feat: declare and test support for Python 3.14

.coveragerc

@@ -11,5 +11,9 @@ omit =
 [report]
 show_missing = true
 fail_under = 95
+# Python 3.14 (PEP 649) defers annotation evaluation, so a bare `_children_layout:`
+# declaration never executes and coverage stops counting it. Excluding it keeps the
+# total comparable across versions.
 exclude_lines =
     raise NotImplementedError
+    ^\s*_children_layout:

.github/workflows/pr_check.yml

@@ -13,11 +13,11 @@ jobs:
     runs-on: github-hosted-static-ip
     strategy:
       matrix:
-        python-version: ['3.8', '3.9', '3.10', '3.11', '3.12', '3.13']
+        python-version: ['3.8', '3.9', '3.10', '3.11', '3.12', '3.13', '3.14']
     steps:
       - uses: actions/checkout@master
       - name: Set up Python ${{ matrix.python-version }}
-        uses: actions/setup-python@v4
+        uses: actions/setup-python@v5
         with:
           python-version: ${{ matrix.python-version }}
       - name: Install dependencies

CHANGELOG.md

@@ -7,7 +7,10 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ## \[Unreleased\]
 
-- Nothing yet.
+### Added
+
+- Python 3.14 is now tested and declared as supported. No source changes were needed; the full
+  suite passes on 3.14 as-is.
 
 ## \[8.1.4\] - 2026-09-08
 

pyproject.toml

@@ -22,6 +22,7 @@ classifiers = [
     "Programming Language :: Python :: 3.11",
     "Programming Language :: Python :: 3.12",
     "Programming Language :: Python :: 3.13",
+    "Programming Language :: Python :: 3.14",
 ]
 requires-python = ">=3.8.0"
 

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist={py38}-unit,{py39}-unit,{py310}-unit,{py311}-unit,{py312}-unit,{py313}-unit
+envlist={py38}-unit,{py39}-unit,{py310}-unit,{py311}-unit,{py312}-unit,{py313}-unit,{py314}-unit
 skipsdist=true
 
 [gh-actions]
@@ -10,6 +10,7 @@ python =
     3.11: py311-unit
     3.12: py312-unit
     3.13: py313-unit
+    3.14: py314-unit
 
 [testenv]
 commands =