CloudEngineHub · github-actions · Sep 24, 2026
diff --git a/.changeset/loopback-localhost-subdomains.md b/.changeset/loopback-localhost-subdomains.md
diff --git a/packages/client/CHANGELOG.md b/packages/client/CHANGELOG.md
@@ -1,5 +1,14 @@
 # @modelcontextprotocol/client
 
+## 2.1.1
+
+### Patch Changes
+
+- [#2597](https://github.com/modelcontextprotocol/typescript-sdk/pull/2597) [`7f7a94c`](https://github.com/modelcontextprotocol/typescript-sdk/commit/7f7a94c22017e121a960e071bb50ec75e34450bd) Thanks [@arimu1](https://github.com/arimu1)! - Treat hostnames ending in `.localhost` as loopback for the SEP-2207 token-endpoint https guard (RFC 6761 §6.3), so host-based multi-tenant local OAuth works. The SDK does not resolve the name itself: `*.localhost` reaches the local machine only if the system resolver follows RFC 6761.
+
+- Updated dependencies []:
+    - @modelcontextprotocol/core@2.1.1
+
 ## 2.1.0
 
 ### Minor Changes

diff --git a/packages/client/package.json b/packages/client/package.json
@@ -1,6 +1,6 @@
 {
     "name": "@modelcontextprotocol/client",
-    "version": "2.1.0",
+    "version": "2.1.1",
     "description": "Model Context Protocol implementation for TypeScript - Client package",
     "license": "MIT",
     "author": "Anthropic, PBC (https://anthropic.com)",

diff --git a/packages/codemod/CHANGELOG.md b/packages/codemod/CHANGELOG.md
@@ -1,5 +1,7 @@
 # @modelcontextprotocol/codemod
 
+## 2.1.1
+
 ## 2.1.0
 
 ### Patch Changes

diff --git a/packages/codemod/package.json b/packages/codemod/package.json
@@ -1,6 +1,6 @@
 {
     "name": "@modelcontextprotocol/codemod",
-    "version": "2.1.0",
+    "version": "2.1.1",
     "description": "Codemod to migrate MCP TypeScript SDK code from v1 to v2",
     "license": "MIT",
     "author": "Anthropic, PBC (https://anthropic.com)",

diff --git a/packages/core-internal/CHANGELOG.md b/packages/core-internal/CHANGELOG.md
@@ -1,5 +1,12 @@
 # @modelcontextprotocol/core-internal
 
+## 2.0.2
+
+### Patch Changes
+
+- Updated dependencies []:
+    - @modelcontextprotocol/core@2.1.1
+
 ## 2.0.1
 
 ### Patch Changes

diff --git a/packages/core-internal/package.json b/packages/core-internal/package.json
@@ -1,7 +1,7 @@
 {
     "name": "@modelcontextprotocol/core-internal",
     "private": true,
-    "version": "2.0.1",
+    "version": "2.0.2",
     "description": "Model Context Protocol implementation for TypeScript - Core package",
     "license": "MIT",
     "author": "Anthropic, PBC (https://anthropic.com)",

diff --git a/packages/core/CHANGELOG.md b/packages/core/CHANGELOG.md
@@ -1,5 +1,7 @@
 # @modelcontextprotocol/core
 
+## 2.1.1
+
 ## 2.1.0
 
 ### Minor Changes

diff --git a/packages/core/package.json b/packages/core/package.json
@@ -1,6 +1,6 @@
 {
     "name": "@modelcontextprotocol/core",
-    "version": "2.1.0",
+    "version": "2.1.1",
     "description": "Model Context Protocol for TypeScript — public Zod schemas (spec + OAuth/OpenID)",
     "license": "MIT",
     "author": "Anthropic, PBC (https://anthropic.com)",

diff --git a/packages/server-legacy/CHANGELOG.md b/packages/server-legacy/CHANGELOG.md
@@ -1,5 +1,12 @@
 # @modelcontextprotocol/server-legacy
 
+## 2.1.1
+
+### Patch Changes
+
+- Updated dependencies []:
+    - @modelcontextprotocol/core@2.1.1
+
 ## 2.1.0
 
 ### Patch Changes

diff --git a/packages/server-legacy/package.json b/packages/server-legacy/package.json
@@ -1,7 +1,7 @@
 {
     "name": "@modelcontextprotocol/server-legacy",
     "private": false,
-    "version": "2.1.0",
+    "version": "2.1.1",
     "description": "Frozen v1 SSE transport and OAuth Authorization Server helpers for the Model Context Protocol TypeScript SDK. Deprecated; use StreamableHTTP and a dedicated OAuth server in production.",
     "deprecated": "This package is a frozen copy of v1's SSE transport and OAuth Authorization Server helpers for migration purposes only. Use StreamableHTTP from @modelcontextprotocol/server and a dedicated OAuth server in production. Will not receive new features.",
     "license": "MIT",

diff --git a/packages/server/CHANGELOG.md b/packages/server/CHANGELOG.md
@@ -1,5 +1,12 @@
 # @modelcontextprotocol/server
 
+## 2.1.1
+
+### Patch Changes
+
+- Updated dependencies []:
+    - @modelcontextprotocol/core@2.1.1
+
 ## 2.1.0
 
 ### Minor Changes

diff --git a/packages/server/package.json b/packages/server/package.json
@@ -1,6 +1,6 @@
 {
     "name": "@modelcontextprotocol/server",
-    "version": "2.1.0",
+    "version": "2.1.1",
     "description": "Model Context Protocol implementation for TypeScript - Server package",
     "license": "MIT",
     "author": "Anthropic, PBC (https://anthropic.com)",