diff --git a/src/bundled/mentions/session-agents.test.tsx b/src/bundled/mentions/session-agents.test.tsx
index 6eef6dc01..b047eecae 100644
--- a/src/bundled/mentions/session-agents.test.tsx
+++ b/src/bundled/mentions/session-agents.test.tsx
@@ -42,6 +42,7 @@ import { createMessages } from "../../features/relay/messages";
 import type { Outbox } from "../../features/relay/outbox";
 import { MessageMarkdown } from "../../features/messages/MessageMarkdown";
 import { profileTarget } from "../../features/profiles/target";
+import { npubEncode } from "nostr-tools/nip19";
 afterEach(() => {
   cleanup();
   vi.useRealTimers();
@@ -110,6 +111,7 @@ function setup(parent: boolean | null = true, archived = false) {
       subscribe: () => () => {},
       snapshot: () => 0,
       resolve: (_key: string, fallback: string) => fallback,
+      scope: () => () => undefined,
     },
     agentLibrary: library.queries,
     agentChoices: createAgentChoices({
@@ -1632,6 +1634,10 @@ it("uses base matches and visible lexical ties for Fizz in both chooser surfaces
     names: {
       ...names,
       resolve: (key: string) => rows.find((row) => row.key === key)?.label,
+      scope: () => (key: string) => {
+        const name = rows.find((row) => row.key === key)?.label;
+        return name ? { name, source: "agent-directory" as const } : undefined;
+      },
     },
   } satisfies RelaySession;
   const expected = [rows[5], rows[4], rows[1], rows[2], rows[3], rows[0]].map(
@@ -1887,3 +1893,81 @@ it("the persistent toolbar picker reads an empty search again after close and re
   );
   t.library.dispose();
 });
+
+it("names the choice set only while the picker is shown, and qualifies namesakes in both menus", async () => {
+  const t = setup();
+  const member = "a".repeat(64),
+    namesake = "c".repeat(64);
+  const profiles = new Map([
+    [member, { name: "Larry" }],
+    [namesake, { name: "Larry" }],
+  ]);
+  const list = {
+    status: "ready" as const,
+    channels: [
+      {
+        id: "parent",
+        name: "Parent",
+        channelType: "stream" as const,
+        members: [member, namesake],
+      },
+    ],
+  };
+  const session = {
+    ...t.session,
+    profiles: { ...t.session.profiles, snapshot: () => profiles },
+    channels: { ...t.session.channels, list: () => list },
+  };
+  const names = bindNames(
+    { profiles: session.profiles, agentLibrary: t.library.queries },
+    { snapshot: () => [createAgentDirectory()], subscribe: () => () => {} },
+  );
+  const scope = vi.spyOn(names, "scope");
+  const labels = [member, namesake].map(
+    (key) => `Larry · ${npubEncode(key).slice(-4)}`,
+  );
+  const picker = (disabled: boolean) => (
+    <MentionPicker
+      scope="test"
+      session={{ ...session, names }}
+      channelId="parent"
+      disabled={disabled}
+      select={() => true}
+    />
+  );
+  const view = render(picker(false));
+  view.rerender(picker(false));
+  expect(scope).not.toHaveBeenCalled();
+  await userEvent
+    .setup()
+    .click(screen.getByRole("button", { name: "Mention a member" }));
+  for (const [index, key] of [member, namesake].entries())
+    expect(
+      await screen.findByRole("button", { name: `${labels[index]} ${key}` }),
+    ).toBeInTheDocument();
+  view.rerender(picker(true));
+  scope.mockClear();
+  view.rerender(picker(true));
+  expect(scope).not.toHaveBeenCalled();
+  view.unmount();
+  const publish = vi.fn();
+  render(
+    <MentionCompletion
+      session={{ ...session, names }}
+      scope="test"
+      channelId="parent"
+      observation={{ revision: 1, text: "@Larry", start: 6, end: 6 }}
+      query={{ start: 0, end: 6, query: "Larry" }}
+      publish={publish}
+    />,
+  );
+  await waitFor(() =>
+    expect(
+      (publish.mock.lastCall?.[0] as CompletionResult | undefined)?.items
+        .map((item) => item.label)
+        .sort(),
+    ).toEqual([...labels].sort()),
+  );
+  names.dispose();
+  t.library.dispose();
+});
diff --git a/src/bundled/mentions/use-mention-choices.ts b/src/bundled/mentions/use-mention-choices.ts
index 82ae33ef1..ac250ff5e 100644
--- a/src/bundled/mentions/use-mention-choices.ts
+++ b/src/bundled/mentions/use-mention-choices.ts
@@ -94,9 +94,10 @@ export function useMentionChoices(
     ];
     // Directory pages are menu-local, not cached profiles. Name them only when no
     // other source knows the key, so namesakes in this choice set are qualified.
+    const known = session.names?.scope();
     const facts = [
       ...people
-        .filter((person) => !session.names?.resolve(person.pubkey))
+        .filter((person) => !known?.(person.pubkey))
         .map(({ pubkey, name, isAgent }) => ({
           pubkey,
           name,
@@ -104,15 +105,11 @@ export function useMentionChoices(
         })),
       ...selected,
     ];
+    // One naming scope per choice set, not one normalization per row.
+    const name = session.names?.scope(keys, facts);
     return candidates.map((choice) => ({
       ...choice,
-      label:
-        session.names?.resolve(
-          choice.recipient.pubkey,
-          choice.recipient.name,
-          keys,
-          facts,
-        ) ?? choice.recipient.name,
+      label: name?.(choice.recipient.pubkey)?.name ?? choice.recipient.name,
     }));
   }, [session, channelId, invite, roster, selected, people]);
   const { candidates, local } = useMemo(() => {
@@ -122,6 +119,8 @@ export function useMentionChoices(
     void agents;
     void archives;
     void resolve;
+    // A closed or disabled chooser shows nothing, so it names nothing.
+    if (!open) return { candidates: [], local: new Set<string>() };
     return {
       candidates: current(),
       // Keys known without the directory search: members and agent choices.
@@ -132,6 +131,7 @@ export function useMentionChoices(
       ),
     };
   }, [
+    open,
     current,
     session,
     channelId,
diff --git a/src/bundled/profiles/ProfilePanel.test.tsx b/src/bundled/profiles/ProfilePanel.test.tsx
index 9a7384cc1..b1a1acc94 100644
--- a/src/bundled/profiles/ProfilePanel.test.tsx
+++ b/src/bundled/profiles/ProfilePanel.test.tsx
@@ -31,7 +31,7 @@ it("updates a mounted profile from the shared name view without replacing its id
               activate() {
                 return undefined;
               },
-              resolve: () => name,
+              scope: () => () => ({ name }),
             },
           ],
           subscribe(listener) {
diff --git a/src/features/identity-names/directory.test.ts b/src/features/identity-names/directory.test.ts
index 8ec9e2533..a2dd07f77 100644
--- a/src/features/identity-names/directory.test.ts
+++ b/src/features/identity-names/directory.test.ts
@@ -2,7 +2,12 @@ import { expect, it, vi } from "vitest";
 import type { AgentControlState, AgentView } from "../agents/control";
 import { bindNames, type NameSource } from "./service";
 import { npubEncode } from "nostr-tools/nip19";
-import { agentDirectory, createAgentDirectory } from "./testing";
+import {
+  agentDirectory,
+  createAgentDirectory,
+  defaultNamingPolicy,
+} from "./testing";
+import { createNameProvider } from "./directory";
 
 it("scopes native names to the session community and follows edits and disposal", () => {
   const key = "a".repeat(64);
@@ -67,11 +72,12 @@ it("scopes native names to the session community and follows edits and disposal"
   for (const listener of listeners) listener();
   expect(changed).toHaveBeenCalledOnce();
   expect(names.resolve(key)).toBe("Edited");
-  expect(provider.resolve({ ...source, relayUrl: undefined }, key)).toBe(
+  expect(provider.scope({ ...source, relayUrl: undefined })(key)?.name).toBe(
     "Legacy",
   );
   expect(
-    provider.resolve({ ...source, relayUrl: "https://unrelated.example" }, key),
+    provider.scope({ ...source, relayUrl: "https://unrelated.example" })(key)
+      ?.name,
   ).toBe("Legacy");
   state = { ...state, status: "error" };
   expect(names.resolve(key)).toBe("Legacy");
@@ -109,14 +115,14 @@ it("suffixes equal names across profiles, without merging keys or suffixing uniq
     },
   };
   for (const key of [a, b, c, d]) {
-    expect(agentDirectory.resolve(source, key)).toBe(
+    expect(agentDirectory.scope(source)(key)?.name).toBe(
       `Bad Janet · ${npubEncode(key).slice(-4)}`,
     );
   }
-  expect(agentDirectory.resolve(source, e)).toBe("Larry");
+  expect(agentDirectory.scope(source)(e)?.name).toBe("Larry");
   library = { ...library, identities: identities.slice(0, 2) };
-  expect(agentDirectory.resolve(source, a)).toBe("Bad Janet");
-  expect(agentDirectory.resolve(source, b)).toBeUndefined();
+  expect(agentDirectory.scope(source)(a)?.name).toBe("Bad Janet");
+  expect(agentDirectory.scope(source)(b)?.name).toBeUndefined();
 });
 
 it("recomputes collisions for native edits, community scope, and profile fallbacks", () => {
@@ -183,7 +189,7 @@ it("recomputes collisions for native edits, community scope, and profile fallbac
   expect(names.resolve(a)).toBe("Native Larry");
   expect(names.resolve(b)).toBe("Legacy");
   expect(
-    provider.resolve({ ...source, relayUrl: "https://other.test" }, a),
+    provider.scope({ ...source, relayUrl: "https://other.test" })(a)?.name,
   ).toBe(`Legacy · ${npubEncode(a).slice(-4)}`);
   expect(agent.name).toBe("Native Larry");
 
@@ -244,18 +250,18 @@ it("includes native-only identities but ignores other-community and unready nati
     refresh: async () => {},
   });
   for (const key of [a, b])
-    expect(provider.resolve(source, key)).toBe(
+    expect(provider.scope(source)(key)?.name).toBe(
       `Larry · ${npubEncode(key).slice(-4)}`,
     );
   expect(
-    provider.resolve({ ...source, relayUrl: "https://elsewhere.test" }, a),
+    provider.scope({ ...source, relayUrl: "https://elsewhere.test" })(a)?.name,
   ).toBe("Larry");
   expect(
-    provider.resolve({ ...source, relayUrl: "https://elsewhere.test" }, b),
+    provider.scope({ ...source, relayUrl: "https://elsewhere.test" })(b)?.name,
   ).toBeUndefined();
   native = { ...native, status: "error" };
-  expect(provider.resolve(source, a)).toBe("Larry");
-  expect(provider.resolve(source, b)).toBeUndefined();
+  expect(provider.scope(source)(a)?.name).toBe("Larry");
+  expect(provider.scope(source)(b)?.name).toBeUndefined();
 });
 
 it("applies viewer and owner metadata through the shared view and follows owner edits", () => {
@@ -296,7 +302,7 @@ it("applies viewer and owner metadata through the shared view and follows owner
   });
   expect(names.resolve(a)).toBe("Honey");
   expect(names.resolve(b)).toBe("Wes’s Honey");
-  expect(provider.resolve({ ...source, viewer: other }, a)).toBe(
+  expect(provider.scope({ ...source, viewer: other })(a)?.name).toBe(
     "Logan’s Honey",
   );
   expect(names.resolve(a)).toBe("Honey");
@@ -308,3 +314,72 @@ it("applies viewer and owner metadata through the shared view and follows owner
   expect(names.resolve(b)).toBe("Wesley’s Honey");
   names.dispose();
 });
+
+it("reuses one policy run per candidate scope across mixed case, outside keys, and updates", () => {
+  const [a, b, c, d] = ["a", "b", "c", "d"].map((key) => key.repeat(64));
+  if (!a || !b || !c || !d) throw new Error("Missing fixture keys");
+  let profiles = new Map([
+    [a, { name: "Alex" }],
+    [b, { name: "Alex" }],
+    [c, { name: "Alex" }],
+    [d, { name: "Dana" }],
+  ]);
+  const library = {
+    status: "ready",
+    definitions: [],
+    identities: [],
+  } as const;
+  const listeners = new Set<() => void>();
+  const source: NameSource = {
+    profiles: {
+      snapshot: () => profiles,
+      subscribe: (listener) => {
+        listeners.add(listener);
+        return () => listeners.delete(listener);
+      },
+      ensure: async () => {},
+    },
+    agentLibrary: {
+      snapshot: () => library,
+      subscribe: () => () => {},
+      refresh: async () => {},
+      retain: () => () => {},
+    },
+  };
+  const resolve = vi.fn(defaultNamingPolicy.resolve);
+  const names = bindNames(source, {
+    snapshot: () => [createNameProvider({ id: "spy", resolve })],
+    subscribe: () => () => {},
+  });
+  const suffixed = (key: string) => `Alex · ${npubEncode(key).slice(-4)}`;
+  const candidates = [a.toUpperCase(), b, d];
+  const scoped = names.scope(candidates);
+  expect(scoped(a)?.name).toBe(suffixed(a));
+  expect(scoped(b.toUpperCase())).toEqual({
+    name: suffixed(b),
+    qualifier: npubEncode(b).slice(-4),
+    source: "agent-directory",
+  });
+  expect(scoped(d)?.name).toBe("Dana");
+  expect(names.lookup(b, candidates)).toEqual(scoped(b));
+  // Interleaved unscoped lookups keep their own cached scope.
+  expect(names.resolve(d)).toBe("Dana");
+  expect(scoped(a)?.name).toBe(suffixed(a));
+  expect(resolve).toHaveBeenCalledTimes(2);
+  // An outside historical reference joins the scope only for its own lookup.
+  expect(names.scope([d])(a)?.name).toBe("Alex");
+  expect(scoped(c)?.name).toBe(suffixed(c));
+  expect(scoped(a)?.name).toBe(suffixed(a));
+  expect(resolve).toHaveBeenCalledTimes(4);
+  // A hot scope survives a stream of distinct historical lookups.
+  for (const digit of "01234567") {
+    expect(names.scope([digit.repeat(64)])(a)?.name).toBe("Alex");
+    expect(scoped(a)?.name).toBe(suffixed(a));
+  }
+  expect(resolve).toHaveBeenCalledTimes(12);
+  profiles = new Map([...profiles, [b, { name: "Blake" }]]);
+  for (const listener of listeners) listener();
+  expect(scoped(a)?.name).toBe("Alex");
+  expect(scoped(b)?.name).toBe("Blake");
+  expect(resolve).toHaveBeenCalledTimes(13);
+});
diff --git a/src/features/identity-names/directory.ts b/src/features/identity-names/directory.ts
index c2776a8e7..fa40d2e14 100644
--- a/src/features/identity-names/directory.ts
+++ b/src/features/identity-names/directory.ts
@@ -1,6 +1,5 @@
 import type { NamingIdentity } from "./policy";
-import type { NamingPolicy } from "./service";
-import type { NameProvider } from "./service";
+import type { NameProvider, NameSource, NamingPolicy } from "./service";
 import type { AgentControl } from "../agents/control";
 import { relayOrigin } from "../communities/destination";
 
@@ -17,13 +16,99 @@ export function createNameProvider(
   policy: NamingPolicy,
   control?: Pick<AgentControl, "snapshot" | "subscribe" | "refresh">,
 ): NameProvider {
-  let cached:
+  let base:
     | {
         inputs: readonly unknown[];
         names: Map<string, string>;
-        suffixes: Map<string, string>;
+        identities: Map<string, NamingIdentity>;
+        // Recently used scopes (LRU), so a hot scope survives interleaved lookups.
+        scopes: Map<
+          string | undefined,
+          { displayFacts: unknown; labels: ReturnType<NamingPolicy["resolve"]> }
+        >;
       }
     | undefined;
+  const current = (source: NameSource) => {
+    const native = control?.snapshot();
+    const relayUrl = source.relayUrl;
+    const library = source.agentLibrary.snapshot();
+    const profiles = source.profiles.snapshot();
+    const inputs = [library, native, profiles, relayUrl, source.viewer];
+    if (base && inputs.every((input, index) => input === base?.inputs[index]))
+      return base;
+    const names = new Map<string, string>();
+    if (library.status === "ready") {
+      for (const row of library.identities) {
+        const key = row.pubkey.toLowerCase();
+        if (!names.has(key))
+          names.set(
+            key,
+            row.name.trim() || profiles.get(key)?.name.trim() || "Agent",
+          );
+      }
+    }
+    if (relayUrl && native?.status === "ready") {
+      const seen = new Set<string>();
+      for (const agent of native.data?.agents ?? []) {
+        const key = agent.pubkey.toLowerCase();
+        if (seen.has(key) || !sameCommunity(agent.relayUrl, relayUrl)) continue;
+        seen.add(key);
+        const name = agent.name.trim();
+        if (name) names.set(key, name);
+      }
+    }
+    const identities = new Map<string, NamingIdentity>(
+      [...profiles].map(([pubkey, profile]) => [
+        pubkey,
+        { pubkey, ...profile },
+      ]),
+    );
+    for (const [pubkey, name] of names) {
+      identities.set(pubkey, {
+        ...profiles.get(pubkey),
+        pubkey,
+        name,
+        isAgent: true,
+      });
+    }
+    base = { inputs, names, identities, scopes: new Map() };
+    return base;
+  };
+  const labels = (
+    source: NameSource,
+    selection: readonly string[] | undefined,
+    id: string | undefined,
+    displayFacts: readonly NamingIdentity[] | undefined,
+  ) => {
+    const { identities, scopes } = current(source);
+    const cached = scopes.get(id);
+    if (cached && cached.displayFacts === displayFacts) {
+      scopes.delete(id);
+      scopes.set(id, cached);
+      return cached.labels;
+    }
+    // View-local labels (authored draft text or cross-community management rows)
+    // supplement display facts only; they never select recipients or grant control.
+    const displayed = (displayFacts ?? []).map((fact) => {
+      const key = fact.pubkey.toLowerCase();
+      return { ...identities.get(key), ...fact, pubkey: key };
+    });
+    const displayedKeys = new Set(displayed.map((fact) => fact.pubkey));
+    const resolved = policy.resolve(
+      [
+        ...[...identities.values()].filter(
+          (row) => !displayedKeys.has(row.pubkey),
+        ),
+        ...displayed,
+      ],
+      source.viewer,
+      selection,
+    );
+    scopes.delete(id);
+    if (scopes.size >= 8) scopes.delete(scopes.keys().next().value);
+    scopes.set(id, { displayFacts, labels: resolved });
+    return resolved;
+  };
   return {
     id: policy.id,
     ...(control ? { subscribe: control.subscribe } : {}),
@@ -31,96 +116,25 @@ export function createNameProvider(
       void control?.refresh();
       return source.agentLibrary.retain();
     },
-    resolve(source, pubkey, candidates, displayFacts) {
-      const key = pubkey.toLowerCase();
-      const native = control?.snapshot();
-      const relayUrl = source.relayUrl;
-      const library = source.agentLibrary.snapshot();
-      const profiles = source.profiles.snapshot();
-      // Include the requested identity even for historical non-member references.
-      const selection =
-        candidates &&
-        [
-          ...new Set([...candidates, key].map((key) => key.toLowerCase())),
-        ].sort();
-      const inputs = [
-        library,
-        native,
-        profiles,
-        relayUrl,
-        source.viewer,
-        selection?.join(":"),
-        displayFacts,
-      ];
-      if (
-        !cached ||
-        inputs.some((input, index) => input !== cached?.inputs[index])
-      ) {
-        const names = new Map<string, string>();
-        if (library.status === "ready") {
-          for (const row of library.identities) {
-            const key = row.pubkey.toLowerCase();
-            if (!names.has(key))
-              names.set(
-                key,
-                row.name.trim() || profiles.get(key)?.name.trim() || "Agent",
-              );
-          }
-        }
-        if (relayUrl && native?.status === "ready") {
-          const seen = new Set<string>();
-          for (const agent of native.data?.agents ?? []) {
-            const key = agent.pubkey.toLowerCase();
-            if (seen.has(key) || !sameCommunity(agent.relayUrl, relayUrl))
-              continue;
-            seen.add(key);
-            const name = agent.name.trim();
-            if (name) names.set(key, name);
-          }
-        }
-        const identities = new Map<string, NamingIdentity>(
-          [...profiles].map(([pubkey, profile]) => [
-            pubkey,
-            { pubkey, ...profile },
-          ]),
-        );
-        for (const [pubkey, name] of names) {
-          identities.set(pubkey, {
-            ...profiles.get(pubkey),
-            pubkey,
-            name,
-            isAgent: true,
-          });
-        }
-        // View-local labels (authored draft text or cross-community management rows)
-        // supplement display facts only; they never select recipients or grant control.
-        const displayed = (displayFacts ?? []).map((fact) => {
-          const key = fact.pubkey.toLowerCase();
-          return { ...identities.get(key), ...fact, pubkey: key };
-        });
-        const displayedKeys = new Set(displayed.map((fact) => fact.pubkey));
-        const resolved = policy.resolve(
-          [
-            ...[...identities.values()].filter(
-              (row) => !displayedKeys.has(row.pubkey),
-            ),
-            ...displayed,
-          ],
-          source.viewer,
-          selection,
-        );
-        const suffixes = new Map<string, string>();
-        for (const [key, label] of resolved) {
-          names.set(key, label.name);
-          if (label.qualifier) suffixes.set(key, label.qualifier);
-        }
-        cached = { inputs, names, suffixes };
-      }
-      return cached.names.get(key);
-    },
-    qualifier(source, pubkey, candidates, displayFacts) {
-      this.resolve(source, pubkey, candidates, displayFacts);
-      return cached?.suffixes.get(pubkey.toLowerCase());
+    scope(source, candidates, displayFacts) {
+      const selected =
+        candidates && new Set(candidates.map((key) => key.toLowerCase()));
+      const selection = selected && [...selected].sort();
+      const id = selection?.join(":");
+      return (pubkey) => {
+        const key = pubkey.toLowerCase();
+        // Include the requested identity even for historical non-member references.
+        const outside =
+          selected && !selected.has(key) && [...selected, key].sort();
+        const label = (
+          outside
+            ? labels(source, outside, outside.join(":"), displayFacts)
+            : labels(source, selection, id, displayFacts)
+        ).get(key);
+        if (label) return label;
+        const name = current(source).names.get(key);
+        return name ? { name } : undefined;
+      };
     },
   };
 }
diff --git a/src/features/identity-names/service.test.ts b/src/features/identity-names/service.test.ts
index f4fa8efc2..ece8f7eaa 100644
--- a/src/features/identity-names/service.test.ts
+++ b/src/features/identity-names/service.test.ts
@@ -113,7 +113,11 @@ it("rebinds a live name view on plugin replacement and disable", async () => {
 it("ignores competing providers and cannot reactivate a disposed view", () => {
   const f = fixture();
   const activate = vi.fn();
-  const provider = { ...agentDirectory, activate, resolve: () => "Override" };
+  const provider = {
+    ...agentDirectory,
+    activate,
+    scope: () => () => ({ name: "Override" }),
+  };
   let entries = [provider, provider];
   let update = () => {};
   const view = bindNames(f.source, {
diff --git a/src/features/identity-names/service.ts b/src/features/identity-names/service.ts
index 6bf2bf264..8a9a895a6 100644
--- a/src/features/identity-names/service.ts
+++ b/src/features/identity-names/service.ts
@@ -30,19 +30,15 @@ export type NameSource = {
 };
 export type NameProvider = {
   id: string;
-  resolve(
+  /** Resolve keys against one candidate scope; the requested key always joins it. */
+  scope(
     source: NameSource,
-    pubkey: string,
     candidates?: readonly string[],
     displayFacts?: readonly NamingIdentity[],
-  ): string | undefined;
-  activate(source: NameSource): undefined | (() => void);
-  qualifier?(
-    source: NameSource,
+  ): (
     pubkey: string,
-    candidates?: readonly string[],
-    displayFacts?: readonly NamingIdentity[],
-  ): string | undefined;
+  ) => { name: string; qualifier?: string | undefined } | undefined;
+  activate(source: NameSource): undefined | (() => void);
   subscribe?(listener: () => void): () => void;
 };
 export type IdentityName = Readonly<{
@@ -56,6 +52,11 @@ export interface IdentityNameView {
     candidates?: readonly string[],
     displayFacts?: readonly NamingIdentity[],
   ): IdentityName | undefined;
+  /** Normalize one candidate scope once for many lookups. */
+  scope(
+    candidates?: readonly string[],
+    displayFacts?: readonly NamingIdentity[],
+  ): (pubkey: string) => IdentityName | undefined;
   resolve(
     pubkey: string,
     fallback?: string,
@@ -148,29 +149,37 @@ export function bindNames(
   const stops = [source.profiles.subscribe(emit)];
   if (providers) stops.push(providers.subscribe(select));
   select();
+  const scope = (
+    candidates?: readonly string[],
+    displayFacts?: readonly NamingIdentity[],
+  ) => {
+    let owner: NameProvider | undefined;
+    let local: ReturnType<NameProvider["scope"]> | undefined;
+    return (pubkey: string): IdentityName | undefined => {
+      if (closed) return undefined;
+      if (owner !== provider) {
+        owner = provider;
+        local = provider?.scope(source, candidates, displayFacts);
+      }
+      const label = local?.(pubkey);
+      if (label?.name)
+        return {
+          name: label.name,
+          qualifier: label.qualifier,
+          source: "agent-directory",
+        };
+      const name = source.profiles.snapshot().get(pubkey.toLowerCase())?.name;
+      return name ? { name, source: "public-profile" } : undefined;
+    };
+  };
   const lookup = (
     pubkey: string,
     candidates?: readonly string[],
     displayFacts?: readonly NamingIdentity[],
-  ): IdentityName | undefined => {
-    if (closed) return undefined;
-    const local = provider?.resolve(source, pubkey, candidates, displayFacts);
-    if (local)
-      return {
-        name: local,
-        qualifier: provider?.qualifier?.(
-          source,
-          pubkey,
-          candidates,
-          displayFacts,
-        ),
-        source: "agent-directory",
-      };
-    const name = source.profiles.snapshot().get(pubkey.toLowerCase())?.name;
-    return name ? { name, source: "public-profile" } : undefined;
-  };
+  ) => scope(candidates, displayFacts)(pubkey);
   return {
     lookup,
+    scope,
     resolve(pubkey, fallback, candidates, displayFacts) {
       return lookup(pubkey, candidates, displayFacts)?.name ?? fallback;
     },
diff --git a/src/features/messages/MessageComposer.test.tsx b/src/features/messages/MessageComposer.test.tsx
index 097ee716b..6bb901c64 100644
--- a/src/features/messages/MessageComposer.test.tsx
+++ b/src/features/messages/MessageComposer.test.tsx
@@ -2555,8 +2555,7 @@ it("uses the full channel choice set for one selected chip and follows membershi
     providers = [
       {
         ...createAgentDirectory(),
-        resolve: () => "Alternative",
-        qualifier: () => undefined,
+        scope: () => () => ({ name: "Alternative" }),
       },
     ];
     policyChanged();
diff --git a/src/features/messages/mention-candidates.ts b/src/features/messages/mention-candidates.ts
index d2a2af1e6..4c1cdcc81 100644
--- a/src/features/messages/mention-candidates.ts
+++ b/src/features/messages/mention-candidates.ts
@@ -26,6 +26,7 @@ export function mentionCandidates(
     .list()
     .channels.find((c) => c.id === channelId);
   const members = roster?.map((p) => p.pubkey) ?? channel?.members ?? [];
+  const memberKeys = new Set(members);
   const agents = session.agentChoices.snapshot().identities;
   const profiles = session.profiles.snapshot();
   const known = knownAgentPubkeys(profiles, {
@@ -66,7 +67,7 @@ export function mentionCandidates(
     )
     .map((recipient) => ({
       recipient,
-      member: members.includes(recipient.pubkey),
+      member: memberKeys.has(recipient.pubkey),
       agent:
         known.has(recipient.pubkey) ||
         directory.some((p) => p.pubkey === recipient.pubkey && p.isAgent),