fix(slack): only treat the agent's own bot as the last-agent-reply boundary

.changeset/slack-thread-last-agent-reply-own-bot.md

@@ -0,0 +1,5 @@
+---
+"eve": patch
+---
+
+Fix Slack `threadContext: { since: "last-agent-reply" }` treating every bot's message as the agent's own. In a thread where another Slack app also posts, the boundary was cut at the other bot's last message, silently dropping context (and sometimes leaving the agent with none). The channel now resolves its own bot id via `auth.test` and only marks the agent's own replies as the boundary.

packages/eve/src/public/channels/slack/api.test.ts

@@ -40,6 +40,11 @@ function buildFetchMock(): { fetch: ReturnType<typeof vi.fn>; calls: FetchCall[]
         { headers: { "content-type": "application/json" } },
       );
     }
+    if (url === "https://slack.com/api/auth.test") {
+      return new Response(JSON.stringify({ ok: true, bot_id: "B01", user_id: "U_BOT" }), {
+        headers: { "content-type": "application/json" },
+      });
+    }
     if (url === "https://slack.com/api/conversations.replies") {
       return new Response(
         JSON.stringify({
@@ -446,6 +451,51 @@ describe("SlackThread.refresh", () => {
     expect("author" in firstMessage).toBe(false);
     expect("metadata" in firstMessage).toBe(false);
   });
+
+  it("marks only the agent's own bot messages as isMe, not other apps", async () => {
+    // auth.test resolves our own bot id; a different bot in the thread must
+    // not count as the agent so "last-agent-reply" context isn't cut short.
+    const fetch = vi.fn(async (input: string | URL | Request) => {
+      const url = String(input);
+      if (url === "https://slack.com/api/auth.test") {
+        return new Response(JSON.stringify({ ok: true, bot_id: "B_SELF", user_id: "U_SELF" }), {
+          headers: { "content-type": "application/json" },
+        });
+      }
+      if (url === "https://slack.com/api/conversations.replies") {
+        return new Response(
+          JSON.stringify({
+            ok: true,
+            messages: [
+              { text: "hi", ts: "1.000001", thread_ts: "1.000001", user: "U01" },
+              { text: "our reply", ts: "1.000002", thread_ts: "1.000001", bot_id: "B_SELF" },
+              { text: "other bot", ts: "1.000003", thread_ts: "1.000001", bot_id: "B_OTHER" },
+            ],
+          }),
+          { headers: { "content-type": "application/json" } },
+        );
+      }
+      return new Response(JSON.stringify({ ok: true }), {
+        headers: { "content-type": "application/json" },
+      });
+    });
+    vi.stubGlobal("fetch", fetch);
+
+    const { thread } = buildSlackBinding({
+      botToken: "xoxb-test",
+      channelId: "C01",
+      threadTs: "1.000001",
+      teamId: undefined,
+    });
+
+    await thread.refresh();
+
+    expect(thread.recentMessages.map((m) => [m.botId, m.isMe])).toEqual([
+      [undefined, false],
+      ["B_SELF", true],
+      ["B_OTHER", false],
+    ]);
+  });
 });
 
 describe("SlackThread.postEphemeral", () => {

packages/eve/src/public/channels/slack/api.ts

@@ -195,6 +195,10 @@ export interface SlackThreadMessage {
   readonly botId: string | undefined;
   readonly ts: string;
   readonly threadTs: string;
+  /**
+   * True only when this message was posted by the agent's own Slack app.
+   * Messages from other bots have `botId` set but are not `isMe`.
+   */
   readonly isMe: boolean;
   readonly raw: Record<string, unknown>;
 }
@@ -343,6 +347,30 @@ export function buildSlackBinding(input: {
     input.onThreadTsChanged?.(ts);
   }
 
+  // Slack thread replies expose only a `bot_id` per message, so telling the
+  // agent's own replies apart from other apps' bots requires knowing our own
+  // bot id. Resolve it once per binding via `auth.test`; on failure we treat
+  // no message as agent-authored (safer to over-include thread context than to
+  // silently cut it at another bot's message).
+  let ownBotIdPromise: Promise<string | undefined> | undefined;
+  function resolveOwnBotId(): Promise<string | undefined> {
+    if (ownBotIdPromise) return ownBotIdPromise;
+    const promise = (async () => {
+      try {
+        const response = await request("auth.test", {});
+        return typeof response.bot_id === "string" ? response.bot_id : undefined;
+      } catch (error) {
+        logError(log, "auth.test threw — cannot identify own bot for thread context", error, {
+          channelId: input.channelId,
+        });
+        ownBotIdPromise = undefined;
+        return undefined;
+      }
+    })();
+    ownBotIdPromise = promise;
+    return promise;
+  }
+
   async function uploadFiles(
     files: readonly FileUpload[],
     options?: SlackUploadFilesOptions,
@@ -441,14 +469,17 @@ export function buildSlackBinding(input: {
       messages.length = 0;
       if (!input.channelId || !currentThreadTs) return;
       try {
-        const response = await fetchSlackThreadReplies({
-          ...createSlackApiOptions(input.botToken),
-          channel: input.channelId,
-          limit: 50,
-          ts: currentThreadTs,
-        });
+        const [response, ownBotId] = await Promise.all([
+          fetchSlackThreadReplies({
+            ...createSlackApiOptions(input.botToken),
+            channel: input.channelId,
+            limit: 50,
+            ts: currentThreadTs,
+          }),
+          resolveOwnBotId(),
+        ]);
         for (const raw of response.messages as Record<string, unknown>[]) {
-          messages.push(parseThreadMessage(raw, currentThreadTs));
+          messages.push(parseThreadMessage(raw, currentThreadTs, ownBotId));
         }
       } catch (error) {
         logError(log, "refresh threw — swallowed", error, { channelId: input.channelId });
@@ -552,6 +583,7 @@ function normalizeFileData(data: FileUpload["data"]): SlackFileUpload["data"] {
 function parseThreadMessage(
   raw: Record<string, unknown>,
   threadRootTs: string,
+  ownBotId: string | undefined,
 ): SlackThreadMessage {
   const text = typeof raw.text === "string" ? raw.text : "";
   const ts = typeof raw.ts === "string" ? raw.ts : "";
@@ -565,7 +597,7 @@ function parseThreadMessage(
     botId,
     ts,
     threadTs,
-    isMe: botId !== undefined,
+    isMe: ownBotId !== undefined && botId === ownBotId,
     raw,
   };
 }