diff --git a/src/discord/monitor.tool-result.test.ts b/src/discord/monitor.tool-result.test.ts
index 84d1e5d2f..9606b0388 100644
--- a/src/discord/monitor.tool-result.test.ts
+++ b/src/discord/monitor.tool-result.test.ts
@@ -272,4 +272,108 @@ describe("discord tool result dispatch", () => {
     expect(capturedCtx?.ThreadStarterBody).toContain("starter message");
     expect(capturedCtx?.ThreadLabel).toContain("Discord thread #general");
   });
+
+  it("scopes thread sessions to the routed agent", async () => {
+    const { createDiscordMessageHandler } = await import("./monitor.js");
+
+    let capturedCtx:
+      | {
+          SessionKey?: string;
+          ParentSessionKey?: string;
+        }
+      | undefined;
+    dispatchMock.mockImplementationOnce(async ({ ctx, dispatcher }) => {
+      capturedCtx = ctx;
+      dispatcher.sendFinalReply({ text: "hi" });
+      return { queuedFinal: true, counts: { final: 1 } };
+    });
+
+    const cfg = {
+      agent: { model: "anthropic/claude-opus-4-5", workspace: "/tmp/clawd" },
+      session: { store: "/tmp/clawdbot-sessions.json" },
+      messages: { responsePrefix: "PFX" },
+      discord: {
+        dm: { enabled: true, policy: "open" },
+        guilds: { "*": { requireMention: false } },
+      },
+      routing: {
+        allowFrom: [],
+        bindings: [
+          { agentId: "support", match: { provider: "discord", guildId: "g1" } },
+        ],
+      },
+    } as ReturnType<typeof import("../config/config.js").loadConfig>;
+
+    const handler = createDiscordMessageHandler({
+      cfg,
+      token: "token",
+      runtime: {
+        log: vi.fn(),
+        error: vi.fn(),
+        exit: (code: number): never => {
+          throw new Error(`exit ${code}`);
+        },
+      },
+      botUserId: "bot-id",
+      guildHistories: new Map(),
+      historyLimit: 0,
+      mediaMaxBytes: 10_000,
+      textLimit: 2000,
+      replyToMode: "off",
+      dmEnabled: true,
+      groupDmEnabled: false,
+      guildEntries: { "*": { requireMention: false } },
+    });
+
+    const threadChannel = {
+      type: ChannelType.GuildText,
+      name: "thread-name",
+      parentId: "p1",
+      parent: { id: "p1", name: "general" },
+      isThread: () => true,
+    };
+
+    const client = {
+      fetchChannel: vi.fn().mockResolvedValue({
+        type: ChannelType.GuildText,
+        name: "thread-name",
+      }),
+      rest: {
+        get: vi.fn().mockResolvedValue({
+          content: "starter message",
+          author: { id: "u1", username: "Alice", discriminator: "0001" },
+          timestamp: new Date().toISOString(),
+        }),
+      },
+    } as unknown as Client;
+
+    await handler(
+      {
+        message: {
+          id: "m5",
+          content: "thread reply",
+          channelId: "t1",
+          channel: threadChannel,
+          timestamp: new Date().toISOString(),
+          type: MessageType.Default,
+          attachments: [],
+          embeds: [],
+          mentionedEveryone: false,
+          mentionedUsers: [],
+          mentionedRoles: [],
+          author: { id: "u2", bot: false, username: "Bob", tag: "Bob#2" },
+        },
+        author: { id: "u2", bot: false, username: "Bob", tag: "Bob#2" },
+        member: { displayName: "Bob" },
+        guild: { id: "g1", name: "Guild" },
+        guild_id: "g1",
+      },
+      client,
+    );
+
+    expect(capturedCtx?.SessionKey).toBe("agent:support:discord:channel:t1");
+    expect(capturedCtx?.ParentSessionKey).toBe(
+      "agent:support:discord:channel:p1",
+    );
+  });
 });
diff --git a/src/slack/monitor.tool-result.test.ts b/src/slack/monitor.tool-result.test.ts
index e7d7a3338..540a065b8 100644
--- a/src/slack/monitor.tool-result.test.ts
+++ b/src/slack/monitor.tool-result.test.ts
@@ -388,6 +388,73 @@ describe("monitorSlackProvider tool results", () => {
     expect(ctx.ThreadLabel).toContain("Slack thread #general");
   });
 
+  it("scopes thread session keys to the routed agent", async () => {
+    replyMock.mockResolvedValue({ text: "ok" });
+    config = {
+      messages: { responsePrefix: "PFX" },
+      slack: {
+        dm: { enabled: true, policy: "open", allowFrom: ["*"] },
+        channels: { C1: { allow: true, requireMention: false } },
+      },
+      routing: {
+        allowFrom: [],
+        bindings: [
+          { agentId: "support", match: { provider: "slack", teamId: "T1" } },
+        ],
+      },
+    };
+
+    const client = getSlackClient();
+    if (client?.auth?.test) {
+      client.auth.test.mockResolvedValue({
+        user_id: "bot-user",
+        team_id: "T1",
+      });
+    }
+    if (client?.conversations?.info) {
+      client.conversations.info.mockResolvedValue({
+        channel: { name: "general", is_channel: true },
+      });
+    }
+
+    const controller = new AbortController();
+    const run = monitorSlackProvider({
+      botToken: "bot-token",
+      appToken: "app-token",
+      abortSignal: controller.signal,
+    });
+
+    await waitForEvent("message");
+    const handler = getSlackHandlers()?.get("message");
+    if (!handler) throw new Error("Slack message handler not registered");
+
+    await handler({
+      event: {
+        type: "message",
+        user: "U1",
+        text: "thread reply",
+        ts: "123.456",
+        thread_ts: "111.222",
+        channel: "C1",
+        channel_type: "channel",
+      },
+    });
+
+    await flush();
+    controller.abort();
+    await run;
+
+    expect(replyMock).toHaveBeenCalledTimes(1);
+    const ctx = replyMock.mock.calls[0]?.[0] as {
+      SessionKey?: string;
+      ParentSessionKey?: string;
+    };
+    expect(ctx.SessionKey).toBe(
+      "agent:support:slack:channel:C1:thread:111.222",
+    );
+    expect(ctx.ParentSessionKey).toBe("agent:support:slack:channel:C1");
+  });
+
   it("keeps replies in channel root when message is not threaded", async () => {
     replyMock.mockResolvedValue({ text: "root reply" });