diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index d0d087a3..6d9e5fc0 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,3 +1,3 @@
 {
-  ".": "1.19.0"
+  ".": "1.20.0"
 }
diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 00000000..b565f41e
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,33 @@
+# Changelog
+
+## [1.20.0](https://github.com/modelix/modelix.editor/compare/1.19.0...1.20.0) (2026-07-17)
+
+
+### Features
+
+* show all model checker messages, including on nodes without a visible cell ([44fa9c0](https://github.com/modelix/modelix.editor/commit/44fa9c09c54be97f26107e1ce60dececf07cfab1))
+* show model checker errors in the projectional editor ([82a53e0](https://github.com/modelix/modelix.editor/commit/82a53e0aa220486d8daa9c73e938cfe959fbc741))
+* underline the whole cell range of a node-level check message ([8ef4663](https://github.com/modelix/modelix.editor/commit/8ef466392bdd43f02ffcbb7b9f210ca6c30dffb9))
+
+
+### Bug Fixes
+
+* **deps:** update commitlint monorepo to v20.5.3 ([#542](https://github.com/modelix/modelix.editor/issues/542)) ([f8bd041](https://github.com/modelix/modelix.editor/commit/f8bd041eba4111671f573c6d70521a3a4b4b1528))
+* **deps:** update dependency org.jetbrains.kotlinx:kotlinx-collections-immutable to v0.5.1 ([#544](https://github.com/modelix/modelix.editor/issues/544)) ([04adf6b](https://github.com/modelix/modelix.editor/commit/04adf6b274669381f1d26af315d9668ad1cfae40))
+* don't shift line text when the gutter marks an error or warning ([3dbcc22](https://github.com/modelix/modelix.editor/commit/3dbcc227f6a9ad4215dd1a3e24f6b428630c0a50))
+* don't underline indentation inside a message's cell range ([1926f0a](https://github.com/modelix/modelix.editor/commit/1926f0ad2888974fbf3ac979a22d42198dac61a5))
+* eliminate false model checker errors from wrapper node identity ([3af3e93](https://github.com/modelix/modelix.editor/commit/3af3e935244e195a849795c12c0b280c54271893))
+* implement FlagCellTemplate.getInstantiationActions ([b2d2066](https://github.com/modelix/modelix.editor/commit/b2d206629afb0c0f95980dea18b474b3d694d52c))
+* make ModelixNodeAsMPSNode a real jetbrains.mps.smodel.SNode ([8882f03](https://github.com/modelix/modelix.editor/commit/8882f03d7d7fba1ed57e634c5de56b032aa16f57))
+* model checker failed on nodes wrapped as MPS nodes ([dd14925](https://github.com/modelix/modelix.editor/commit/dd149258b09576039d3ee4f055e71aa56899fcd9))
+
+
+### Performance Improvements
+
+* more fine-grained caching in IncrementalModelChecker ([945cf5c](https://github.com/modelix/modelix.editor/commit/945cf5c937794d64d71f7858a67b77134715cadb))
+
+
+### Code Refactoring
+
+* attach each check message to a single cell; underline the range while rendering ([bacfc87](https://github.com/modelix/modelix.editor/commit/bacfc87a96633e40351f9af798bb288d1f59799a))
+* remove unused helpers from IncrementalModelChecker ([2844109](https://github.com/modelix/modelix.editor/commit/28441098222fe4f4093e0207a08ce7df1196e580))