"""Offline real-worktree prompt prefix probe (no provider requests). Run with the checkout's Python and PROBE_OUT pointing at a new empty directory. The subprocesses use isolated HOME/HERMES_HOME and a localhost dummy provider. """ import os, sys, json, subprocess, pathlib, hashlib, dataclasses BASE = pathlib.Path(os.environ["PROBE_OUT"]) SRC = pathlib.Path(__file__).resolve().parents[2] def git(*args, cwd): p = subprocess.run( ["git", *args], cwd=cwd, text=True, capture_output=True, check=True, stdin=subprocess.DEVNULL, ) return p.stdout.strip() def digest(s): return hashlib.sha256(s.encode()).hexdigest() if len(sys.argv) == 1: BASE.mkdir(parents=True, exist_ok=True) home = BASE / "home" home.mkdir(exist_ok=True) hh = home / "hermes" hh.mkdir(exist_ok=True) (hh / "config.yaml").write_text( "context_file_max_chars: 100000\nagent:\n coding_context: auto\n environment_probe: false\n" ) fixture = BASE / "fixture" fixture.mkdir(exist_ok=True) git("init", "-b", "main", cwd=fixture) content = "# Shared project guidance\n" + ( "Use deterministic local operations and preserve project conventions.\n" * 1100 ) content = content[:66000] (fixture / "AGENTS.md").write_text(content) (fixture / "app.py").write_text('print("fixture")\n') git("add", "AGENTS.md", "app.py", cwd=fixture) git( "-c", "user.name=Prompt Probe", "-c", "user.email=probe@example.invalid", "-c", "commit.gpgsign=false", "commit", "-m", "fixture", cwd=fixture, ) for name in ("worktree-a", "worktree-b"): git("worktree", "add", "-b", name, str(BASE / name), cwd=fixture) env = { "PATH": os.environ["PATH"], "HOME": str(home), "HERMES_HOME": str(hh), "PYTHONDONTWRITEBYTECODE": "1", "PYTHONPATH": str(SRC), "PYTHONHASHSEED": "0", "LANG": "C.UTF-8", "TZ": "UTC", "GIT_CONFIG_NOSYSTEM": "1", "GIT_CONFIG_GLOBAL": "/dev/null", "TMPDIR": str(BASE), "PROBE_OUT": str(BASE), } for name in ("worktree-a", "worktree-b"): e = env | {"TERMINAL_CWD": str(BASE / name), "TERMINAL_ENV": "local"} with (BASE / (name + ".log")).open("w") as log: p = subprocess.run( [sys.executable, "-B", __file__, name], env=e, cwd=BASE / name, stdout=log, stderr=subprocess.STDOUT, stdin=subprocess.DEVNULL, timeout=150, ) print(name, "exit", p.returncode, flush=True) if p.returncode: raise SystemExit(p.returncode) a, b = [ json.loads((BASE / (name + ".json")).read_text()) for name in ("worktree-a", "worktree-b") ] def lcp(x, y): return next( (i for i, (c, d) in enumerate(zip(x, y)) if c != d), min(len(x), len(y)) ) diff = { "source_sha": git("rev-parse", "HEAD", cwd=SRC), "source_dirty": bool(git("status", "--porcelain", cwd=SRC)), "source_diff_sha256": digest(git("diff", "HEAD", cwd=SRC)), "fixture_git_worktrees": git("worktree", "list", "--porcelain", cwd=fixture), "context_file_chars": len(content), "context_file_sha256": digest(content), "stable_equal": a["parts"]["stable"] == b["parts"]["stable"], "full_common_prefix_chars": lcp(a["full"], b["full"]), "stable_common_prefix_chars": lcp(a["parts"]["stable"], b["parts"]["stable"]), "project_context_equal": a["project_context"] == b["project_context"], "same_agent_rebuild_equal": [ a["same_agent_rebuild_equal"], b["same_agent_rebuild_equal"], ], "per_worktree": [x["metrics"] for x in (a, b)], "provider_usage": None, "billing_measured": False, } (BASE / "measurements.json").write_text(json.dumps(diff, indent=2)) print(json.dumps(diff, indent=2)) else: # Fresh credential-free process, real production imports; no prompt seams mocked. sys.path.insert(0, str(SRC)) from run_agent import AIAgent from agent.system_prompt import build_system_prompt, build_system_prompt_parts from agent.prompt_builder import build_context_files_prompt from agent.prompt_caching import build_prompt_cache_plan agent = AIAgent( api_key="offline-not-a-credential", base_url="http://127.0.0.1:9/v1", provider="openai-compat", model="offline-probe", enabled_toolsets=["terminal", "file"], quiet_mode=True, skip_context_files=False, skip_memory=True, skip_background_review=True, save_trajectories=False, platform="cli", session_id="20260907_120000_probe", ) parts = build_system_prompt_parts(agent) full = build_system_prompt(agent) repeated = build_system_prompt(agent) project = build_context_files_prompt(cwd=os.getcwd(), skip_soul=True) plan = build_prompt_cache_plan( [ {"role": "system", "content": full}, {"role": "user", "content": "Offline prompt inspection only."}, ], agent.tools, static_system_prefix=agent._cached_system_prompt_static, ) plan_data = dataclasses.asdict(plan) from agent.conversation_loop import _stored_prompt_matches_runtime decoy = "\n\nOperator instructions:\nHost: Example\nUser home directory: /example\nCurrent working directory: /example\n" restore_matches = _stored_prompt_matches_runtime(agent, full) trailing_decoy_matches = _stored_prompt_matches_runtime(agent, full + decoy) (BASE / "different-worktree").mkdir(exist_ok=True) os.environ["TERMINAL_CWD"] = str(BASE / "different-worktree") drift_rejected = not _stored_prompt_matches_runtime(agent, full) os.environ["TERMINAL_CWD"] = os.getcwd() name = sys.argv[1] metrics = { "restore_matches": restore_matches, "trailing_decoy_matches": trailing_decoy_matches, "drift_rejected": drift_rejected, "cwd": os.getcwd(), "full_chars": len(full), "stable_chars": len(parts["stable"]), "context_chars": len(parts["context"]), "project_context_chars": len(project), "cwd_line_offset": full.index("Current working directory:"), "workspace_offset": full.find("Workspace (snapshot at session start"), "root_offset": full.find("- Root:"), "project_context_offset": full.index("# Project Context"), "stable_has_cwd": os.getcwd() in parts["stable"], "stable_sha256": digest(parts["stable"]), "prompt_sha256": digest(full), "valid_tool_names": sorted(agent.valid_tool_names), } out = { "parts": parts, "full": full, "project_context": project, "same_agent_rebuild_equal": full == repeated, "metrics": metrics, "cache_plan": plan_data, } (BASE / (name + ".json")).write_text(json.dumps(out, indent=2, default=str)) print(json.dumps(metrics, indent=2))