diff --git a/.github/workflows/claude-review.yml b/.github/workflows/claude-review.yml
index 9d54ff323..1bf7d9213 100644
--- a/.github/workflows/claude-review.yml
+++ b/.github/workflows/claude-review.yml
@@ -5,22 +5,62 @@ on:
         types: [created]
 
 jobs:
-    review-with-tracking:
+    check-pr-origin:
         if: |
-            github.event.issue.pull_request && contains(github.event.comment.body, '@claude')
+            github.event.issue.pull_request &&
+            contains(github.event.comment.body, '@claude') &&
+            (
+                github.event.comment.author_association == 'OWNER' ||
+                github.event.comment.author_association == 'MEMBER' ||
+                github.event.comment.author_association == 'COLLABORATOR'
+            )
+        runs-on: ubuntu-latest
+        permissions:
+            pull-requests: read
+        outputs:
+            is_internal: ${{ steps.pr-origin.outputs.is_internal }}
+        steps:
+            # issue_comment payloads identify PR comments, but do not include the PR
+            # head repo. Query the PR and only run Claude when the head repo matches this repository (skip forks/external PRs).
+            - name: Check PR origin
+              id: pr-origin
+              env:
+                  GH_TOKEN: ${{ github.token }}
+                  ISSUE_NUMBER: ${{ github.event.issue.number }}
+                  REPOSITORY: ${{ github.repository }}
+              run: |
+                  set -euo pipefail
+                  if ! head_repo="$(gh api "repos/${REPOSITORY}/pulls/${ISSUE_NUMBER}" --jq '.head.repo.full_name')"; then
+                    echo "Unable to determine PR head repository for #${ISSUE_NUMBER}; skipping Claude."
+                    echo "is_internal=false" >> "$GITHUB_OUTPUT"
+                    exit 0
+                  fi
+
+                  if [ "$head_repo" = "$REPOSITORY" ]; then
+                    echo "is_internal=true" >> "$GITHUB_OUTPUT"
+                  else
+                    echo "is_internal=false" >> "$GITHUB_OUTPUT"
+                    echo "Skipping Claude for external PR from ${head_repo:-unknown}."
+                  fi
+
+
+    review-with-tracking:
+        needs: check-pr-origin
+        if: needs.check-pr-origin.outputs.is_internal == 'true'
         runs-on: ubuntu-latest
         permissions:
             contents: read
             pull-requests: write
-            id-token: write
+            id-token: write # Required by claude-code-action for GitHub App token exchange.
         steps:
             - name: Checkout repository
-              uses: actions/checkout@v5
+              uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5
               with:
                   fetch-depth: 1
+                  persist-credentials: false
 
             - name: PR Review with Progress Tracking
-              uses: anthropics/claude-code-action@v1
+              uses: anthropics/claude-code-action@6a838f847a10bc4b88da6ae796ff68e74cf9f4cc # v1.0.158
               with:
                   anthropic_api_key: ${{ secrets.ANTHROPIC_API_KEY }}
                   track_progress: true
@@ -56,7 +96,6 @@ jobs:
                          - Check API documentation accuracy
 
                       Provide detailed feedback using inline comments for specific issues.
-                      Use top-level comments for general observations or praise.
 
                   claude_args: |
-                      --allowedTools "mcp__github_inline_comment__create_inline_comment,Bash(gh pr comment:*),Bash(gh pr diff:*),Bash(gh pr view:*)"
+                      --allowedTools "mcp__github_inline_comment__create_inline_comment,Bash(gh pr diff:*),Bash(gh pr view:*)"