diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index b7b8a5cd3335..361290e55a1d 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -26,7 +26,7 @@ repos:
     hooks:
       - id: codespell
         args:
-          - --ignore-words-list=HAX,ccompiler,ot,statics,whet,zar
+          - --ignore-words-list=HAX,Nam,ccompiler,ot,statics,whet,zar
         exclude: ^(mypy/test/|mypy/typeshed/|mypyc/test-data/|test-data/).+$
   - repo: https://github.com/rhysd/actionlint
     rev: v1.7.7
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 16335fae0bb1..7b4a6449087d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,7 +2,37 @@
 
 ## Next Release
 
-### Better narrowing
+### Planned Changes to Defaults in Mypy 2.0
+
+As a reminder, we are planning to enable `--local-partial-types` by default in mypy 2.0, which
+will likely be the next feature release. This will often require at least minor code changes. This
+option is implicitly enabled by mypy daemon, so this makes the behavior of daemon and non-daemon
+modes consistent.
+
+Note that this release improves the compatibility of `--local-partial-types` significantly to
+make the switch easier (see below for more).
+
+This can also be configured in a mypy configuration file (use `False` to disable):
+
+```
+local_partial_types = True
+```
+
+For more information, refer to the
+[documentation](https://mypy.readthedocs.io/en/stable/command_line.html#cmdoption-mypy-local-partial-types).
+
+We will also enable `--strict-bytes` by default in mypy 2.0. This usually requires at most
+minor code changes to adopt. For more information, refer to the
+[documentation](https://mypy.readthedocs.io/en/stable/command_line.html#cmdoption-mypy-strict-bytes).
+
+Finally, `--allow-redefinition-new` will be renamed to `--allow-redefinition`. If you want
+to continue using the older `--allow-redefinition` semantics, you can switch to
+`--allow-redefinition-old`, which is now supported as an alias to `--allow-redefinition`.
+To use `--allow-redefinition-old` in the upcoming mypy 2.0, you will also have to use
+`--no-local-partial-types`. For more information, refer to the
+[documentation](https://mypy.readthedocs.io/en/stable/command_line.html#cmdoption-mypy-allow-redefinition-new).
+
+### Better Type Narrowing
 
 Mypy's implementation of narrowing has been substantially reworked. Mypy will now narrow more
 aggressively, more consistently, and more correctly. In particular, you are likely to notice new
@@ -69,7 +99,7 @@ Contributed by Shantanu Jain.
 
 ### Drop Support for Python 3.9
 
-Mypy no longer supports running with Python 3.9, which has reached end-of-life.
+Mypy no longer supports running with Python 3.9, which has reached end of life.
 When running mypy with Python 3.10+, it is still possible to type check code
 that needs to support Python 3.9 with the `--python-version 3.9` argument.
 Support for this will be dropped in the first half of 2026!
@@ -88,7 +118,279 @@ Contributed by Marc Mueller
 (PR [mypy_mypyc-wheels#106](https://github.com/mypyc/mypy_mypyc-wheels/pull/106),
 PR [mypy_mypyc-wheels#110](https://github.com/mypyc/mypy_mypyc-wheels/pull/110)).
 
-### Removed flags `--force-uppercase-builtins` and `--force-union-syntax`
+### Improved Compatibility for Local Partial Types
+
+Compatibility between mypy's default behavior and the `--local-partial-types` flag
+is now improved. This improves compatibility between mypy daemon and non-daemon modes,
+since the mypy daemon requires local partial types to be enabled.
+
+Also, we are planning to turn local partial types on by default in mypy 2.0 (to be
+released soon), and this makes the change much less disruptive. However, explicitly
+disabling local partial types will continue to be supported indefinitely.
+
+In particular, code like this now behaves consistently independent of
+whether local partial types are enabled or not:
+
+```python
+x = None
+
+def foo() -> None:
+    global x
+    x = 1
+
+# The inferred type of 'x' is always 'int | None'.
+```
+
+This feature was contributed by Ivan Levkivskyi (PR [20938](https://github.com/python/mypy/pull/20938)).
+
+### Python 3.14 T-String Support (PEP 750)
+
+Mypy now supports t-strings that were introduced in Python 3.14.
+
+- Add support for Python 3.14 t-strings (PEP 750) (Neil Schemenauer and Brian Schubert, PR [20850](https://github.com/python/mypy/pull/20850))
+- Add implicit module dependency if using t-string (Jukka Lehtosalo, PR [20900](https://github.com/python/mypy/pull/20900))
+
+### Experimental New Parser
+
+If you install mypy using `pip install mypy[native-parse]` and run mypy with
+`--native-parser`, you can experiment with a new Python parser. It is based on
+the Ruff parser, and it's more efficient than the default parser. It will also enable
+access to all Python syntax independent of which Python version you use to run mypy.
+The new parser is still not feature-complete and has known issues.
+
+Related changes:
+
+- Add work-in-progress implementation of a new Python parser (Jukka Lehtosalo, PR [20856](https://github.com/python/mypy/pull/20856))
+- Skip redundant analysis pass when using the native parser (Ivan Levkivskyi, PR [21015](https://github.com/python/mypy/pull/21015))
+- Add t-string support to native parser (Ivan Levkivskyi, PR [21007](https://github.com/python/mypy/pull/21007))
+- Handle hex bigint literals in native parser (Ivan Levkivskyi, PR [20988](https://github.com/python/mypy/pull/20988))
+- Pass all relevant options to native parser (Ivan Levkivskyi, PR [20984](https://github.com/python/mypy/pull/20984))
+- Support `@no_type_check` with native parser (Ivan Levkivskyi, PR [20959](https://github.com/python/mypy/pull/20959))
+- Fix error code handling in native parser (Ivan Levkivskyi, PR [20952](https://github.com/python/mypy/pull/20952))
+- Add `ast-serialize` as an optional dependency (Ivan Levkivskyi, PR [21028](https://github.com/python/mypy/pull/21028))
+
+### Performance Improvements
+
+Mypy now uses a binary cache format (fixed-format cache) by default to speed up incremental
+checking. You can still use `--no-fixed-format-cache` to use the legacy JSON cache format,
+but we will remove the JSON cache format in a future release. Mypy includes a tool to convert
+individual fixed-format cache files (.ff) to the JSON format to make it possible to inspect
+cache contents:
+
+```python
+python -m mypy.exportjson <path> ...
+```
+
+If the SQLite cache is enabled, you will first need to convert the SQLite cache into
+individual files using the [`misc/convert-cache.py`](https://github.com/python/mypy/blob/master/misc/convert-cache.py)
+tool available in the mypy GitHub repository. You can also disable the SQLite
+cache using `--no-sqlite-cache`.
+
+The SQLite cache (`--sqlite-cache`) is now enabled by default. It improves mypy
+performance significantly in certain environments where slow file system operations
+used to be a bottleneck.
+
+List of all performance improvements (for mypyc improvements there is a separate section below):
+
+- Flip fixed-format cache to on by default (Ivan Levkivskyi, PR [20758](https://github.com/python/mypy/pull/20758))
+- Enable `--sqlite-cache` by default (Shantanu, PR [21041](https://github.com/python/mypy/pull/21041))
+- Save work on emitting ignored diagnostics (Shantanu, PR [20621](https://github.com/python/mypy/pull/20621))
+- Skip logging and stats collection calls if they are no-ops (Jukka Lehtosalo, PR [20839](https://github.com/python/mypy/pull/20839))
+- Speed up large incremental builds by optimizing internal state construction (Jukka Lehtosalo, PR [20838](https://github.com/python/mypy/pull/20838))
+- Speed up suppressed dependencies options processing (Jukka Lehtosalo, PR [20806](https://github.com/python/mypy/pull/20806))
+- Avoid path operations that need syscalls (Jukka Lehtosalo, PR [20802](https://github.com/python/mypy/pull/20802))
+- Use faster algorithm for topological sort (Jukka Lehtosalo, PR [20790](https://github.com/python/mypy/pull/20790))
+- Replace old topological sort (Jukka Lehtosalo, PR [20805](https://github.com/python/mypy/pull/20805))
+- Fix quadratic performance in dependency graph loading for incremental builds (Jukka Lehtosalo, PR [20786](https://github.com/python/mypy/pull/20786))
+- Micro-optimize transitive dependency hash calculation (Jukka Lehtosalo, PR [20798](https://github.com/python/mypy/pull/20798))
+- Speed up options snapshot calculation (Jukka Lehtosalo, PR [20797](https://github.com/python/mypy/pull/20797))
+- Micro-optimize read buffering, metastore `abspath`, path joining (Shantanu, PR [20810](https://github.com/python/mypy/pull/20810))
+- Speed up type comparisons and hashing for literal types (Shantanu, PR [20423](https://github.com/python/mypy/pull/20423))
+- Optimize overloaded signatures check (asce, PR [20378](https://github.com/python/mypy/pull/20378))
+- Avoid unnecessary work when checking deferred functions (Ivan Levkivskyi, PR [20860](https://github.com/python/mypy/pull/20860))
+- Improve `--allow-redefinition-new` performance for code with loops (Ivan Levkivskyi, PR [20862](https://github.com/python/mypy/pull/20862))
+- Avoid `setattr`/`getattr` with fixed format cache (Ivan Levkivskyi, PR [20826](https://github.com/python/mypy/pull/20826))
+
+### Improvements to Allowing Redefinitions
+
+Mypy now allows significantly more flexible variable redefinitions when using `--allow-redefinition-new`.
+In particular, function parameters can now be redefined with a different type:
+
+```python
+# mypy: allow-redefinition-new, local-partial-types
+
+def process(items: list[str]) -> None:
+    # Reassign parameter to a completely different type.
+    # Without --allow-redefinition-new, this is a type error because
+    # list[list[str]] is not compatible with list[str].
+    items = [item.split() for item in items]
+    ...
+```
+
+In mypy 2.0, we will update `--allow-redefinition` to mean `--allow-redefinition-new`.
+This release adds `--allow-redefinition-old` as an alias of `--allow-redefinition`, which
+can be used to continue using the old redefinition behavior in mypy 2.0 and later.
+
+List of changes:
+
+- Add `--allow-redefinition-old` as an alias of `--allow-redefinition` (Ivan Levkivskyi, PR [20764](https://github.com/python/mypy/pull/20764))
+- Allow redefinitions for function arguments (Ivan Levkivskyi, PR [20853](https://github.com/python/mypy/pull/20853))
+- Fix regression on redefinition in deferred loop (Ivan Levkivskyi, PR [20879](https://github.com/python/mypy/pull/20879))
+- Fix loop convergence with redefinitions (Ivan Levkivskyi, PR [20865](https://github.com/python/mypy/pull/20865))
+- Make sure new redefinition semantics only apply to inferred variables (Ivan Levkivskyi, PR [20909](https://github.com/python/mypy/pull/20909))
+- Fix union edge case in function argument redefinition (Ivan Levkivskyi, PR [20908](https://github.com/python/mypy/pull/20908))
+- Show an error when old and new redefinition are enabled in a file (Ivan Levkivskyi, PR [20920](https://github.com/python/mypy/pull/20920))
+- Fix type inference for nested union types (Ivan Levkivskyi, PR [20912](https://github.com/python/mypy/pull/20912))
+- Fix type inference regression for multiple variables in loops (Ivan Levkivskyi, PR [20892](https://github.com/python/mypy/pull/20892))
+- Improve type inference for empty collections in conditional contexts (Ivan Levkivskyi, PR [20851](https://github.com/python/mypy/pull/20851))
+
+### Incremental Checking Improvements
+
+This release includes multiple fixes to incremental type checking:
+
+- Invalidate cache when `--enable-incomplete-feature` changes (kaushal trivedi, PR [20849](https://github.com/python/mypy/pull/20849))
+- Add back support for `warn_unused_configs` (Ivan Levkivskyi, PR [20801](https://github.com/python/mypy/pull/20801))
+- Recover from corrupted fixed-format cache meta file (Jukka Lehtosalo, PR [20780](https://github.com/python/mypy/pull/20780))
+- Distinguish not found versus skipped modules (Ivan Levkivskyi, PR [20812](https://github.com/python/mypy/pull/20812))
+- Fix undetected submodule deletion on warm run (Ivan Levkivskyi, PR [20784](https://github.com/python/mypy/pull/20784))
+- Fix staleness on changed follow-imports options (Ivan Levkivskyi, PR [20773](https://github.com/python/mypy/pull/20773))
+- Verify indirect dependencies reachable on incremental run (Ivan Levkivskyi, PR [20735](https://github.com/python/mypy/pull/20735))
+- Fix indirect dependencies for protocols (Ivan Levkivskyi, PR [20752](https://github.com/python/mypy/pull/20752))
+- Show error locations in other modules on warm runs (Ivan Levkivskyi, PR [20635](https://github.com/python/mypy/pull/20635))
+- Don't read errors from cache on silent import (Sjoerd Job Postmus, PR [20509](https://github.com/python/mypy/pull/20509))
+- More robust fix for re-export of `__all__` (Ivan Levkivskyi, PR [20487](https://github.com/python/mypy/pull/20487))
+
+### Fixes to Crashes
+
+- Fix crash on partially typed namespace package (Ivan Levkivskyi, PR [20742](https://github.com/python/mypy/pull/20742))
+- Fix internal error caused by the generic type alias with an unpacked list (Kai (Kazuya Ito), PR [20689](https://github.com/python/mypy/pull/20689))
+- Fix crash when missing format character (Shantanu, PR [20524](https://github.com/python/mypy/pull/20524))
+- Fix crash when passing literal values as type arguments to variadic generics (Aaron Wieczorek, PR [20543](https://github.com/python/mypy/pull/20543))
+- Fix crash on circular star import in incremental mode (Ivan Levkivskyi, PR [20511](https://github.com/python/mypy/pull/20511))
+- Fix crash with tuple unpack inside TypeVar default (Marc Mueller, PR [20456](https://github.com/python/mypy/pull/20456))
+- Fix crash on typevar with forward reference used in other module (Ivan Levkivskyi, PR [20334](https://github.com/python/mypy/pull/20334))
+- Fix crash on star import of redefinition (Ivan Levkivskyi, PR [20333](https://github.com/python/mypy/pull/20333))
+- Fix crash involving Unpack-ed `TypeVarTuple` (Shantanu, PR [20323](https://github.com/python/mypy/pull/20323))
+- Fix crashes caused by type variable defaults in-place modifications (Stanislav Terliakov, PR [20139](https://github.com/python/mypy/pull/20139))
+- Fix crash when calling `len()` with no arguments (Jukka Lehtosalo, PR [20774](https://github.com/python/mypy/pull/20774))
+- Fix crash when checking `async for` inside nested comprehensions (A5rocks, PR [20540](https://github.com/python/mypy/pull/20540))
+- Fix `ParamSpec` related crash (Stanislav Terliakov, PR [20119](https://github.com/python/mypy/pull/20119))
+
+### Mypyc: Faster Imports on macOS
+
+Imports in native (compiled) modules that target other native modules that are compiled
+together are now significantly faster on macOS, especially on the first run after a compiled
+package has been installed. This also speeds up the first mypy run after installation/update
+on macOS.
+
+This was contributed by Jukka Lehtosalo (PR [21101](https://github.com/python/mypy/pull/21101)).
+
+### librt: Mypyc Standard Library
+
+Mypyc now has a dedicated standard library, `librt`, to provide basic features that are optimized
+for compiled code. They are faster than corresponding Python stdlib functionality. There is no
+plan to replace the Python stdlib, though. We'll only include a carefully selected set of features
+that help with common performance bottlenecks in compiled code.
+
+Currently, we provide `librt.base64` that has optimized SIMD (Single Instruction, Multiple
+Data) base64 encoding and decoding functions. In future mypyc releases we are planning to
+add efficient data structures, string/bytes utilities, and more.
+
+Use `python3 -m pip install librt` to make `librt` available to compiled modules. Compiled
+modules don't require `librt` unless they explicitly import `librt`. If you install mypy, you
+will also get a compatible version of `librt` as a dependency. We will keep `librt` backward
+compatible, so you should always be able to update to a newer version of the library.
+
+Related changes:
+
+- Add minimal, experimental `librt.base64` module (Jukka Lehtosalo, PR [20226](https://github.com/python/mypy/pull/20226))
+- Use faster base64 encode implementation in `librt.base64` (Jukka Lehtosalo, PR [20237](https://github.com/python/mypy/pull/20237))
+- Add efficient `librt.base64.b64decode` (Jukka Lehtosalo, PR [20263](https://github.com/python/mypy/pull/20263))
+- Enable SIMD for `librt.base64` on x86-64 (Jukka Lehtosalo, PR [20244](https://github.com/python/mypy/pull/20244))
+- Add primitive for `librt.base64.b64decode` (Jukka Lehtosalo, PR [20272](https://github.com/python/mypy/pull/20272))
+- Add `urlsafe_b64encode` and `urlsafe_b64decode` to `librt.base64` (Jukka Lehtosalo, PR [20274](https://github.com/python/mypy/pull/20274))
+- Make `librt.base64` non-experimental (Ivan Levkivskyi, PR [20783](https://github.com/python/mypy/pull/20783))
+- Support pyodide for Python 3.12 (Michael R. Crusoe, PR [20342](https://github.com/python/mypy/pull/20342))
+- Support pyodide via the NEON intrinsics (Michael R. Crusoe, PR [20316](https://github.com/python/mypy/pull/20316))
+- Fix `librt` compilation on platforms with OpenMP (Ivan Levkivskyi, PR [20583](https://github.com/python/mypy/pull/20583))
+- Fix cross-compiling `librt` by enabling x86_64 optimizations with pragmas (James Le Cuirot, PR [20815](https://github.com/python/mypy/pull/20815))
+- Use existing SIMD CPU dispatch by customizing build flags (Michael R. Crusoe, PR [20253](https://github.com/python/mypy/pull/20253))
+
+### Mypyc: Acyclic Classes
+
+Mypyc now supports defining acyclic native classes that don't participate in the tracing
+garbage collection:
+
+```python
+from mypy_extensions import mypyc_attr
+
+@mypyc_attr(acyclic=True)
+class Item:
+    def __init__(self, key: str, value: str) -> None:
+        self.key = key
+        self.value = value
+```
+
+Allocating and freeing instances of acyclic classes is faster than regular native class
+instances, and they use less memory, but if they participate in reference cycles, there
+may be memory leaks.
+
+This was contributed by Jukka Lehtosalo (PR [20795](https://github.com/python/mypy/pull/20795)).
+
+### Additional Mypyc Fixes and Improvements
+
+- Fix range loop variable off-by-one after loop exit (Vaggelis Danias, PR [21098](https://github.com/python/mypy/pull/21098))
+- Fix memory leak on property setter call (Piotr Sawicki, PR [21095](https://github.com/python/mypy/pull/21095))
+- Fix `ClassVar` self-references in class bodies (Vaggelis Danias, PR [21011](https://github.com/python/mypy/pull/21011))
+- Fix cross-module class attribute defaults causing KeyError (Vaggelis Danias, PR [21012](https://github.com/python/mypy/pull/21012))
+- Fix shadow vtable misalignment for `@property` getters/setters (Vaggelis Danias, PR [21010](https://github.com/python/mypy/pull/21010))
+- Fix lambda inside comprehension (Vaggelis Danias, PR [21009](https://github.com/python/mypy/pull/21009))
+- Use cached ASCII characters in `CPyStr_GetItem` (Vaggelis Danias, PR [21035](https://github.com/python/mypy/pull/21035))
+- Speed up int to bytes conversion (Piotr Sawicki, PR [21036](https://github.com/python/mypy/pull/21036))
+- Add missing primitive documentation (Jukka Lehtosalo, PR [21037](https://github.com/python/mypy/pull/21037))
+- Fix undefined behavior in generated C (Jukka Lehtosalo, PR [21094](https://github.com/python/mypy/pull/21094))
+- Fix vtable construction for deep trait inheritance (Vaggelis Danias, PR [20917](https://github.com/python/mypy/pull/20917))
+- Fix `__init_subclass__` running before `ClassVar` instantiations (Vaggelis Danias, PR [20916](https://github.com/python/mypy/pull/20916))
+- Add support for `str.lower()` and `str.upper()` (Vaggelis Danias, PR [20948](https://github.com/python/mypy/pull/20948))
+- Add `str.isdigit()` primitive (Vaggelis Danias, PR [20893](https://github.com/python/mypy/pull/20893))
+- Add `str.isalnum()` primitive (Vaggelis Danias, PR [20852](https://github.com/python/mypy/pull/20852))
+- Add `str.isspace()` primitive (Vaggelis Danias, PR [20842](https://github.com/python/mypy/pull/20842))
+- Reduce memory usage when compiling large files (Vaggelis Danias, PR [20897](https://github.com/python/mypy/pull/20897))
+- Generate error if using Python 3.14 t-string (Jukka Lehtosalo, PR [20899](https://github.com/python/mypy/pull/20899))
+- Fix undefined attribute in nested coroutines (Piotr Sawicki, PR [20654](https://github.com/python/mypy/pull/20654))
+- Do not emit tracebacks with negative line numbers (Piotr Sawicki, PR [20641](https://github.com/python/mypy/pull/20641))
+- Fix crash on multiple nested decorated functions with same name (Piotr Sawicki, PR [20666](https://github.com/python/mypy/pull/20666))
+- Fix `Final` load in unreachable branches (BobTheBuidler, PR [20617](https://github.com/python/mypy/pull/20617))
+- Add new primitive for `int.to_bytes` (BobTheBuidler, PR [19674](https://github.com/python/mypy/pull/19674))
+- Support constant folding in f-string to `str` conversion (BobTheBuidler, PR [19970](https://github.com/python/mypy/pull/19970))
+- Implement `bytes.endswith` (esarp, PR [20447](https://github.com/python/mypy/pull/20447))
+- Fix coercion from short tagged int to fixed-width int (Jukka Lehtosalo, PR [20587](https://github.com/python/mypy/pull/20587))
+- Fix generation of function wrappers for decorated functions (Piotr Sawicki, PR [20584](https://github.com/python/mypy/pull/20584))
+- Generate function wrappers for each callable class instance (Piotr Sawicki, PR [20575](https://github.com/python/mypy/pull/20575))
+- Speed up `ord(str[n])` by inlining (Jukka Lehtosalo, PR [20578](https://github.com/python/mypy/pull/20578))
+- Add inline primitives for `bytes.__getitem__` (Jukka Lehtosalo, PR [20552](https://github.com/python/mypy/pull/20552))
+- Add primitive type for `bytearray` (Jukka Lehtosalo, PR [20551](https://github.com/python/mypy/pull/20551))
+- Fix and clean up `bytearray` support in primitives (Jukka Lehtosalo, PR [20550](https://github.com/python/mypy/pull/20550))
+- Enable `--strict-bytes` by default in mypyc (and require it) (Jukka Lehtosalo, PR [20548](https://github.com/python/mypy/pull/20548))
+- Fix exception reraising when awaiting a future (Piotr Sawicki, PR [20547](https://github.com/python/mypy/pull/20547))
+- Add inline primitives for BytesBuilder get item and set item (Jukka Lehtosalo, PR [20546](https://github.com/python/mypy/pull/20546))
+- Optimize loops over `enumerate`, `map`, `zip`, `range`, and other builtins with known lengths (BobTheBuidler, PR [19927](https://github.com/python/mypy/pull/19927))
+- Raise `ValueError` if int too big for native int type (Jukka Lehtosalo, PR [20385](https://github.com/python/mypy/pull/20385))
+- Fix generator regression with empty tuple (BobTheBuidler, PR [20371](https://github.com/python/mypy/pull/20371))
+- Improve constant folding for `len()` of string literals and Final values (BobTheBuidler, PR [20074](https://github.com/python/mypy/pull/20074))
+- Add primitive for `bytes.startswith` (esarp, PR [20387](https://github.com/python/mypy/pull/20387))
+- Fix calling async methods through vectorcall (Piotr Sawicki, PR [20393](https://github.com/python/mypy/pull/20393))
+- Extend loop optimization to use constant folding for determining sequence lengths (BobTheBuidler, PR [19930](https://github.com/python/mypy/pull/19930))
+- Wrap async functions with function-like type (Piotr Sawicki, PR [20260](https://github.com/python/mypy/pull/20260))
+- Add a primitive for bytes `translate` method (Jukka Lehtosalo, PR [20305](https://github.com/python/mypy/pull/20305))
+- Add primitives for bytes and str multiply (Jukka Lehtosalo, PR [20303](https://github.com/python/mypy/pull/20303))
+- Match int arguments to primitives with native int parameters (Jukka Lehtosalo, PR [20299](https://github.com/python/mypy/pull/20299))
+- Allow disabling extra flags with `MYPYC_NO_EXTRA_FLAGS` environment variable (James Hilliard, PR [20507](https://github.com/python/mypy/pull/20507))
+- Fix unsupported imports for type annotations (Lukas Geiger, PR [20390](https://github.com/python/mypy/pull/20390))
+- Fix unaligned memory access in librt internal helper function (Gregor Riepl, PR [20474](https://github.com/python/mypy/pull/20474))
+- Fix build issue (James Hilliard, PR [20510](https://github.com/python/mypy/pull/20510))
+
+### Removed Flags `--force-uppercase-builtins` and `--force-union-syntax`
 
 The `--force-uppercase-builtins` flag was deprecated and has been a no-op since mypy 1.17.0.
 Since mypy has dropped support for Python 3.9, the `--force-union-syntax` flag is no longer
@@ -97,6 +399,110 @@ necessary.
 Contributed by Marc Mueller (PR [20410](https://github.com/python/mypy/pull/20410))
 and (PR [20405](https://github.com/python/mypy/pull/20405)).
 
+### Stubgen Improvements
+
+- Fix mis-parsing of double colon ("::") (Jeremy Nimmer, PR [20285](https://github.com/python/mypy/pull/20285))
+
+### Stubtest Improvements
+
+- Attempt to resolve decorators from their type (Shantanu, PR [20867](https://github.com/python/mypy/pull/20867))
+- Fix crash on instances with redefined `__class__` (sobolevn, PR [20926](https://github.com/python/mypy/pull/20926))
+- Improve checking of positional-only parameters in dunder methods (Brian Schubert, PR [19593](https://github.com/python/mypy/pull/19593))
+- Check `Final` variables with literal values against runtime (Vikash Kumar, PR [20858](https://github.com/python/mypy/pull/20858))
+- Fix duplicate errors with invalid line numbers (Joren Hammudoglu, PR [20417](https://github.com/python/mypy/pull/20417))
+- Ignore `__conditional_annotations__` (Joren Hammudoglu, PR [20392](https://github.com/python/mypy/pull/20392))
+- Transparent `@type_check_only` types (Joren Hammudoglu, PR [20352](https://github.com/python/mypy/pull/20352))
+- Check runtime availability of private types not marked `@type_check_only` (Brian Schubert, PR [19574](https://github.com/python/mypy/pull/19574))
+
+### Documentation Updates
+
+- Document semantics of function argument redefinition (Ivan Levkivskyi, PR [20910](https://github.com/python/mypy/pull/20910))
+- Update common issues: document how the type ignore must come first (wyattscarpenter, PR [20886](https://github.com/python/mypy/pull/20886))
+- Update "type inference and annotations" (Kai (Kazuya Ito), PR [20619](https://github.com/python/mypy/pull/20619))
+- Document unreachability handling of `return NotImplemented` (wyattscarpenter, PR [20561](https://github.com/python/mypy/pull/20561))
+
+### Changes to Messages
+
+- Simpler/cleaner `reveal_type()` (Ivan Levkivskyi, PR [20929](https://github.com/python/mypy/pull/20929))
+- Use "parameter" instead of "argument" in overload error (Kai (Kazuya Ito), PR [20994](https://github.com/python/mypy/pull/20994))
+- Use "parameter" instead of "argument" in unpacking error (Kai (Kazuya Ito), PR [20683](https://github.com/python/mypy/pull/20683))
+- Use "type arguments" instead of "type parameters" for bare generics (Kai (Kazuya Ito), PR [20494](https://github.com/python/mypy/pull/20494))
+- Update "arguments" to "parameters" (Kai (Kazuya Ito), PR [20711](https://github.com/python/mypy/pull/20711))
+- Use "parameter" instead of "argument" in default value error messages (Kai (Kazuya Ito), PR [20964](https://github.com/python/mypy/pull/20964))
+- Update error message for parameter overlap in TypedDict (Kai (Kazuya Ito), PR [20956](https://github.com/python/mypy/pull/20956))
+- Correct "Duplicate argument" error messages (Kai (Kazuya Ito), PR [20957](https://github.com/python/mypy/pull/20957))
+- Use standard formatting for note on unexpected keyword (Ivan Levkivskyi, PR [20808](https://github.com/python/mypy/pull/20808))
+- Fix edge cases in pretty formatting (Ivan Levkivskyi, PR [20809](https://github.com/python/mypy/pull/20809))
+- Add function definition notes for missing named argument errors (Kevin Kannammalil, PR [20794](https://github.com/python/mypy/pull/20794))
+- Make overloaded constructors consistent in error messages (Ivan Levkivskyi, PR [20483](https://github.com/python/mypy/pull/20483))
+- Improve error message for invalid Python package (Shantanu, PR [20482](https://github.com/python/mypy/pull/20482))
+- Emit end line/column in JSON format for span tracking (Adam Turner, PR [20734](https://github.com/python/mypy/pull/20734))
+- Wrap callable in union syntax (Marc Mueller, PR [20406](https://github.com/python/mypy/pull/20406))
+
+### Other Notable Fixes and Improvements
+
+- Unify handling of self attributes in daemon (Ivan Levkivskyi, PR [21025](https://github.com/python/mypy/pull/21025))
+- Improve support for `hasattr()` (Ivan Levkivskyi, PR [20914](https://github.com/python/mypy/pull/20914))
+- Warn when `@disjoint_base` is used on protocols or TypedDicts (Brian Schubert, PR [21029](https://github.com/python/mypy/pull/21029))
+- Model tuple type aliases better (Shantanu, PR [20967](https://github.com/python/mypy/pull/20967))
+- Fix incorrect type inference for container literals inside loops (Ivan Levkivskyi, PR [20875](https://github.com/python/mypy/pull/20875))
+- Fix edge case in type comparison for type variables with narrowed bounds (Ivan Levkivskyi, PR [20874](https://github.com/python/mypy/pull/20874))
+- Prohibit access via class for instance-only attributes (Ivan Levkivskyi, PR [20855](https://github.com/python/mypy/pull/20855))
+- Update JSON export tool to support binary meta cache files (Jukka Lehtosalo, PR [20096](https://github.com/python/mypy/pull/20096))
+- Better handling for uncaught top-level exceptions (Ivan Levkivskyi, PR [20749](https://github.com/python/mypy/pull/20749))
+- Attrs field level `kw_only=False` overrides `kw_only=True` at class level (getzze, PR [20949](https://github.com/python/mypy/pull/20949))
+- Fix `__slots__` issue with deferred base (Shantanu, PR [20573](https://github.com/python/mypy/pull/20573))
+- Fix deferral logic for special types (Ivan Levkivskyi, PR [20678](https://github.com/python/mypy/pull/20678))
+- Fix false negatives in walrus versus inference fallback logic (Ivan Levkivskyi, PR [20622](https://github.com/python/mypy/pull/20622))
+- Fix enum value inference with user-defined data type mixin (E. M. Bray, PR [16320](https://github.com/python/mypy/pull/16320))
+- Fix incorrect classification of class attributes versus enum members (Stanislav Terliakov, PR [19687](https://github.com/python/mypy/pull/19687))
+- Improve type inference when finding common types for callable types (Shantanu, PR [18406](https://github.com/python/mypy/pull/18406))
+- Remove special case for Union type context (Shantanu, PR [20610](https://github.com/python/mypy/pull/20610))
+- Evaluate argument expressions in runtime evaluation order (Shantanu, PR [20491](https://github.com/python/mypy/pull/20491))
+- Allow empty type applications for `ParamSpec` (A5rocks, PR [20572](https://github.com/python/mypy/pull/20572))
+- Make `X[()]` count as a type application (A5rocks, PR [20568](https://github.com/python/mypy/pull/20568))
+- Accept `value` as keyword argument in `TypeAliasType` (Ali Hamdan, PR [20556](https://github.com/python/mypy/pull/20556))
+- Avoid treating `pass` and `...` as no-op for reachability (Shantanu, PR [20488](https://github.com/python/mypy/pull/20488))
+- Fix specialization leak in generic `TypedDict.update()` (Aaron Wieczorek, PR [20517](https://github.com/python/mypy/pull/20517))
+- Fix false positive redundant expression warnings with `isinstance()` on `Any | Protocol` unions (Randolf Scholz, PR [20450](https://github.com/python/mypy/pull/20450))
+- Fix type checking of class-scope imports accessed via `self` or `cls` (bzoracler, PR [20480](https://github.com/python/mypy/pull/20480))
+- Prevent synthetic intersections from leaking to module public interfaces (bzoracler, PR [20459](https://github.com/python/mypy/pull/20459))
+- Fix package build failure when the compiler types are not defined (Steven Pitman, PR [20429](https://github.com/python/mypy/pull/20429))
+- Fix `--strict-equality` for iteratively visited code (Christoph Tyralla, PR [19635](https://github.com/python/mypy/pull/19635))
+- Allow literals as kwargs dict keys (Shantanu, PR [20416](https://github.com/python/mypy/pull/20416))
+- Error for invalid varargs and varkwargs to `Any` call (Shantanu, PR [20324](https://github.com/python/mypy/pull/20324))
+- Fix type inference for binary operators with tuple subclasses (Randolf Scholz, PR [19046](https://github.com/python/mypy/pull/19046))
+- Improve type inference for ternary expressions with literals and collections (Randolf Scholz, PR [19563](https://github.com/python/mypy/pull/19563))
+- Do not treat match value patterns as `isinstance` checks (Stanislav Terliakov, PR [20146](https://github.com/python/mypy/pull/20146))
+- Fix noncommutative joins with bounded TypeVars (Shantanu, PR [20345](https://github.com/python/mypy/pull/20345))
+- Fix error location reporting for `**rest` patterns in match statements (Marc Mueller, PR [20407](https://github.com/python/mypy/pull/20407))
+- Fix matching against union of tuples (Saul Shanabrook, PR [19600](https://github.com/python/mypy/pull/19600))
+- Allow `types.NoneType` in match cases (A5rocks, PR [20383](https://github.com/python/mypy/pull/20383))
+- Treat `Literal["xyz"]` as iterable (Shantanu, PR [20347](https://github.com/python/mypy/pull/20347))
+- Treat functions that return `None` as returning `None` (Shantanu, PR [20350](https://github.com/python/mypy/pull/20350))
+- Fix str unpack type propagation, use dedicated error code (Shantanu, PR [20325](https://github.com/python/mypy/pull/20325))
+- Unpack unions inside tuples in except handlers (asce, PR [17762](https://github.com/python/mypy/pull/17762))
+- Ignore empty error codes from `type: ignore` (Donghoon Nam, PR [20052](https://github.com/python/mypy/pull/20052))
+- Make `NoneType` annotation error use a new error code (wyattscarpenter, PR [20222](https://github.com/python/mypy/pull/20222))
+- Fail with an explicit error on PyPy (Ivan Levkivskyi, PR [20384](https://github.com/python/mypy/pull/20384))
+- Add hidden `--overwrite-union-syntax` option (Marc Mueller, PR [20332](https://github.com/python/mypy/pull/20332))
+- Fix `possibly-undefined` false-positive with nesting (grayjk, PR [20276](https://github.com/python/mypy/pull/20276))
+- Fix spurious `possibly-undefined` errors in for-else with `break` (Łukasz Langa, PR [19696](https://github.com/python/mypy/pull/19696))
+- Avoid false `possibly-undefined` errors due to omitted unrequired else statements (Christoph Tyralla, PR [20149](https://github.com/python/mypy/pull/20149))
+- Fix generator expression behavior for `reveal_type` (michaelm-openai, PR [20594](https://github.com/python/mypy/pull/20594))
+- Fix error on instance property and init-only variable with the same name in a dataclass (Roberto Fernández Iglesias, PR [17219](https://github.com/python/mypy/pull/17219))
+- Improve error messages when `__module__` or `__qualname__` are used as type annotations (A5rocks, PR [20288](https://github.com/python/mypy/pull/20288))
+- Check for multiple type var tuples for PEP 695 (A5rocks, PR [20289](https://github.com/python/mypy/pull/20289))
+- Improve interaction between `--local-partial-types` and hashability (Shantanu, PR [20719](https://github.com/python/mypy/pull/20719))
+- Stop looking for `.gitignore` at top level of working tree (Colin Watson, PR [20775](https://github.com/python/mypy/pull/20775))
+- Try fixing Cygwin build (Ivan Levkivskyi, PR [20830](https://github.com/python/mypy/pull/20830))
+- Fix daemon dependencies in `diff-cache.py` tool (Jukka Lehtosalo, PR [20837](https://github.com/python/mypy/pull/20837))
+- Support fixed-format cache in `diff-cache.py` tool (Jukka Lehtosalo, PR [20827](https://github.com/python/mypy/pull/20827))
+- Update `convert-cache.py` tool to work with fixed-format caches (Ivan Levkivskyi, PR [20761](https://github.com/python/mypy/pull/20761))
+- Write errors to a separate cache file (Ivan Levkivskyi, PR [21022](https://github.com/python/mypy/pull/21022))
+- Write ignored lines to cache meta (Ivan Levkivskyi, PR [20747](https://github.com/python/mypy/pull/20747))
+- Serialize raw errors in cache metas (Ivan Levkivskyi, PR [20372](https://github.com/python/mypy/pull/20372))
+
 ## Mypy 1.19
 
 We’ve just uploaded mypy 1.19.0 to the Python Package Index ([PyPI](https://pypi.org/project/mypy/)).