Limitations
Grimace’s current public runtime is exact for its supported writer language, not for every string RDKit can serialize.
Runtime options
The supported runtime mode is:
canonical=FalsedoRandom=TruerootedAtAtom=-1for all roots, orrootedAtAtom >= 0for one explicit root
Supported writer-surface flags are listed in Runtime.
RDKit serializer parity
Full RDKit serializer parity is not complete. The current reviewed RDKit
2026.03.1 serializer ledger is checked in and summarized by:
python scripts/report_rdkit_serializer_coverage.py
Known gaps are concentrated in coupled directional double-bond and ring-closure stereo cases. They are pinned as executable known-gap fixtures and summarized in RDKit serializer coverage.
Install surface
Package metadata declares Python >=3.11 and rdkit>=2026.3.
The exercised release assets are Linux x86_64 wheels for CPython 3.12 and
3.13, plus a source distribution. Other Python versions and non-Linux
platforms are expected source-build paths today.