feat: widen requires-python to include Python 3.15

.gitlab/scripts/prune-unsupported-wheels.sh

@@ -24,8 +24,9 @@ set -euo pipefail
 #
 # TODO(py-315): cp315 wheels are built by "build linux" and "build linux serverless" under
 # allow_failure so that 3.15 keeps producing CI signal, but they are compiled against the
-# 3.15.0b1 PyThreadState layout and are ABI-broken. Drop cp315 from this list once #19861
-# makes those wheels correct and 3.15 is a supported target.
+# 3.15.0b1 PyThreadState layout and are ABI-broken. #19861 does not fix that ABI; it only
+# makes cp315 optional in the package validator. Drop cp315 from this list after IMAGE_TAG
+# is on images that can build a correct wheel, and only once 3.15 is a supported target.
 UNSUPPORTED_TAGS=("cp315")
 
 if [ "$#" -eq 0 ]; then

.gitlab/templates/cached-testrunner.yml

@@ -18,8 +18,8 @@
     fi
 
     source $EXT_CACHE_VENV/bin/activate
-    # Cython 3.3.0's cp315 wheel SIGSEGVs on pre-rc1 3.15. The pyproject.toml
-    # [build-system] pin (#19861) does not apply to this EXT_CACHE_VENV install.
+    # Cython 3.3 cp315 wheels SIGSEGV on pre-rc1 3.15; pyproject.toml pin does not apply here.
+    # TODO(py-315): drop this pin once testrunner 3.15 is 3.15.0rc1+.
     if [ "$PYTHON_VERSION" = "3.15" ]; then
         python -m pip install cmake setuptools_rust 'Cython<3.3'
     else

ddtrace/internal/bytecode_injection/__init__.py

@@ -1,4 +1,5 @@
 from collections import deque
+import sys
 from types import CodeType
 from types import FunctionType
 from typing import Any  # noqa:F401
@@ -8,6 +9,7 @@
 from bytecode import Instr
 
 from ddtrace.internal.assembly import Assembly
+from ddtrace.internal.compat import PY_315_VERSION_INFO
 from ddtrace.internal.compat import PYTHON_VERSION_INFO as PY
 from ddtrace.internal.wrapping import get_function_code
 from ddtrace.internal.wrapping import set_function_code
@@ -25,7 +27,10 @@ class InvalidLine(Exception):
     """
 
 
-if PY >= (3, 15):
+# mypy only folds sys.version_info against literals. PY_315_VERSION_INFO is the
+# runtime floor; the literal keeps this 3.15-only import off the 3.10 checker.
+assert PY_315_VERSION_INFO == (3, 15)
+if sys.version_info >= (3, 15):
     from ddtrace.internal import monitoring as _monitoring
     from ddtrace.internal.threads import Lock
     from ddtrace.internal.utils.inspection import linenos
@@ -40,7 +45,7 @@ def __init__(self) -> None:
         def on_py_line(self, code: Any, line_number: int) -> Any:
             hooks: "list[tuple[HookType, Any]] | None" = self._hooks.get(line_number)
             if not hooks:
-                return _monitoring._DISABLE  # type: ignore[has-type]
+                return _monitoring._DISABLE
             for hook, arg in hooks:
                 hook(arg)
             return None

ddtrace/internal/compat.py

@@ -11,37 +11,29 @@
 
 __all__ = [
     "maybe_stringify",
+    "MAX_PY",
     "MAX_PY_VERSION",
-    "MAX_PY_VERSION_INFO",
     "NEXT_PY_UNSUPPORTED_MSG",
-    "NEXT_MAX_PY_VERSION",
-    "NEXT_MAX_PY_VERSION_INFO",
-    "PY_GTE_MAX",
-    "PY_GTE_NEXT_MAX",
+    "NEXT_MAX_PY",
+    "PY_315_VERSION_INFO",
     "PYTHON_VERSION_INFO",
 ]
 
 PYTHON_VERSION_INFO = sys.version_info
 
+# Last officially supported CPython. Matches requires-python <3.15.
+# TODO(py-315): bump MAX_PY to (3, 15) after 3.15 GAs
+MAX_PY: tuple[int, int] = (3, 14)
+MAX_PY_VERSION: str = f"{MAX_PY[0]}.{MAX_PY[1]}"
 
-def _py_version_info(version: str) -> tuple[int, int]:
-    major, minor = version.split(".")[:2]
-    return (int(major), int(minor))
-
-
-# Upper bound of CPythons we code against.
-MAX_PY_VERSION: str = "3.15"
-MAX_PY_VERSION_INFO: tuple[int, int] = _py_version_info(MAX_PY_VERSION)
-
-# First CPython past MAX (exclusive upper bound / fail-closed default).
-NEXT_MAX_PY_VERSION: str = "3.16"
-NEXT_MAX_PY_VERSION_INFO: tuple[int, int] = _py_version_info(NEXT_MAX_PY_VERSION)
+# First unsupported CPython for packaging (last-supported+1). wrap() fail-closes
+# at (3, 16), not here.
+NEXT_MAX_PY: tuple[int, int] = (MAX_PY[0], MAX_PY[1] + 1)
 NEXT_PY_UNSUPPORTED_MSG: str = "This version of CPython is not supported yet: {}.{}".format(*sys.version_info[:2])
 
-# Support / fail-closed predicates (not API/bytecode introduction floors).
-# TODO(py-315): compare to NEXT_MAX_PY_VERSION_INFO after 3.15 GAs
-PY_GTE_MAX: bool = PYTHON_VERSION_INFO >= MAX_PY_VERSION_INFO
-PY_GTE_NEXT_MAX: bool = PYTHON_VERSION_INFO >= NEXT_MAX_PY_VERSION_INFO
+# CPython 3.15 introduced sys.monitoring PY_UNWIND / PEP 810 import packing.
+# Not MAX_PY — do not bump this when MAX_PY moves.
+PY_315_VERSION_INFO: tuple[int, int] = (3, 15)
 
 
 def ensure_text(s, encoding="utf-8", errors="ignore") -> str:

ddtrace/internal/coverage/instrumentation_py3_12.py

@@ -16,7 +16,7 @@
 from bytecode import Bytecode
 
 from ddtrace.internal.bytecode_injection import HookType
-from ddtrace.internal.compat import MAX_PY_VERSION_INFO
+from ddtrace.internal.compat import PY_315_VERSION_INFO
 from ddtrace.internal.coverage.import_instrumentation_py3_12 import ImportName
 from ddtrace.internal.coverage.import_instrumentation_py3_12 import ImportNamesByLine
 from ddtrace.internal.coverage.import_instrumentation_py3_12 import import_names_by_line
@@ -45,7 +45,7 @@
 # In Python 3.15 (PEP 810 lazy imports), IMPORT_NAME's arg is bit-packed:
 # bits 2+ = name index into co_names, bits 0-1 = lazy/eager flags.
 # So the index is arg >> 2. On 3.12-3.14, arg is a plain index (shift by 0).
-_IMPORT_NAME_ARG_SHIFT = 2 if sys.version_info >= MAX_PY_VERSION_INFO else 0
+_IMPORT_NAME_ARG_SHIFT = 2 if sys.version_info >= PY_315_VERSION_INFO else 0
 
 # Detect empty modules: the bytecode pattern varies across Python versions.
 # Python 3.12-3.13: RESUME + RETURN_CONST
@@ -57,7 +57,7 @@
 # Check if file-level coverage is requested
 _USE_FILE_LEVEL_COVERAGE = asbool(env.get("_DD_COVERAGE_FILE_LEVEL", "true"))
 _ACCURATE_IMPORTS_REQUESTED = asbool(env.get("_DD_COVERAGE_ACCURATE_IMPORTS", "false"))
-_USE_ACCURATE_IMPORTS = sys.version_info < MAX_PY_VERSION_INFO and _ACCURATE_IMPORTS_REQUESTED
+_USE_ACCURATE_IMPORTS = sys.version_info < PY_315_VERSION_INFO and _ACCURATE_IMPORTS_REQUESTED
 if _ACCURATE_IMPORTS_REQUESTED and not _USE_ACCURATE_IMPORTS:
     log.info(
         "_DD_COVERAGE_ACCURATE_IMPORTS is enabled, but accurate import tracking is not supported on Python %s; "

ddtrace/internal/module.py

@@ -829,17 +829,16 @@ def _trace(frame, event, arg):
 
 
 def lazy(f: t.Callable[[], None]) -> None:
-    from ddtrace.internal.compat import PY_GTE_MAX
-
     _globals = sys._getframe(1).f_globals
     _initialized = False
 
-    if not PY_GTE_MAX:
+    # WrappingContext.wrap() (sys.monitoring) is live on 3.15; fallback from 3.16.
+    if sys.version_info < (3, 16):
         LazyWrappingContext(t.cast(FunctionType, f)).wrap()
 
     def __getattr__(name: str) -> t.Any:
         nonlocal _initialized
-        if PY_GTE_MAX:
+        if sys.version_info >= (3, 16):
             if not _initialized:
                 _exec_lazy_init(t.cast(FunctionType, f), _globals)
                 _initialized = True

ddtrace/internal/monitoring.py

@@ -21,14 +21,17 @@
 from typing import Optional
 import weakref
 
-from ddtrace.internal.compat import MAX_PY_VERSION
-from ddtrace.internal.compat import MAX_PY_VERSION_INFO
+from ddtrace.internal.compat import PY_315_VERSION_INFO
 from ddtrace.internal.logger import get_logger
 from ddtrace.internal.threads import Lock
 
 
-if sys.version_info < MAX_PY_VERSION_INFO:
-    raise ImportError("ddtrace.internal.monitoring requires Python %s+" % MAX_PY_VERSION)
+if sys.version_info < PY_315_VERSION_INFO:
+    raise ImportError("ddtrace.internal.monitoring requires Python %s.%s+" % PY_315_VERSION_INFO)
+# mypy only folds sys.version_info against literals. A named alias leaves this
+# 3.15-only body reachable under python_version 3.10, where sys.monitoring is
+# missing (attr-defined / no-any-return). Keep the tuple equal to PY_315_VERSION_INFO.
+assert sys.version_info >= (3, 15)
 
 log = get_logger(__name__)
 

ddtrace/internal/wrapping/__init__.py

@@ -14,7 +14,6 @@
 
 from ddtrace.internal.assembly import Assembly
 from ddtrace.internal.compat import NEXT_PY_UNSUPPORTED_MSG
-from ddtrace.internal.compat import PY_GTE_MAX
 from ddtrace.internal.threads import Lock
 from ddtrace.internal.wrapping.asyncs import wrap_async
 from ddtrace.internal.wrapping.generators import wrap_generator
@@ -300,7 +299,8 @@ def wrap_bytecode(wrapper: Wrapper, wrapped: FunctionType) -> bc.Bytecode:
     return a coroutine function, and so on. The signature is also preserved to
     avoid breaking, e.g., usages of the ``inspect`` module.
     """
-    if PY_GTE_MAX:
+    # wrap() trampoline is live on 3.15. Fail closed from 3.16, not NEXT_MAX_PY.
+    if PY >= (3, 16):
         raise NotImplementedError(NEXT_PY_UNSUPPORTED_MSG)
 
     code = wrapped.__code__
@@ -349,7 +349,7 @@ def wrap(f: FunctionType, wrapper: Wrapper) -> WrappedFunction:
     Note that this changes the behavior of the original function with the
     wrapper function, instead of creating a new function object.
     """
-    if PY_GTE_MAX:
+    if PY >= (3, 16):
         raise NotImplementedError(NEXT_PY_UNSUPPORTED_MSG)
     wrapped = FunctionType(
         code := f.__code__,

ddtrace/internal/wrapping/asyncs.py

@@ -6,6 +6,7 @@
 import bytecode as bc
 
 from ddtrace.internal.assembly import Assembly
+from ddtrace.internal.compat import PY_315_VERSION_INFO
 
 
 PY = sys.version_info[:2]
@@ -56,7 +57,7 @@ def _ensure_common_constant_none() -> None:
 ASYNC_GEN_ASSEMBLY = Assembly()
 ASYNC_HEAD_ASSEMBLY: Optional[Assembly] = None
 
-if PY >= (3, 15):
+if PY >= PY_315_VERSION_INFO:
     _ensure_common_constant_none()
     ASYNC_HEAD_ASSEMBLY = Assembly()
     ASYNC_HEAD_ASSEMBLY.parse(

ddtrace/internal/wrapping/context.py

@@ -16,7 +16,7 @@
 from bytecode import Bytecode
 
 from ddtrace.internal.assembly import Assembly
-from ddtrace.internal.compat import PY_GTE_NEXT_MAX
+from ddtrace.internal.compat import PY_315_VERSION_INFO
 from ddtrace.internal.logger import get_logger
 from ddtrace.internal.threads import Lock
 from ddtrace.internal.threads import RLock
@@ -221,9 +221,11 @@ def _release_storage_var(name: str, var: StorageVar) -> None:
 CONTEXT_RETURN = Assembly()
 CONTEXT_FOOT = Assembly()
 
-if PY_GTE_NEXT_MAX:
+# Hard 3.16 floor: wrapping already works on 3.15 via sys.monitoring.
+# NEXT_MAX_PY is 3.15 until 3.15 GAs; using it here would skip that path.
+if sys.version_info >= (3, 16):
     raise NotImplementedError("This version of Python is not supported yet")
-elif sys.version_info >= (3, 15):
+elif sys.version_info >= PY_315_VERSION_INFO:
     # We rely on sys.monitoring for wrapping, so no bytecode manipulation is
     # needed.
     pass
@@ -440,8 +442,9 @@ def _release_storage_var(name: str, var: StorageVar) -> None:
 # (3.15+) the stack is:
 #   monitored function → monitoring._on_py_start → uwc.on_py_start → __enter__
 # so the monitored frame is three levels up.
-_ENTER_FRAME_DEPTH = 3 if sys.version_info >= (3, 15) else 1
+_ENTER_FRAME_DEPTH = 3 if sys.version_info >= PY_315_VERSION_INFO else 1
 
+# PY_315_VERSION_INFO — mypy folds literals only
 if sys.version_info >= (3, 15):
     from ddtrace.internal import monitoring as _monitoring
 
@@ -605,6 +608,7 @@ def unwrap(self) -> None:
             pass
 
 
+# PY_315_VERSION_INFO — mypy folds literals only
 if sys.version_info >= (3, 15):
     # Monitoring-based instrumentation has negligible per-function overhead, so
     # there is no benefit to deferring wrapping until first call. On Python 3.15+
@@ -700,6 +704,7 @@ def __call__(self, *args: t.Any, **kwargs: t.Any) -> t.Any:
 
 # On 3.15+ _UniversalWrappingContext also implements MonitoringEventHandler so
 # it can be registered directly with the multiplexer via register(code, self).
+# PY_315_VERSION_INFO — mypy folds literals only
 if sys.version_info >= (3, 15):
     from ddtrace.internal.monitoring import MonitoringEventHandler as _MonitoringEventHandler
 
@@ -818,6 +823,7 @@ def __return__(self, value: T) -> T:
 
         return t.cast(T, super().__return__(value))
 
+    # PY_315_VERSION_INFO — mypy folds literals only
     if sys.version_info >= (3, 15):
         # Exceptions here are deliberately left uncaught (see the propagation
         # warning on MonitoringEventHandler), which matches bytecode-path
@@ -1243,6 +1249,7 @@ def unwrap(self) -> None:
                             _registry.pop(f, None)
 
 
+# PY_315_VERSION_INFO — mypy folds literals only
 if sys.version_info >= (3, 15):
 
     def _finalize_monitoring_wrap(

ddtrace/internal/wrapping/generators.py

@@ -5,6 +5,7 @@
 import bytecode as bc
 
 from ddtrace.internal.assembly import Assembly
+from ddtrace.internal.compat import PY_315_VERSION_INFO
 
 
 PY = sys.version_info[:2]
@@ -34,7 +35,7 @@
 GENERATOR_ASSEMBLY = Assembly()
 GENERATOR_HEAD_ASSEMBLY: Optional[Assembly] = None
 
-if PY >= (3, 15):
+if PY >= PY_315_VERSION_INFO:
     GENERATOR_HEAD_ASSEMBLY = Assembly()
     GENERATOR_HEAD_ASSEMBLY.parse(
         r"""

hooks/pre-commit/05-run-bandit

@@ -1,6 +1,6 @@
 #!/bin/sh
 LINT_CMD="${LINT_CMD:-scripts/lint}"
-staged_files=$(git diff --staged --name-only HEAD --diff-filter=ACMR | grep -E '\.py$' | grep -v '^tests/' | grep -v '^lib-injection/' | tr '\n' ' ')
+staged_files=$(git diff --staged --name-only HEAD --diff-filter=ACMR | grep -E '\.py$' | grep -v '^tests/' | tr '\n' ' ')
 if [ -n "$staged_files" ]; then
     file_count=$(echo "$staged_files" | wc -w | tr -d ' ')
     echo "Running security scan on $file_count staged Python file(s)..."

hooks/scripts/run-mypy.sh

@@ -1,6 +1,6 @@
 #!/bin/sh
 LINT_CMD="${LINT_CMD:-scripts/lint}"
-staged_files=$(git diff --staged --name-only HEAD --diff-filter=ACMR | grep -E '\.(py|pyi)$' | grep -v '^lib-injection/' | tr '\n' ' ')
+staged_files=$(git diff --staged --name-only HEAD --diff-filter=ACMR | grep -E '\.(py|pyi)$' | tr '\n' ' ')
 if [ -n "$staged_files" ]; then
     # Drop .pyi stubs whose .py counterpart is also staged to avoid mypy
     # "Duplicate module named ..." errors. mypy discovers stubs automatically.

lib-injection/sources/sitecustomize.py

@@ -40,13 +40,12 @@ def parse_version(version):
 
 TELEMETRY_DATA = []
 SCRIPT_DIR = os.path.dirname(__file__)
-# Exclusive upper bound. Same tuple as NEXT_MAX_PY_VERSION_INFO in ddtrace.internal.compat
-# (this bootstrap cannot import ddtrace).
-NEXT_MAX_PY_VERSION_INFO = (3, 16)
+# Exclusive upper bound. Keep 3.16 so 3.15 is injected (#19843). Not NEXT_MAX_PY
+# in compat (3.15 until 3.15 GAs). This bootstrap cannot import ddtrace.
 RUNTIMES_ALLOW_LIST = {
     "cpython": {
         "min": Version(version=(3, 9), constraint=""),
-        "max": Version(version=NEXT_MAX_PY_VERSION_INFO, constraint=""),
+        "max": Version(version=(3, 16), constraint=""),
     }
 }
 

pyproject.toml

@@ -1,13 +1,7 @@
 [build-system]
 requires = [
-    # Cython 3.3.0 is the first stable release to publish compiled cp315 wheels,
-    # and its cp315 manylinux wheel is compiled against the 3.15.0rc1 PyThreadState
-    # layout, which grew a member in 3.15.0b4 (python/cpython#151614). Our
-    # manylinux2014 images still ship 3.15.0b1, so that wheel segfaults the moment
-    # setup.py imports Cython.Build. <3.3 has no cp315-tagged wheel, so on these
-    # images 3.15 resolves the pure-Python cython-*-py3-none-any.whl instead, which
-    # has no ABI to mismatch. Drop this once the image mirror ships a cp315
-    # interpreter >= 3.15.0rc1; pypa manylinux 2026.08.04-1 is the first such tag.
+    # Cython 3.3 cp315 manylinux wheels SIGSEGV on the current 3.15 interpreter; <3.3 pins 3.2.x.
+    # TODO(py-315): drop this pin once IMAGE_TAG is on the 2026.08.04-1 images.
     "cython<3.3; python_version >= '3.15'",
     "cython; python_version < '3.15'",
     "cmake>=3.24.2,<3.28",
@@ -25,7 +19,7 @@ license = { text = "LICENSE.BSD3" }
 # ddtrace has many sub-components which can break when CPython internals
 # change over versions, e.g. profiling. So we explicitly mark incompatibility
 # with versions we don't support yet.
-requires-python = ">=3.9,<3.15"
+requires-python = ">=3.9,<3.16"
 authors = [
     { name = "Datadog, Inc.", email = "dev@datadoghq.com" },
 ]
@@ -40,6 +34,7 @@ classifiers = [
     "Programming Language :: Python :: 3.12",
     "Programming Language :: Python :: 3.13",
     "Programming Language :: Python :: 3.14",
+    "Programming Language :: Python :: 3.15",
 ]
 dependencies = [
     "bytecode>=0.19.0,<1; python_version>='3.15.0'",
@@ -135,7 +130,9 @@ lint = [
     "cmake-format==0.6.13",
     "ruamel.yaml==0.18.6",
     "ast-grep-cli==0.39.4",
-    "bytecode==0.18.1; python_version >= '3.15'",
+    # Lint extra; 0.19.0 matches the runtime lower bound so uv can resolve
+    # both extras when requires-python includes 3.15.
+    "bytecode==0.19.0; python_version >= '3.15'",
     "bytecode==0.17.0; python_version < '3.15'",
 ]
 clean = [