diff --git a/extensions/telegram/src/action-runtime.ts b/extensions/telegram/src/action-runtime.ts
index 5aeac6c9511..6ca3982d5db 100644
--- a/extensions/telegram/src/action-runtime.ts
+++ b/extensions/telegram/src/action-runtime.ts
@@ -79,6 +79,10 @@ type RawTelegramButton = {
   text?: unknown;
 };
 
+function resolveTelegramForumTopicIconColor(value: number | undefined) {
+  return typeof value === "number" ? value : undefined;
+}
+
 function resolveTelegramPollVisibility(params: {
   pollAnonymous?: boolean;
   pollPublic?: boolean;
@@ -581,7 +585,9 @@ export async function handleTelegramAction(
     }
     const chatId = readTelegramChatId(params);
     const name = readStringParam(params, "name", { required: true });
-    const iconColor = readNumberParam(params, "iconColor", { integer: true });
+    const iconColor = resolveTelegramForumTopicIconColor(
+      readNumberParam(params, "iconColor", { integer: true }) ?? undefined,
+    );
     const iconCustomEmojiId = readStringParam(params, "iconCustomEmojiId");
     if (
       typeof iconColor === "number" &&
diff --git a/extensions/telegram/src/bot-message-context.ts b/extensions/telegram/src/bot-message-context.ts
index 26537325805..3186dc18353 100644
--- a/extensions/telegram/src/bot-message-context.ts
+++ b/extensions/telegram/src/bot-message-context.ts
@@ -76,7 +76,6 @@ export type TelegramMessageContext = {
   statusReactionController: StatusReactionController | null;
   accountId: string;
 };
-
 export const buildTelegramMessageContext = async ({
   primaryCtx,
   allMedia,
@@ -429,7 +428,7 @@ export const buildTelegramMessageContext = async ({
       : null;
 
   // When status reactions are enabled, setQueued() replaces the simple ack reaction
-  const ackReactionPromise = statusReactionController
+  const ackReactionPromise: Promise<boolean> | null = statusReactionController
     ? shouldAckReaction()
       ? Promise.resolve(statusReactionController.setQueued()).then(
           () => true,
@@ -469,7 +468,7 @@ export const buildTelegramMessageContext = async ({
     route,
     rawBody: bodyResult.rawBody,
     bodyText: bodyResult.bodyText,
-    historyKey: bodyResult.historyKey,
+    historyKey: bodyResult.historyKey ?? "",
     historyLimit,
     groupHistories,
     groupConfig,
@@ -493,7 +492,7 @@ export const buildTelegramMessageContext = async ({
     threadSpec,
     replyThreadId,
     isForum,
-    historyKey: bodyResult.historyKey,
+    historyKey: bodyResult.historyKey ?? "",
     historyLimit,
     groupHistories,
     route,
diff --git a/extensions/telegram/src/bot/types.ts b/extensions/telegram/src/bot/types.ts
index 3089317161d..516da65b23c 100644
--- a/extensions/telegram/src/bot/types.ts
+++ b/extensions/telegram/src/bot/types.ts
@@ -5,6 +5,7 @@ export type TelegramStreamMode = "off" | "partial" | "block";
 
 export type TelegramGetFile = () => Promise<{ file_path?: string }>;
 export type TelegramChatDetails = {
+  id?: number | string;
   available_reactions?: ChatFullInfo["available_reactions"] | null;
   is_forum?: boolean;
 };
diff --git a/extensions/telegram/src/draft-stream.ts b/extensions/telegram/src/draft-stream.ts
index bc9147664db..d44122e14d0 100644
--- a/extensions/telegram/src/draft-stream.ts
+++ b/extensions/telegram/src/draft-stream.ts
@@ -23,6 +23,16 @@ type TelegramSendMessageDraft = (
 
 type TelegramSendMessageParams = Parameters<Bot["api"]["sendMessage"]>[2];
 
+function hasNumericMessageThreadId(
+  params: TelegramSendMessageParams | undefined,
+): params is TelegramSendMessageParams & { message_thread_id: number } {
+  return (
+    typeof params === "object" &&
+    params !== null &&
+    typeof (params as { message_thread_id?: unknown }).message_thread_id === "number"
+  );
+}
+
 /**
  * Keep draft-id allocation shared across bundled chunks so concurrent preview
  * lanes do not accidentally reuse draft ids when code-split entries coexist.
@@ -179,9 +189,7 @@ export function createTelegramDraftStream(params: {
           parse_mode: sendArgs.renderedParseMode,
         }
       : replyParams;
-    const usedThreadParams =
-      typeof (sendParams as { message_thread_id?: unknown } | undefined)?.message_thread_id ===
-      "number";
+    const usedThreadParams = hasNumericMessageThreadId(sendParams);
     try {
       return {
         sent: await params.api.sendMessage(chatId, sendArgs.renderedText, sendParams),