fix: handle signal reactions safely (#616) (thanks @neist)

CHANGELOG.md

@@ -102,6 +102,7 @@
 - Pairing: replies now include sender ids for Discord/Slack/Signal/iMessage/WhatsApp; pairing list labels them explicitly.
 - Messages: default inbound/outbound prefixes from the routed agent’s `identity.name` when set. (#578) — thanks @p6l-richard
 - Signal: accept UUID-only senders for pairing/allowlists/routing when sourceNumber is missing. (#523) — thanks @neist
+- Signal: ignore reaction-only messages so they don't surface as unknown media. (#616) — thanks @neist
 - Agent system prompt: avoid automatic self-updates unless explicitly requested.
 - Onboarding: tighten QuickStart hint copy for configuring later.
 - Onboarding: set Gemini 3 Pro as the default model for Gemini API key auth. (#489) — thanks @jonasjancarik

src/signal/monitor.tool-result.test.ts

@@ -153,6 +153,42 @@ describe("monitorSignalProvider tool results", () => {
     );
   });
 
+  it("ignores reaction-only messages", async () => {
+    const abortController = new AbortController();
+
+    streamMock.mockImplementation(async ({ onEvent }) => {
+      const payload = {
+        envelope: {
+          sourceNumber: "+15550001111",
+          sourceName: "Ada",
+          timestamp: 1,
+          reactionMessage: {
+            emoji: "👍",
+            targetAuthor: "+15550002222",
+            targetSentTimestamp: 2,
+          },
+        },
+      };
+      await onEvent({
+        event: "receive",
+        data: JSON.stringify(payload),
+      });
+      abortController.abort();
+    });
+
+    await monitorSignalProvider({
+      autoStart: false,
+      baseUrl: "http://127.0.0.1:8080",
+      abortSignal: abortController.signal,
+    });
+
+    await flush();
+
+    expect(replyMock).not.toHaveBeenCalled();
+    expect(sendMock).not.toHaveBeenCalled();
+    expect(updateLastRouteMock).not.toHaveBeenCalled();
+  });
+
   it("does not resend pairing code when a request is already pending", async () => {
     config = {
       ...config,

src/signal/monitor.ts

@@ -315,11 +315,12 @@ export async function monitorSignalProvider(
       if (!envelope) return;
       if (envelope.syncMessage) return;
 
-      // Handle reaction messages
-      if (envelope.reactionMessage) {
+      const dataMessage =
+        envelope.dataMessage ?? envelope.editMessage?.dataMessage;
+      if (envelope.reactionMessage && !dataMessage) {
         const reaction = envelope.reactionMessage;
         if (reaction.isRemove) return; // Ignore reaction removals
-        const emoji = reaction.emoji ?? "👍";
+        const emoji = reaction.emoji ?? "unknown";
         const sender = resolveSignalSender(envelope);
         if (!sender) return;
         const senderDisplay = formatSignalSenderDisplay(sender);
@@ -329,9 +330,6 @@ export async function monitorSignalProvider(
         // Future: could dispatch as a notification or store for context
         return;
       }
-
-      const dataMessage =
-        envelope.dataMessage ?? envelope.editMessage?.dataMessage;
       if (!dataMessage) return;
 
       const sender = resolveSignalSender(envelope);