fix(channels): normalize MIME kind parsing and reaction fallbacks

src/channels/plugins/actions/actions.test.ts

@@ -456,6 +456,43 @@ describe("handleDiscordMessageAction", () => {
       expect.objectContaining({ mediaLocalRoots: ["/tmp/agent-root"] }),
     );
   });
+
+  it("falls back to toolContext.currentMessageId for reactions when messageId is omitted", async () => {
+    await handleDiscordMessageAction({
+      action: "react",
+      params: {
+        channelId: "123",
+        emoji: "ok",
+      },
+      cfg: {} as OpenClawConfig,
+      toolContext: { currentMessageId: "9001" },
+    });
+
+    const call = handleDiscordAction.mock.calls.at(-1);
+    expect(call?.[0]).toEqual(
+      expect.objectContaining({
+        action: "react",
+        channelId: "123",
+        messageId: "9001",
+        emoji: "ok",
+      }),
+    );
+  });
+
+  it("rejects reactions when neither messageId nor toolContext.currentMessageId is provided", async () => {
+    await expect(
+      handleDiscordMessageAction({
+        action: "react",
+        params: {
+          channelId: "123",
+          emoji: "ok",
+        },
+        cfg: {} as OpenClawConfig,
+      }),
+    ).rejects.toThrow(/messageId required/i);
+
+    expect(handleDiscordAction).not.toHaveBeenCalled();
+  });
 });
 
 describe("telegramMessageActions", () => {

src/channels/plugins/actions/discord/handle-action.ts

@@ -8,6 +8,7 @@ import { readDiscordParentIdParam } from "../../../../agents/tools/discord-actio
 import { handleDiscordAction } from "../../../../agents/tools/discord-actions.js";
 import { resolveDiscordChannelId } from "../../../../discord/targets.js";
 import type { ChannelMessageActionContext } from "../../types.js";
+import { resolveReactionMessageId } from "../reaction-message-id.js";
 import { tryHandleDiscordMessageActionGuildAdmin } from "./handle-action.guild-admin.js";
 
 const providerId = "discord";
@@ -107,7 +108,13 @@ export async function handleDiscordMessageAction(
   }
 
   if (action === "react") {
-    const messageId = readStringParam(params, "messageId", { required: true });
+    const messageIdRaw = resolveReactionMessageId({ args: params, toolContext: ctx.toolContext });
+    const messageId = messageIdRaw != null ? String(messageIdRaw).trim() : "";
+    if (!messageId) {
+      throw new Error(
+        "messageId required. Provide messageId explicitly or react to the current inbound message.",
+      );
+    }
     const emoji = readStringParam(params, "emoji", { allowEmpty: true });
     const remove = typeof params.remove === "boolean" ? params.remove : undefined;
     return await handleDiscordAction(