Flagship Changes

• Started a new glue library "stimflow" for qec circuit creation
• Added class stim.CliffordString
• Added prebuilt wheels for python 3.13 and python 3.14

Breaking Changes:

• Dropped support for versions of python past their end of life:
  • Python 3.6 (EOL 2021)
  • Python 3.7 (EOL 2023)
  • Python 3.8 (EOL 2024)
  • Python 3.9 (EOL 2025)

Notable Changes:

• stim.PauliString.__init__ now accepts dict[int, int | str] and dict[int | str, Iterable[int]] values
• Added method stim.Circuit.missing_detectors
• Added argument unknown_input=False to method stim.Circuit.count_determined_measurements
• Added method stim.FlipSimulator.append_measurement_flips
• Added pickling support to stim.CompiledMeasurementsToDetectionEventsConverter
• Added support for converting OBSERVABLE_INCLUDE instructions with pauli targets to stimcirq
• Added stim.CliffordString.
• Added sinter.plot_custom
• stim sample now uses loop folding to accelerate the collection of a reference sample from high-repetition-count circuits
  • Added --skip_loop_folding option to stim sample (as loop folding is slower in some cases)
• Added single_measure_key argument to stimcirq.stim_circuit_to_cirq_circuit
• Added basic support for feedback operations to stimcirq
• Added pymatching-correlated as a default supported decoder to sinter

Other Changes:

• Added operator[] to stim::ReferenceSampleTree
• Added more paper data references

Bug Fixes:

• Fixed stim.Circuit.explain_detector_error_model_errors mixing up Y/Z terms of PAULI_CHANNEL_2 errors
• Fixed stim.Circuit.explain_detector_error_model_errors over-counting HERALDED_ERASE measurements
• Fixed sinter not allowing numpy integers to be used as counts
• Fixed stim.Circuit.flow_generators inverting measurement index order within MPP instructions
• Fixed sinter.AnonTaskStats being overly anal about the types of counts it was given
• Fixed sinter postselection failing due to miscalculating an expected quantity

Special thanks to this release's contributors:

• Iftach Yakar (@DeDuckProject)
• Guen Prawiroatmodjo
• Amanda Xu (@amandashoe)
• Paul Conner (@qec-pconner)
• Benjamin Jones (@jenjaminbones)
• Dan Riley (@drqec)
• @akviz
• Alexandre Bourassa (@AlexBourassa)
• Mike Hucka (@mhucka)
• Simon Humpohl (@shumpohl)
• Matthew Neeley (@maffoo)
• Matt McEwen (@m-mcewen)
• Christopher J Wood (@chriseclectic)
• Adam Zalcman (@viathor)