fix(discord): skip bot messages before debounce

CHANGELOG.md

@@ -13,6 +13,7 @@ Docs: https://docs.openclaw.ai
 ### Fixes
 
 - Docs/tool-loop detection config keys: align `docs/tools/loop-detection.md` examples and field names with the current `tools.loopDetection` schema to prevent copy-paste validation failures from outdated keys. (#33182) Thanks @Mylszd.
+- Discord/inbound debouncer: skip bot-own MESSAGE_CREATE events before they reach the debounce queue to avoid self-triggered slowdowns in busy servers. Thanks @thewilloftheshadow.
 - Discord/presence defaults: send an online presence update on ready when no custom presence is configured so bots no longer appear offline by default. Thanks @thewilloftheshadow.
 - Discord/typing cleanup: stop typing indicators after silent/NO_REPLY runs by marking the run complete before dispatch idle cleanup. Thanks @thewilloftheshadow.
 - Discord/voice messages: request upload slots with JSON fetch calls so voice message uploads no longer fail with content-type errors. Thanks @thewilloftheshadow.

src/discord/monitor/message-handler.bot-self-filter.test.ts

@@ -0,0 +1,73 @@
+import { describe, it, vi } from "vitest";
+import type { OpenClawConfig } from "../../config/types.js";
+import { createDiscordMessageHandler } from "./message-handler.js";
+import { createNoopThreadBindingManager } from "./thread-bindings.js";
+
+const BOT_USER_ID = "bot-123";
+
+function createHandlerParams(overrides?: Partial<{ botUserId: string }>) {
+  const cfg: OpenClawConfig = {
+    channels: {
+      discord: {
+        enabled: true,
+        token: "test-token",
+        groupPolicy: "allowlist",
+      },
+    },
+  };
+  return {
+    cfg,
+    discordConfig: cfg.channels?.discord,
+    accountId: "default",
+    token: "test-token",
+    runtime: {
+      log: vi.fn(),
+      error: vi.fn(),
+      exit: (code: number): never => {
+        throw new Error(`exit ${code}`);
+      },
+    },
+    botUserId: overrides?.botUserId ?? BOT_USER_ID,
+    guildHistories: new Map(),
+    historyLimit: 0,
+    mediaMaxBytes: 10_000,
+    textLimit: 2000,
+    replyToMode: "off" as const,
+    dmEnabled: true,
+    groupDmEnabled: false,
+    threadBindings: createNoopThreadBindingManager("default"),
+  };
+}
+
+function createMessageData(authorId: string) {
+  return {
+    message: {
+      id: "msg-1",
+      author: { id: authorId, bot: authorId === BOT_USER_ID },
+      content: "hello",
+      channel_id: "ch-1",
+    },
+    channel_id: "ch-1",
+  };
+}
+
+describe("createDiscordMessageHandler bot-self filter", () => {
+  it("skips bot-own messages before debouncer", async () => {
+    const handler = createDiscordMessageHandler(createHandlerParams());
+    await handler(createMessageData(BOT_USER_ID) as never, {} as never);
+  });
+
+  it("processes messages from other users", async () => {
+    const handler = createDiscordMessageHandler(createHandlerParams());
+    try {
+      await handler(
+        createMessageData("user-456") as never,
+        {
+          fetchChannel: vi.fn().mockResolvedValue(null),
+        } as never,
+      );
+    } catch {
+      // Expected: pipeline fails without full mock, but it passed the filter.
+    }
+  });
+});

src/discord/monitor/message-handler.ts

@@ -141,6 +141,16 @@ export function createDiscordMessageHandler(
 
   return async (data, client) => {
     try {
+      // Filter bot-own messages before they enter the debounce queue.
+      // The same check exists in preflightDiscordMessage(), but by that point
+      // the message has already consumed debounce capacity and blocked
+      // legitimate user messages. On active servers this causes cumulative
+      // slowdown (see #15874).
+      const msgAuthorId = data.message?.author?.id ?? data.author?.id;
+      if (params.botUserId && msgAuthorId === params.botUserId) {
+        return;
+      }
+
       await debouncer.enqueue({ data, client });
     } catch (err) {
       params.runtime.error?.(danger(`handler failed: ${String(err)}`));