diff --git a/config/entrypoint.sh b/config/entrypoint.sh
index 782e463..cbbfd82 100644
--- a/config/entrypoint.sh
+++ b/config/entrypoint.sh
@@ -51,6 +51,8 @@ create_worktree() {
     # Create destination directory if it doesn't exist
     mkdir -p "$(dirname "$WORKTREE_PATH")"
 
+    WORKTREE_BASE_SHA=$(git -C /workspace rev-parse HEAD 2>/dev/null || echo "")
+
     # Add worktree (idempotent: if branch already exists, reuses it)
     if git -C /workspace worktree add "$WORKTREE_PATH" -b "$WORKTREE_BRANCH" 2>/dev/null; then
         echo "[entrypoint] Worktree created on new branch: ${WORKTREE_BRANCH}"
@@ -124,8 +126,10 @@ run_agent() {
 
     # Collect post-run metrics
     local commit_count last_commit finished_at end_epoch duration_secs
-    commit_count=$(git -C "$WORKTREE_PATH" rev-list --count HEAD 2>/dev/null || echo 0)
-    last_commit=$(git -C "$WORKTREE_PATH" log --oneline -1 2>/dev/null || echo "none")
+    commit_count=$(git -C "$WORKTREE_PATH" -c "safe.directory=$WORKTREE_PATH" \
+        rev-list --count "${WORKTREE_BASE_SHA:-HEAD}..HEAD" 2>/dev/null || echo 0)
+    last_commit=$(git -C "$WORKTREE_PATH" -c "safe.directory=$WORKTREE_PATH" \
+        log --oneline -1 2>/dev/null || echo "none")
     finished_at=$(date -u +"%Y-%m-%dT%H:%M:%SZ")
     end_epoch=$(date +%s)
     duration_secs=$((end_epoch - start_epoch))
diff --git a/config/spec/entrypoint_spec.sh b/config/spec/entrypoint_spec.sh
index 879f2b8..0770c0e 100644
--- a/config/spec/entrypoint_spec.sh
+++ b/config/spec/entrypoint_spec.sh
@@ -61,6 +61,9 @@ git() {
     [[ "$GIT_WORKTREE_NEW_BRANCH_SUCCEEDS" == "true" ]] && return 0 || return 1
   elif [[ "$*" == *"worktree add"* ]]; then
     [[ "$GIT_WORKTREE_EXISTING_BRANCH_SUCCEEDS" == "true" ]] && return 0 || return 1
+  elif [[ "$*" == *"rev-parse HEAD"* ]]; then
+    echo "basef00d"
+    return 0
   elif [[ "$*" == *"rev-list --count"* ]]; then
     echo "3"
     return 0
@@ -486,7 +489,19 @@ WRAPPER_EOF
 
     It "collects commit count after agent finishes"
       When run run_entrypoint --worktree agent-br --task "do work"
-      The output should include "[MOCK] git -C /worktrees/agent-br rev-list --count HEAD"
+      The output should include "rev-list --count"
+      The status should equal 0
+    End
+
+    It "uses safe.directory flag when collecting git metrics"
+      When run run_entrypoint --worktree agent-br --task "do work"
+      The output should include "safe.directory=/worktrees/agent-br"
+      The status should equal 0
+    End
+
+    It "counts only agent commits using BASE..HEAD"
+      When run run_entrypoint --worktree agent-br --task "do work"
+      The output should include "basef00d..HEAD"
       The status should equal 0
     End
   End