diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 9e66823..cc7f998 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -55,10 +55,8 @@ repos:
     rev: cb8c523fd4835aba42af70f4cad5568db4df0b6c  # frozen: v0.16.0
     hooks:
       - id: ruff
-        files: ^(scripts|tests|custom_components)/.+\.py$
         args: [--fix, --exit-non-zero-on-fix]
       - id: ruff-format
-        files: ^(scripts|tests|custom_components)/.+\.py$
 
   - repo: https://github.com/pre-commit/mirrors-mypy
     rev: 41e691678310dfd3833f7ab4e180ddb014310356  # frozen: v2.3.0
diff --git a/.ruff.toml b/.ruff.toml
new file mode 100644
index 0000000..e8050e3
--- /dev/null
+++ b/.ruff.toml
@@ -0,0 +1,41 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: 2026 The Linux Foundation
+
+# Ruff configuration for repositories created from this template.
+#
+# The `select` list is pinned deliberately.  Without it ruff applies its
+# *default* rule set, and that default is not stable across releases:
+#
+#     ruff 0.15.22 ->  59 rules across  2 categories (E, F)
+#     ruff 0.16.0  -> 413 rules across 38 categories
+#
+# A routine pre-commit autoupdate therefore changed which rules run and
+# broke fifteen repositories in this organisation simultaneously, on code
+# that had not been touched.
+#
+# Pinning does not decline the unselected rules.  It makes adopting them a
+# deliberate, reviewed change instead of a side effect of a version bump.
+#
+# `line-length` and `target-version` are intentionally left unset so that
+# ruff's own defaults -- and its inference from `requires-python` where a
+# `pyproject.toml` exists -- continue to apply unchanged.
+
+[lint]
+# The de-facto standard across this organisation: present as a superset in
+# 13 of the 16 repositories that already pin their rules.
+select = ["E", "W", "F", "I", "B", "C4", "UP"]
+
+ignore = [
+  "E501", # line-too-long: the formatter owns line length
+  "B008", # function call in argument default: typer/click idiom
+]
+
+[lint.per-file-ignores]
+# Test suites legitimately break rules that matter in library code.
+# Listed even though some are not currently selected, so that widening
+# `select` later does not immediately flag every test module.
+#
+# PLR0917 in particular cannot be satisfied in tests that stack
+# `@patch` decorators: unittest.mock injects its mocks positionally, so a
+# keyword-only signature is impossible, not merely inconvenient.
+"tests/**/*.py" = ["S101", "ARG", "PLR0913", "PLR0917", "PLR2004"]