diff --git a/desktop/src-tauri/src/commands/agent_discovery/relay_directory.rs b/desktop/src-tauri/src/commands/agent_discovery/relay_directory.rs
index db0573acd7c..c087031195f 100644
--- a/desktop/src-tauri/src/commands/agent_discovery/relay_directory.rs
+++ b/desktop/src-tauri/src/commands/agent_discovery/relay_directory.rs
@@ -145,11 +145,38 @@ async fn list_relay_agents_for_selection(
     if let Some(channel_id) = channel_id {
         membership_filter["#d"] = serde_json::json!([channel_id]);
     }
-    let membership_events = query_all_relay_pages(state, membership_filter)
-        .await
-        .map_err(|error| format!("relay agent channel-membership query failed: {error}"))?;
+    let mut dm_metadata_filter = serde_json::json!({
+        "kinds": [39000],
+        "authors": [&relay_pubkey],
+        "#p": [&viewer_pubkey],
+    });
+    if let Some(channel_id) = channel_id {
+        dm_metadata_filter["#d"] = serde_json::json!([channel_id]);
+    }
+    let (membership_events, dm_metadata_events) = tokio::try_join!(
+        async {
+            query_all_relay_pages(state, membership_filter)
+                .await
+                .map_err(|error| format!("relay agent channel-membership query failed: {error}"))
+        },
+        async {
+            query_all_relay_pages(state, dm_metadata_filter)
+                .await
+                .map_err(|error| format!("relay agent DM-participant query failed: {error}"))
+        },
+    )?;
     let mut member_agent_channel_ids =
         nostr_convert::member_agent_channel_ids_from_events(&membership_events, &relay_pubkey);
+    for (pubkey, channel_ids) in nostr_convert::dm_participant_channel_ids_from_events(
+        &dm_metadata_events,
+        &relay_pubkey,
+        &viewer_pubkey,
+    ) {
+        let existing = member_agent_channel_ids.entry(pubkey).or_default();
+        existing.extend(channel_ids);
+        existing.sort();
+        existing.dedup();
+    }
     if let Some(requested_pubkeys) = requested_pubkeys {
         member_agent_channel_ids.retain(|pubkey, _| requested_pubkeys.contains(pubkey));
     }
diff --git a/desktop/src-tauri/src/nostr_convert.rs b/desktop/src-tauri/src/nostr_convert.rs
index 64c8df05a79..748d14d8aa0 100644
--- a/desktop/src-tauri/src/nostr_convert.rs
+++ b/desktop/src-tauri/src/nostr_convert.rs
@@ -499,9 +499,9 @@ pub fn agents_from_events(events: &[Event]) -> Value {
 
 mod agent_directory;
 pub use agent_directory::{
-    managed_agent_pubkeys_from_events, member_agent_channel_ids_from_events,
-    relay_agents_from_directory_events, relay_agents_from_managed_agent_events,
-    verified_agent_owners_from_profiles,
+    dm_participant_channel_ids_from_events, managed_agent_pubkeys_from_events,
+    member_agent_channel_ids_from_events, relay_agents_from_directory_events,
+    relay_agents_from_managed_agent_events, verified_agent_owners_from_profiles,
 };
 
 // ── kind:13534 (relay membership list) ──────────────────────────────────────
diff --git a/desktop/src-tauri/src/nostr_convert/agent_directory.rs b/desktop/src-tauri/src/nostr_convert/agent_directory.rs
index 28604de5e5f..1e0bf8167d3 100644
--- a/desktop/src-tauri/src/nostr_convert/agent_directory.rs
+++ b/desktop/src-tauri/src/nostr_convert/agent_directory.rs
@@ -6,7 +6,9 @@ use nostr::Event;
 
 use crate::managed_agents::{agent_events::managed_agent_content_from_event, RelayAgentInfo};
 
-use super::{agents_from_events, first_tag_value, profile_valid_oa_owner_pubkey, tags_named};
+use super::{
+    agents_from_events, first_tag_value, has_tag, profile_valid_oa_owner_pubkey, tags_named,
+};
 
 /// Collect valid agent pubkeys from kind:30177 `d` tags for follow-up relay
 /// queries. Malformed tags are ignored so one hostile event cannot invalidate
@@ -189,3 +191,70 @@ pub fn member_agent_channel_ids_from_events(
         .map(|(pubkey, ids)| (pubkey, ids.into_iter().collect()))
         .collect()
 }
+
+/// Build a pubkey-to-channel-id candidate map from relay-signed DM metadata.
+///
+/// Stream and forum agent membership carries an explicit `bot` role in
+/// kind:39002. DM creation deliberately records every participant as an
+/// ordinary member instead, while the current relay-signed kind:39000 head
+/// carries the authoritative participant list in `p` tags. Only a current DM
+/// head that includes the viewer can admit its other participants as agent
+/// candidates; downstream signed runtime-directory and managed-policy checks
+/// still decide which candidates are actually agents and whether they may
+/// respond to that viewer.
+pub fn dm_participant_channel_ids_from_events(
+    events: &[Event],
+    relay_pubkey: &str,
+    viewer_pubkey: &str,
+) -> HashMap<String, Vec<String>> {
+    let Ok(viewer_pubkey) = nostr::PublicKey::from_hex(viewer_pubkey) else {
+        return HashMap::new();
+    };
+    let viewer_pubkey = viewer_pubkey.to_hex();
+
+    // Fail closed on stale replacement heads: choose exactly one current
+    // relay-signed metadata event per channel before reading participants.
+    let mut latest_by_channel: HashMap<String, &Event> = HashMap::new();
+    for event in events {
+        if !event.pubkey.to_hex().eq_ignore_ascii_case(relay_pubkey) {
+            continue;
+        }
+        if first_tag_value(event, "t") != Some("dm") && !has_tag(event, "hidden") {
+            continue;
+        }
+        let Some(channel_id) = first_tag_value(event, "d") else {
+            continue;
+        };
+        if latest_by_channel
+            .get(channel_id)
+            .is_none_or(|previous| event_is_newer(event, previous))
+        {
+            latest_by_channel.insert(channel_id.to_string(), event);
+        }
+    }
+
+    let mut channel_ids: HashMap<String, BTreeSet<String>> = HashMap::new();
+    for (channel_id, event) in latest_by_channel {
+        let participants: Vec<String> = tags_named(event, "p")
+            .filter_map(|tag| tag.get(1))
+            .filter_map(|pubkey| nostr::PublicKey::from_hex(pubkey).ok())
+            .map(|pubkey| pubkey.to_hex())
+            .collect();
+        if !participants.contains(&viewer_pubkey) {
+            continue;
+        }
+        for pubkey in participants {
+            if pubkey != viewer_pubkey {
+                channel_ids
+                    .entry(pubkey)
+                    .or_default()
+                    .insert(channel_id.clone());
+            }
+        }
+    }
+
+    channel_ids
+        .into_iter()
+        .map(|(pubkey, ids)| (pubkey, ids.into_iter().collect()))
+        .collect()
+}
diff --git a/desktop/src-tauri/src/nostr_convert/tests.rs b/desktop/src-tauri/src/nostr_convert/tests.rs
index 9401d19add4..c730cc69937 100644
--- a/desktop/src-tauri/src/nostr_convert/tests.rs
+++ b/desktop/src-tauri/src/nostr_convert/tests.rs
@@ -520,6 +520,89 @@ fn managed_agent_candidates_use_only_relay_signed_bot_membership() {
     assert!(!channel_ids.contains_key(&stranger));
 }
 
+#[test]
+fn managed_agent_candidates_include_relay_signed_dm_participants() {
+    let relay_keys = Keys::generate();
+    let viewer_pubkey = Keys::generate().public_key().to_hex();
+    let agent_pubkey = Keys::generate().public_key().to_hex();
+    let stranger = Keys::generate().public_key().to_hex();
+    let dm = EventBuilder::new(Kind::Custom(39000), "")
+        .tags([
+            Tag::parse(["d", "pm-dm"]).expect("parse d tag"),
+            Tag::parse(["t", "dm"]).expect("parse type tag"),
+            Tag::parse(["p", &viewer_pubkey]).expect("parse viewer tag"),
+            Tag::parse(["p", &agent_pubkey]).expect("parse agent tag"),
+        ])
+        .sign_with_keys(&relay_keys)
+        .expect("sign DM metadata");
+    let forged = ev(
+        39000,
+        "",
+        vec![
+            vec!["d", "forged-dm"],
+            vec!["t", "dm"],
+            vec!["p", &viewer_pubkey],
+            vec!["p", &stranger],
+        ],
+    );
+    let stream = EventBuilder::new(Kind::Custom(39000), "")
+        .tags([
+            Tag::parse(["d", "general"]).expect("parse d tag"),
+            Tag::parse(["t", "stream"]).expect("parse type tag"),
+            Tag::parse(["p", &viewer_pubkey]).expect("parse viewer tag"),
+            Tag::parse(["p", &stranger]).expect("parse stranger tag"),
+        ])
+        .sign_with_keys(&relay_keys)
+        .expect("sign stream metadata");
+
+    let channel_ids = dm_participant_channel_ids_from_events(
+        &[forged, stream, dm],
+        &relay_keys.public_key().to_hex(),
+        &viewer_pubkey,
+    );
+
+    assert_eq!(
+        channel_ids.get(&agent_pubkey),
+        Some(&vec!["pm-dm".to_string()])
+    );
+    assert!(!channel_ids.contains_key(&viewer_pubkey));
+    assert!(!channel_ids.contains_key(&stranger));
+}
+
+#[test]
+fn managed_agent_dm_candidates_follow_only_the_latest_metadata_head() {
+    let relay_keys = Keys::generate();
+    let viewer_pubkey = Keys::generate().public_key().to_hex();
+    let removed_agent_pubkey = Keys::generate().public_key().to_hex();
+    let old_head = EventBuilder::new(Kind::Custom(39000), "")
+        .tags([
+            Tag::parse(["d", "pm-dm"]).expect("parse d tag"),
+            Tag::parse(["hidden"]).expect("parse hidden tag"),
+            Tag::parse(["p", &viewer_pubkey]).expect("parse viewer tag"),
+            Tag::parse(["p", &removed_agent_pubkey]).expect("parse agent tag"),
+        ])
+        .custom_created_at(nostr::Timestamp::from(10))
+        .sign_with_keys(&relay_keys)
+        .expect("sign old DM metadata");
+    let new_head = EventBuilder::new(Kind::Custom(39000), "")
+        .tags([
+            Tag::parse(["d", "pm-dm"]).expect("parse d tag"),
+            Tag::parse(["t", "dm"]).expect("parse type tag"),
+            Tag::parse(["p", &viewer_pubkey]).expect("parse viewer tag"),
+        ])
+        .custom_created_at(nostr::Timestamp::from(20))
+        .sign_with_keys(&relay_keys)
+        .expect("sign new DM metadata");
+
+    let channel_ids = dm_participant_channel_ids_from_events(
+        &[old_head, new_head],
+        &relay_keys.public_key().to_hex(),
+        &viewer_pubkey,
+    );
+
+    assert!(channel_ids.is_empty());
+}
+
 #[test]
 fn managed_agent_directory_query_pubkeys_reject_malformed_d_tags() {
     let valid_pubkey = Keys::generate().public_key().to_hex();
diff --git a/desktop/src/features/agents/lib/agentAutocompleteEligibility.test.mjs b/desktop/src/features/agents/lib/agentAutocompleteEligibility.test.mjs
index 21880eca2ff..38f1498d9ab 100644
--- a/desktop/src/features/agents/lib/agentAutocompleteEligibility.test.mjs
+++ b/desktop/src/features/agents/lib/agentAutocompleteEligibility.test.mjs
@@ -224,7 +224,7 @@ test("getMentionableAgentPubkeys: scopes channel composers and fails closed with
 test("autocomplete helper extraction preserves safe filtering and labels", () => {
   assert.equal(isAgentMentionChannelType("stream"), true);
   assert.equal(isAgentMentionChannelType("forum"), true);
-  assert.equal(isAgentMentionChannelType("dm"), false);
+  assert.equal(isAgentMentionChannelType("dm"), true);
   assert.equal(isAgentMentionChannelType(null), false);
 
   assert.deepEqual(
diff --git a/desktop/src/features/agents/lib/agentAutocompleteEligibility.ts b/desktop/src/features/agents/lib/agentAutocompleteEligibility.ts
index 4e1c787f92e..98f0d571536 100644
--- a/desktop/src/features/agents/lib/agentAutocompleteEligibility.ts
+++ b/desktop/src/features/agents/lib/agentAutocompleteEligibility.ts
@@ -216,7 +216,7 @@ export function filterAdmittedMentionPubkeys(
 }
 
 export function isAgentMentionChannelType(type?: string | null) {
-  return type === "stream" || type === "forum";
+  return type === "stream" || type === "forum" || type === "dm";
 }
 
 export function uniqueAutocompleteLabels(
diff --git a/desktop/src/features/channels/hooks.ts b/desktop/src/features/channels/hooks.ts
index 9069b052da4..e97b00f6e6c 100644
--- a/desktop/src/features/channels/hooks.ts
+++ b/desktop/src/features/channels/hooks.ts
@@ -832,7 +832,20 @@ export function useAddChannelMembersMutation(channelId: string | null) {
       // Invalidate the effective channel (the one actually mutated) not the
       // live hook-closure channel, which may have changed mid-send.
       const effectiveChannelId = variables?.channelId ?? channelId;
-      await invalidateChannelState(queryClient, effectiveChannelId);
+      await Promise.all([
+        invalidateChannelState(queryClient, effectiveChannelId),
+        // Relay-agent discovery is membership-backed. Without this refresh,
+        // adding an existing agent through the members picker leaves the
+        // autocomplete directory stale and the same-named local persona can
+        // be offered as a new agent until the five-minute focus refresh.
+        ...(variables?.role === "bot"
+          ? [
+              queryClient.invalidateQueries({
+                queryKey: ["relay-agents"],
+              }),
+            ]
+          : []),
+      ]);
     },
   });
 }
diff --git a/desktop/tests/e2e/mentions.spec.ts b/desktop/tests/e2e/mentions.spec.ts
index edcf523e36c..a2110f7ed0a 100644
--- a/desktop/tests/e2e/mentions.spec.ts
+++ b/desktop/tests/e2e/mentions.spec.ts
@@ -1394,6 +1394,61 @@ test("relay-only shared agents stay hidden from DM mentions", async ({
   await expect(autocomplete(page)).toHaveCount(0);
 });
 
+test("an existing remote agent in a DM is mentioned without creating a local runtime", async ({
+  page,
+}) => {
+  const remoteAgentPubkey = "7".repeat(64);
+  await installMockBridge(page, {
+    acpRuntimesCatalog: [],
+    personas: [
+      {
+        id: "pm-persona",
+        displayName: "PM Bot",
+        systemPrompt: "Own product management.",
+        isActive: true,
+      },
+    ],
+    relayAgents: [
+      {
+        pubkey: remoteAgentPubkey,
+        ownerPubkey: MOCK_VIEWER_PUBKEY,
+        name: "PM Bot",
+        channelNames: ["alice-tyler"],
+        respondTo: "owner-only",
+      },
+    ],
+    searchProfiles: [
+      {
+        pubkey: remoteAgentPubkey,
+        displayName: "PM Bot",
+        ownerPubkey: MOCK_VIEWER_PUBKEY,
+        isAgent: true,
+      },
+    ],
+  });
+  await page.goto("/");
+  await expect(page.getByTestId("channel-alice-tyler")).toBeVisible();
+  await page.getByTestId("channel-alice-tyler").click();
+  await expect(page.getByTestId("chat-title")).toHaveText("alice-tyler");
+
+  const input = page.getByTestId("message-input");
+  await input.fill("@PM Bot");
+  await autocomplete(page)
+    .getByTestId(`mention-suggestion-${remoteAgentPubkey}`)
+    .click();
+  await input.press("End");
+  await input.type("keep going");
+  await input.press("Enter");
+
+  await expect
+    .poll(() => readOutgoingMentionPubkeys(page, "@PM Bot keep going"))
+    .toContain(remoteAgentPubkey);
+  expect(await readCommandLog(page)).not.toContain("create_managed_agent");
+  await expect(
+    page.getByText(/No agent runtime available/, { exact: false }),
+  ).toHaveCount(0);
+});
+
 test("cached relay-agent suggestions are removed when channel authorization disappears", async ({
   page,
 }) => {