diff --git a/src/config/sessions.test.ts b/src/config/sessions.test.ts
index f33bae2b2..a89caeae7 100644
--- a/src/config/sessions.test.ts
+++ b/src/config/sessions.test.ts
@@ -121,8 +121,10 @@ describe("sessions", () => {
     await updateLastRoute({
       storePath,
       sessionKey: mainSessionKey,
-      channel: "telegram",
-      to: "  12345  ",
+      deliveryContext: {
+        channel: "telegram",
+        to: "  12345  ",
+      },
     });
 
     const store = loadSessionStore(storePath);
@@ -142,6 +144,36 @@ describe("sessions", () => {
     expect(store[mainSessionKey]?.compactionCount).toBe(2);
   });
 
+  it("updateLastRoute prefers explicit deliveryContext", async () => {
+    const mainSessionKey = "agent:main:main";
+    const dir = await fs.mkdtemp(path.join(os.tmpdir(), "clawdbot-sessions-"));
+    const storePath = path.join(dir, "sessions.json");
+    await fs.writeFile(storePath, "{}", "utf-8");
+
+    await updateLastRoute({
+      storePath,
+      sessionKey: mainSessionKey,
+      channel: "whatsapp",
+      to: "111",
+      accountId: "legacy",
+      deliveryContext: {
+        channel: "telegram",
+        to: "222",
+        accountId: "primary",
+      },
+    });
+
+    const store = loadSessionStore(storePath);
+    expect(store[mainSessionKey]?.lastChannel).toBe("telegram");
+    expect(store[mainSessionKey]?.lastTo).toBe("222");
+    expect(store[mainSessionKey]?.lastAccountId).toBe("primary");
+    expect(store[mainSessionKey]?.deliveryContext).toEqual({
+      channel: "telegram",
+      to: "222",
+      accountId: "primary",
+    });
+  });
+
   it("updateSessionStore preserves concurrent additions", async () => {
     const dir = await fs.mkdtemp(path.join(os.tmpdir(), "clawdbot-sessions-"));
     const storePath = path.join(dir, "sessions.json");
diff --git a/src/config/sessions/store.ts b/src/config/sessions/store.ts
index 3544cdcf0..3c8ead721 100644
--- a/src/config/sessions/store.ts
+++ b/src/config/sessions/store.ts
@@ -4,7 +4,13 @@ import path from "node:path";
 
 import JSON5 from "json5";
 import { getFileMtimeMs, isCacheEnabled, resolveCacheTtlMs } from "../cache-utils.js";
-import { normalizeSessionDeliveryFields } from "../../utils/delivery-context.js";
+import {
+  deliveryContextFromSession,
+  mergeDeliveryContext,
+  normalizeDeliveryContext,
+  normalizeSessionDeliveryFields,
+  type DeliveryContext,
+} from "../../utils/delivery-context.js";
 import { mergeSessionEntry, type SessionEntry } from "./types.js";
 
 // ============================================================================
@@ -323,20 +329,29 @@ export async function updateSessionStoreEntry(params: {
 export async function updateLastRoute(params: {
   storePath: string;
   sessionKey: string;
-  channel: SessionEntry["lastChannel"];
+  channel?: SessionEntry["lastChannel"];
   to?: string;
   accountId?: string;
+  deliveryContext?: DeliveryContext;
 }) {
   const { storePath, sessionKey, channel, to, accountId } = params;
   return await withSessionStoreLock(storePath, async () => {
     const store = loadSessionStore(storePath);
     const existing = store[sessionKey];
     const now = Date.now();
+    const explicitContext = normalizeDeliveryContext(params.deliveryContext);
+    const inlineContext = normalizeDeliveryContext({
+      channel,
+      to,
+      accountId,
+    });
+    const mergedInput = mergeDeliveryContext(explicitContext, inlineContext);
+    const merged = mergeDeliveryContext(mergedInput, deliveryContextFromSession(existing));
     const normalized = normalizeSessionDeliveryFields({
       deliveryContext: {
-        channel: channel ?? existing?.lastChannel ?? existing?.deliveryContext?.channel,
-        to: to ?? existing?.lastTo ?? existing?.deliveryContext?.to,
-        accountId: accountId ?? existing?.lastAccountId ?? existing?.deliveryContext?.accountId,
+        channel: merged?.channel,
+        to: merged?.to,
+        accountId: merged?.accountId,
       },
     });
     const next = mergeSessionEntry(existing, {
diff --git a/src/discord/monitor/message-handler.process.ts b/src/discord/monitor/message-handler.process.ts
index 46abc522d..d669cf4dd 100644
--- a/src/discord/monitor/message-handler.process.ts
+++ b/src/discord/monitor/message-handler.process.ts
@@ -272,9 +272,11 @@ export async function processDiscordMessage(ctx: DiscordMessagePreflightContext)
     await updateLastRoute({
       storePath,
       sessionKey: route.mainSessionKey,
-      channel: "discord",
-      to: `user:${author.id}`,
-      accountId: route.accountId,
+      deliveryContext: {
+        channel: "discord",
+        to: `user:${author.id}`,
+        accountId: route.accountId,
+      },
     });
   }
 
diff --git a/src/imessage/monitor.updates-last-route-chat-id-direct-messages.test.ts b/src/imessage/monitor.updates-last-route-chat-id-direct-messages.test.ts
index 37bb277dd..7fe151561 100644
--- a/src/imessage/monitor.updates-last-route-chat-id-direct-messages.test.ts
+++ b/src/imessage/monitor.updates-last-route-chat-id-direct-messages.test.ts
@@ -121,8 +121,10 @@ describe("monitorIMessageProvider", () => {
 
     expect(updateLastRouteMock).toHaveBeenCalledWith(
       expect.objectContaining({
-        channel: "imessage",
-        to: "+15550004444",
+        deliveryContext: expect.objectContaining({
+          channel: "imessage",
+          to: "+15550004444",
+        }),
       }),
     );
   });
diff --git a/src/imessage/monitor/monitor-provider.ts b/src/imessage/monitor/monitor-provider.ts
index 099b0779e..6593d0bb1 100644
--- a/src/imessage/monitor/monitor-provider.ts
+++ b/src/imessage/monitor/monitor-provider.ts
@@ -453,9 +453,11 @@ export async function monitorIMessageProvider(opts: MonitorIMessageOpts = {}): P
         await updateLastRoute({
           storePath,
           sessionKey: route.mainSessionKey,
-          channel: "imessage",
-          to,
-          accountId: route.accountId,
+          deliveryContext: {
+            channel: "imessage",
+            to,
+            accountId: route.accountId,
+          },
         });
       }
     }
diff --git a/src/signal/monitor/event-handler.ts b/src/signal/monitor/event-handler.ts
index 754fd3584..8a86ef945 100644
--- a/src/signal/monitor/event-handler.ts
+++ b/src/signal/monitor/event-handler.ts
@@ -143,9 +143,11 @@ export function createSignalEventHandler(deps: SignalEventHandlerDeps) {
       await updateLastRoute({
         storePath,
         sessionKey: route.mainSessionKey,
-        channel: "signal",
-        to: entry.senderRecipient,
-        accountId: route.accountId,
+        deliveryContext: {
+          channel: "signal",
+          to: entry.senderRecipient,
+          accountId: route.accountId,
+        },
       });
     }
 
diff --git a/src/slack/monitor/message-handler/dispatch.ts b/src/slack/monitor/message-handler/dispatch.ts
index 9f8d3ba7e..d50abacf5 100644
--- a/src/slack/monitor/message-handler/dispatch.ts
+++ b/src/slack/monitor/message-handler/dispatch.ts
@@ -32,9 +32,11 @@ export async function dispatchPreparedSlackMessage(prepared: PreparedSlackMessag
     await updateLastRoute({
       storePath,
       sessionKey: route.mainSessionKey,
-      channel: "slack",
-      to: `user:${message.user}`,
-      accountId: route.accountId,
+      deliveryContext: {
+        channel: "slack",
+        to: `user:${message.user}`,
+        accountId: route.accountId,
+      },
     });
   }
 
diff --git a/src/telegram/bot-message-context.ts b/src/telegram/bot-message-context.ts
index 5d068df4c..046ea3b6b 100644
--- a/src/telegram/bot-message-context.ts
+++ b/src/telegram/bot-message-context.ts
@@ -489,9 +489,11 @@ export const buildTelegramMessageContext = async ({
     await updateLastRoute({
       storePath,
       sessionKey: route.mainSessionKey,
-      channel: "telegram",
-      to: String(chatId),
-      accountId: route.accountId,
+      deliveryContext: {
+        channel: "telegram",
+        to: String(chatId),
+        accountId: route.accountId,
+      },
     });
   }
 
diff --git a/src/web/auto-reply/monitor/last-route.ts b/src/web/auto-reply/monitor/last-route.ts
index 692a2cfa0..6e52628d3 100644
--- a/src/web/auto-reply/monitor/last-route.ts
+++ b/src/web/auto-reply/monitor/last-route.ts
@@ -28,9 +28,11 @@ export function updateLastRouteInBackground(params: {
   const task = updateLastRoute({
     storePath,
     sessionKey: params.sessionKey,
-    channel: params.channel,
-    to: params.to,
-    accountId: params.accountId,
+    deliveryContext: {
+      channel: params.channel,
+      to: params.to,
+      accountId: params.accountId,
+    },
   }).catch((err) => {
     params.warn(
       {