diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index c3f1463..41ea87d 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,3 +1,3 @@
 {
-  ".": "1.2.0"
+  ".": "1.2.1"
 }
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 20db2dd..dc90d24 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,13 @@
 # Changelog
 
+## [1.2.1](https://github.com/agentclientprotocol/typescript-sdk/compare/v1.2.0...v1.2.1) (2026-07-07)
+
+
+### Bug Fixes
+
+* **http:** make SSE close and response delivery deterministic ([#209](https://github.com/agentclientprotocol/typescript-sdk/issues/209)) ([2adee0f](https://github.com/agentclientprotocol/typescript-sdk/commit/2adee0f5071bd1201c84b7d8a2836cfe011d4c9a))
+* Preserve extensible union semantics in TS schemas ([#215](https://github.com/agentclientprotocol/typescript-sdk/issues/215)) ([e323221](https://github.com/agentclientprotocol/typescript-sdk/commit/e3232216ac172283e4f77f9d75c12f820952b5e9))
+
 ## [1.2.0](https://github.com/agentclientprotocol/typescript-sdk/compare/v1.1.0...v1.2.0) (2026-07-06)
 
 
diff --git a/package-lock.json b/package-lock.json
index bc93863..17c9d5f 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "@agentclientprotocol/sdk",
-  "version": "1.2.0",
+  "version": "1.2.1",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@agentclientprotocol/sdk",
-      "version": "1.2.0",
+      "version": "1.2.1",
       "license": "Apache-2.0",
       "devDependencies": {
         "@eslint/js": "^10.0.1",
diff --git a/package.json b/package.json
index 0a54e00..7684b51 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@agentclientprotocol/sdk",
-  "version": "1.2.0",
+  "version": "1.2.1",
   "publishConfig": {
     "access": "public"
   },