diff --git a/.github/workflows/publish-sonatype.yml b/.github/workflows/publish-sonatype.yml
index 5c493fc..dc4f083 100644
--- a/.github/workflows/publish-sonatype.yml
+++ b/.github/workflows/publish-sonatype.yml
@@ -16,6 +16,17 @@ jobs:
     steps:
       - uses: actions/checkout@v7
 
+      - name: Check version matches release tag
+        if: github.event_name == 'release'
+        run: |-
+          version="$(sed -nE 's/.*version = "([^"]+)" \/\/ x-release-please-version.*/\1/p' build.gradle.kts)"
+          if [ "v$version" != "$RELEASE_TAG" ]; then
+            echo "::error::build.gradle.kts version ($version) doesn't match the release tag ($RELEASE_TAG). Merge the release PR that bumps the version, then create the release from that commit."
+            exit 1
+          fi
+        env:
+          RELEASE_TAG: ${{ github.event.release.tag_name }}
+
       - name: Set up Java
         uses: actions/setup-java@v6
         with:
diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index 37fcefa..895bf0e 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,3 +1,3 @@
 {
-  ".": "1.0.0"
+  ".": "2.0.0"
 }
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 29a04da..cdd15fa 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,22 @@
 # Changelog
 
+## 2.0.0 (2026-09-30)
+
+Full Changelog: [v1.0.0...v2.0.0](https://github.com/knocklabs/knock-java/compare/v1.0.0...v2.0.0)
+
+### BREAKING CHANGES
+
+* 204 endpoints return nothing, message lists read `items`, guide message actions use the path-less endpoints, `messages().activities()` is removed, and recipient filters accept object references. The SDK now depends on OkHttp 5 and Kotlin stdlib 2.2+. See [MIGRATION.md](MIGRATION.md).
+
+### Features
+
+* modernize SDK against current OpenAPI spec (knock-node parity) ([#40](https://github.com/knocklabs/knock-java/issues/40)) ([d3d321d](https://github.com/knocklabs/knock-java/commit/d3d321db71a178495801bce18af90ea34f120404))
+
+
+### Build System
+
+* **deps:** bring build, runtime, and test dependencies up to date for 2.0.0 ([#41](https://github.com/knocklabs/knock-java/issues/41)) ([1925443](https://github.com/knocklabs/knock-java/commit/19254433621d0920f0a6d753019954d57753d74d))
+
 ## 1.0.0 (2025-05-09)
 
 Full Changelog: [v0.2.10...v1.0.0](https://github.com/knocklabs/knock-java/compare/v0.2.10...v1.0.0)
diff --git a/README.md b/README.md
index b5c542b..9d75f93 100644
--- a/README.md
+++ b/README.md
@@ -2,8 +2,8 @@
 
 <!-- x-release-please-start-version -->
 
-[![Maven Central](https://img.shields.io/maven-central/v/app.knock.api/knock-java)](https://central.sonatype.com/artifact/app.knock.api/knock-java/1.0.0)
-[![javadoc](https://javadoc.io/badge2/app.knock.api/knock-java/1.0.0/javadoc.svg)](https://javadoc.io/doc/app.knock.api/knock-java/1.0.0)
+[![Maven Central](https://img.shields.io/maven-central/v/app.knock.api/knock-java)](https://central.sonatype.com/artifact/app.knock.api/knock-java/2.0.0)
+[![javadoc](https://javadoc.io/badge2/app.knock.api/knock-java/2.0.0/javadoc.svg)](https://javadoc.io/doc/app.knock.api/knock-java/2.0.0)
 
 <!-- x-release-please-end -->
 
@@ -13,7 +13,7 @@ It is generated with [Stainless](https://www.stainless.com/).
 
 <!-- x-release-please-start-version -->
 
-The REST API documentation can be found on [docs.knock.app](https://docs.knock.app). Javadocs are available on [javadoc.io](https://javadoc.io/doc/app.knock.api/knock-java/1.0.0).
+The REST API documentation can be found on [docs.knock.app](https://docs.knock.app). Javadocs are available on [javadoc.io](https://javadoc.io/doc/app.knock.api/knock-java/2.0.0).
 
 <!-- x-release-please-end -->
 
@@ -24,7 +24,7 @@ The REST API documentation can be found on [docs.knock.app](https://docs.knock.a
 ### Gradle
 
 ```kotlin
-implementation("app.knock.api:knock-java:1.0.0")
+implementation("app.knock.api:knock-java:2.0.0")
 ```
 
 ### Maven
@@ -33,7 +33,7 @@ implementation("app.knock.api:knock-java:1.0.0")
 <dependency>
   <groupId>app.knock.api</groupId>
   <artifactId>knock-java</artifactId>
-  <version>1.0.0</version>
+  <version>2.0.0</version>
 </dependency>
 ```
 
diff --git a/build.gradle.kts b/build.gradle.kts
index 382bbb7..571a568 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -8,7 +8,7 @@ repositories {
 
 allprojects {
     group = "app.knock.api"
-    version = "1.0.0" // x-release-please-version
+    version = "2.0.0" // x-release-please-version
 
     // Dokka's isolated build-tool classpaths otherwise resolve Jackson and jsoup versions with known
     // vulnerabilities. This doesn't affect the SDK's published or test dependencies.