From 0b5999d43490ee26a9aacccb2a68e868ca872131 Mon Sep 17 00:00:00 2001
From: moss-bryophyta <261561981+moss-bryophyta@users.noreply.github.com>
Date: Sat, 7 Mar 2026 13:19:54 -0800
Subject: [PATCH 1/4] refactor: replace hardcoded 'en' defaults with
 LIBRARY_DEFAULT_LOCALE

---
 .../src/generaltranslation_intl_messageformat/_formatter.py | 5 +++--
 .../src/generaltranslation/formatting/_helpers.py           | 6 ++++--
 .../src/generaltranslation/locales/_get_locale_name.py      | 3 ++-
 .../generaltranslation/locales/_get_locale_properties.py    | 4 +++-
 .../src/generaltranslation/locales/_get_plural_form.py      | 5 +++--
 .../generaltranslation/locales/_get_region_properties.py    | 3 ++-
 .../src/generaltranslation/locales/_is_valid_locale.py      | 6 ++++--
 packages/gt-fastapi/src/gt_fastapi/_setup.py                | 3 ++-
 packages/gt-flask/src/gt_flask/_setup.py                    | 3 ++-
 9 files changed, 25 insertions(+), 13 deletions(-)

diff --git a/packages/generaltranslation-intl-messageformat/src/generaltranslation_intl_messageformat/_formatter.py b/packages/generaltranslation-intl-messageformat/src/generaltranslation_intl_messageformat/_formatter.py
index a81890f..999dd96 100644
--- a/packages/generaltranslation-intl-messageformat/src/generaltranslation_intl_messageformat/_formatter.py
+++ b/packages/generaltranslation-intl-messageformat/src/generaltranslation_intl_messageformat/_formatter.py
@@ -9,6 +9,7 @@
 from babel import Locale
 from babel.core import UnknownLocaleError
 from babel.numbers import format_decimal
+from generaltranslation._settings import LIBRARY_DEFAULT_LOCALE
 from generaltranslation_icu_messageformat_parser import Parser
 
 _parser = Parser()
@@ -27,13 +28,13 @@ class IntlMessageFormat:
         mf.format({"count": 5})  # "5 items"
     """
 
-    def __init__(self, pattern: str, locale: str = "en") -> None:
+    def __init__(self, pattern: str, locale: str = LIBRARY_DEFAULT_LOCALE) -> None:
         self._pattern = pattern
         self._ast = _parser.parse(pattern)
         try:
             self._locale = Locale.parse(locale, sep="-")
         except (UnknownLocaleError, ValueError):
-            self._locale = Locale("en")
+            self._locale = Locale(LIBRARY_DEFAULT_LOCALE)
 
     @property
     def pattern(self) -> str:
diff --git a/packages/generaltranslation/src/generaltranslation/formatting/_helpers.py b/packages/generaltranslation/src/generaltranslation/formatting/_helpers.py
index a88cb4c..bdad80a 100644
--- a/packages/generaltranslation/src/generaltranslation/formatting/_helpers.py
+++ b/packages/generaltranslation/src/generaltranslation/formatting/_helpers.py
@@ -9,6 +9,8 @@
 from babel import Locale
 from babel.core import UnknownLocaleError
 
+from generaltranslation._settings import LIBRARY_DEFAULT_LOCALE
+
 
 def _resolve_babel_locale(locales: str | list[str] | None = None) -> Locale:
     """Convert BCP 47 locale(s) to a Babel :class:`Locale` instance.
@@ -22,7 +24,7 @@ def _resolve_babel_locale(locales: str | list[str] | None = None) -> Locale:
         A :class:`babel.Locale` instance.
     """
     if locales is None:
-        return Locale("en")
+        return Locale(LIBRARY_DEFAULT_LOCALE)
     if isinstance(locales, str):
         locales = [locales]
     for tag in locales:
@@ -30,7 +32,7 @@ def _resolve_babel_locale(locales: str | list[str] | None = None) -> Locale:
             return Locale.parse(tag, sep="-")
         except (UnknownLocaleError, ValueError):
             continue
-    return Locale("en")
+    return Locale(LIBRARY_DEFAULT_LOCALE)
 
 
 def _get_language_code(locales: str | list[str] | None = None) -> str:
diff --git a/packages/generaltranslation/src/generaltranslation/locales/_get_locale_name.py b/packages/generaltranslation/src/generaltranslation/locales/_get_locale_name.py
index 91402eb..ee4a08b 100644
--- a/packages/generaltranslation/src/generaltranslation/locales/_get_locale_name.py
+++ b/packages/generaltranslation/src/generaltranslation/locales/_get_locale_name.py
@@ -8,12 +8,13 @@
 
 from babel import Locale
 
+from generaltranslation._settings import LIBRARY_DEFAULT_LOCALE
 from generaltranslation.locales._types import CustomMapping
 
 
 def get_locale_name(
     locale: str,
-    default_locale: str | None = "en",
+    default_locale: str | None = LIBRARY_DEFAULT_LOCALE,
     custom_mapping: CustomMapping | None = None,
 ) -> str:
     """Return the display name of *locale* rendered in *default_locale*.
diff --git a/packages/generaltranslation/src/generaltranslation/locales/_get_locale_properties.py b/packages/generaltranslation/src/generaltranslation/locales/_get_locale_properties.py
index ac995dd..2ee77c1 100644
--- a/packages/generaltranslation/src/generaltranslation/locales/_get_locale_properties.py
+++ b/packages/generaltranslation/src/generaltranslation/locales/_get_locale_properties.py
@@ -8,6 +8,8 @@
 from __future__ import annotations
 
 from babel import Locale
+
+from generaltranslation._settings import LIBRARY_DEFAULT_LOCALE
 from babel.core import get_global
 
 from generaltranslation.locales._types import CustomMapping, LocaleProperties
@@ -105,7 +107,7 @@ def _build_component_name(
 
 def get_locale_properties(
     locale: str,
-    default_locale: str | None = "en",
+    default_locale: str | None = LIBRARY_DEFAULT_LOCALE,
     custom_mapping: CustomMapping | None = None,
 ) -> LocaleProperties:
     """Return a :class:`LocaleProperties` for *locale*."""
diff --git a/packages/generaltranslation/src/generaltranslation/locales/_get_plural_form.py b/packages/generaltranslation/src/generaltranslation/locales/_get_plural_form.py
index c28cc3c..1d84912 100644
--- a/packages/generaltranslation/src/generaltranslation/locales/_get_plural_form.py
+++ b/packages/generaltranslation/src/generaltranslation/locales/_get_plural_form.py
@@ -11,6 +11,7 @@
 
 from babel import Locale
 
+from generaltranslation._settings import LIBRARY_DEFAULT_LOCALE
 from generaltranslation.locales._types import PLURAL_FORMS, PluralType
 
 # Aliases between our custom form names and CLDR form names
@@ -54,7 +55,7 @@ def get_plural_form(
     if forms is None:
         forms = list(PLURAL_FORMS)
     if locales is None:
-        locales = ["en"]
+        locales = [LIBRARY_DEFAULT_LOCALE]
 
     forms_set = set(forms)
 
@@ -95,7 +96,7 @@ def _get_cldr_category(n: int | float, locales: list[str]) -> str:
             continue
     # Default to English rules
     try:
-        rule = Locale("en").plural_form
+        rule = Locale(LIBRARY_DEFAULT_LOCALE).plural_form
         return rule(abs(n))
     except Exception:
         return "other"
diff --git a/packages/generaltranslation/src/generaltranslation/locales/_get_region_properties.py b/packages/generaltranslation/src/generaltranslation/locales/_get_region_properties.py
index a8cca79..2c0cc4f 100644
--- a/packages/generaltranslation/src/generaltranslation/locales/_get_region_properties.py
+++ b/packages/generaltranslation/src/generaltranslation/locales/_get_region_properties.py
@@ -9,13 +9,14 @@
 
 from babel import Locale
 
+from generaltranslation._settings import LIBRARY_DEFAULT_LOCALE
 from generaltranslation.locales._get_locale_emoji import DEFAULT_EMOJI, EMOJIS
 from generaltranslation.locales._types import CustomRegionMapping
 
 
 def get_region_properties(
     region: str,
-    default_locale: str | None = "en",
+    default_locale: str | None = LIBRARY_DEFAULT_LOCALE,
     custom_mapping: CustomRegionMapping | None = None,
 ) -> dict[str, str]:
     """Return metadata for a region code.
diff --git a/packages/generaltranslation/src/generaltranslation/locales/_is_valid_locale.py b/packages/generaltranslation/src/generaltranslation/locales/_is_valid_locale.py
index 3538076..bc2e859 100644
--- a/packages/generaltranslation/src/generaltranslation/locales/_is_valid_locale.py
+++ b/packages/generaltranslation/src/generaltranslation/locales/_is_valid_locale.py
@@ -9,6 +9,8 @@
 from babel import Locale
 from babel.core import UnknownLocaleError
 
+from generaltranslation._settings import LIBRARY_DEFAULT_LOCALE
+
 from generaltranslation.locales._types import CustomMapping
 
 # Scripts that are valid but may not be recognised by all display-name APIs.
@@ -109,7 +111,7 @@ def is_valid_locale(
     # For region codes, verify they're known
     if parsed.territory:
         try:
-            display_locale = Locale("en")
+            display_locale = Locale(LIBRARY_DEFAULT_LOCALE)
             if parsed.territory not in display_locale.territories:
                 return False
         except Exception:
@@ -119,7 +121,7 @@ def is_valid_locale(
     if parsed.script:
         if parsed.script not in SCRIPT_EXCEPTIONS:
             try:
-                display_locale = Locale("en")
+                display_locale = Locale(LIBRARY_DEFAULT_LOCALE)
                 if parsed.script not in display_locale.scripts:
                     return False
             except Exception:
diff --git a/packages/gt-fastapi/src/gt_fastapi/_setup.py b/packages/gt-fastapi/src/gt_fastapi/_setup.py
index 3f0fcf6..4717ea6 100644
--- a/packages/gt-fastapi/src/gt_fastapi/_setup.py
+++ b/packages/gt-fastapi/src/gt_fastapi/_setup.py
@@ -6,6 +6,7 @@
 from contextlib import asynccontextmanager
 from typing import Any
 
+from generaltranslation._settings import LIBRARY_DEFAULT_LOCALE
 from generaltranslation.locales import determine_locale
 from gt_i18n import I18nManager, set_i18n_manager, t  # noqa: F401
 
@@ -45,7 +46,7 @@ def _detect_from_accept_language(request: Any, manager: I18nManager) -> str:
 def initialize_gt(
     app: Any,
     *,
-    default_locale: str = "en",
+    default_locale: str = LIBRARY_DEFAULT_LOCALE,
     locales: list[str] | None = None,
     project_id: str | None = None,
     cache_url: str | None = None,
diff --git a/packages/gt-flask/src/gt_flask/_setup.py b/packages/gt-flask/src/gt_flask/_setup.py
index 5268f58..0cf17ed 100644
--- a/packages/gt-flask/src/gt_flask/_setup.py
+++ b/packages/gt-flask/src/gt_flask/_setup.py
@@ -6,6 +6,7 @@
 from collections.abc import Callable
 from typing import Any
 
+from generaltranslation._settings import LIBRARY_DEFAULT_LOCALE
 from generaltranslation.locales import determine_locale
 from gt_i18n import I18nManager, set_i18n_manager, t  # noqa: F401
 
@@ -47,7 +48,7 @@ def _detect_from_accept_language(request: Any, manager: I18nManager) -> str:
 def initialize_gt(
     app: Any,
     *,
-    default_locale: str = "en",
+    default_locale: str = LIBRARY_DEFAULT_LOCALE,
     locales: list[str] | None = None,
     project_id: str | None = None,
     cache_url: str | None = None,

From e910efbf330e4022066d2a3fe40e0dc05aa1beb1 Mon Sep 17 00:00:00 2001
From: moss-bryophyta <261561981+moss-bryophyta@users.noreply.github.com>
Date: Sat, 7 Mar 2026 13:22:53 -0800
Subject: [PATCH 2/4] fix: define LIBRARY_DEFAULT_LOCALE locally in
 intl-messageformat package

The intl-messageformat package doesn't depend on generaltranslation,
so importing from generaltranslation._settings would break standalone
installs. Define the constant locally instead.
---
 .../src/generaltranslation_intl_messageformat/_formatter.py    | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/packages/generaltranslation-intl-messageformat/src/generaltranslation_intl_messageformat/_formatter.py b/packages/generaltranslation-intl-messageformat/src/generaltranslation_intl_messageformat/_formatter.py
index 999dd96..d787137 100644
--- a/packages/generaltranslation-intl-messageformat/src/generaltranslation_intl_messageformat/_formatter.py
+++ b/packages/generaltranslation-intl-messageformat/src/generaltranslation_intl_messageformat/_formatter.py
@@ -9,9 +9,10 @@
 from babel import Locale
 from babel.core import UnknownLocaleError
 from babel.numbers import format_decimal
-from generaltranslation._settings import LIBRARY_DEFAULT_LOCALE
 from generaltranslation_icu_messageformat_parser import Parser
 
+LIBRARY_DEFAULT_LOCALE = "en"
+
 _parser = Parser()
 
 

From fe0476f0add899098d32702cc13bc8f6633181af Mon Sep 17 00:00:00 2001
From: moss-bryophyta <261561981+moss-bryophyta@users.noreply.github.com>
Date: Sat, 7 Mar 2026 13:36:10 -0800
Subject: [PATCH 3/4] chore: add changeset for centralized default locale

---
 .sampo/changesets/centralize-default-locale.md | 8 ++++++++
 1 file changed, 8 insertions(+)
 create mode 100644 .sampo/changesets/centralize-default-locale.md

diff --git a/.sampo/changesets/centralize-default-locale.md b/.sampo/changesets/centralize-default-locale.md
new file mode 100644
index 0000000..1718cf5
--- /dev/null
+++ b/.sampo/changesets/centralize-default-locale.md
@@ -0,0 +1,8 @@
+---
+pypi/generaltranslation: patch
+pypi/gt-fastapi: patch
+pypi/gt-flask: patch
+pypi/generaltranslation-intl-messageformat: patch
+---
+
+Centralize hardcoded `"en"` locale defaults into a `LIBRARY_DEFAULT_LOCALE` constant. No behavioral change.

From 042c0fbcc1b4695cb671ff180d2f5cd00491a9cc Mon Sep 17 00:00:00 2001
From: moss-bryophyta <261561981+moss-bryophyta@users.noreply.github.com>
Date: Sat, 7 Mar 2026 13:42:15 -0800
Subject: [PATCH 4/4] style: fix import sorting (ruff I001)

---
 .../src/generaltranslation/locales/_get_locale_properties.py   | 3 +--
 .../src/generaltranslation/locales/_is_valid_locale.py         | 1 -
 2 files changed, 1 insertion(+), 3 deletions(-)

diff --git a/packages/generaltranslation/src/generaltranslation/locales/_get_locale_properties.py b/packages/generaltranslation/src/generaltranslation/locales/_get_locale_properties.py
index 2ee77c1..5546bd4 100644
--- a/packages/generaltranslation/src/generaltranslation/locales/_get_locale_properties.py
+++ b/packages/generaltranslation/src/generaltranslation/locales/_get_locale_properties.py
@@ -8,10 +8,9 @@
 from __future__ import annotations
 
 from babel import Locale
-
-from generaltranslation._settings import LIBRARY_DEFAULT_LOCALE
 from babel.core import get_global
 
+from generaltranslation._settings import LIBRARY_DEFAULT_LOCALE
 from generaltranslation.locales._types import CustomMapping, LocaleProperties
 
 _likely_subtags: dict[str, str] = dict(get_global("likely_subtags"))
diff --git a/packages/generaltranslation/src/generaltranslation/locales/_is_valid_locale.py b/packages/generaltranslation/src/generaltranslation/locales/_is_valid_locale.py
index bc2e859..d6c6775 100644
--- a/packages/generaltranslation/src/generaltranslation/locales/_is_valid_locale.py
+++ b/packages/generaltranslation/src/generaltranslation/locales/_is_valid_locale.py
@@ -10,7 +10,6 @@
 from babel.core import UnknownLocaleError
 
 from generaltranslation._settings import LIBRARY_DEFAULT_LOCALE
-
 from generaltranslation.locales._types import CustomMapping
 
 # Scripts that are valid but may not be recognised by all display-name APIs.