fix: make session mutations atomic (#4212)

2026-08-06 14:49:57 +09:00
parent b47a0e4be7
commit 4a1773f405
13 changed files with 5586 additions and 502 deletions
@@ -450,7 +450,7 @@ Notes:

 -   `from_uri(...)` creates and owns the `AsyncMongoClient` and closes it on `session.close()`. An owned-client session is terminal after `close()`, and subsequent session operations raise `RuntimeError`. If your application already manages a client, construct `MongoDBSession(...)` directly with `client=...`; in that case `session.close()` is a no-op, and lifecycle plus session usability stay with the caller.
 -   Connect to [MongoDB Atlas](https://www.mongodb.com/products/platform) by passing an `mongodb+srv://user:password@cluster.example.mongodb.net` URI to `from_uri(...)` with no other changes.
-   Two collections are used and both names are configurable via `sessions_collection=` (default `agent_sessions`) and `messages_collection=` (default `agent_messages`). Indexes are created automatically on first use. Each message document carries a monotonically increasing `seq` counter that preserves ordering across concurrent writers and processes.
+-   Two collections are used and both names are configurable via `sessions_collection=` (default `agent_sessions`) and `messages_collection=` (default `agent_messages`). Indexes are created automatically on first use. Each non-empty `add_items()` call writes one logical-batch document whose monotonically increasing `seq` orders the batch by its final item; legacy per-item message documents remain readable. A logical batch must fit within MongoDB's single-document size limit; an oversized batch fails atomically without storing a partial batch.
 -   Use `await session.ping()` to verify connectivity before your first run.

 ### Advanced SQLite sessions