diff --git a/src/features/messages/MessageRow.test.tsx b/src/features/messages/MessageRow.test.tsx
index 5c9f7d4a84..fc5298f322 100644
--- a/src/features/messages/MessageRow.test.tsx
+++ b/src/features/messages/MessageRow.test.tsx
@@ -1,5 +1,7 @@
 // @vitest-environment jsdom
 import { StrictMode } from "react";
+import { schnorr } from "@noble/curves/secp256k1.js";
+import { bytesToHex } from "nostr-tools/utils";
 import { npubEncode } from "nostr-tools/nip19";
 import "@testing-library/jest-dom/vitest";
 import { stubAvatarBrowserApis } from "../agents/avatar-testing";
@@ -23,11 +25,18 @@ import { ToastProvider } from "../../shared/design-system/ui/Toast";
 import { ConversationPresentation } from "../conversation/ConversationPresentation";
 import { MessageRow } from "./MessageRow";
 import { MessageManagement } from "./MessageManagement";
-import type { ChannelMessage } from "../relay/contracts";
+import type { ChannelMessage, Profile } from "../relay/contracts";
 import type { UnreadCapability, UnreadSnapshot } from "../relay/unread";
 import type { RelaySession } from "../relay/session";
 import type { TypingEntry } from "../relay/typing";
 import { LinkLabel } from "../../bundled/links/InlineLink";
+import { attestedOwner } from "../agents/owner-attestation";
+
+// Real verification, observed so tests can wait for its verdict.
+vi.mock("../agents/owner-attestation", async (original) => {
+  const actual = await original<typeof import("../agents/owner-attestation")>();
+  return { ...actual, attestedOwner: vi.fn(actual.attestedOwner) };
+});
 
 const row: ChannelMessage = {
   id: "root",
@@ -3617,3 +3626,130 @@ it("keeps a failed card's attachments listed under StrictMode", () => {
     error.mockRestore();
   }
 });
+
+const listed = { channels: [], status: "ready" };
+
+it.each([
+  {
+    case: "signed owner",
+    forged: false,
+    viewer: undefined,
+    label: "Logan’s agent",
+  },
+  // The viewer's own agent shows only the mark.
+  { case: "viewer's agent", forged: false, viewer: "owner", label: undefined },
+  { case: "forged owner", forged: true, viewer: undefined, label: undefined },
+])(
+  "names an agent's owner from its signed profile ($case)",
+  async ({ forged, viewer, label }) => {
+    const agent = keypair();
+    const owner = keypair();
+    const signer = forged ? keypair() : owner;
+    const conditions = "";
+    const sig = bytesToHex(
+      schnorr.sign(
+        new Uint8Array(
+          await crypto.subtle.digest(
+            "SHA-256",
+            new TextEncoder().encode(
+              `nostr:agent-auth:${agent.pubkey}:${conditions}`,
+            ),
+          ),
+        ),
+        signer.secret,
+      ),
+    );
+    const head = signed(agent, {
+      kind: 0,
+      content: JSON.stringify({ name: "Quinn" }),
+      tags: [["auth", owner.pubkey, conditions, sig]],
+    });
+    const quinn: Profile = { name: "Quinn", isAgent: true };
+    let profiles = new Map<string, Profile>([[agent.pubkey, quinn]]);
+    const listeners = new Set<() => void>();
+    // The owner's name arrives after verification, as a background load.
+    const ensure = vi.fn(async () => {
+      // Later than the render that requested it, so only a subscription shows it.
+      await new Promise((resolve) => setTimeout(resolve, 0));
+      profiles = new Map(profiles).set(owner.pubkey, { name: "Logan" });
+      for (const listener of listeners) listener();
+    });
+    const subscribe = () => () => {};
+    const verifications = vi.mocked(attestedOwner);
+    verifications.mockClear();
+    const session = {
+      channels: { list: () => listed, subscribeList: subscribe },
+      messages: {},
+      profiles: {
+        snapshot: () => profiles,
+        subscribe: (listener: () => void) => {
+          listeners.add(listener);
+          return () => listeners.delete(listener);
+        },
+        ensure,
+        event: (key: string) => (key === agent.pubkey ? head : undefined),
+      },
+    } as unknown as RelaySession;
+    const view = renderMessage({
+      row: { ...row, authorId: agent.pubkey },
+      profile: quinn,
+      // Timelines pass row-selected profiles, which never include the owner.
+      participantProfiles: new Map([[agent.pubkey, quinn]]),
+      session,
+      viewer: viewer === "owner" ? owner.pubkey : row.authorId,
+    });
+    try {
+      const byline = view.container.querySelector("strong")?.parentElement;
+      // The mention-chip agent mark sits beside the name either way.
+      expect(byline?.querySelector("svg")).not.toBeNull();
+      expect(verifications).toHaveBeenCalledWith(head);
+      // Barrier: the real signature check has returned its verdict.
+      await act(async () => {
+        await verifications.mock.results[0]?.value;
+      });
+      if (label) {
+        await waitFor(() =>
+          expect(view.container).toHaveTextContent(`Quinn· ${label}`),
+        );
+        expect(ensure).toHaveBeenCalledWith([owner.pubkey], "background");
+      } else if (viewer === "owner") {
+        await expect(verifications.mock.results[0]?.value).resolves.toBe(
+          owner.pubkey,
+        );
+        // Barrier: the owner's name has loaded, so a label would show now.
+        await waitFor(() => expect(profiles.has(owner.pubkey)).toBe(true));
+        expect(view.container).not.toHaveTextContent("agent");
+      } else {
+        await expect(verifications.mock.results[0]?.value).resolves.toBe(
+          undefined,
+        );
+        expect(view.container).not.toHaveTextContent("agent");
+        expect(ensure).not.toHaveBeenCalled();
+      }
+    } finally {
+      view.unmount();
+    }
+  },
+);
+
+it("shows no agent mark or owner for a person", () => {
+  const event = vi.fn();
+  const subscribe = () => () => {};
+  const none = new Map();
+  const session = {
+    channels: { list: () => listed, subscribeList: subscribe },
+    messages: {},
+    profiles: { snapshot: () => none, subscribe, event, ensure: vi.fn() },
+  } as unknown as RelaySession;
+  const view = renderMessage({ session, profile: { name: "Ana" } });
+  try {
+    expect(
+      view.container
+        .querySelector("strong")
+        ?.parentElement?.querySelector("svg"),
+    ).toBeNull();
+    expect(event).not.toHaveBeenCalled();
+  } finally {
+    view.unmount();
+  }
+});
diff --git a/src/features/messages/MessageRow.tsx b/src/features/messages/MessageRow.tsx
index 2cc9d83bd3..a7791ae2d2 100644
--- a/src/features/messages/MessageRow.tsx
+++ b/src/features/messages/MessageRow.tsx
@@ -11,7 +11,9 @@ import { Avatar } from "../../shared/design-system/ui/Avatar";
 import {
   ArrowRightIcon,
   LightningIcon,
+  RobotIcon,
 } from "../../shared/design-system/icons";
+import { useProfileOwner } from "../profiles/useProfileOwner";
 import { messagePreviewText } from "../conversation/message-preview-text";
 import { profileMentionParts } from "./profile-mentions";
 import { addressedMessage } from "./audience-address";
@@ -310,6 +312,19 @@ function MessageRowContent({
       : undefined,
     row.authorId,
   );
+  const agentAuthor = !row.workflowOwnerId && avatarShape === "squircle";
+  const owner = useProfileOwner(
+    session,
+    agentAuthor && !stackPrevious ? row.authorId : undefined,
+  );
+  // The viewer's own agents carry only the agent mark.
+  const ownerLabel =
+    owner &&
+    owner.id !== viewer &&
+    owner.profile &&
+    !owner.profile.nameIsFallback
+      ? `${resolveName(owner.id, owner.profile.name)}’s agent`
+      : undefined;
   const presenceId = useId();
   const shown = shownRow ?? row;
   const timeReply = shown.diff ? undefined : parseMediaTimeReply(shown.content);
@@ -884,7 +899,16 @@ function MessageRowContent({
                   />
                 ) : (
                   <span className={styles.authorWithStatus}>
-                    <strong className={styles.author}>{name}</strong>
+                    <strong className={styles.author}>
+                      {/* Inside the name, so the byline keeps the text baseline. */}
+                      {agentAuthor && !stackPrevious && (
+                        <RobotIcon
+                          aria-hidden="true"
+                          className={styles.authorAgentIcon}
+                        />
+                      )}
+                      {name}
+                    </strong>
                     {session && !stackPrevious && (
                       <UserStatusDisplay
                         session={session}
@@ -895,6 +919,12 @@ function MessageRowContent({
                     )}
                   </span>
                 )}
+                {ownerLabel && (
+                  <span className={styles.authorOwner}>
+                    <span aria-hidden="true">· </span>
+                    {ownerLabel}
+                  </span>
+                )}
                 {!stackPrevious && (
                   <MessageTimestamp createdAt={row.createdAt} />
                 )}
diff --git a/src/features/messages/Messages.module.css b/src/features/messages/Messages.module.css
index d9fa80d6f2..a99847e4b4 100644
--- a/src/features/messages/Messages.module.css
+++ b/src/features/messages/Messages.module.css
@@ -205,6 +205,18 @@
   font-weight: var(--type-weight-medium);
   min-width: 0;
 }
+.authorAgentIcon {
+  display: inline-block;
+  width: 1em;
+  height: 1em;
+  margin-inline-end: var(--space-1);
+  vertical-align: -0.125em;
+}
+.authorOwner {
+  color: var(--text-subtle);
+  min-width: 0;
+  overflow-wrap: anywhere;
+}
 .text {
   white-space: normal;
 }
diff --git a/src/features/profiles/useProfileOwner.ts b/src/features/profiles/useProfileOwner.ts
new file mode 100644
index 0000000000..2f417d6c2e
--- /dev/null
+++ b/src/features/profiles/useProfileOwner.ts
@@ -0,0 +1,60 @@
+import { useEffect, useState, useSyncExternalStore } from "react";
+import { attestedOwner } from "../agents/owner-attestation";
+import type { Profile } from "../relay/contracts";
+import type { RelayEvent } from "../relay/events";
+import type { RelaySession } from "../relay/session";
+
+const noSubscribe = () => () => {};
+const none = () => undefined;
+// One verification per retained signed head, shared by every row that shows it.
+const checks = new WeakMap<RelayEvent, Promise<string | undefined>>();
+const results = new WeakMap<RelayEvent, { owner: string | undefined }>();
+
+function verify(head: RelayEvent) {
+  let check = checks.get(head);
+  if (!check) {
+    check = attestedOwner(head).then((owner) => {
+      results.set(head, { owner });
+      return owner;
+    });
+    checks.set(head, check);
+  }
+  return check;
+}
+
+/** Verified NIP-OA owner of the profile head the session already retains, for
+ * display only, never authorization. Reads no agent profile: the profile pane
+ * owns live evidence (`useAgentOwnerEvidence`). Reads the owner's profile from
+ * the session directory, since row-selected profiles do not include owners. */
+export function useProfileOwner(
+  session: RelaySession | undefined,
+  pubkey: string | undefined,
+): { id: string; profile: Profile | undefined } | undefined {
+  const profiles = pubkey ? session?.profiles : undefined;
+  const head = useSyncExternalStore(
+    profiles?.subscribe ?? noSubscribe,
+    profiles?.event && pubkey ? () => profiles.event?.(pubkey) : none,
+    profiles?.event && pubkey ? () => profiles.event?.(pubkey) : none,
+  );
+  const [, settled] = useState<RelayEvent>();
+  useEffect(() => {
+    if (!head || results.has(head)) return;
+    let active = true;
+    void verify(head).then(() => {
+      if (active) settled(head);
+    });
+    return () => {
+      active = false;
+    };
+  }, [head]);
+  const owner = head ? results.get(head)?.owner : undefined;
+  useEffect(() => {
+    if (owner) void profiles?.ensure([owner], "background").catch(() => {});
+  }, [profiles, owner]);
+  const profile = useSyncExternalStore(
+    owner && profiles ? profiles.subscribe : noSubscribe,
+    owner && profiles ? () => profiles.snapshot().get(owner) : none,
+    owner && profiles ? () => profiles.snapshot().get(owner) : none,
+  );
+  return owner ? { id: owner, profile } : undefined;
+}