarUrl && !hasAvatarError ? (
           <img
             alt={`${message.author} avatar`}
-            className="h-9 w-9 shrink-0 rounded-xl object-cover shadow-sm"
+            className="h-8 w-8 shrink-0 rounded-lg object-cover shadow-sm"
             data-testid="message-avatar-image"
             onError={() => {
               setHasAvatarError(true);
@@ -177,7 +177,7 @@ export function MessageRow({
         ) : (
           <div
             className={cn(
-              "flex h-9 w-9 shrink-0 items-center justify-center rounded-xl text-xs font-semibold shadow-sm",
+              "flex h-8 w-8 shrink-0 items-center justify-center rounded-lg text-[11px] font-semibold shadow-sm",
               message.accent
                 ? "bg-primary text-primary-foreground"
                 : "bg-secondary text-secondary-foreground",
@@ -188,8 +188,8 @@ export function MessageRow({
           </div>
         )}
 
-        <div className="min-w-0 flex-1 space-y-0">
-          <div className="flex min-w-0 flex-wrap items-center gap-2">
+        <div className="min-w-0 flex-1 space-y-0.5">
+          <div className="flex min-w-0 flex-wrap items-center gap-x-2 gap-y-1">
             {message.pubkey ? (
               <UserProfilePopover pubkey={message.pubkey}>
                 <button
@@ -231,13 +231,13 @@ export function MessageRow({
           </div>
           {renderBody()}
           {reactions.length > 0 ? (
-            <div className="mt-2 flex flex-wrap items-center gap-2">
+            <div className="mt-1.5 flex flex-wrap items-center gap-1.5">
               {reactions.map((reaction: TimelineReaction) => (
                 <button
                   aria-label={`Toggle ${reaction.emoji} reaction`}
                   aria-pressed={reaction.reactedByCurrentUser}
                   className={cn(
-                    "inline-flex items-center gap-1 rounded-full border px-2.5 py-1 text-xs font-medium transition-colors",
+                    "inline-flex items-center gap-1 rounded-full border px-2 py-0.5 text-xs font-medium transition-colors",
                     reaction.reactedByCurrentUser
                       ? "border-primary/40 bg-primary/10 text-primary"
                       : "border-border/70 bg-muted/70 text-foreground/90",
@@ -267,14 +267,14 @@ export function MessageRow({
             </div>
           ) : null}
           {reactionErrorMessage ? (
-            <p className="mt-2 text-xs text-destructive">
+            <p className="mt-1.5 text-xs text-destructive">
               {reactionErrorMessage}
             </p>
           ) : null}
           {expandedDiffId === message.id ? (
             <React.Suspense
               fallback={
-                <div className="p-4 text-sm text-muted-foreground">
+                <div className="p-3 text-sm text-muted-foreground">
                   Loading diff viewer…
                 </div>
               }
diff --git a/desktop/src/features/messages/ui/MessageTimeline.tsx b/desktop/src/features/messages/ui/MessageTimeline.tsx
index 934826731c..e7f0c8448a 100644
--- a/desktop/src/features/messages/ui/MessageTimeline.tsx
+++ b/desktop/src/features/messages/ui/MessageTimeline.tsx
@@ -60,17 +60,17 @@ export function MessageTimeline({
   return (
     <div className="relative min-h-0 flex-1">
       <div
-        className="h-full overflow-y-auto overflow-x-hidden overscroll-contain px-4 py-4 [overflow-anchor:none] sm:px-6"
+        className="h-full overflow-y-auto overflow-x-hidden overscroll-contain px-4 py-3 [overflow-anchor:none] sm:px-6"
         data-testid="message-timeline"
         onScroll={syncScrollState}
         ref={timelineRef}
       >
         <div
-          className="mx-auto flex w-full max-w-4xl flex-col gap-3"
+          className="mx-auto flex w-full max-w-4xl flex-col gap-2"
           ref={contentRef}
         >
           <div
-            className="flex items-center gap-4"
+            className="flex items-center gap-3"
             data-testid="message-timeline-day-divider"
           >
             <Separator className="flex-1" />
diff --git a/desktop/src/features/messages/ui/SystemMessageRow.tsx b/desktop/src/features/messages/ui/SystemMessageRow.tsx
index 30019331b1..eda1ce45cc 100644
--- a/desktop/src/features/messages/ui/SystemMessageRow.tsx
+++ b/desktop/src/features/messages/ui/SystemMessageRow.tsx
@@ -80,10 +80,10 @@ export function SystemMessageRow({
 
   return (
     <div
-      className="flex items-center gap-3 px-2 py-1.5"
+      className="flex items-center gap-2.5 px-2 py-1"
       data-testid="system-message-row"
     >
-      <div className="flex h-5 w-5 shrink-0 items-center justify-center rounded-full bg-muted">
+      <div className="flex h-4 w-4 shrink-0 items-center justify-center rounded-full bg-muted">
         <ArrowRightLeft className="h-3 w-3 text-muted-foreground" />
       </div>
       <p className="text-xs text-muted-foreground">{description}</p>
diff --git a/desktop/src/features/messages/ui/TimelineSkeleton.tsx b/desktop/src/features/messages/ui/TimelineSkeleton.tsx
index d2aac09aff..f1132a2f60 100644
--- a/desktop/src/features/messages/ui/TimelineSkeleton.tsx
+++ b/desktop/src/features/messages/ui/TimelineSkeleton.tsx
@@ -6,9 +6,9 @@ export function TimelineSkeleton() {
   return (
     <>
       {skeletonRows.map((row) => (
-        <div className="flex gap-3" key={row}>
-          <Skeleton className="h-9 w-9 rounded-xl" />
-          <div className="min-w-0 flex-1 space-y-1.5">
+        <div className="flex gap-2.5" key={row}>
+          <Skeleton className="h-8 w-8 rounded-lg" />
+          <div className="min-w-0 flex-1 space-y-1">
             <Skeleton className="h-3.5 w-44" />
             <Skeleton className="h-4 w-full max-w-2xl" />
             <Skeleton className="h-4 w-full max-w-xl" />
diff --git a/desktop/src/features/profile/hooks.ts b/desktop/src/features/profile/hooks.ts
index ed47fb2d33..95f8451678 100644
--- a/desktop/src/features/profile/hooks.ts
+++ b/desktop/src/features/profile/hooks.ts
@@ -2,6 +2,7 @@ import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
 
 import {
   getProfile,
+  searchUsers,
   getUserProfile,
   getUsersBatch,
   updateProfile,
@@ -9,6 +10,7 @@ import {
 import type {
   Profile,
   UpdateProfileInput,
+  UserSearchResult,
   UsersBatchResponse,
 } from "@/shared/api/types";
 
@@ -54,6 +56,25 @@ export function useUsersBatchQuery(
   });
 }
 
+export function useUserSearchQuery(
+  query: string,
+  options?: {
+    enabled?: boolean;
+    limit?: number;
+  },
+) {
+  const normalizedQuery = query.trim().toLowerCase();
+  const enabled = (options?.enabled ?? true) && normalizedQuery.length > 0;
+
+  return useQuery<UserSearchResult[]>({
+    enabled,
+    queryKey: ["user-search", normalizedQuery, options?.limit ?? 8],
+    queryFn: () => searchUsers(normalizedQuery, options?.limit ?? 8),
+    staleTime: 30_000,
+    gcTime: 5 * 60 * 1_000,
+  });
+}
+
 export function useUpdateProfileMutation() {
   const queryClient = useQueryClient();
 
diff --git a/desktop/src/shared/api/tauri.ts b/desktop/src/shared/api/tauri.ts
index 928259324e..856b355e1b 100644
--- a/desktop/src/shared/api/tauri.ts
+++ b/desktop/src/shared/api/tauri.ts
@@ -33,6 +33,7 @@ import type {
   UpdateProfileInput,
   UpdateChannelInput,
   UserProfileSummary,
+  UserSearchResult,
   UsersBatchResponse,
   CreateManagedAgentInput,
   CreateManagedAgentResponse,
@@ -65,6 +66,17 @@ type RawUsersBatchResponse = {
   missing: string[];
 };
 
+type RawUserSearchResult = {
+  pubkey: string;
+  display_name: string | null;
+  avatar_url: string | null;
+  nip05_handle: string | null;
+};
+
+type RawSearchUsersResponse = {
+  users: RawUserSearchResult[];
+};
+
 type RawPresenceLookup = Record<string, PresenceStatus>;
 
 type RawSetPresenceResult = {
@@ -392,6 +404,15 @@ function fromRawUserProfileSummary(
   };
 }
 
+function fromRawUserSearchResult(user: RawUserSearchResult): UserSearchResult {
+  return {
+    pubkey: user.pubkey,
+    displayName: user.display_name,
+    avatarUrl: user.avatar_url,
+    nip05Handle: user.nip05_handle,
+  };
+}
+
 export async function getIdentity(): Promise<Identity> {
   const identity = await invokeTauri<RawIdentity>("get_identity");
 
@@ -436,6 +457,17 @@ export async function getUsersBatch(
   };
 }
 
+export async function searchUsers(
+  query: string,
+  limit = 8,
+): Promise<UserSearchResult[]> {
+  const response = await invokeTauri<RawSearchUsersResponse>("search_users", {
+    query,
+    limit,
+  });
+  return response.users.map(fromRawUserSearchResult);
+}
+
 export async function getPresence(pubkeys: string[]): Promise<PresenceLookup> {
   const response = await invokeTauri<RawPresenceLookup>("get_presence", {
     pubkeys,
diff --git a/desktop/src/shared/api/types.ts b/desktop/src/shared/api/types.ts
index e4b0987152..89991131a7 100644
--- a/desktop/src/shared/api/types.ts
+++ b/desktop/src/shared/api/types.ts
@@ -99,6 +99,13 @@ export type UsersBatchResponse = {
   missing: string[];
 };
 
+export type UserSearchResult = {
+  pubkey: string;
+  displayName: string | null;
+  avatarUrl: string | null;
+  nip05Handle: string | null;
+};
+
 export type UpdateProfileInput = {
   displayName?: string;
   avatarUrl?: string;
diff --git a/desktop/src/shared/ui/markdown.tsx b/desktop/src/shared/ui/markdown.tsx
index a155c80b30..649719bd62 100644
--- a/desktop/src/shared/ui/markdown.tsx
+++ b/desktop/src/shared/ui/markdown.tsx
@@ -13,121 +13,134 @@ type MarkdownProps = {
   tight?: boolean;
 };
 
-const markdownComponents: Components = {
-  a: ({ children, href, ...props }) => (
-    <a
-      {...props}
-      className="font-medium text-primary underline underline-offset-4 transition-colors hover:text-primary/80"
-      href={href}
-      rel="noreferrer"
-      target="_blank"
-    >
-      {children}
-    </a>
-  ),
-  blockquote: ({ children }) => (
-    <blockquote className="border-l-2 border-border pl-4 italic text-muted-foreground">
-      {children}
-    </blockquote>
-  ),
-  br: () => <br />,
-  code: ({
-    children,
-    className,
-    ...props
-  }: React.ComponentProps<"code"> & { inline?: boolean }) => {
-    const code = String(children).replace(/\n$/, "");
-    const isBlock =
-      typeof className === "string" && className.includes("language-")
-        ? true
-        : code.includes("\n");
+type MarkdownVariant = "default" | "compact" | "tight";
+
+function createMarkdownComponents(variant: MarkdownVariant): Components {
+  const paragraphClassName =
+    variant === "tight"
+      ? "leading-5"
+      : variant === "compact"
+        ? "leading-6"
+        : "leading-7";
+  const listItemClassName =
+    variant === "tight" ? "my-0.5 [&_p]:inline" : "my-1 [&_p]:inline";
+  const listClassName =
+    variant === "tight"
+      ? "space-y-0.5 pl-6 marker:text-muted-foreground"
+      : "space-y-1 pl-6 marker:text-muted-foreground";
+
+  return {
+    a: ({ children, href, ...props }) => (
+      <a
+        {...props}
+        className="font-medium text-primary underline underline-offset-4 transition-colors hover:text-primary/80"
+        href={href}
+        rel="noreferrer"
+        target="_blank"
+      >
+        {children}
+      </a>
+    ),
+    blockquote: ({ children }) => (
+      <blockquote className="border-l-2 border-border pl-4 italic text-muted-foreground">
+        {children}
+      </blockquote>
+    ),
+    br: () => <br />,
+    code: ({
+      children,
+      className,
+      ...props
+    }: React.ComponentProps<"code"> & { inline?: boolean }) => {
+      const code = String(children).replace(/\n$/, "");
+      const isBlock =
+        typeof className === "string" && className.includes("language-")
+          ? true
+          : code.includes("\n");
+
+      if (isBlock) {
+        return (
+          <code
+            {...props}
+            className={cn(
+              "block min-w-full whitespace-pre font-mono text-[13px] leading-6 text-foreground",
+              className,
+            )}
+          >
+            {code}
+          </code>
+        );
+      }
 
-    if (isBlock) {
       return (
         <code
           {...props}
           className={cn(
-            "block min-w-full whitespace-pre font-mono text-[13px] leading-6 text-foreground",
+            "rounded-md bg-muted px-1.5 py-0.5 font-mono text-[13px] text-foreground",
             className,
           )}
         >
-          {code}
+          {children}
         </code>
       );
-    }
-
-    return (
-      <code
-        {...props}
-        className={cn(
-          "rounded-md bg-muted px-1.5 py-0.5 font-mono text-[13px] text-foreground",
-          className,
-        )}
-      >
+    },
+    h1: ({ children }) => (
+      <h1 className="text-lg font-semibold tracking-tight">{children}</h1>
+    ),
+    h2: ({ children }) => (
+      <h2 className="text-base font-semibold tracking-tight">{children}</h2>
+    ),
+    h3: ({ children }) => (
+      <h3 className="font-semibold tracking-tight">{children}</h3>
+    ),
+    hr: () => <hr className="border-border/80" />,
+    img: ({ alt, src }) => (
+      <img
+        alt={alt}
+        className="max-h-96 rounded-2xl border border-border/70 object-cover"
+        src={src}
+      />
+    ),
+    li: ({ children }) => <li className={listItemClassName}>{children}</li>,
+    ol: ({ children }) => (
+      <ol className={cn("list-decimal", listClassName)}>{children}</ol>
+    ),
+    p: ({ children }) => <p className={paragraphClassName}>{children}</p>,
+    pre: ({ children }) => (
+      <pre className="overflow-x-auto rounded-2xl border border-border/70 bg-muted/60 px-4 py-3 shadow-sm">
         {children}
-      </code>
-    );
-  },
-  h1: ({ children }) => (
-    <h1 className="text-lg font-semibold tracking-tight">{children}</h1>
-  ),
-  h2: ({ children }) => (
-    <h2 className="text-base font-semibold tracking-tight">{children}</h2>
-  ),
-  h3: ({ children }) => (
-    <h3 className="font-semibold tracking-tight">{children}</h3>
-  ),
-  hr: () => <hr className="border-border/80" />,
-  img: ({ alt, src }) => (
-    <img
-      alt={alt}
-      className="max-h-96 rounded-2xl border border-border/70 object-cover"
-      src={src}
-    />
-  ),
-  li: ({ children }) => <li className="my-1 [&_p]:inline">{children}</li>,
-  ol: ({ children }) => (
-    <ol className="list-decimal space-y-1 pl-6 marker:text-muted-foreground">
-      {children}
-    </ol>
-  ),
-  p: ({ children }) => <p className="leading-7">{children}</p>,
-  pre: ({ children }) => (
-    <pre className="overflow-x-auto rounded-2xl border border-border/70 bg-muted/60 px-4 py-3 shadow-sm">
-      {children}
-    </pre>
-  ),
-  strong: ({ children }) => (
-    <strong className="font-semibold">{children}</strong>
-  ),
-  table: ({ children }) => (
-    <div className="overflow-x-auto rounded-2xl border border-border/70">
-      <table className="w-full border-collapse text-left text-sm">
+      </pre>
+    ),
+    strong: ({ children }) => (
+      <strong className="font-semibold">{children}</strong>
+    ),
+    table: ({ children }) => (
+      <div className="overflow-x-auto rounded-2xl border border-border/70">
+        <table className="w-full border-collapse text-left text-sm">
+          {children}
+        </table>
+      </div>
+    ),
+    td: ({ children }) => (
+      <td className="border-t border-border/70 px-3 py-2 align-top">
         {children}
-      </table>
-    </div>
-  ),
-  td: ({ children }) => (
-    <td className="border-t border-border/70 px-3 py-2 align-top">
-      {children}
-    </td>
-  ),
-  th: ({ children }) => (
-    <th className="bg-muted/60 px-3 py-2 font-semibold text-foreground">
-      {children}
-    </th>
-  ),
-  ul: ({ children }) => (
-    <ul className="list-disc space-y-1 pl-6 marker:text-muted-foreground">
-      {children}
-    </ul>
-  ),
-  mention: ({ children }: { children?: React.ReactNode }) => (
-    <span className="rounded-md bg-primary/15 px-1 py-0.5 text-sm font-medium text-primary">
-      {children}
-    </span>
-  ),
-} as Components;
+      </td>
+    ),
+    th: ({ children }) => (
+      <th className="bg-muted/60 px-3 py-2 font-semibold text-foreground">
+        {children}
+      </th>
+    ),
+    ul: ({ children }) => (
+      <ul className={cn("list-disc", listClassName)}>{children}</ul>
+    ),
+    mention: ({ children }: { children?: React.ReactNode }) => (
+      <span className="rounded-md bg-primary/15 px-1 py-0.5 text-sm font-medium text-primary">
+        {children}
+      </span>
+    ),
+  } as Components;
+}
 
 export function Markdown({
   className,
@@ -135,6 +148,7 @@ export function Markdown({
   content,
   tight = false,
 }: MarkdownProps) {
+  const variant = tight ? "tight" : compact ? "compact" : "default";
   let processedContent = content;
 
   if (/^(?:\s{2}\n)+/.test(content)) {
@@ -157,7 +171,7 @@ export function Markdown({
       )}
     >
       <ReactMarkdown
-        components={markdownComponents}
+        components={createMarkdownComponents(variant)}
         remarkPlugins={[remarkGfm, remarkBreaks, remarkMentions]}
       >
         {processedContent}
diff --git a/desktop/src/testing/e2eBridge.ts b/desktop/src/testing/e2eBridge.ts
index 53aa1c44e5..97ed222ea1 100644
--- a/desktop/src/testing/e2eBridge.ts
+++ b/desktop/src/testing/e2eBridge.ts
@@ -52,6 +52,17 @@ type RawUsersBatchResponse = {
   missing: string[];
 };
 
+type RawUserSearchResult = {
+  pubkey: string;
+  display_name: string | null;
+  avatar_url: string | null;
+  nip05_handle: string | null;
+};
+
+type RawSearchUsersResponse = {
+  users: RawUserSearchResult[];
+};
+
 type PresenceStatus = "online" | "away" | "offline";
 
 type RawPresenceLookup = Record<string, PresenceStatus>;
@@ -526,6 +537,18 @@ function getMockProfileByPubkey(pubkey: string): RawProfile | null {
   };
 }
 
+function listMockProfiles(): RawProfile[] {
+  const pubkeys = new Set<string>([
+    ...mockProfiles.keys(),
+    ...mockDisplayNames.keys(),
+    DEFAULT_REAL_IDENTITY.pubkey,
+  ]);
+
+  return [...pubkeys]
+    .map((pubkey) => getMockProfileByPubkey(pubkey))
+    .filter((profile): profile is RawProfile => profile !== null);
+}
+
 function listMockChannels(): RawChannelWithMembership[] {
   return mockChannels.map(toRawChannel);
 }
@@ -1311,6 +1334,59 @@ async function handleGetUsersBatch(
   });
 }
 
+async function handleSearchUsers(
+  args: {
+    query: string;
+    limit?: number;
+  },
+  config: E2eConfig | undefined,
+) {
+  const identity = getIdentity(config);
+  if (!identity) {
+    const normalizedQuery = args.query.trim().toLowerCase();
+    if (normalizedQuery.length === 0) {
+      return { users: [] } satisfies RawSearchUsersResponse;
+    }
+
+    const results = listMockProfiles()
+      .filter((profile) => {
+        const displayName = profile.display_name?.toLowerCase() ?? "";
+        const nip05Handle = profile.nip05_handle?.toLowerCase() ?? "";
+        const pubkey = profile.pubkey.toLowerCase();
+        return (
+          displayName.includes(normalizedQuery) ||
+          nip05Handle.includes(normalizedQuery) ||
+          pubkey.includes(normalizedQuery)
+        );
+      })
+      .sort((left, right) => {
+        const leftName = left.display_name ?? left.nip05_handle ?? left.pubkey;
+        const rightName =
+          right.display_name ?? right.nip05_handle ?? right.pubkey;
+        return leftName.localeCompare(rightName);
+      })
+      .slice(0, args.limit ?? 8)
+      .map((profile) => ({
+        pubkey: profile.pubkey,
+        display_name: profile.display_name,
+        avatar_url: profile.avatar_url,
+        nip05_handle: profile.nip05_handle,
+      }));
+
+    return {
+      users: results,
+    } satisfies RawSearchUsersResponse;
+  }
+
+  const searchParams = new URLSearchParams();
+  searchParams.set("q", args.query);
+  searchParams.set("limit", String(args.limit ?? 8));
+  return relayJsonRequest<RawSearchUsersResponse>(
+    config,
+    `/api/users/search?${searchParams.toString()}`,
+  );
+}
+
 async function handleGetPresence(
   args: {
     pubkeys: string[];
@@ -2671,6 +2747,11 @@ export function maybeInstallE2eTauriMocks() {
           payload as Parameters<typeof handleGetUsersBatch>[0],
           activeConfig,
         );
+      case "search_users":
+        return handleSearchUsers(
+          payload as Parameters<typeof handleSearchUsers>[0],
+          activeConfig,
+        );
       case "get_presence":
         return handleGetPresence(
           (payload as Parameters<typeof handleGetPresence>[0]) ?? {
diff --git a/desktop/tests/e2e/channels.spec.ts b/desktop/tests/e2e/channels.spec.ts
index 6b90284e8e..70e850e65c 100644
--- a/desktop/tests/e2e/channels.spec.ts
+++ b/desktop/tests/e2e/channels.spec.ts
@@ -253,13 +253,26 @@ test("manage channel can invite and remove members", async ({ page }) => {
   await page.goto("/");
   await openChannelManagement(page, "general");
 
+  await page.getByTestId("channel-management-search-users").fill("char");
+  await expect(
+    page.getByTestId(
+      `channel-user-search-result-${TEST_IDENTITIES.charlie.pubkey}`,
+    ),
+  ).toBeVisible();
   await page
-    .getByTestId("channel-management-add-pubkeys")
-    .fill(TEST_IDENTITIES.charlie.pubkey);
+    .getByTestId(`channel-user-search-result-${TEST_IDENTITIES.charlie.pubkey}`)
+    .click();
+  await expect(
+    page.getByTestId(`selected-invitee-${TEST_IDENTITIES.charlie.pubkey}`),
+  ).toContainText("charlie");
+
   await page.getByTestId("channel-management-add-role").selectOption("admin");
   await page.getByTestId("channel-management-add-members").click();
 
-  await expect(page.getByTestId("channel-management-add-pubkeys")).toHaveValue(
+  await expect(
+    page.getByTestId(`selected-invitee-${TEST_IDENTITIES.charlie.pubkey}`),
+  ).toHaveCount(0);
+  await expect(page.getByTestId("channel-management-search-users")).toHaveValue(
     "",
   );
   await expect(
diff --git a/desktop/tests/e2e/mentions.spec.ts b/desktop/tests/e2e/mentions.spec.ts
index a0e7e4c2d4..4a0dd3b1ac 100644
--- a/desktop/tests/e2e/mentions.spec.ts
+++ b/desktop/tests/e2e/mentions.spec.ts
@@ -56,6 +56,24 @@ test("selecting a mention inserts @Name into input", async ({ page }) => {
   await expect(input).toHaveValue("Hey @alice ");
 });
 
+test("mention button opens autocomplete and inserts a selected member", async ({
+  page,
+}) => {
+  await page.goto("/");
+  await page.getByTestId("channel-general").click();
+  await expect(page.getByTestId("chat-title")).toHaveText("general");
+
+  const input = page.getByTestId("message-input");
+  await input.fill("Hey ");
+  await page.getByTestId("message-insert-mention").click();
+
+  const dropdown = autocomplete(page);
+  await expect(dropdown).toBeVisible();
+  await dropdown.getByText("alice").click();
+
+  await expect(input).toHaveValue("Hey @alice ");
+});
+
 test("keyboard navigation selects mention with Enter", async ({ page }) => {
   await page.goto("/");
   await page.getByTestId("channel-general").click();