fix(telegram): avoid duplicate dm chat window context

sweetcornna · sweetcornna · commit d68002acdcaa · 2026-06-03T21:38:13.000+08:00
diff --git a/extensions/telegram/src/bot-message-context.prompt-context.test.ts b/extensions/telegram/src/bot-message-context.prompt-context.test.ts
@@ -0,0 +1,78 @@
+import { describe, expect, it } from "vitest";
+import { buildTelegramMessageContextForTest } from "./bot-message-context.test-harness.js";
+import type { TelegramPromptContextEntry } from "./bot-message-context.types.js";
+
+const telegramChatWindowContext: TelegramPromptContextEntry = {
+  label: "Conversation context",
+  source: "telegram",
+  type: "chat_window",
+  payload: {
+    order: "chronological",
+    relation: "selected_for_current_message",
+    messages: [
+      {
+        message_id: "10",
+        sender: "Pat",
+        timestamp_ms: 1_700_000_000_000,
+        body: "Earlier DM turn already in the transcript",
+      },
+    ],
+  },
+};
+
+describe("buildTelegramMessageContext prompt context", () => {
+  it("omits Telegram chat-window context for existing unthreaded private DM sessions", async () => {
+    const ctx = await buildTelegramMessageContextForTest({
+      message: {
+        chat: { id: 1234, type: "private", first_name: "Pat" },
+        from: { id: 1234, first_name: "Pat" },
+        text: "continue",
+      },
+      promptContext: [telegramChatWindowContext],
+      sessionRuntime: {
+        readSessionUpdatedAt: ({ sessionKey }) =>
+          sessionKey === "agent:main:main" ? 1_700_000_000_000 : undefined,
+      },
+    });
+
+    expect(ctx?.ctxPayload.SessionKey).toBe("agent:main:main");
+    expect(ctx?.ctxPayload.UntrustedStructuredContext).toBeUndefined();
+  });
+
+  it("keeps Telegram chat-window context for fresh private DM sessions", async () => {
+    const ctx = await buildTelegramMessageContextForTest({
+      message: {
+        chat: { id: 1234, type: "private", first_name: "Pat" },
+        from: { id: 1234, first_name: "Pat" },
+        text: "start",
+      },
+      promptContext: [telegramChatWindowContext],
+    });
+
+    expect(ctx?.ctxPayload.UntrustedStructuredContext).toEqual([telegramChatWindowContext]);
+  });
+
+  it("keeps Telegram chat-window context for existing private DM replies", async () => {
+    const ctx = await buildTelegramMessageContextForTest({
+      message: {
+        chat: { id: 1234, type: "private", first_name: "Pat" },
+        from: { id: 1234, first_name: "Pat" },
+        text: "replying with context",
+        reply_to_message: {
+          chat: { id: 1234, type: "private", first_name: "Pat" },
+          from: { id: 1234, first_name: "Pat" },
+          text: "older referenced turn",
+          date: 1_700_000_000,
+          message_id: 10,
+        },
+      },
+      promptContext: [telegramChatWindowContext],
+      sessionRuntime: {
+        readSessionUpdatedAt: ({ sessionKey }) =>
+          sessionKey === "agent:main:main" ? 1_700_000_000_000 : undefined,
+      },
+    });
+
+    expect(ctx?.ctxPayload.UntrustedStructuredContext).toEqual([telegramChatWindowContext]);
+  });
+});
diff --git a/extensions/telegram/src/bot-message-context.session.ts b/extensions/telegram/src/bot-message-context.session.ts
@@ -101,6 +101,10 @@ export async function resolveTelegramMessageContextStorePath(params: {
   });
 }
 
+function isTelegramChatWindowPromptContext(entry: TelegramPromptContextEntry): boolean {
+  return entry.source === "telegram" && entry.type === "chat_window";
+}
+
 function replyTargetToChainEntry(replyTarget: TelegramReplyTarget): TelegramReplyChainEntry {
   return {
     ...(replyTarget.id ? { messageId: replyTarget.id } : {}),
@@ -361,6 +365,17 @@ export async function buildTelegramInboundContextPayload(params: {
     storePath,
     sessionKey: route.sessionKey,
   });
+  const shouldSuppressPersistedDmChatWindowContext =
+    !isGroup &&
+    previousTimestamp !== undefined &&
+    dmThreadId == null &&
+    visibleReplyChain.length === 0 &&
+    !visibleReplyTarget;
+  // Existing plain DMs already carry their history through the persistent
+  // transcript. Keep chat windows for fresh DMs, topics, replies, and groups.
+  const visiblePromptContext = shouldSuppressPersistedDmChatWindowContext
+    ? promptContext.filter((entry) => !isTelegramChatWindowPromptContext(entry))
+    : promptContext;
   const body = formatInboundEnvelope({
     channel: "Telegram",
     from: conversationLabel,
@@ -530,7 +545,7 @@ export async function buildTelegramInboundContextPayload(params: {
           }
         : undefined,
       groupSystemPrompt: isGroup || (!isGroup && groupConfig) ? groupSystemPrompt : undefined,
-      untrustedContext: promptContext.length > 0 ? promptContext : undefined,
+      untrustedContext: visiblePromptContext.length > 0 ? visiblePromptContext : undefined,
     },
     contextVisibility: contextVisibilityMode,
     extra: {
diff --git a/extensions/telegram/src/bot-message-context.test-harness.ts b/extensions/telegram/src/bot-message-context.test-harness.ts
@@ -22,6 +22,7 @@ type BuildTelegramMessageContextForTestParams = {
   message: Record<string, unknown>;
   me?: Record<string, unknown>;
   allMedia?: TelegramMediaRef[];
+  promptContext?: BuildTelegramMessageContextParams["promptContext"];
   options?: BuildTelegramMessageContextParams["options"];
   cfg?: Record<string, unknown>;
   accountId?: string;
@@ -111,6 +112,7 @@ export async function buildTelegramMessageContextForTest(
       me: { id: 7, username: "bot", ...params.me },
     } as never,
     allMedia: params.allMedia ?? [],
+    promptContext: params.promptContext ?? [],
     storeAllowFrom: [],
     options: params.options ?? {},
     bot: {
