diff --git a/src/commands/telegram.ts b/src/commands/telegram.ts
index d709432a..05d1360b 100644
--- a/src/commands/telegram.ts
+++ b/src/commands/telegram.ts
@@ -1,4 +1,4 @@
-import { ensureProjectClaudeMd, run, runUserMessage, runFork, killActive, isMainBusy, compactCurrentSession, compactCurrentThreadSession, isRateLimited, getRateLimitResetAt, getPermissionMode, setPermissionMode, type PermissionMode } from "../runner";
+import { ensureProjectClaudeMd, run, runUserMessage, runFork, killActive, isThreadBusy, isGlobalBusy, compactCurrentSession, compactCurrentThreadSession, isRateLimited, getRateLimitResetAt, getPermissionMode, setPermissionMode, type PermissionMode } from "../runner";
 import { wrapUntrusted } from "../prompt-safety";
 import { isAllowed } from "../allowlist";
 import { extractErrorDetail } from "../messaging";
@@ -1444,14 +1444,16 @@ async function handleMessage(message: TelegramMessage): Promise<void> {
       );
     }
     const prefixedPrompt = promptParts.join("\n");
-    const busy = isMainBusy();
+    // Per-thread busy check: only reject if THIS topic's queue (or the global
+    // session for non-topic chats) is mid-run. Different topics run in parallel.
+    const busy = sessionKey ? isThreadBusy(sessionKey) : isGlobalBusy();
     const verbose = verboseChats.has(chatId);
     const modelOverride = chatModels.get(chatId);
     let result;
     let streamMsgId: number | null = null;
     let hadToolLines = false;
     if (busy) {
-      await sendMessage(config.token, chatId, "Claude is busy — try again in a moment, or use /fork for a quick parallel task.", threadId);
+      await sendMessage(config.token, chatId, "Claude is still working on the previous message in this topic — try again in a moment, or use /fork for a quick parallel task.", threadId);
       return;
     } else {
       const stream = makeStreamCallback(config.token, chatId, threadId, { verbose });
diff --git a/src/runner.ts b/src/runner.ts
index 7d0ee6a1..00cacd2c 100644
--- a/src/runner.ts
+++ b/src/runner.ts
@@ -298,6 +298,22 @@ export function isMainBusy(): boolean {
   return mainRunCount > 0;
 }
 
+// Busy state per thread queue + global queue, so handlers can allow
+// parallel runs across different topics/threads while still rejecting
+// a second message to the SAME thread (or the global session).
+const busyThreads = new Set<string>();
+let busyGlobalCount = 0;
+
+/** True while THIS thread's queue is processing a task. */
+export function isThreadBusy(threadId: string): boolean {
+  return busyThreads.has(threadId);
+}
+
+/** True while a global-session (non-thread) run is in flight. */
+export function isGlobalBusy(): boolean {
+  return busyGlobalCount > 0;
+}
+
 function extractRateLimitMessage(stdout: string, stderr: string): string | null {
   const candidates = [stdout, stderr];
   for (const text of candidates) {
@@ -1031,6 +1047,7 @@ async function execClaude(
   onToolEvent?: (line: string) => void
 ): Promise<RunResult> {
   mainRunCount++;
+  if (threadId) busyThreads.add(threadId); else busyGlobalCount++;
   persistRunCount();
   try {
   await mkdir(LOGS_DIR, { recursive: true });
@@ -1426,6 +1443,7 @@ async function execClaude(
   return result;
   } finally {
     mainRunCount--;
+    if (threadId) busyThreads.delete(threadId); else busyGlobalCount = Math.max(0, busyGlobalCount - 1);
     persistRunCount();
   }
 }