diff --git a/dev/dev-agent.sh b/dev/dev-agent.sh
index 55de5d0..b1208f9 100755
--- a/dev/dev-agent.sh
+++ b/dev/dev-agent.sh
@@ -1271,8 +1271,8 @@ Instructions:
     status "needs human input on issue #${ISSUE}"
     HUMAN_REASON=$(sed -n '2p' "$PHASE_FILE" 2>/dev/null | sed 's/^Reason: //' || echo "")
     notify "⚠️ Issue #${ISSUE} (PR #${PR_NUMBER:-none}) needs human input.${HUMAN_REASON:+ Reason: ${HUMAN_REASON}}"
-    log "phase: needs_human — notified via Matrix, waiting for injection from #81/#82/#83"
-    # Don't inject anything — other scripts (#81, #82, #83) will inject human replies
+    log "phase: needs_human — notified via Matrix, waiting for external injection"
+    # Don't inject anything — supervisor-poll.sh (#81) and review-poll.sh (#82) inject replies
 
   # ── PHASE: done ─────────────────────────────────────────────────────────────
   elif [ "$CURRENT_PHASE" = "PHASE:done" ]; then
diff --git a/docs/PHASE-PROTOCOL.md b/docs/PHASE-PROTOCOL.md
index 4dbd7cb..ce97690 100644
--- a/docs/PHASE-PROTOCOL.md
+++ b/docs/PHASE-PROTOCOL.md
@@ -78,8 +78,10 @@ PHASE:awaiting_review → wait for review-poll.sh to post review comment
                          on timeout (3h)    → inject "no review, escalating"
 
 PHASE:needs_human     → send Matrix notification with issue/PR link
-                         on reply   → inject human reply into session
-                         on timeout → re-notify, then escalate after 24h
+                         on reply   → supervisor-poll.sh injects reply into tmux session
+                                      (gardener-poll.sh as backup if supervisor missed it)
+                                      reply file: /tmp/dev-escalation-reply (written by matrix_listener.sh)
+                         on timeout → re-notify at 6h, escalate at 24h (supervisor-poll.sh)
 
 PHASE:done            → verify PR merged on Codeberg
                          if merged   → kill tmux session, clean labels, close issue
@@ -139,6 +141,8 @@ file and git history.
 | `/tmp/dev-session-{proj}-{issue}.phase` | Claude (in session) | Current phase |
 | `/tmp/ci-result-{proj}-{issue}.txt` | Orchestrator | Last CI output for injection |
 | `/tmp/dev-{proj}-{issue}.log` | Orchestrator | Session transcript (aspirational — path TBD when tmux session manager is implemented in #80) |
+| `/tmp/dev-escalation-reply` | matrix_listener.sh | Human reply to `needs_human` escalation (consumed by supervisor-poll.sh) |
+| `/tmp/dev-renotify-{proj}-{issue}` | supervisor-poll.sh | Marker to prevent duplicate 6h re-notifications |
 | `WORKTREE` (git worktree) | dev-agent.sh | Code checkpoint |
 
 ## Sequence Diagram
diff --git a/gardener/gardener-poll.sh b/gardener/gardener-poll.sh
index f363257..3dd58a6 100755
--- a/gardener/gardener-poll.sh
+++ b/gardener/gardener-poll.sh
@@ -64,6 +64,47 @@ if [ -s /tmp/gardener-escalation-reply ]; then
   log "Got escalation reply: $(echo "$ESCALATION_REPLY" | head -1)"
 fi
 
+# ── Inject human replies into needs_human dev sessions (backup to supervisor) ─
+HUMAN_REPLY_FILE="/tmp/dev-escalation-reply"
+if [ -s "$HUMAN_REPLY_FILE" ]; then
+  _gr_reply=$(cat "$HUMAN_REPLY_FILE")
+  for _gr_phase_file in /tmp/dev-session-"${PROJECT_NAME}"-*.phase; do
+    [ -f "$_gr_phase_file" ] || continue
+    _gr_phase=$(head -1 "$_gr_phase_file" 2>/dev/null | tr -d '[:space:]' || true)
+    [ "$_gr_phase" = "PHASE:needs_human" ] || continue
+
+    _gr_issue=$(basename "$_gr_phase_file" .phase)
+    _gr_issue="${_gr_issue#dev-session-${PROJECT_NAME}-}"
+    [ -z "$_gr_issue" ] && continue
+    _gr_session="dev-${PROJECT_NAME}-${_gr_issue}"
+
+    tmux has-session -t "$_gr_session" 2>/dev/null || continue
+
+    _gr_inject_msg="Human reply received for issue #${_gr_issue}:
+
+${_gr_reply}
+
+Instructions:
+1. Read the human's guidance carefully.
+2. Continue your work based on their input.
+3. When done, push your changes and write the appropriate phase:
+   echo \"PHASE:awaiting_ci\" > \"${_gr_phase_file}\""
+
+    _gr_tmpfile=$(mktemp /tmp/human-inject-XXXXXX)
+    printf '%s' "$_gr_inject_msg" > "$_gr_tmpfile"
+    tmux load-buffer -b "human-inject-${_gr_issue}" "$_gr_tmpfile" || true
+    tmux paste-buffer -t "$_gr_session" -b "human-inject-${_gr_issue}" || true
+    sleep 0.5
+    tmux send-keys -t "$_gr_session" "" Enter || true
+    tmux delete-buffer -b "human-inject-${_gr_issue}" 2>/dev/null || true
+    rm -f "$_gr_tmpfile"
+
+    rm -f "$HUMAN_REPLY_FILE"
+    log "${PROJECT_NAME}: #${_gr_issue} human reply injected into session ${_gr_session} (gardener)"
+    break  # only one reply to deliver
+  done
+fi
+
 # ── Fetch all open issues ─────────────────────────────────────────────────
 ISSUES_JSON=$(codeberg_api GET "/issues?state=open&type=issues&limit=50&sort=updated&direction=desc" 2>/dev/null || true)
 if [ -z "$ISSUES_JSON" ] || [ "$ISSUES_JSON" = "null" ]; then
diff --git a/lib/matrix_listener.sh b/lib/matrix_listener.sh
index 5e0a82f..a87e57c 100755
--- a/lib/matrix_listener.sh
+++ b/lib/matrix_listener.sh
@@ -141,6 +141,10 @@ while true; do
         printf '%s\t%s\t%s\n' "$(date -u +%Y-%m-%dT%H:%M:%SZ)" "$SENDER" "$BODY" >> /tmp/gardener-escalation-reply
         matrix_send "gardener" "✓ received, will act on next poll" "$THREAD_ROOT" >/dev/null 2>&1 || true
         ;;
+      dev)
+        printf '%s\t%s\t%s\n' "$(date -u +%Y-%m-%dT%H:%M:%SZ)" "$SENDER" "$BODY" >> /tmp/dev-escalation-reply
+        matrix_send "dev" "✓ received, will inject on next supervisor poll" "$THREAD_ROOT" >/dev/null 2>&1 || true
+        ;;
       vault)
         # Parse APPROVE <id> or REJECT <id> from reply
         VAULT_CMD=$(echo "$BODY" | tr '[:lower:]' '[:upper:]' | grep -oP '^\s*(APPROVE|REJECT)\s+\S+' | head -1 || true)
diff --git a/supervisor/supervisor-poll.sh b/supervisor/supervisor-poll.sh
index a62a1a1..b1615f0 100755
--- a/supervisor/supervisor-poll.sh
+++ b/supervisor/supervisor-poll.sh
@@ -513,6 +513,76 @@ check_project() {
     --argjson prs "${_PR_COUNT:-0}" \
     '{ts:$ts,type:"dev",project:$proj,issues_in_backlog:$backlog,issues_blocked:$blocked,pr_open:$prs}' 2>/dev/null)" 2>/dev/null || true
 
+  # ===========================================================================
+  # P2d: NEEDS_HUMAN — inject human replies into blocked dev sessions
+  # ===========================================================================
+  status "P2: ${proj_name}: checking needs_human sessions"
+
+  HUMAN_REPLY_FILE="/tmp/dev-escalation-reply"
+
+  for _nh_phase_file in /tmp/dev-session-"${proj_name}"-*.phase; do
+    [ -f "$_nh_phase_file" ] || continue
+    _nh_phase=$(head -1 "$_nh_phase_file" 2>/dev/null | tr -d '[:space:]' || true)
+    [ "$_nh_phase" = "PHASE:needs_human" ] || continue
+
+    _nh_issue=$(basename "$_nh_phase_file" .phase)
+    _nh_issue="${_nh_issue#dev-session-${proj_name}-}"
+    [ -z "$_nh_issue" ] && continue
+    _nh_session="dev-${proj_name}-${_nh_issue}"
+
+    # Check tmux session is alive
+    if ! tmux has-session -t "$_nh_session" 2>/dev/null; then
+      flog "${proj_name}: #${_nh_issue} phase=needs_human but tmux session gone"
+      continue
+    fi
+
+    # Inject human reply if available
+    if [ -s "$HUMAN_REPLY_FILE" ]; then
+      _nh_reply=$(cat "$HUMAN_REPLY_FILE")
+      _nh_inject_msg="Human reply received for issue #${_nh_issue}:
+
+${_nh_reply}
+
+Instructions:
+1. Read the human's guidance carefully.
+2. Continue your work based on their input.
+3. When done, push your changes and write the appropriate phase:
+   echo \"PHASE:awaiting_ci\" > \"${_nh_phase_file}\""
+
+      _nh_tmpfile=$(mktemp /tmp/human-inject-XXXXXX)
+      printf '%s' "$_nh_inject_msg" > "$_nh_tmpfile"
+      # All tmux calls guarded: session may die between has-session and here
+      tmux load-buffer -b "human-inject-${_nh_issue}" "$_nh_tmpfile" || true
+      tmux paste-buffer -t "$_nh_session" -b "human-inject-${_nh_issue}" || true
+      sleep 0.5
+      tmux send-keys -t "$_nh_session" "" Enter || true
+      tmux delete-buffer -b "human-inject-${_nh_issue}" 2>/dev/null || true
+      rm -f "$_nh_tmpfile"
+
+      rm -f "$HUMAN_REPLY_FILE"
+      rm -f "/tmp/dev-renotify-${proj_name}-${_nh_issue}"
+      flog "${proj_name}: #${_nh_issue} human reply injected into session ${_nh_session}"
+      fixed "${proj_name}: Injected human reply into dev session #${_nh_issue}"
+    else
+      # No reply yet — check for timeout (re-notify at 6h, alert at 24h)
+      _nh_mtime=$(stat -c %Y "$_nh_phase_file" 2>/dev/null || echo 0)
+      _nh_now=$(date +%s)
+      _nh_age=$(( _nh_now - _nh_mtime ))
+
+      if [ "$_nh_age" -gt 86400 ]; then
+        p2 "${proj_name}: Dev session #${_nh_issue} stuck in needs_human for >24h"
+      elif [ "$_nh_age" -gt 21600 ]; then
+        _nh_renotify="/tmp/dev-renotify-${proj_name}-${_nh_issue}"
+        if [ ! -f "$_nh_renotify" ]; then
+          _nh_age_h=$(( _nh_age / 3600 ))
+          matrix_send "dev" "⏰ Reminder: Issue #${_nh_issue} still needs human input (waiting ${_nh_age_h}h)" 2>/dev/null || true
+          touch "$_nh_renotify"
+          flog "${proj_name}: #${_nh_issue} re-notified (needs_human for ${_nh_age_h}h)"
+        fi
+      fi
+    fi
+  done
+
   # ===========================================================================
   # P4-PROJECT: Clean stale worktrees for this project
   # ===========================================================================