feat(backend): read time of my messages from the archive, exact dates and group readers asked from telegram on demand

backend/src/api/mcp/server.py

@@ -23,6 +23,7 @@ from utils.files import resolve_mime
 from utils.read import annotations, chats, media, peers, presence, social, watches
 from utils.read.accounts import self_user_id, unknown_account_hint
 from utils.read.models import DEFAULT_LIMIT, Page
+from utils.read.read_receipts import read_info
 from utils.search.models import SearchFilters
 from utils.search.repository import search_messages
 from utils.storage import ContentAddressedStorage
@@ -295,6 +296,23 @@ async def get_callbacks(
     return _dump(items)
 
 
+@mcp.tool
+async def get_read_info(
+    account_id: int, chat_id: int, message_id: int
+) -> dict[str, Any] | None:
+    """When the user's own message was read, from the archive only.
+
+    `observed_at` is when the archive saw the chat read up to this message,
+    `exact_at` the read date Telegram reported for a private chat, `readers`
+    who read it in a group and when, `listened_at` when a voice or round
+    video was played. `outcome` is the last Telegram answer: ok, not_read_yet,
+    user_privacy (they hide read time), your_privacy (the user hides theirs),
+    chat_too_big, too_old, unavailable, flood or error.
+    """
+    info = await read_info(await _pool(), account_id, chat_id, message_id)
+    return info.model_dump(mode="json") if info else None
+
+
 @mcp.tool
 async def presence_history(
     account_id: int,