diff --git a/dev/dev-poll.sh b/dev/dev-poll.sh
index 91a39c2..d08e08d 100755
--- a/dev/dev-poll.sh
+++ b/dev/dev-poll.sh
@@ -115,8 +115,8 @@ dep_is_merged() {
 # =============================================================================
 get_deps() {
   local issue_body="$1"
-  # Shared parser: lib/parse-deps.py (single source of truth)
-  echo "$issue_body" | python3 "${FACTORY_ROOT}/lib/parse-deps.py"
+  # Shared parser: lib/parse-deps.sh (single source of truth)
+  echo "$issue_body" | bash "${FACTORY_ROOT}/lib/parse-deps.sh"
 }
 
 # =============================================================================
diff --git a/lib/parse-deps.py b/lib/parse-deps.py
deleted file mode 100755
index 3214688..0000000
--- a/lib/parse-deps.py
+++ /dev/null
@@ -1,59 +0,0 @@
-#!/usr/bin/env python3
-"""Extract dependency issue numbers from an issue body.
-
-Usage:
-    echo "$ISSUE_BODY" | python3 lib/parse-deps.py
-    python3 lib/parse-deps.py "$ISSUE_BODY"
-    python3 lib/parse-deps.py --json < issues.json
-
-Modes:
-    stdin/arg:  reads a single issue body, prints one dep number per line
-    --json:     reads a JSON array of issues from stdin, prints JSON
-                dep graph: {"issue_num": [dep1, dep2], ...}
-
-Matches the same logic as dev-poll.sh get_deps():
-  - Sections: ## Dependencies / ## Depends on / ## Blocked by
-  - Inline: "depends on #NNN" / "blocked by #NNN" anywhere
-  - Ignores: ## Related (safe for sibling cross-references)
-"""
-import json
-import re
-import sys
-
-
-def parse_deps(body):
-    """Return sorted list of unique dependency issue numbers from an issue body."""
-    deps = set()
-    in_section = False
-    for line in (body or "").split("\n"):
-        if re.match(r"^##?\s*(Depends on|Blocked by|Dependencies)", line, re.IGNORECASE):
-            in_section = True
-            continue
-        if in_section and re.match(r"^##?\s", line):
-            in_section = False
-        if in_section:
-            deps.update(int(m) for m in re.findall(r"#(\d+)", line))
-        if re.search(r"(depends on|blocked by)", line, re.IGNORECASE):
-            deps.update(int(m) for m in re.findall(r"#(\d+)", line))
-    return sorted(deps)
-
-
-if __name__ == "__main__":
-    if len(sys.argv) > 1 and sys.argv[1] == "--json":
-        issues = json.load(sys.stdin)
-        graph = {}
-        for issue in issues:
-            num = issue["number"]
-            deps = parse_deps(issue.get("body", ""))
-            deps = [d for d in deps if d != num]
-            if deps:
-                graph[num] = deps
-        json.dump(graph, sys.stdout)
-        print()
-    else:
-        if len(sys.argv) > 1:
-            body = sys.argv[1]
-        else:
-            body = sys.stdin.read()
-        for dep in parse_deps(body):
-            print(dep)
diff --git a/lib/parse-deps.sh b/lib/parse-deps.sh
new file mode 100755
index 0000000..c0c58b4
--- /dev/null
+++ b/lib/parse-deps.sh
@@ -0,0 +1,27 @@
+#!/usr/bin/env bash
+# parse-deps.sh — Extract dependency issue numbers from an issue body
+#
+# Usage:
+#   echo "$ISSUE_BODY" | bash lib/parse-deps.sh
+#
+# Output: one dep number per line, sorted and deduplicated
+#
+# Matches:
+#   - Sections: ## Dependencies / ## Depends on / ## Blocked by
+#   - Inline: "depends on #NNN" / "blocked by #NNN" anywhere
+#   - Ignores: ## Related (safe for sibling cross-references)
+
+BODY=$(cat)
+
+{
+  # Extract #NNN from dependency sections
+  echo "$BODY" | awk '
+    BEGIN { IGNORECASE=1 }
+    /^##? *(Depends on|Blocked by|Dependencies)/ { capture=1; next }
+    capture && /^##? / { capture=0 }
+    capture { print }
+  ' | grep -oP '#\K[0-9]+' || true
+
+  # Also check inline deps on same line as keyword
+  echo "$BODY" | grep -iE '(depends on|blocked by)' | grep -oP '#\K[0-9]+' || true
+} | sort -un
diff --git a/supervisor/supervisor-poll.sh b/supervisor/supervisor-poll.sh
index 8c8f99b..b1d44df 100755
--- a/supervisor/supervisor-poll.sh
+++ b/supervisor/supervisor-poll.sh
@@ -297,57 +297,61 @@ status "P3: checking for circular dependencies"
 BACKLOG_FOR_DEPS=$(codeberg_api GET "/issues?state=open&labels=backlog&type=issues&limit=50" 2>/dev/null || true)
 if [ -n "$BACKLOG_FOR_DEPS" ] && [ "$BACKLOG_FOR_DEPS" != "null" ] && [ "$(echo "$BACKLOG_FOR_DEPS" | jq 'length' 2>/dev/null || echo 0)" -gt 0 ]; then
 
-  PARSE_DEPS="${FACTORY_ROOT}/lib/parse-deps.py"
+  PARSE_DEPS="${FACTORY_ROOT}/lib/parse-deps.sh"
+  ISSUE_COUNT=$(echo "$BACKLOG_FOR_DEPS" | jq 'length')
 
-  CYCLES=$(echo "$BACKLOG_FOR_DEPS" | python3 -c '
-import sys, json, importlib.util
+  # Build dep graph: DEPS_OF[issue_num]="dep1 dep2 ..."
+  declare -A DEPS_OF
+  declare -A BACKLOG_NUMS
+  for i in $(seq 0 $((ISSUE_COUNT - 1))); do
+    NUM=$(echo "$BACKLOG_FOR_DEPS" | jq -r ".[$i].number")
+    BODY=$(echo "$BACKLOG_FOR_DEPS" | jq -r ".[$i].body // \"\"")
+    ISSUE_DEPS=$(echo "$BODY" | bash "$PARSE_DEPS" | grep -v "^${NUM}$" || true)
+    [ -n "$ISSUE_DEPS" ] && DEPS_OF[$NUM]="$ISSUE_DEPS"
+    BACKLOG_NUMS[$NUM]=1
+  done
 
-spec = importlib.util.spec_from_file_location("parse_deps", sys.argv[1])
-mod = importlib.util.module_from_spec(spec)
-spec.loader.exec_module(mod)
+  # DFS cycle detection using color marking (0=white, 1=gray, 2=black)
+  declare -A NODE_COLOR
+  for node in "${!DEPS_OF[@]}"; do NODE_COLOR[$node]=0; done
 
-issues = json.load(sys.stdin)
-graph = {}
-for issue in issues:
-    num = issue["number"]
-    deps = [d for d in mod.parse_deps(issue.get("body", "")) if d != num]
-    if deps:
-        graph[num] = set(deps)
+  FOUND_CYCLES=""
+  declare -A SEEN_CYCLES
 
-WHITE, GRAY, BLACK = 0, 1, 2
-color = {n: WHITE for n in graph}
-cycles = []
+  dfs_detect_cycle() {
+    local node="$1" path="$2"
+    NODE_COLOR[$node]=1
+    for dep in ${DEPS_OF[$node]:-}; do
+      [ -z "${NODE_COLOR[$dep]+x}" ] && continue  # not in graph
+      if [ "${NODE_COLOR[$dep]}" = "1" ]; then
+        # Cycle found — normalize for dedup
+        local cycle_key=$(echo "$path $dep" | tr ' ' '\n' | sort -n | tr '\n' ' ')
+        if [ -z "${SEEN_CYCLES[$cycle_key]+x}" ]; then
+          SEEN_CYCLES[$cycle_key]=1
+          # Extract cycle portion from path (from $dep onward)
+          local in_cycle=0 cycle_str=""
+          for p in $path $dep; do
+            [ "$p" = "$dep" ] && in_cycle=1
+            [ "$in_cycle" = "1" ] && cycle_str="${cycle_str:+$cycle_str -> }#${p}"
+          done
+          FOUND_CYCLES="${FOUND_CYCLES}${cycle_str}\n"
+        fi
+      elif [ "${NODE_COLOR[$dep]}" = "0" ]; then
+        dfs_detect_cycle "$dep" "$path $dep"
+      fi
+    done
+    NODE_COLOR[$node]=2
+  }
 
-def dfs(u, path):
-    color[u] = GRAY
-    path.append(u)
-    for v in graph.get(u, set()):
-        if v not in color:
-            continue
-        if color[v] == GRAY:
-            cycles.append(path[path.index(v):] + [v])
-        elif color[v] == WHITE:
-            dfs(v, path)
-    path.pop()
-    color[u] = BLACK
+  for node in "${!DEPS_OF[@]}"; do
+    [ "${NODE_COLOR[$node]:-2}" = "0" ] && dfs_detect_cycle "$node" "$node"
+  done
 
-for node in list(graph.keys()):
-    if color.get(node) == WHITE:
-        dfs(node, [])
-
-seen = set()
-for cycle in cycles:
-    key = tuple(sorted(set(cycle)))
-    if key not in seen:
-        seen.add(key)
-        print(" -> ".join(f"#{n}" for n in cycle))
-' "$PARSE_DEPS" 2>/dev/null || true)
-
-  if [ -n "$CYCLES" ]; then
-    while IFS= read -r cycle; do
+  if [ -n "$FOUND_CYCLES" ]; then
+    echo -e "$FOUND_CYCLES" | while IFS= read -r cycle; do
       [ -z "$cycle" ] && continue
       p3 "Circular dependency deadlock: ${cycle}"
-    done <<< "$CYCLES"
+    done
   fi
 
   # ===========================================================================
@@ -355,59 +359,42 @@ for cycle in cycles:
   # ===========================================================================
   status "P3: checking for stale dependencies"
 
-  STALE_DEPS=$(echo "$BACKLOG_FOR_DEPS" | CODEBERG_TOKEN="$CODEBERG_TOKEN" CODEBERG_API="$CODEBERG_API" python3 -c '
-import sys, json, os, importlib.util
-from datetime import datetime, timezone
-from urllib.request import Request, urlopen
+  NOW_EPOCH=$(date +%s)
+  THIRTY_DAYS=$((30 * 86400))
+  declare -A DEP_CACHE
 
-spec = importlib.util.spec_from_file_location("parse_deps", sys.argv[1])
-mod = importlib.util.module_from_spec(spec)
-spec.loader.exec_module(mod)
+  for issue_num in "${!DEPS_OF[@]}"; do
+    for dep in ${DEPS_OF[$issue_num]}; do
+      # Check cache first
+      if [ -n "${DEP_CACHE[$dep]+x}" ]; then
+        DEP_INFO="${DEP_CACHE[$dep]}"
+      else
+        DEP_JSON=$(codeberg_api GET "/issues/${dep}" 2>/dev/null || true)
+        [ -z "$DEP_JSON" ] && continue
+        DEP_STATE=$(echo "$DEP_JSON" | jq -r '.state // "unknown"')
+        DEP_CREATED=$(echo "$DEP_JSON" | jq -r '.created_at // ""')
+        DEP_TITLE=$(echo "$DEP_JSON" | jq -r '.title // ""' | head -c 50)
+        DEP_INFO="${DEP_STATE}|${DEP_CREATED}|${DEP_TITLE}"
+        DEP_CACHE[$dep]="$DEP_INFO"
+      fi
 
-issues = json.load(sys.stdin)
-token = os.environ.get("CODEBERG_TOKEN", "")
-api = os.environ.get("CODEBERG_API", "")
-issue_map = {i["number"]: i for i in issues}
-now = datetime.now(timezone.utc)
+      DEP_STATE="${DEP_INFO%%|*}"
+      [ "$DEP_STATE" != "open" ] && continue
 
-checked = {}
-for issue in issues:
-    num = issue["number"]
-    deps = [d for d in mod.parse_deps(issue.get("body", "")) if d != num]
-    for dep in deps:
-        if dep in checked:
-            dep_data = checked[dep]
-        elif dep in issue_map:
-            dep_data = issue_map[dep]
-            checked[dep] = dep_data
-        else:
-            try:
-                req = Request(f"{api}/issues/{dep}",
-                    headers={"Authorization": f"token {token}"})
-                with urlopen(req, timeout=5) as resp:
-                    dep_data = json.loads(resp.read())
-                checked[dep] = dep_data
-            except Exception:
-                continue
-        if dep_data.get("state") != "open":
-            continue
-        created = dep_data.get("created_at", "")
-        try:
-            created_dt = datetime.fromisoformat(created.replace("Z", "+00:00"))
-            age_days = (now - created_dt).days
-            if age_days > 30:
-                dep_title = dep_data.get("title", "")[:50]
-                print(f"#{num} blocked by #{dep} \"{dep_title}\" (open {age_days} days)")
-        except Exception:
-            pass
-' "$PARSE_DEPS" 2>/dev/null || true)
+      DEP_REST="${DEP_INFO#*|}"
+      DEP_CREATED="${DEP_REST%%|*}"
+      DEP_TITLE="${DEP_REST#*|}"
 
-  if [ -n "$STALE_DEPS" ]; then
-    while IFS= read -r stale; do
-      [ -z "$stale" ] && continue
-      p3 "Stale dependency: ${stale}"
-    done <<< "$STALE_DEPS"
-  fi
+      [ -z "$DEP_CREATED" ] && continue
+      CREATED_EPOCH=$(date -d "$DEP_CREATED" +%s 2>/dev/null || echo 0)
+      AGE_DAYS=$(( (NOW_EPOCH - CREATED_EPOCH) / 86400 ))
+      if [ "$AGE_DAYS" -gt 30 ]; then
+        p3 "Stale dependency: #${issue_num} blocked by #${dep} \"${DEP_TITLE}\" (open ${AGE_DAYS} days)"
+      fi
+    done
+  done
+
+  unset DEPS_OF BACKLOG_NUMS NODE_COLOR SEEN_CYCLES DEP_CACHE
 fi
 
 # =============================================================================