diff --git a/.woodpecker/agent-smoke.sh b/.woodpecker/agent-smoke.sh
index cbb50e7..591653e 100644
--- a/.woodpecker/agent-smoke.sh
+++ b/.woodpecker/agent-smoke.sh
@@ -21,9 +21,9 @@ FAILED=0
 # Uses awk instead of grep -Eo for busybox/Alpine compatibility (#296).
 get_fns() {
   local f="$1"
-  awk '/^[[:space:]]*[a-zA-Z_][a-zA-Z0-9_]+[[:space:]]*\(\)/ {
-    sub(/^[[:space:]]+/, "")
-    sub(/[[:space:]]*\(\).*/, "")
+  awk '/^[ \t]*[a-zA-Z_][a-zA-Z0-9_]+[ \t]*\(\)/ {
+    sub(/^[ \t]+/, "")
+    sub(/[ \t]*\(\).*/, "")
     print
   }' "$f" 2>/dev/null | sort -u || true
 }
@@ -157,7 +157,7 @@ check_script dev/dev-agent.sh          dev/phase-handler.sh
 check_script dev/phase-handler.sh      dev/dev-agent.sh
 check_script dev/dev-poll.sh
 check_script dev/phase-test.sh
-check_script gardener/gardener-agent.sh
+check_script gardener/gardener-agent.sh  lib/agent-session.sh
 check_script gardener/gardener-poll.sh
 check_script review/review-pr.sh
 check_script review/review-poll.sh
diff --git a/dev/dev-poll.sh b/dev/dev-poll.sh
index bb44ee3..f20ab0d 100755
--- a/dev/dev-poll.sh
+++ b/dev/dev-poll.sh
@@ -339,20 +339,35 @@ if [ "$ORPHAN_COUNT" -gt 0 ]; then
         exit 0
       fi
       # Direct merge failed (conflicts?) — fall back to dev-agent
-      log "falling back to dev-agent for PR #${HAS_PR} merge"
-      nohup "${SCRIPT_DIR}/dev-agent.sh" "$ISSUE_NUM" >> "$LOGFILE" 2>&1 &
-      log "started dev-agent PID $! for issue #${ISSUE_NUM} (agent-merge)"
+      SESSION_NAME="dev-${PROJECT_NAME}-${ISSUE_NUM}"
+      if tmux has-session -t "$SESSION_NAME" 2>/dev/null; then
+        log "issue #${ISSUE_NUM} already has active session ${SESSION_NAME} — skipping"
+      else
+        log "falling back to dev-agent for PR #${HAS_PR} merge"
+        nohup "${SCRIPT_DIR}/dev-agent.sh" "$ISSUE_NUM" >> "$LOGFILE" 2>&1 &
+        log "started dev-agent PID $! for issue #${ISSUE_NUM} (agent-merge)"
+      fi
       exit 0
 
     # Do NOT gate REQUEST_CHANGES on ci_passed: act immediately even if CI is
     # pending/unknown. Definitive CI failure is handled by the elif below.
     elif [ "${HAS_CHANGES:-0}" -gt 0 ] && { ci_passed "$CI_STATE" || [ "$CI_STATE" = "pending" ] || [ "$CI_STATE" = "unknown" ] || [ -z "$CI_STATE" ]; }; then
-      log "issue #${ISSUE_NUM} PR #${HAS_PR} has REQUEST_CHANGES — spawning agent"
-      nohup "${SCRIPT_DIR}/dev-agent.sh" "$ISSUE_NUM" >> "$LOGFILE" 2>&1 &
-      log "started dev-agent PID $! for issue #${ISSUE_NUM} (review fix)"
+      SESSION_NAME="dev-${PROJECT_NAME}-${ISSUE_NUM}"
+      if tmux has-session -t "$SESSION_NAME" 2>/dev/null; then
+        log "issue #${ISSUE_NUM} already has active session ${SESSION_NAME} — skipping"
+      else
+        log "issue #${ISSUE_NUM} PR #${HAS_PR} has REQUEST_CHANGES — spawning agent"
+        nohup "${SCRIPT_DIR}/dev-agent.sh" "$ISSUE_NUM" >> "$LOGFILE" 2>&1 &
+        log "started dev-agent PID $! for issue #${ISSUE_NUM} (review fix)"
+      fi
       exit 0
 
     elif ! ci_passed "$CI_STATE" && [ "$CI_STATE" != "" ] && [ "$CI_STATE" != "pending" ] && [ "$CI_STATE" != "unknown" ]; then
+      SESSION_NAME="dev-${PROJECT_NAME}-${ISSUE_NUM}"
+      if tmux has-session -t "$SESSION_NAME" 2>/dev/null; then
+        log "issue #${ISSUE_NUM} already has active session ${SESSION_NAME} — skipping"
+        exit 0
+      fi
       if handle_ci_exhaustion "$HAS_PR" "$ISSUE_NUM"; then
         # Fall through to backlog scan instead of exit
         :
@@ -367,9 +382,14 @@ if [ "$ORPHAN_COUNT" -gt 0 ]; then
       log "issue #${ISSUE_NUM} has open PR #${HAS_PR} (CI: ${CI_STATE}, waiting)"
     fi
   else
-    log "recovering orphaned issue #${ISSUE_NUM} (no PR found)"
-    nohup "${SCRIPT_DIR}/dev-agent.sh" "$ISSUE_NUM" >> "$LOGFILE" 2>&1 &
-    log "started dev-agent PID $! for issue #${ISSUE_NUM} (recovery)"
+    SESSION_NAME="dev-${PROJECT_NAME}-${ISSUE_NUM}"
+    if tmux has-session -t "$SESSION_NAME" 2>/dev/null; then
+      log "issue #${ISSUE_NUM} already has active session ${SESSION_NAME} — skipping"
+    else
+      log "recovering orphaned issue #${ISSUE_NUM} (no PR found)"
+      nohup "${SCRIPT_DIR}/dev-agent.sh" "$ISSUE_NUM" >> "$LOGFILE" 2>&1 &
+      log "started dev-agent PID $! for issue #${ISSUE_NUM} (recovery)"
+    fi
     exit 0
   fi
 fi
@@ -424,9 +444,14 @@ for i in $(seq 0 $(($(echo "$OPEN_PRS" | jq 'length') - 1))); do
       exit 0
     fi
     # Direct merge failed (conflicts?) — fall back to dev-agent
-    log "falling back to dev-agent for PR #${PR_NUM} merge"
-    nohup "${SCRIPT_DIR}/dev-agent.sh" "$STUCK_ISSUE" >> "$LOGFILE" 2>&1 &
-    log "started dev-agent PID $! for stuck PR #${PR_NUM} (agent-merge)"
+    SESSION_NAME="dev-${PROJECT_NAME}-${STUCK_ISSUE}"
+    if tmux has-session -t "$SESSION_NAME" 2>/dev/null; then
+      log "issue #${STUCK_ISSUE} already has active session ${SESSION_NAME} — skipping"
+    else
+      log "falling back to dev-agent for PR #${PR_NUM} merge"
+      nohup "${SCRIPT_DIR}/dev-agent.sh" "$STUCK_ISSUE" >> "$LOGFILE" 2>&1 &
+      log "started dev-agent PID $! for stuck PR #${PR_NUM} (agent-merge)"
+    fi
     exit 0
   fi
 
@@ -436,19 +461,28 @@ for i in $(seq 0 $(($(echo "$OPEN_PRS" | jq 'length') - 1))); do
   # CI to settle. Definitive CI failure (non-pending, non-unknown) is handled by
   # the elif below, so we only spawn here when CI has not definitively failed.
   if [ "${HAS_CHANGES:-0}" -gt 0 ] && { ci_passed "$CI_STATE" || [ "$CI_STATE" = "pending" ] || [ "$CI_STATE" = "unknown" ] || [ -z "$CI_STATE" ]; }; then
+    SESSION_NAME="dev-${PROJECT_NAME}-${STUCK_ISSUE}"
+    if tmux has-session -t "$SESSION_NAME" 2>/dev/null; then
+      log "issue #${STUCK_ISSUE} already has active session ${SESSION_NAME} — skipping"
+      continue
+    fi
     log "PR #${PR_NUM} (issue #${STUCK_ISSUE}) has REQUEST_CHANGES — fixing first"
     nohup "${SCRIPT_DIR}/dev-agent.sh" "$STUCK_ISSUE" >> "$LOGFILE" 2>&1 &
     log "started dev-agent PID $! for stuck PR #${PR_NUM}"
     exit 0
   elif ! ci_passed "$CI_STATE" && [ "$CI_STATE" != "" ] && [ "$CI_STATE" != "pending" ] && [ "$CI_STATE" != "unknown" ]; then
+    SESSION_NAME="dev-${PROJECT_NAME}-${STUCK_ISSUE}"
+    if tmux has-session -t "$SESSION_NAME" 2>/dev/null; then
+      log "issue #${STUCK_ISSUE} already has active session ${SESSION_NAME} — skipping"
+      continue
+    fi
     if handle_ci_exhaustion "$PR_NUM" "$STUCK_ISSUE"; then
       continue  # skip this PR, check next stuck PR or fall through to backlog
-    else
-      log "PR #${PR_NUM} (issue #${STUCK_ISSUE}) CI failed — fixing (attempt ${CI_FIX_ATTEMPTS}/3)"
-      nohup "${SCRIPT_DIR}/dev-agent.sh" "$STUCK_ISSUE" >> "$LOGFILE" 2>&1 &
-      log "started dev-agent PID $! for stuck PR #${PR_NUM}"
-      exit 0
     fi
+    log "PR #${PR_NUM} (issue #${STUCK_ISSUE}) CI failed — fixing (attempt ${CI_FIX_ATTEMPTS}/3)"
+    nohup "${SCRIPT_DIR}/dev-agent.sh" "$STUCK_ISSUE" >> "$LOGFILE" 2>&1 &
+    log "started dev-agent PID $! for stuck PR #${PR_NUM}"
+    exit 0
   fi
 done