diff --git a/.woodpecker/agent-smoke.sh b/.woodpecker/agent-smoke.sh
new file mode 100644
index 0000000..d280992
--- /dev/null
+++ b/.woodpecker/agent-smoke.sh
@@ -0,0 +1,175 @@
+#!/usr/bin/env bash
+# .woodpecker/agent-smoke.sh — CI smoke test: syntax check + function resolution
+#
+# Checks:
+#   1. bash -n syntax check on all .sh files in agent directories
+#   2. Every custom function called by agent scripts is defined in lib/ or the script itself
+#
+# Fast (<10s): no network, no tmux, no Claude needed.
+# Would have caught: kill_tmux_session (renamed), create_agent_session (missing),
+#                    read_phase (missing from dev-agent.sh scope)
+
+set -euo pipefail
+
+cd "$(dirname "$0")/.."
+
+FAILED=0
+
+# ── helpers ─────────────────────────────────────────────────────────────────
+
+# Extract function names defined in a bash script (top-level or indented).
+get_fns() {
+  local f="$1"
+  grep -Eo '[a-zA-Z_][a-zA-Z0-9_]+[[:space:]]*\(\)' "$f" 2>/dev/null \
+    | sed 's/[[:space:]]*()//' | sort -u || true
+}
+
+# Extract call-position identifiers that look like custom function calls:
+#   - strip comment lines
+#   - split into statements by ; and $(
+#   - strip leading shell keywords (if/while/! etc.) from each statement
+#   - take the first word; skip if it looks like an assignment (var= or var =)
+#   - keep only lowercase identifiers containing underscore
+#   - skip if the identifier is followed by ) or : (case labels, Python patterns)
+get_candidates() {
+  local script="$1"
+  awk '
+    /^[[:space:]]*#/ { next }
+    {
+      n = split($0, parts, /;|\$\(/)
+      for (i = 1; i <= n; i++) {
+        p = parts[i]
+        gsub(/^[[:space:]]+/, "", p)
+
+        # Skip variable assignments (var= or var =value, including Python-style "var = value")
+        if (p ~ /^[a-zA-Z_][a-zA-Z0-9_]* *=/) continue
+
+        # Strip leading shell keywords and negation operator
+        do {
+          changed = 0
+          if (p ~ /^(if|while|until|for|case|do|done|then|else|elif|fi|esac|!) /) {
+            sub(/^[^ ]+ /, "", p)
+            changed = 1
+          }
+        } while (changed)
+
+        # Skip for-loop iteration variable ("varname in list")
+        if (p ~ /^[a-zA-Z_][a-zA-Z0-9_]* in /) continue
+
+        # Extract first word if it looks like a custom function (lowercase + underscore)
+        if (match(p, /^[a-z][a-zA-Z0-9_]*_[a-zA-Z0-9_]+/)) {
+          word = substr(p, RSTART, RLENGTH)
+          rest = substr(p, RSTART + RLENGTH, 1)
+          # Skip: case labels (word)), Python/jq patterns (word:),
+          #        object method calls (word.method), assignments (word=)
+          if (rest == ")" || rest == ":" || rest == "." || rest == "=") continue
+          print word
+        }
+      }
+    }
+  ' "$script" | sort -u || true
+}
+
+# ── 1. bash -n syntax check ──────────────────────────────────────────────────
+
+echo "=== 1/2  bash -n syntax check ==="
+while IFS= read -r -d '' f; do
+  if ! bash -n "$f" 2>&1; then
+    printf 'FAIL [syntax] %s\n' "$f"
+    FAILED=1
+  fi
+done < <(find dev gardener review planner supervisor lib vault -name "*.sh" -print0 2>/dev/null)
+echo "syntax check done"
+
+# ── 2. Function-resolution check ─────────────────────────────────────────────
+
+echo "=== 2/2  Function resolution ==="
+
+# Functions provided by shared lib files (available to all agent scripts via source)
+LIB_FUNS=$(
+  for f in lib/agent-session.sh lib/env.sh lib/ci-helpers.sh lib/load-project.sh; do
+    if [ -f "$f" ]; then get_fns "$f"; fi
+  done | sort -u
+)
+
+# Known external commands and shell builtins — never flag these
+# (shell keywords are quoted to satisfy shellcheck SC1010)
+KNOWN_CMDS=(
+  awk bash break builtin cat cd chmod chown claude command continue
+  cp curl cut date declare 'do' 'done' elif else eval exit export
+  false 'fi' find flock for getopts git grep gzip gunzip head hash
+  'if' jq kill local ln ls mapfile mkdir mktemp mv nc pgrep printf
+  python3 python read readarray return rm sed set sh shift sleep
+  sort source stat tail tar test 'then' tmux touch tr trap true type
+  unset until wait wc while which xargs
+)
+
+is_known_cmd() {
+  local fn="$1"
+  for k in "${KNOWN_CMDS[@]}"; do
+    [ "$fn" = "$k" ] && return 0
+  done
+  return 1
+}
+
+# check_script SCRIPT [EXTRA_DEFINITION_SOURCES...]
+# Checks that every custom function called by SCRIPT is defined in:
+#   - SCRIPT itself
+#   - Any EXTRA_DEFINITION_SOURCES (for cross-sourced scripts)
+#   - The shared lib files (LIB_FUNS)
+check_script() {
+  local script="$1"
+  shift
+  [ -f "$script" ] || { printf 'SKIP (not found): %s\n' "$script"; return; }
+
+  # Collect all function definitions available to this script
+  local all_fns
+  all_fns=$(
+    {
+      printf '%s\n' "$LIB_FUNS"
+      get_fns "$script"
+      for extra in "$@"; do
+        if [ -f "$extra" ]; then get_fns "$extra"; fi
+      done
+    } | sort -u
+  )
+
+  local candidates
+  candidates=$(get_candidates "$script")
+
+  while IFS= read -r fn; do
+    [ -z "$fn" ] && continue
+    is_known_cmd "$fn" && continue
+    if ! printf '%s\n' "$all_fns" | grep -qxF "$fn"; then
+      printf 'FAIL [undef] %s: %s\n' "$script" "$fn"
+      FAILED=1
+    fi
+  done <<< "$candidates"
+}
+
+# Agent scripts — list cross-sourced files where function scope flows across files.
+# dev-agent.sh sources phase-handler.sh; phase-handler.sh calls helpers defined in dev-agent.sh.
+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-poll.sh
+check_script review/review-pr.sh
+check_script review/review-poll.sh
+check_script planner/planner-agent.sh
+check_script planner/planner-poll.sh
+check_script supervisor/supervisor-poll.sh
+check_script supervisor/update-prompt.sh
+check_script vault/vault-agent.sh
+check_script vault/vault-fire.sh
+check_script vault/vault-poll.sh
+check_script vault/vault-reject.sh
+
+echo "function resolution check done"
+
+if [ "$FAILED" -ne 0 ]; then
+  echo "=== SMOKE TEST FAILED ==="
+  exit 1
+fi
+echo "=== SMOKE TEST PASSED ==="
diff --git a/.woodpecker/ci.yml b/.woodpecker/ci.yml
index 85310bd..f42f07c 100644
--- a/.woodpecker/ci.yml
+++ b/.woodpecker/ci.yml
@@ -14,6 +14,12 @@ steps:
     commands:
       - find . -name "*.sh" -not -path "./.git/*" -print0 | xargs -0 -r shellcheck --severity=warning
 
+  - name: agent-smoke
+    image: alpine:3
+    commands:
+      - apk add --no-cache bash
+      - bash .woodpecker/agent-smoke.sh
+
   - name: duplicate-detection
     image: python:3-alpine
     commands:
diff --git a/lib/agent-session.sh b/lib/agent-session.sh
index 4e48c94..c2ae7da 100644
--- a/lib/agent-session.sh
+++ b/lib/agent-session.sh
@@ -146,3 +146,10 @@ agent_kill_session() {
   local session="${1:-}"
   [ -n "$session" ] && tmux kill-session -t "$session" 2>/dev/null || true
 }
+
+# Read the current phase from a phase file, stripped of whitespace.
+# Usage: read_phase [file]  — defaults to $PHASE_FILE
+read_phase() {
+  local file="${1:-${PHASE_FILE:-}}"
+  { cat "$file" 2>/dev/null || true; } | head -1 | tr -d '[:space:]'
+}