#!/usr/bin/env python3 """Plan-18 MVP-0 Ask CASAN read-only evidence assistant. The primitive is deliberately deterministic: no free command execution, no writes outside chat audit/H6 telemetry, no model dependency. It reads only whitelisted CASAN documentation/evidence artifacts and returns answer + sources. """ import argparse import hashlib import json import os import re import subprocess import sys import tempfile import uuid from datetime import datetime, timezone GENESIS_HASH = "0" * 64 STOPWORDS = { "a", "an", "and", "are", "as", "ask", "cua", "cho", "co", "con", "còn", "do", "for", "gi", "gì", "hay", "how", "is", "ke", "kế", "la", "là", "of", "on", "the", "to", "trong", "ve", "về", "what", "with", } def project_root() -> str: d = os.path.abspath(os.path.dirname(__file__)) p = d while p != os.path.dirname(p): if os.path.isdir(os.path.join(p, ".specify")) or os.path.isdir(os.path.join(p, "packages/casan-harness")): return p p = os.path.dirname(p) return os.path.abspath(os.path.join(d, "..", "..", "..")) ROOT = project_root() HARNESS_BIN = os.path.join(ROOT, "packages", "casan-harness", "scripts", "bash") ROUTER = os.path.join(HARNESS_BIN, "prompt-mode-router.py") SECURITY = os.path.join(HARNESS_BIN, "security-check.sh") TENANT_STORE = os.path.join(HARNESS_BIN, "tenant-store.sh") TENANT_CRYPT = os.path.join(HARNESS_BIN, "tenant-crypt.sh") def state_root() -> str: return os.environ.get("CASAN_STATE_ROOT") or os.path.join(ROOT, ".specify") def tenant_path(logical: str, fallback: str) -> str: if os.environ.get("CASAN_TENANT_ID"): r = subprocess.run(["bash", TENANT_STORE, "resolve", logical], cwd=ROOT, capture_output=True, text=True) if r.returncode != 0: raise SystemExit((r.stderr or r.stdout or "TENANT_DENIED").strip()) return r.stdout.strip() return os.path.join(state_root(), fallback) def guarded_override(path: str) -> str: if path and os.environ.get("CASAN_TENANT_ID"): r = subprocess.run(["bash", TENANT_STORE, "guard", path], cwd=ROOT, capture_output=True, text=True) if r.returncode != 0: raise SystemExit((r.stderr or r.stdout or "TENANT_DENIED").strip()) return path def audit_path() -> str: return guarded_override(os.environ["CASAN_CHAT_AUDIT_LOG"]) if os.environ.get("CASAN_CHAT_AUDIT_LOG") else tenant_path("chat/chat-turns.jsonl", "logs/chat/chat-turns.jsonl") def head_path() -> str: return guarded_override(os.environ["CASAN_CHAT_AUDIT_HEAD"]) if os.environ.get("CASAN_CHAT_AUDIT_HEAD") else tenant_path("chat/chat-head.txt", "logs/chat/chat-head.txt") def metrics_path() -> str: return guarded_override(os.environ["CASAN_CHAT_METRICS_LOG"]) if os.environ.get("CASAN_CHAT_METRICS_LOG") else tenant_path("telemetry/cost/metrics.jsonl", "logs/cost/metrics.jsonl") def now_iso() -> str: return datetime.now(timezone.utc).strftime("%Y-%m-%dT%H:%M:%SZ") def sha(text: str) -> str: return hashlib.sha256(text.encode("utf-8")).hexdigest() def git_commit() -> str: try: r = subprocess.run(["git", "rev-parse", "HEAD"], cwd=ROOT, capture_output=True, text=True, timeout=5) if r.returncode == 0: return r.stdout.strip() except Exception: pass return "unknown" def provenance(source: str, path: str, verified=True): return { "source": source, "artifact_path": os.path.relpath(path, ROOT), "commit": git_commit(), "run_at": now_iso(), "verified": bool(verified), } def run_security(text: str, mode: str): with tempfile.TemporaryDirectory() as td: inp = os.path.join(td, "in.txt") out = os.path.join(td, "out.txt") with open(inp, "w", encoding="utf-8") as fh: fh.write(text) r = subprocess.run(["bash", SECURITY, inp, out, mode], cwd=ROOT, capture_output=True, text=True) safe = "" if os.path.exists(out): safe = open(out, encoding="utf-8").read() return r.returncode, safe.strip(), (r.stdout + r.stderr).strip() def classify(message: str): r = subprocess.run(["python3", ROUTER, "classify", "--message", message], cwd=ROOT, capture_output=True, text=True) if r.returncode != 0: return {"mode": "BLOCK", "risk": "high", "reason": "router_failed", "matched_rules": [r.stderr.strip()]} try: return json.loads(r.stdout) except ValueError: return {"mode": "BLOCK", "risk": "high", "reason": "router_invalid_json", "matched_rules": []} def whitelist_roots(): raw = os.environ.get("CASAN_CHAT_CONTEXT_ROOTS") if raw: roots = [os.path.abspath(p) for p in raw.split(":") if p] else: roots = [ os.path.join(ROOT, "docs", "plans"), os.path.join(ROOT, "docs", "packaging"), os.path.join(ROOT, "docs", "output", "casan"), ] return [r for r in roots if os.path.isdir(r)] def allowed_file(path: str, roots) -> bool: ap = os.path.abspath(path) if not any(ap == root or ap.startswith(root + os.sep) for root in roots): return False return os.path.splitext(ap)[1].lower() in {".md", ".txt", ".json", ".jsonl", ".yaml", ".yml"} def terms(text: str): raw = re.findall(r"[A-Za-z0-9_\-]{2,}|[À-ỹ]{3,}", text.lower()) return [t for t in raw if t not in STOPWORDS][:20] def collect_sources(query: str): roots = whitelist_roots() qterms = terms(query) scored = [] for root in roots: for base, _, files in os.walk(root): for name in files: path = os.path.join(base, name) if not allowed_file(path, roots): continue try: with open(path, encoding="utf-8", errors="ignore") as fh: lines = fh.readlines() except OSError: continue best = [] for idx, line in enumerate(lines, start=1): l = line.strip() if not l: continue low = l.lower() score = sum(1 for t in qterms if t in low) if score: best.append((score, idx, l[:260])) if best: best.sort(key=lambda x: (-x[0], x[1])) score, line_no, excerpt = best[0] path_low = os.path.relpath(path, ROOT).lower() score += sum(2 for t in qterms if t in path_low) scored.append((score, path, line_no, excerpt)) scored.sort(key=lambda x: (-x[0], x[1])) out = [] for score, path, line_no, excerpt in scored[:5]: out.append({ "path": os.path.relpath(path, ROOT), "line": line_no, "excerpt": excerpt, "score": score, "envelope": provenance("chat-context-whitelist", path, True), }) if not out: fallback = os.path.join(ROOT, "docs", "plans", "CASAN_PLAN_18_CHAT_CONSOLE.md") if os.path.isfile(fallback): out.append({ "path": os.path.relpath(fallback, ROOT), "line": 1, "excerpt": "# KẾ HOẠCH 18 — Governed Chat Console (Chat-as-Loop qua Control Plane)", "score": 0, "envelope": provenance("chat-context-whitelist-fallback", fallback, True), }) return out def answer_from_sources(message: str, sources): if not sources: return "Khong tim thay nguon trong whitelist evidence/docs nen khong tra loi suy doan." bullets = [] for s in sources[:3]: bullets.append(f"- {s['path']}:{s['line']} — {s['excerpt']}") return "Ask CASAN read-only answer (evidence-backed):\n" + "\n".join(bullets) def append_jsonl(path: str, rec): os.makedirs(os.path.dirname(path), exist_ok=True) with open(path, "a", encoding="utf-8") as fh: fh.write(json.dumps(rec, ensure_ascii=False) + "\n") def load_head() -> str: try: return open(head_path(), encoding="utf-8").read().strip() or GENESIS_HASH except OSError: return GENESIS_HASH def record_turn(base): path = audit_path() os.makedirs(os.path.dirname(path), exist_ok=True) seq = 1 if os.path.isfile(path): with open(path, encoding="utf-8") as fh: seq = sum(1 for line in fh if line.strip()) + 1 prev = load_head() core = {"seq": seq, **base, "prev_hash": prev} record_hash = sha(json.dumps(core, sort_keys=True, ensure_ascii=False)) rec = {**core, "record_hash": record_hash} append_jsonl(path, rec) os.makedirs(os.path.dirname(head_path()), exist_ok=True) with open(head_path(), "w", encoding="utf-8") as fh: fh.write(record_hash + "\n") encrypt_chat_audit_snapshot(path) return rec def encrypt_chat_audit_snapshot(path: str): if not os.environ.get("CASAN_TENANT_ID"): return if not os.path.isfile(path): return subprocess.run(["bash", TENANT_CRYPT, "encrypt", path, path + ".enc"], cwd=ROOT, stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL) def record_metrics(trace_id: str, message: str, answer: str, status: str, latency_ms: int): input_tokens = len(message.split()) output_tokens = len(answer.split()) rec = { "timestamp": now_iso(), "trace_id": trace_id, "harness": "H6-agentops", "agent": "chat.ask-casan", "step": "ask-casan-readonly", "status": status, "exit_code": 0 if status == "success" else 2, "latency_ms": latency_ms, "retry_count": 0, "input_tokens": input_tokens, "output_tokens": output_tokens, "total_tokens": input_tokens + output_tokens, "cost_estimate": 0.0, "cost_source": "readonly_word_count", "hallucination_signals": 0, "alerts": [], "input_hash": sha(message), "output_hash": sha(answer), } append_jsonl(metrics_path(), rec) def ask(args): if args.tenant and args.tenant != "default": os.environ["CASAN_TENANT_ID"] = args.tenant started = datetime.now(timezone.utc) trace_id = str(uuid.uuid4()) message = args.message router = classify(message) actor = args.actor or "anonymous" chat_id = args.chat_id or "chat-default" turn_id = args.turn_id or f"turn-{trace_id[:12]}" tenant_id = args.tenant or "default" def finish(decision: str, answer: str, sources=None, safe_message=""): elapsed = int((datetime.now(timezone.utc) - started).total_seconds() * 1000) sources = sources or [] rec = record_turn({ "timestamp": now_iso(), "trace_id": trace_id, "chat_id": chat_id, "turn_id": turn_id, "tenant_id": tenant_id, "actor": actor, "mode": router.get("mode", "BLOCK"), "risk": router.get("risk", "high"), "decision": decision, "router": router, "user_msg_ref": sha(message), "safe_preview": (safe_message or "")[:180], "answer_ref": sha(answer), "sources": [{"path": s.get("path"), "line": s.get("line")} for s in sources], }) record_metrics(trace_id, safe_message or message, answer, "success" if decision == "ANSWERED" else "failed", elapsed) return { "success": decision == "ANSWERED", "chat_id": chat_id, "turn_id": turn_id, "trace_id": trace_id, "mode": router.get("mode", "BLOCK"), "risk": router.get("risk", "high"), "decision": decision, "answer": answer, "sources": sources, "certified": decision == "ANSWERED", "audit": {"seq": rec["seq"], "record_hash": rec["record_hash"], "head": rec["record_hash"]}, "router": router, } if router.get("mode") != "READ_ONLY": answer = f"Denied by Prompt Router: mode={router.get('mode')} reason={router.get('reason')}" print(json.dumps(finish("NOT_SUPPORTED" if router.get("mode") == "NOT_SUPPORTED" else "DENIED", answer), ensure_ascii=False)) return 2 rc, safe_input, scan_msg = run_security(message, "input") if rc != 0: router["mode"] = "BLOCK" router["reason"] = "h4_input_denied" router["matched_rules"] = router.get("matched_rules", []) + [scan_msg] answer = "Denied by H4 input scan." print(json.dumps(finish("DENIED", answer), ensure_ascii=False)) return 2 sources = collect_sources(safe_input) answer = answer_from_sources(safe_input, sources) rc, safe_answer, scan_msg = run_security(answer, "output") if rc != 0: router["mode"] = "BLOCK" router["reason"] = "h4_output_denied" router["matched_rules"] = router.get("matched_rules", []) + [scan_msg] print(json.dumps(finish("DENIED", "Denied by H4 output scan.", sources, safe_input), ensure_ascii=False)) return 2 print(json.dumps(finish("ANSWERED", safe_answer, sources, safe_input), ensure_ascii=False)) return 0 def verify_audit() -> int: prev = GENESIS_HASH count = 0 try: fh = open(audit_path(), encoding="utf-8") except OSError: print("CHAT_AUDIT ok=true records=0 head=" + prev) return 0 with fh: for line in fh: if not line.strip(): continue count += 1 rec = json.loads(line) got = rec.get("record_hash") rest = {k: v for k, v in rec.items() if k != "record_hash"} if rest.get("prev_hash") != prev or sha(json.dumps(rest, sort_keys=True, ensure_ascii=False)) != got: print(f"CHAT_AUDIT ok=false brokenAt={count}") return 1 prev = got print(f"CHAT_AUDIT ok=true records={count} head={prev}") return 0 def main() -> int: ap = argparse.ArgumentParser() sub = ap.add_subparsers(dest="cmd", required=True) askp = sub.add_parser("ask") askp.add_argument("--message", required=True) askp.add_argument("--actor", default="anonymous") askp.add_argument("--chat-id", default="") askp.add_argument("--turn-id", default="") askp.add_argument("--tenant", default="default") sub.add_parser("verify-audit") args = ap.parse_args() if args.cmd == "ask": return ask(args) if args.cmd == "verify-audit": return verify_audit() return 2 if __name__ == "__main__": raise SystemExit(main())