diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index 6db2420..65f5cc4 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,3 +1,3 @@
 {
-  ".": "5.0.0-alpha.21.1"
+  ".": "5.0.0-alpha.21.0"
 }
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 90107db..74efb91 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,35 @@
 # Changelog
 
+## [5.0.0-alpha.21.0](https://github.com/fable-compiler/Fable.Python/compare/v5.0.0-alpha.21.1...v5.0.0-alpha.21.0) (2025-12-18)
+
+
+### Features
+
+* Add exception types ([#173](https://github.com/fable-compiler/Fable.Python/issues/173)) ([72f09b2](https://github.com/fable-compiler/Fable.Python/commit/72f09b2ff6e208e3ab057430a355814611abd46c))
+* Add Json static class with Fable-aware serialization ([#175](https://github.com/fable-compiler/Fable.Python/issues/175)) ([1eb5005](https://github.com/fable-compiler/Fable.Python/commit/1eb500523c6d6f43247bc3510a6045ec8d9d9d4e))
+* add Python stdlib bindings for logging, random, and expand string module ([#166](https://github.com/fable-compiler/Fable.Python/issues/166)) ([709d6c2](https://github.com/fable-compiler/Fable.Python/commit/709d6c2b29199965926ff639727fdcc1bb2e1fb8))
+* add write ([334e800](https://github.com/fable-compiler/Fable.Python/commit/334e80089c081bda25633f83dae037fc6c8fe6f5))
+* Added bindings for Pydantic and FastAPI + examples ([#151](https://github.com/fable-compiler/Fable.Python/issues/151)) ([826629e](https://github.com/fable-compiler/Fable.Python/commit/826629e465fca15d444a4ca37b851b8aab488f9a))
+* Fable v5 ([#147](https://github.com/fable-compiler/Fable.Python/issues/147)) ([abf8e6a](https://github.com/fable-compiler/Fable.Python/commit/abf8e6a1f7bbc2eae152431d04d6b8b5675f7795))
+* FastAPI async handlers ([#174](https://github.com/fable-compiler/Fable.Python/issues/174)) ([26cec1f](https://github.com/fable-compiler/Fable.Python/commit/26cec1f239f9244a7c1da1d00bbf1a479596bb3c))
+
+
+### Bug Fixes
+
+* add missing models.py for pydantic example and update README ([#168](https://github.com/fable-compiler/Fable.Python/issues/168)) ([b76ce98](https://github.com/fable-compiler/Fable.Python/commit/b76ce989e0598d0007a8a1be9addfea97936eae7))
+* handle return type correctly ([a634168](https://github.com/fable-compiler/Fable.Python/commit/a6341684ac8bb3f1b244f448c22e1fe6f208fbc0))
+* relax FSharp.Core dependency to >= 5.0.0 ([#163](https://github.com/fable-compiler/Fable.Python/issues/163)) ([10eb65b](https://github.com/fable-compiler/Fable.Python/commit/10eb65b22a157078e1b66bd8fb202b0cd2acbedc))
+* remove versioning strategy from release-please config ([ce84cae](https://github.com/fable-compiler/Fable.Python/commit/ce84caeeb7caa24eaecd96fb8e0723e7cb6e7c6a))
+* update pyproject toml details ([#62](https://github.com/fable-compiler/Fable.Python/issues/62)) ([b511351](https://github.com/fable-compiler/Fable.Python/commit/b5113514ca6b4a9ba00734e9b3caaf363f3385af))
+* update release-please to use prerelease versioning ([7c219e8](https://github.com/fable-compiler/Fable.Python/commit/7c219e848fd3201d4567685ddfefae48c362856c))
+* use plain int/string types for open ([b202a25](https://github.com/fable-compiler/Fable.Python/commit/b202a25bd7f48538fadc50125294a9252714d364))
+* use string types for open ([f211f8b](https://github.com/fable-compiler/Fable.Python/commit/f211f8bb9445dd6930926fe48aab6a69720dd30f))
+
+
+### Miscellaneous Chores
+
+* sync with Fable 5.0.0-alpha.21 ([fd2685c](https://github.com/fable-compiler/Fable.Python/commit/fd2685c2f992c2d8058ac1bc1261d647271359df))
+
 ## [5.0.0-alpha.21.0](https://github.com/fable-compiler/Fable.Python/compare/v5.0.0-alpha.21...v5.0.0-alpha.21.0) (2025-12-16)