Elior Nataf LackritzandGitHub
658541c496
Follow-up to review on #8537: turn on ruff's `PLC0415` (`import-outside-top-level`) so deferred imports in tests stop accumulating. Scoped to `checkpoint-postgres` and `checkpoint-sqlite` rather than repo-wide, because the sweep turns up three different things and only one of them is a style problem. ### What the rule finds today ``` package tests src files checkpoint 13 10 11 checkpoint-conformance 0 10 4 checkpoint-postgres 6 0 2 checkpoint-sqlite 9 0 3 langgraph 130 23 32 prebuilt 14 3 7 cli 9 14 10 sdk-py 189 23 38 ──────────────────── 370 83 107 ``` 453 violations across 107 files, and ruff has no autofix for this rule. ### Three categories, not one **Style — hoist.** `checkpoint-sqlite/tests/test_store.py` deferred `math`, `random`, `time`, `Counter` and `defaultdict` inside methods for no reason. **Deliberate — keep, annotate.** `checkpoint-postgres/tests/test_async.py` defers behind `pytest.importorskip("langgraph.channels.delta")` because langgraph core is *not* a test dependency of that package. Hoisting would break the skip. Those get `# noqa: PLC0415` and a comment. **Redundant guard — hoist.** `checkpoint-sqlite/tests/test_conformance_delta.py` deferred imports only to get past its own `importorskip`. Imports move up; the `aiosqlite` guard stays, since that dependency genuinely can be absent. The second category is why I did not enable this everywhere in one go. Most of the 83 source-level violations look like the same pattern — optional-dependency handling and circular-import avoidance in `jsonplus.py`, `embed.py`, `encrypted.py` and friends. Blanket-enabling would mean `# noqa` on a lot of correct code, and each one wants an owner's eye rather than a mechanical pass. These two packages are clean to enforce today because both have **zero** source-level violations. ### Suggested rollout for the rest Either extend package by package as owners confirm which deferrals are intentional, or enable everywhere at once with `per-file-ignores` grandfathering the current 107 files so new code is blocked immediately and the debt burns down. Happy to do either — the second is a smaller diff but leaves a long ignore list. ### Verified `checkpoint-sqlite` 118 passed, `checkpoint-postgres` 264 passed on PG 15 and 16, `make lint` clean in both. One overlap worth flagging: `checkpoint-sqlite/tests/test_conformance_delta.py` is also touched by #8537. The change is identical in both, so it should merge cleanly either way.
LangGraph SQLite Checkpoint
To help you ship LangGraph apps to production faster, check out LangSmith. LangSmith is a unified developer platform for building, testing, and monitoring LLM applications.
Quick Install
uv add langgraph-checkpoint-sqlite
🤔 What is this?
This library provides a SQLite implementation of LangGraph's checkpoint saver, with both sync and async support via aiosqlite. Use it when you want LangGraph state persistence backed by SQLite for local development, testing, or lightweight deployments.
📖 Documentation
For full documentation, see the API reference. For conceptual guides on persistence and memory, see the LangGraph Docs.
Security
Important
Set
LANGGRAPH_STRICT_MSGPACK=trueor pass an explicitallowed_msgpack_moduleslist when creating your checkpointer. This restricts checkpoint deserialization to known-safe types, preventing code execution if the database is compromised. See the langgraph-checkpoint README for details.
Usage
from langgraph.checkpoint.sqlite import SqliteSaver
write_config = {"configurable": {"thread_id": "1", "checkpoint_ns": ""}}
read_config = {"configurable": {"thread_id": "1"}}
with SqliteSaver.from_conn_string(":memory:") as checkpointer:
checkpoint = {
"v": 4,
"ts": "2024-07-31T20:14:19.804150+00:00",
"id": "1ef4f797-8335-6428-8001-8a1503f9b875",
"channel_values": {
"my_key": "meow",
"node": "node"
},
"channel_versions": {
"__start__": 2,
"my_key": 3,
"start:node": 3,
"node": 3
},
"versions_seen": {
"__input__": {},
"__start__": {
"__start__": 1
},
"node": {
"start:node": 2
}
},
}
# store checkpoint
checkpointer.put(write_config, checkpoint, {}, {})
# load checkpoint
checkpointer.get(read_config)
# list checkpoints
list(checkpointer.list(read_config))
Async
from langgraph.checkpoint.sqlite.aio import AsyncSqliteSaver
async with AsyncSqliteSaver.from_conn_string(":memory:") as checkpointer:
checkpoint = {
"v": 4,
"ts": "2024-07-31T20:14:19.804150+00:00",
"id": "1ef4f797-8335-6428-8001-8a1503f9b875",
"channel_values": {
"my_key": "meow",
"node": "node"
},
"channel_versions": {
"__start__": 2,
"my_key": 3,
"start:node": 3,
"node": 3
},
"versions_seen": {
"__input__": {},
"__start__": {
"__start__": 1
},
"node": {
"start:node": 2
}
},
}
# store checkpoint
await checkpointer.aput(write_config, checkpoint, {}, {})
# load checkpoint
await checkpointer.aget(read_config)
# list checkpoints
[c async for c in checkpointer.alist(read_config)]
📕 Releases & Versioning
See our Releases and Versioning policies.
💁 Contributing
As an open-source project in a rapidly developing field, we are extremely open to contributions, whether it be in the form of a new feature, improved infrastructure, or better documentation.
For detailed information on how to contribute, see the Contributing Guide.