Authoritative Sources

This skill was refreshed on 2026-07-23 against the sources below. Examples target the current stable package release at that date: FlowIO 1.4.0, published 2025-05-09.

When upstream behavior and this skill differ, prefer the tagged upstream source and official API documentation, then update this skill and increment its version.

Package and Release

• FlowIO on PyPI — stable version, release date, supported Python classifiers, dependency metadata, and project links.
• FlowIO 1.4.0 release notes — Python 3.13 support, as_array(), constructor rename, convenience attributes, NumPy dependency, public fcs_keywords, Path support, and writer/timestep changes.
• All FlowIO releases — migration and bug-fix history.
• FlowIO 1.4.0 tagged source — immutable implementation baseline used to verify edge behavior.
• FlowIO 1.4.0 package metadata — supported Python versions and NumPy dependency.

Official Documentation and User Guide

• FlowIO documentation — official entry point and installation overview.
• FlowIO tutorial — official 1.4.0 user guide covering FCS segments, metadata, event values, export, keyword lists, multiple datasets, creation, and exceptions.
• FlowIO API — generated signatures and public API reference.
• FlowData 1.4.0 source — metadata normalization, offset behavior, event parsing, preprocessing, and write_fcs().
• create_fcs 1.4.0 source — writer signature, validation, metadata rules, output representation, and float precision.
• read_multiple_data_sets 1.4.0 source — relative $NEXTDATA traversal and invalid-offset handling.
• FlowIO exceptions 1.4.0 source — warning and exception hierarchy.

Flow Cytometry Standard

• Spidlen J, et al. Data File Standard for Flow Cytometry, version FCS 3.1. Cytometry Part A. 2010;77A(1):97-100. doi:10.1002/cyto.a.20825
• Bray C, Spidlen J, Brinkman RR. FCS 3.1 Implementation Guidance. Cytometry Part A. 2012;81(6):523-526. doi:10.1002/cyto.a.22018
• Free full text of the FCS 3.1 implementation guidance — spillover, display, and compatibility guidance.

FlowIO reads FCS 2.0/3.0/3.1 and writes FCS 3.1. The standard publications are needed when byte offsets, keywords, spillover metadata, or representation details affect scientific interpretation.

Higher-Level Analysis Boundary

• FlowKit project — related package for compensation, transformations, gating, GatingML, and FlowJo workspace support.
• FlowKit documentation — use when a task moves beyond low-level FCS I/O.

Verification Notes

During this refresh:

• PyPI, the latest GitHub release endpoint, and official documentation all identified 1.4.0 as the stable release.
• Runtime signatures were checked in an isolated flowio==1.4.0 environment.
• Read/write behavior was round-tripped with a generated FCS 3.1 file.
• Runtime edge tests covered null-channel storage, literal $ removal from TEXT values, caller-owned handle closure, and PnG/timestep loss during write_fcs().
• The tagged implementation was used where generated API prose omitted details, especially metadata normalization and writer behavior.
• No FlowIO-specific Context7 documentation entry was available; official Read the Docs, tagged source, PyPI, and GitHub releases were used instead.
• Big-endian writer portability remains unverified. The 1.4.0 writer declares little-endian output while using Python's native-endian array('f') bytes; validate exports on big-endian hardware rather than assuming portability.