diff --git a/.github/workflows/publish-pypi.yml b/.github/workflows/publish-pypi.yml
index af6786755..68f20007d 100644
--- a/.github/workflows/publish-pypi.yml
+++ b/.github/workflows/publish-pypi.yml
@@ -1,8 +1,11 @@
-# workflow for re-running publishing to PyPI in case it fails for some reason
-# you can run this workflow by navigating to https://www.github.com/anthropics/anthropic-sdk-python/actions/workflows/publish-pypi.yml
+# workflow for publishing to PyPI using Trusted Publishing
+# replaces the manual PYPI_TOKEN approach with OIDC-based authentication
+# see: https://docs.pypi.org/trusted-publishers/
 name: Publish PyPI
+
 on:
-  workflow_dispatch:
+  release:
+    types: [published]
 
 jobs:
   publish:
@@ -10,6 +13,9 @@ jobs:
     runs-on: ubuntu-latest
     environment: production-release
 
+    permissions:
+      id-token: write
+
     steps:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
 
@@ -18,8 +24,8 @@ jobs:
         with:
           version: '0.9.13'
 
+      - name: Build
+        run: uv build
+
       - name: Publish to PyPI
-        run: |
-          bash ./bin/publish-pypi
-        env:
-          PYPI_TOKEN: ${{ secrets.ANTHROPIC_PYPI_TOKEN || secrets.PYPI_TOKEN }}
+        uses: pypa/gh-action-pypi-publish@release/v1
\ No newline at end of file
diff --git a/src/anthropic/lib/tools/_beta_runner.py b/src/anthropic/lib/tools/_beta_runner.py
index 039cb4b52..42455c9a3 100644
--- a/src/anthropic/lib/tools/_beta_runner.py
+++ b/src/anthropic/lib/tools/_beta_runner.py
@@ -279,8 +279,15 @@ def __run__(self) -> Iterator[RunnerItemT]:
                     log.debug("Tool call was not requested, exiting from tool runner loop.")
                     return
 
-                if not self._messages_modified:
-                    self.append_messages(message, response)
+                # If user has called append_messages() to add additional messages but also
+                # called generate_tool_call_response() (e.g., to log the tool result), we need
+                # to clear the cache so the auto-append happens. Otherwise the tool result
+                # is never added to history and the model re-calls the tool forever.
+                if self._messages_modified:
+                    self._cached_tool_call_response = None
+                    self._messages_modified = False
+
+                self.append_messages(message, response)
 
             self._messages_modified = False
             self._cached_tool_call_response = None
@@ -560,8 +567,15 @@ async def __run__(self) -> AsyncIterator[RunnerItemT]:
                     log.debug("Tool call was not requested, exiting from tool runner loop.")
                     return
 
-                if not self._messages_modified:
-                    self.append_messages(message, response)
+                # If user has called append_messages() to add additional messages but also
+                # called generate_tool_call_response() (e.g., to log the tool result), we need
+                # to clear the cache so the auto-append happens. Otherwise the tool result
+                # is never added to history and the model re-calls the tool forever.
+                if self._messages_modified:
+                    self._cached_tool_call_response = None
+                    self._messages_modified = False
+
+                self.append_messages(message, response)
 
             self._messages_modified = False
             self._cached_tool_call_response = None