From 0323b0645e42bf91b5e0b4feebc3a323968b22ed Mon Sep 17 00:00:00 2001
From: Stephen Rosen <sirosen@globus.org>
Date: Thu, 26 Feb 2026 18:11:20 -0600
Subject: [PATCH] Remove support for Python 3.9

---
 .github/workflows/build.yaml |  4 ++--
 .pre-commit-config.yaml      |  2 +-
 CHANGELOG.rst                |  1 +
 pyproject.toml               |  2 +-
 tox.ini                      | 10 +++++-----
 5 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index 99c37e2eb..1a1da8c9f 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -11,7 +11,7 @@ jobs:
         py: ["3.x"]
         include:
           - toxenv: py-mindeps
-            py: "3.9"
+            py: "3.10"
 
     runs-on: ubuntu-latest
     name: "'${{ matrix.toxenv }}' on py${{ matrix.py }}"
@@ -62,7 +62,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu, windows, macos]
-        py: ['3.9', '3.10', '3.11', '3.12', '3.13', '3.14']
+        py: ['3.10', '3.11', '3.12', '3.13', '3.14']
     name: "Test on ${{ matrix.os }}, py${{ matrix.py }}"
     runs-on: "${{ matrix.os }}-latest"
     steps:
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index cad85f659..46d91a2e0 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -47,4 +47,4 @@ repos:
   rev: v3.21.2
   hooks:
     - id: pyupgrade
-      args: ["--py39-plus"]
+      args: ["--py310-plus"]
diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index 3d86a4d55..61aa5ba89 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -12,6 +12,7 @@ Unreleased
 
 - Update vendored schemas: bitbucket-pipelines, circle-ci, gitlab-ci, mergify, renovate
   (2026-02-22)
+- Removed support for Python 3.9
 
 0.36.2
 ------
diff --git a/pyproject.toml b/pyproject.toml
index 4dae456d9..0df83f174 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -30,7 +30,7 @@ classifiers = [
     "License :: OSI Approved :: Apache Software License",
     "Programming Language :: Python :: 3",
 ]
-requires-python = ">=3.9"
+requires-python = ">=3.10"
 dependencies = [
     'tomli>=2.0;python_version<"3.11"',
     "ruamel.yaml>=0.18.10,<0.20.0",
diff --git a/tox.ini b/tox.ini
index 922be7a31..de5e33b1b 100644
--- a/tox.ini
+++ b/tox.ini
@@ -2,10 +2,10 @@
 envlist =
     mypy
     cov_clean
-    py39-mindeps{,-format}
-    py{314,313,312,311,310,39}
-    py{39,314}-{json5,pyjson5}{,-format}
-    py{39,314}-{disable_orjson}
+    py310-mindeps{,-format}
+    py{314,313,312,311,310}
+    py{310,314}-{json5,pyjson5}{,-format}
+    py{310,314}-{disable_orjson}
     cov_combine
     cov_report
 skip_missing_interpreters = true
@@ -45,7 +45,7 @@ description = "combine coverage data"
 deps = coverage
 skip_install = true
 commands = coverage combine
-depends = py{,39,310,311,312,313,314}{,-mindeps,-format,-json5,-pyjson5,-disable_orjson}
+depends = py{,310,311,312,313,314}{,-mindeps,-format,-json5,-pyjson5,-disable_orjson}
 
 [testenv:cov_report]
 description = "report test coverage"