codebase: add encoding='utf-8' to all bare open() calls (PLW1514)

Closes the last Python-on-Windows UTF-8 exposure by making every
text-mode open() call explicit about its encoding.

Before: on Windows, bare open(path, 'r') defaults to the system
locale encoding (cp1252 on US-locale installs).  That means reading
any config/yaml/markdown/json file with non-ASCII content either
crashes with UnicodeDecodeError or silently mis-decodes bytes.

After: all 89 affected call sites in production code now pass
encoding='utf-8' explicitly.  Works identically on every platform
and every locale, no surprise behavior.

Mechanical sweep via:
  ruff check --preview --extend-select PLW1514 --unsafe-fixes --fix     --exclude 'tests,venv,.venv,node_modules,website,optional-skills,               skills,tinker-atropos,plugins' .

All 89 fixes have the same shape: open(x) or open(x, mode) became
open(x, encoding='utf-8') or open(x, mode, encoding='utf-8').  Nothing
else changed.  Every modified file still parses and the Windows/sandbox
test suite is still green (85 passed, 14 skipped, 0 failed across
tests/tools/test_code_execution_windows_env.py +
tests/tools/test_code_execution_modes.py + tests/tools/test_env_passthrough.py +
tests/test_hermes_bootstrap.py).

Scope notes:
  - tests/ excluded: test fixtures can use locale encoding intentionally
    (exercising edge cases).  If we want to tighten tests later that's
    a separate PR.
  - plugins/ excluded: plugin-specific conventions may differ; plugin
    authors own their code.
  - optional-skills/ and skills/ excluded: skill scripts are user-authored
    and we don't want to mass-edit them.
  - website/ and tinker-atropos/ excluded: vendored / generated content.

46 files touched, 89 +/- lines (symmetric replacement).  No behavior
change on POSIX or on Windows when the file is ASCII; bug fix on
Windows when the file contains non-ASCII.

agent/curator.py

@@ -1607,7 +1607,7 @@ def _run_llm_review(prompt: str) -> Dict[str, Any]:
         # terminal. The background-thread runner also hides it; this
         # belt-and-suspenders path matters when a caller invokes
         # run_curator_review(synchronous=True) from the CLI.
-        with open(os.devnull, "w") as _devnull, \
+        with open(os.devnull, "w", encoding="utf-8") as _devnull, \
              contextlib.redirect_stdout(_devnull), \
              contextlib.redirect_stderr(_devnull):
             conv_result = review_agent.run_conversation(user_message=prompt)

agent/model_metadata.py

@@ -754,7 +754,7 @@ def _load_context_cache() -> Dict[str, int]:
     if not path.exists():
         return {}
     try:
-        with open(path) as f:
+        with open(path, encoding="utf-8") as f:
             data = yaml.safe_load(f) or {}
         return data.get("context_lengths", {})
     except Exception as e:
@@ -776,7 +776,7 @@ def save_context_length(model: str, base_url: str, length: int) -> None:
     path = _get_context_cache_path()
     try:
         path.parent.mkdir(parents=True, exist_ok=True)
-        with open(path, "w") as f:
+        with open(path, "w", encoding="utf-8") as f:
             yaml.dump({"context_lengths": cache}, f, default_flow_style=False)
         logger.info("Cached context length %s -> %s tokens", key, f"{length:,}")
     except Exception as e:
@@ -800,7 +800,7 @@ def _invalidate_cached_context_length(model: str, base_url: str) -> None:
     path = _get_context_cache_path()
     try:
         path.parent.mkdir(parents=True, exist_ok=True)
-        with open(path, "w") as f:
+        with open(path, "w", encoding="utf-8") as f:
             yaml.dump({"context_lengths": cache}, f, default_flow_style=False)
     except Exception as e:
         logger.debug("Failed to invalidate context length cache entry %s: %s", key, e)

agent/nous_rate_guard.py

@@ -144,7 +144,7 @@ def nous_rate_limit_remaining() -> Optional[float]:
     """
     path = _state_path()
     try:
-        with open(path) as f:
+        with open(path, encoding="utf-8") as f:
             state = json.load(f)
         reset_at = state.get("reset_at", 0)
         remaining = reset_at - time.time()

agent/shell_hooks.py

@@ -617,7 +617,7 @@ def _locked_update_approvals() -> Iterator[Dict[str, Any]]:
             save_allowlist(data)
         return
 
-    with open(lock_path, "a+") as lock_fh:
+    with open(lock_path, "a+", encoding="utf-8") as lock_fh:
         fcntl.flock(lock_fh.fileno(), fcntl.LOCK_EX)
         try:
             data = load_allowlist()

cli.py

@@ -819,7 +819,7 @@ def _setup_worktree(repo_root: str = None) -> Optional[Dict[str, str]]:
     try:
         existing = gitignore.read_text() if gitignore.exists() else ""
         if _ignore_entry not in existing.splitlines():
-            with open(gitignore, "a") as f:
+            with open(gitignore, "a", encoding="utf-8") as f:
                 if existing and not existing.endswith("\n"):
                     f.write("\n")
                 f.write(f"{_ignore_entry}\n")
@@ -2147,7 +2147,7 @@ def save_config_value(key_path: str, value: any) -> bool:
         
         # Load existing config
         if config_path.exists():
-            with open(config_path, 'r') as f:
+            with open(config_path, 'r', encoding="utf-8") as f:
                 config = yaml.safe_load(f) or {}
         else:
             config = {}
@@ -9843,7 +9843,7 @@ class HermesCLI:
                             # Debug: log to file (stdout may be devnull from redirect_stdout)
                             try:
                                 _dbg = _hermes_home / "interrupt_debug.log"
-                                with open(_dbg, "a") as _f:
+                                with open(_dbg, "a", encoding="utf-8") as _f:
                                     _f.write(f"{time.strftime('%H:%M:%S')} interrupt fired: msg={str(interrupt_msg)[:60]!r}, "
                                              f"children={len(self.agent._active_children)}, "
                                              f"parent._interrupt={self.agent._interrupt_requested}\n")
@@ -10696,7 +10696,7 @@ class HermesCLI:
                         # Debug: log to file when message enters interrupt queue
                         try:
                             _dbg = _hermes_home / "interrupt_debug.log"
-                            with open(_dbg, "a") as _f:
+                            with open(_dbg, "a", encoding="utf-8") as _f:
                                 _f.write(f"{time.strftime('%H:%M:%S')} ENTER: queued interrupt msg={str(payload)[:60]!r}, "
                                          f"agent_running={self._agent_running}\n")
                         except Exception:

cron/scheduler.py

@@ -1268,7 +1268,7 @@ def run_job(job: dict) -> tuple[bool, str, str, Optional[str]]:
             import yaml
             _cfg_path = str(_get_hermes_home() / "config.yaml")
             if os.path.exists(_cfg_path):
-                with open(_cfg_path) as _f:
+                with open(_cfg_path, encoding="utf-8") as _f:
                     _cfg = yaml.safe_load(_f) or {}
                 _cfg = _expand_env_vars(_cfg)
                 _model_cfg = _cfg.get("model", {})
@@ -1651,7 +1651,7 @@ def tick(verbose: bool = True, adapters=None, loop=None) -> int:
     # Cross-platform file locking: fcntl on Unix, msvcrt on Windows
     lock_fd = None
     try:
-        lock_fd = open(lock_file, "w")
+        lock_fd = open(lock_file, "w", encoding="utf-8")
         if fcntl:
             fcntl.flock(lock_fd, fcntl.LOCK_EX | fcntl.LOCK_NB)
         elif msvcrt:

environments/benchmarks/terminalbench_2/terminalbench2_env.py

@@ -365,7 +365,7 @@ class TerminalBench2EvalEnv(HermesAgentBaseEnv):
         os.makedirs(log_dir, exist_ok=True)
         run_ts = datetime.datetime.now().strftime("%Y%m%d_%H%M%S")
         self._streaming_path = os.path.join(log_dir, f"samples_{run_ts}.jsonl")
-        self._streaming_file = open(self._streaming_path, "w")
+        self._streaming_file = open(self._streaming_path, "w", encoding="utf-8")
         self._streaming_lock = __import__("threading").Lock()
         print(f"  Streaming results to: {self._streaming_path}")
 

environments/benchmarks/yc_bench/yc_bench_env.py

@@ -422,7 +422,7 @@ class YCBenchEvalEnv(HermesAgentBaseEnv):
         os.makedirs(log_dir, exist_ok=True)
         run_ts = datetime.datetime.now().strftime("%Y%m%d_%H%M%S")
         self._streaming_path = os.path.join(log_dir, f"samples_{run_ts}.jsonl")
-        self._streaming_file = open(self._streaming_path, "w")
+        self._streaming_file = open(self._streaming_path, "w", encoding="utf-8")
         self._streaming_lock = threading.Lock()
 
         print(f"\nYC-Bench eval matrix: {len(self.all_eval_items)} runs")

gateway/platforms/telegram.py

@@ -744,7 +744,7 @@ class TelegramAdapter(BasePlatformAdapter):
                 return
 
             import yaml as _yaml
-            with open(config_path, "r") as f:
+            with open(config_path, "r", encoding="utf-8") as f:
                 config = _yaml.safe_load(f) or {}
 
             # Navigate to platforms.telegram.extra.dm_topics
@@ -3516,7 +3516,7 @@ class TelegramAdapter(BasePlatformAdapter):
                 return
 
             import yaml as _yaml
-            with open(config_path, "r") as f:
+            with open(config_path, "r", encoding="utf-8") as f:
                 config = _yaml.safe_load(f) or {}
 
             dm_topics = (

gateway/platforms/whatsapp.py

@@ -526,7 +526,7 @@ class WhatsAppAdapter(BasePlatformAdapter):
             # messages are preserved for troubleshooting.
             whatsapp_mode = os.getenv("WHATSAPP_MODE", "self-chat")
             self._bridge_log = self._session_path.parent / "bridge.log"
-            bridge_log_fh = open(self._bridge_log, "a")
+            bridge_log_fh = open(self._bridge_log, "a", encoding="utf-8")
             self._bridge_log_fh = bridge_log_fh
 
             # Build bridge subprocess environment.
@@ -1170,7 +1170,7 @@ class WhatsAppAdapter(BasePlatformAdapter):
                             if file_size > MAX_TEXT_INJECT_BYTES:
                                 print(f"[{self.name}] Skipping text injection for {doc_path} ({file_size} bytes > {MAX_TEXT_INJECT_BYTES})", flush=True)
                                 continue
-                            content = Path(doc_path).read_text(errors="replace")
+                            content = Path(doc_path).read_text(encoding="utf-8", errors="replace")
                             fname = Path(doc_path).name
                             # Remove the doc_<hex>_ prefix for display
                             display_name = fname

gateway/status.py

@@ -113,7 +113,7 @@ def _get_process_start_time(pid: int) -> Optional[int]:
     stat_path = Path(f"/proc/{pid}/stat")
     try:
         # Field 22 in /proc/<pid>/stat is process start time (clock ticks).
-        return int(stat_path.read_text().split()[21])
+        return int(stat_path.read_text(encoding="utf-8").split()[21])
     except (FileNotFoundError, IndexError, PermissionError, ValueError, OSError):
         return None
 
@@ -197,7 +197,7 @@ def _read_json_file(path: Path) -> Optional[dict[str, Any]]:
     if not path.exists():
         return None
     try:
-        raw = path.read_text().strip()
+        raw = path.read_text(encoding="utf-8").strip()
     except OSError:
         return None
     if not raw:
@@ -523,7 +523,7 @@ def acquire_scoped_lock(scope: str, identity: str, metadata: Optional[dict[str,
                     try:
                         _proc_status = Path(f"/proc/{existing_pid}/status")
                         if _proc_status.exists():
-                            for _line in _proc_status.read_text().splitlines():
+                            for _line in _proc_status.read_text(encoding="utf-8").splitlines():
                                 if _line.startswith("State:"):
                                     _state = _line.split()[1]
                                     if _state in ("T", "t"):  # stopped or tracing stop

hermes_cli/backup.py

@@ -573,7 +573,7 @@ def create_quick_snapshot(
         "total_size": sum(manifest.values()),
         "files": manifest,
     }
-    with open(snap_dir / "manifest.json", "w") as f:
+    with open(snap_dir / "manifest.json", "w", encoding="utf-8") as f:
         json.dump(meta, f, indent=2)
 
     # Auto-prune
@@ -599,7 +599,7 @@ def list_quick_snapshots(
         manifest_path = d / "manifest.json"
         if manifest_path.exists():
             try:
-                with open(manifest_path) as f:
+                with open(manifest_path, encoding="utf-8") as f:
                     results.append(json.load(f))
             except (json.JSONDecodeError, OSError):
                 results.append({"id": d.name, "file_count": 0, "total_size": 0})
@@ -629,7 +629,7 @@ def restore_quick_snapshot(
     if not manifest_path.exists():
         return False
 
-    with open(manifest_path) as f:
+    with open(manifest_path, encoding="utf-8") as f:
         meta = json.load(f)
 
     restored = 0

hermes_cli/config.py

@@ -221,7 +221,7 @@ def get_container_exec_info() -> Optional[dict]:
 
     try:
         info = {}
-        with open(container_mode_file, "r") as f:
+        with open(container_mode_file, "r", encoding="utf-8") as f:
             for line in f:
                 line = line.strip()
                 if "=" in line and not line.startswith("#"):
@@ -306,7 +306,7 @@ def _is_container() -> bool:
         return True
     # LXC / cgroup-based detection
     try:
-        with open("/proc/1/cgroup", "r") as f:
+        with open("/proc/1/cgroup", "r", encoding="utf-8") as f:
             cgroup_content = f.read()
         if "docker" in cgroup_content or "lxc" in cgroup_content or "kubepods" in cgroup_content:
             return True
@@ -3461,7 +3461,7 @@ def migrate_config(interactive: bool = True, quiet: bool = False) -> Dict[str, A
                         if not manifest_file.exists():
                             continue
                         try:
-                            with open(manifest_file) as _mf:
+                            with open(manifest_file, encoding="utf-8") as _mf:
                                 manifest = yaml.safe_load(_mf) or {}
                         except Exception:
                             manifest = {}

hermes_cli/doctor.py

@@ -598,7 +598,7 @@ def run_doctor(args):
         # Detect stale root-level model keys (known bug source — PR #4329)
         try:
             import yaml
-            with open(config_path) as f:
+            with open(config_path, encoding="utf-8") as f:
                 raw_config = yaml.safe_load(f) or {}
             stale_root_keys = [k for k in ("provider", "base_url") if k in raw_config and isinstance(raw_config[k], str)]
             if stale_root_keys:
@@ -1406,7 +1406,7 @@ def run_doctor(args):
         import yaml as _yaml
         _mem_cfg_path = HERMES_HOME / "config.yaml"
         if _mem_cfg_path.exists():
-            with open(_mem_cfg_path) as _f:
+            with open(_mem_cfg_path, encoding="utf-8") as _f:
                 _raw_cfg = _yaml.safe_load(_f) or {}
             _active_memory_provider = (_raw_cfg.get("memory") or {}).get("provider", "")
     except Exception:

hermes_cli/hooks.py

@@ -205,7 +205,7 @@ def _cmd_test(args) -> None:
 
     if getattr(args, "payload_file", None):
         try:
-            custom = json.loads(Path(args.payload_file).read_text())
+            custom = json.loads(Path(args.payload_file).read_text(encoding="utf-8"))
             if isinstance(custom, dict):
                 payload.update(custom)
             else:

hermes_cli/kanban_db.py

@@ -2835,7 +2835,7 @@ def _pid_alive(pid: Optional[int]) -> bool:
     # where we have a cheap, deterministic process-state probe.
     if sys.platform == "linux":
         try:
-            with open(f"/proc/{int(pid)}/status", "r") as f:
+            with open(f"/proc/{int(pid)}/status", "r", encoding="utf-8") as f:
                 for line in f:
                     if line.startswith("State:"):
                         # "State:\tZ (zombie)" → dead

hermes_cli/memory_setup.py

@@ -69,7 +69,7 @@ def _install_dependencies(provider_name: str) -> None:
 
     try:
         import yaml
-        with open(yaml_path) as f:
+        with open(yaml_path, encoding="utf-8") as f:
             meta = yaml.safe_load(f) or {}
     except Exception:
         return
@@ -377,7 +377,7 @@ def _write_env_vars(env_path: Path, env_writes: dict) -> None:
         if key not in updated_keys:
             new_lines.append(f"{key}={val}")
 
-    env_path.write_text("\n".join(new_lines) + "\n")
+    env_path.write_text("\n".join(new_lines) + "\n", encoding="utf-8")
 
 
 # ---------------------------------------------------------------------------

hermes_cli/model_catalog.py

@@ -173,7 +173,7 @@ def _read_disk_cache() -> tuple[dict[str, Any] | None, float]:
     except (OSError, FileNotFoundError):
         return (None, 0.0)
     try:
-        with open(path) as fh:
+        with open(path, encoding="utf-8") as fh:
             data = json.load(fh)
     except (OSError, json.JSONDecodeError):
         return (None, 0.0)
@@ -187,7 +187,7 @@ def _write_disk_cache(data: dict[str, Any]) -> None:
     try:
         path.parent.mkdir(parents=True, exist_ok=True)
         tmp = path.with_suffix(path.suffix + ".tmp")
-        with open(tmp, "w") as fh:
+        with open(tmp, "w", encoding="utf-8") as fh:
             json.dump(data, fh, indent=2)
             fh.write("\n")
         atomic_replace(tmp, path)

hermes_cli/oneshot.py

@@ -174,7 +174,7 @@ def run_oneshot(
     # Redirect stderr AND stdout to devnull for the entire call tree.
     # We'll print the final response to the real stdout at the end.
     real_stdout = sys.stdout
-    devnull = open(os.devnull, "w")
+    devnull = open(os.devnull, "w", encoding="utf-8")
 
     try:
         with redirect_stdout(devnull), redirect_stderr(devnull):

hermes_cli/plugins.py

@@ -870,7 +870,7 @@ class PluginManager:
             if yaml is None:
                 logger.warning("PyYAML not installed – cannot load %s", manifest_file)
                 return None
-            data = yaml.safe_load(manifest_file.read_text()) or {}
+            data = yaml.safe_load(manifest_file.read_text(encoding="utf-8")) or {}
 
             name = data.get("name", plugin_dir.name)
             key = f"{prefix}/{plugin_dir.name}" if prefix else name

hermes_cli/plugins_cmd.py

@@ -127,7 +127,7 @@ def _read_manifest(plugin_dir: Path) -> dict:
     try:
         import yaml
 
-        with open(manifest_file) as f:
+        with open(manifest_file, encoding="utf-8") as f:
             return yaml.safe_load(f) or {}
     except Exception as e:
         logger.warning("Failed to read plugin.yaml in %s: %s", plugin_dir, e)
@@ -703,7 +703,7 @@ def _discover_all_plugins() -> list:
             description = ""
             if yaml:
                 try:
-                    with open(manifest_file) as f:
+                    with open(manifest_file, encoding="utf-8") as f:
                         manifest = yaml.safe_load(f) or {}
                     name = manifest.get("name", d.name)
                     version = manifest.get("version", "")

hermes_cli/profiles.py

@@ -395,7 +395,7 @@ def _read_config_model(profile_dir: Path) -> tuple:
         return None, None
     try:
         import yaml
-        with open(config_path, "r") as f:
+        with open(config_path, "r", encoding="utf-8") as f:
             cfg = yaml.safe_load(f) or {}
         model_cfg = cfg.get("model", {})
         if isinstance(model_cfg, str):

hermes_cli/skills_hub.py

@@ -1257,7 +1257,7 @@ def do_snapshot_export(output_path: str, console: Optional[Console] = None) -> N
         sys.stdout.write(payload)
     else:
         out = Path(output_path)
-        out.write_text(payload)
+        out.write_text(payload, encoding="utf-8")
         c.print(f"[bold green]Snapshot exported:[/] {out}")
         c.print(f"[dim]{len(installed)} skill(s), {len(tap_list)} tap(s)[/]\n")
 
@@ -1274,7 +1274,7 @@ def do_snapshot_import(input_path: str, force: bool = False,
         return
 
     try:
-        snapshot = json.loads(inp.read_text())
+        snapshot = json.loads(inp.read_text(encoding="utf-8"))
     except json.JSONDecodeError:
         c.print(f"[bold red]Error:[/] Invalid JSON in {inp}\n")
         return

hermes_cli/web_server.py

@@ -692,7 +692,7 @@ def _tail_lines(path: Path, n: int) -> List[str]:
     if not path.exists():
         return []
     try:
-        text = path.read_text(errors="replace")
+        text = path.read_text(encoding="utf-8", errors="replace")
     except OSError:
         return []
     lines = text.splitlines()

hermes_constants.py

@@ -233,7 +233,7 @@ def is_wsl() -> bool:
     if _wsl_detected is not None:
         return _wsl_detected
     try:
-        with open("/proc/version", "r") as f:
+        with open("/proc/version", "r", encoding="utf-8") as f:
             _wsl_detected = "microsoft" in f.read().lower()
     except Exception:
         _wsl_detected = False
@@ -260,7 +260,7 @@ def is_container() -> bool:
         _container_detected = True
         return True
     try:
-        with open("/proc/1/cgroup", "r") as f:
+        with open("/proc/1/cgroup", "r", encoding="utf-8") as f:
             cgroup = f.read()
             if "docker" in cgroup or "podman" in cgroup or "/lxc/" in cgroup:
                 _container_detected = True

hermes_time.py

@@ -50,7 +50,7 @@ def _resolve_timezone_name() -> str:
         import yaml
         config_path = get_config_path()
         if config_path.exists():
-            with open(config_path) as f:
+            with open(config_path, encoding="utf-8") as f:
                 cfg = yaml.safe_load(f) or {}
             tz_cfg = cfg.get("timezone", "")
             if isinstance(tz_cfg, str) and tz_cfg.strip():

rl_cli.py

@@ -82,7 +82,7 @@ def load_hermes_config() -> dict:
     
     if config_path.exists():
         try:
-            with open(config_path, "r") as f:
+            with open(config_path, "r", encoding='utf-8') as f:
                 file_config = yaml.safe_load(f) or {}
             
             # Get model from config

run_agent.py

@@ -3824,7 +3824,7 @@ class AIAgent:
                 pass
             review_agent = None
             try:
-                with open(os.devnull, "w") as _devnull, \
+                with open(os.devnull, "w", encoding="utf-8") as _devnull, \
                      contextlib.redirect_stdout(_devnull), \
                      contextlib.redirect_stderr(_devnull):
                     # Inherit the parent agent's live runtime (provider, model,

scripts/build_model_catalog.py

@@ -81,7 +81,7 @@ def build_catalog() -> dict:
 def main() -> int:
     catalog = build_catalog()
     os.makedirs(os.path.dirname(OUTPUT_PATH), exist_ok=True)
-    with open(OUTPUT_PATH, "w") as fh:
+    with open(OUTPUT_PATH, "w", encoding="utf-8") as fh:
         json.dump(catalog, fh, indent=2)
         fh.write("\n")
 

scripts/build_skills_index.py

@@ -304,7 +304,7 @@ def main():
     }
 
     os.makedirs(os.path.dirname(OUTPUT_PATH), exist_ok=True)
-    with open(OUTPUT_PATH, "w") as f:
+    with open(OUTPUT_PATH, "w", encoding="utf-8") as f:
         json.dump(index, f, separators=(",", ":"), ensure_ascii=False)
 
     elapsed = time.time() - overall_start

scripts/contributor_audit.py

@@ -291,7 +291,7 @@ def check_release_file(release_file, all_contributors):
         missing: set of handles NOT found in the file
     """
     try:
-        content = Path(release_file).read_text()
+        content = Path(release_file).read_text(encoding="utf-8")
     except FileNotFoundError:
         print(f"  [error] Release file not found: {release_file}", file=sys.stderr)
         return set(), set(all_contributors)

scripts/discord-voice-doctor.py

@@ -242,7 +242,7 @@ def check_config(groq_key, eleven_key):
     if config_path.exists():
         try:
             import yaml
-            with open(config_path) as f:
+            with open(config_path, encoding="utf-8") as f:
                 cfg = yaml.safe_load(f) or {}
 
             stt_provider = cfg.get("stt", {}).get("provider", "local")

scripts/profile-tui.py

@@ -111,7 +111,7 @@ def summarize(log: Path, since_ts_ms: int) -> dict[str, Any]:
     frame_events: list[dict[str, Any]] = []
     if not log.exists():
         return {"error": f"no log at {log}", "react": [], "frame": []}
-    for line in log.read_text().splitlines():
+    for line in log.read_text(encoding="utf-8").splitlines():
         line = line.strip()
         if not line:
             continue
@@ -505,7 +505,7 @@ def main() -> int:
 
     if args.save:
         path = Path(f"/tmp/perf-{args.save}.json")
-        path.write_text(json.dumps(metrics, indent=2))
+        path.write_text(json.dumps(metrics, indent=2), encoding="utf-8")
         print(f"\n• saved: {path}")
 
     if args.compare:

scripts/release.py

@@ -1365,7 +1365,7 @@ def main():
     )
 
     if args.output:
-        Path(args.output).write_text(changelog)
+        Path(args.output).write_text(changelog, encoding="utf-8")
         print(f"Changelog written to {args.output}")
     else:
         print(changelog)

tools/browser_tool.py

@@ -751,7 +751,7 @@ def _run_chrome_fallback_command(
             proc.wait()
             return {"success": False, "error": f"Chrome fallback '{cmd}' timed out"}
         try:
-            with open(stdout_path, "r") as f:
+            with open(stdout_path, "r", encoding="utf-8") as f:
                 stdout = f.read().strip()
             if stdout:
                 return json.loads(stdout.split("\n")[-1])
@@ -1110,7 +1110,7 @@ def _write_owner_pid(socket_dir: str, session_name: str) -> None:
     """
     try:
         path = os.path.join(socket_dir, f"{session_name}.owner_pid")
-        with open(path, "w") as f:
+        with open(path, "w", encoding="utf-8") as f:
             f.write(str(os.getpid()))
     except OSError as exc:
         logger.debug("Could not write owner_pid file for %s: %s",
@@ -1174,7 +1174,7 @@ def _reap_orphaned_browser_sessions():
         owner_alive: Optional[bool] = None  # None = owner_pid missing/unreadable
         if os.path.isfile(owner_pid_file):
             try:
-                owner_pid = int(Path(owner_pid_file).read_text().strip())
+                owner_pid = int(Path(owner_pid_file).read_text(encoding="utf-8").strip())
                 try:
                     os.kill(owner_pid, 0)
                     owner_alive = True
@@ -1209,7 +1209,7 @@ def _reap_orphaned_browser_sessions():
             continue
 
         try:
-            daemon_pid = int(Path(pid_file).read_text().strip())
+            daemon_pid = int(Path(pid_file).read_text(encoding="utf-8").strip())
         except (ValueError, OSError):
             shutil.rmtree(socket_dir, ignore_errors=True)
             continue
@@ -1834,7 +1834,7 @@ def _run_browser_command(
                 # Detect AppArmor user namespace restrictions (Ubuntu 23.10+)
                 _userns_restrict = "/proc/sys/kernel/apparmor_restrict_unprivileged_userns"
                 try:
-                    with open(_userns_restrict) as _f:
+                    with open(_userns_restrict, encoding="utf-8") as _f:
                         if _f.read().strip() == "1":
                             _needs_sandbox_bypass = True
                             logger.debug(
@@ -1879,9 +1879,9 @@ def _run_browser_command(
             result = {"success": False, "error": f"Command timed out after {timeout} seconds"}
             # Fall through to fallback check below
         else:
-            with open(stdout_path, "r") as f:
+            with open(stdout_path, "r", encoding="utf-8") as f:
                 stdout = f.read()
-            with open(stderr_path, "r") as f:
+            with open(stderr_path, "r", encoding="utf-8") as f:
                 stderr = f.read()
             returncode = proc.returncode
 
@@ -3180,7 +3180,7 @@ def _cleanup_single_browser_session(task_id: str) -> None:
                 pid_file = os.path.join(socket_dir, f"{session_name}.pid")
                 if os.path.isfile(pid_file):
                     try:
-                        daemon_pid = int(Path(pid_file).read_text().strip())
+                        daemon_pid = int(Path(pid_file).read_text(encoding="utf-8").strip())
                         os.kill(daemon_pid, signal.SIGTERM)
                         logger.debug("Killed daemon pid %s for %s", daemon_pid, session_name)
                     except (ProcessLookupError, ValueError, PermissionError, OSError):
@@ -3323,7 +3323,7 @@ def _running_in_docker() -> bool:
     if os.path.exists("/.dockerenv"):
         return True
     try:
-        with open("/proc/1/cgroup", "rt") as fp:
+        with open("/proc/1/cgroup", "rt", encoding="utf-8") as fp:
             return "docker" in fp.read()
     except OSError:
         return False

tools/code_execution_tool.py

@@ -517,7 +517,7 @@ def _rpc_server_loop(
                 # their status prints don't leak into the CLI spinner.
                 try:
                     _real_stdout, _real_stderr = sys.stdout, sys.stderr
-                    devnull = open(os.devnull, "w")
+                    devnull = open(os.devnull, "w", encoding="utf-8")
                     try:
                         sys.stdout = devnull
                         sys.stderr = devnull
@@ -791,7 +791,7 @@ def _rpc_poll_loop(
                     # Dispatch through the standard tool handler
                     try:
                         _real_stdout, _real_stderr = sys.stdout, sys.stderr
-                        devnull = open(os.devnull, "w")
+                        devnull = open(os.devnull, "w", encoding="utf-8")
                         try:
                             sys.stdout = devnull
                             sys.stderr = devnull

tools/environments/base.py

@@ -158,7 +158,7 @@ def _load_json_store(path: Path) -> dict:
     """Load a JSON file as a dict, returning ``{}`` on any error."""
     if path.exists():
         try:
-            return json.loads(path.read_text())
+            return json.loads(path.read_text(encoding="utf-8"))
         except Exception:
             pass
     return {}
@@ -167,7 +167,7 @@ def _load_json_store(path: Path) -> dict:
 def _save_json_store(path: Path, data: dict) -> None:
     """Write *data* as pretty-printed JSON to *path*."""
     path.parent.mkdir(parents=True, exist_ok=True)
-    path.write_text(json.dumps(data, indent=2))
+    path.write_text(json.dumps(data, indent=2), encoding="utf-8")
 
 
 def _file_mtime_key(host_path: str) -> tuple[float, int] | None:

tools/environments/file_sync.py

@@ -284,7 +284,7 @@ class FileSyncManager:
             # Windows: no flock — run without serialization
             self._sync_back_impl()
             return
-        lock_fd = open(lock_path, "w")
+        lock_fd = open(lock_path, "w", encoding="utf-8")
         try:
             fcntl.flock(lock_fd, fcntl.LOCK_EX)
             self._sync_back_impl()

tools/environments/local.py

@@ -562,7 +562,7 @@ class LocalEnvironment(BaseEnvironment):
         ``_run_bash`` recovery path will resolve a safe fallback if needed.
         """
         try:
-            with open(self._cwd_file) as f:
+            with open(self._cwd_file, encoding="utf-8") as f:
                 cwd_path = f.read().strip()
             if cwd_path and os.path.isdir(cwd_path):
                 self.cwd = cwd_path

tools/mcp_tool.py

@@ -1992,7 +1992,7 @@ def _snapshot_child_pids() -> set:
     # Linux: read from /proc
     try:
         children_path = f"/proc/{my_pid}/task/{my_pid}/children"
-        with open(children_path) as f:
+        with open(children_path, encoding="utf-8") as f:
             return {int(p) for p in f.read().split() if p.strip()}
     except (FileNotFoundError, OSError, ValueError):
         pass

tools/rl_training_tool.py

@@ -169,7 +169,7 @@ def _scan_environments() -> List[EnvironmentInfo]:
             continue
         
         try:
-            with open(py_file, "r") as f:
+            with open(py_file, "r", encoding="utf-8") as f:
                 tree = ast.parse(f.read())
             
             for node in ast.walk(tree):
@@ -333,7 +333,7 @@ async def _spawn_training_run(run_state: RunState, config_path: Path):
         
         # File must stay open while the subprocess runs; we store the handle
         # on run_state so _stop_training_run() can close it when done.
-        api_log_file = open(api_log, "w")  # closed by _stop_training_run
+        api_log_file = open(api_log, "w", encoding="utf-8")  # closed by _stop_training_run
         run_state.api_log_file = api_log_file
         run_state.api_process = subprocess.Popen(
             ["run-api"],
@@ -356,7 +356,7 @@ async def _spawn_training_run(run_state: RunState, config_path: Path):
         # Step 2: Start the Tinker trainer
         logger.info("[%s] Starting Tinker trainer: launch_training.py --config %s", run_id, config_path)
         
-        trainer_log_file = open(trainer_log, "w")  # closed by _stop_training_run
+        trainer_log_file = open(trainer_log, "w", encoding="utf-8")  # closed by _stop_training_run
         run_state.trainer_log_file = trainer_log_file
         run_state.trainer_process = subprocess.Popen(
             [sys.executable, "launch_training.py", "--config", str(config_path)],
@@ -397,7 +397,7 @@ async def _spawn_training_run(run_state: RunState, config_path: Path):
         
         logger.info("[%s] Starting environment: %s serve", run_id, env_info.file_path)
         
-        env_log_file = open(env_log, "w")  # closed by _stop_training_run
+        env_log_file = open(env_log, "w", encoding="utf-8")  # closed by _stop_training_run
         run_state.env_log_file = env_log_file
         run_state.env_process = subprocess.Popen(
             [sys.executable, str(env_info.file_path), "serve", "--config", str(config_path)],
@@ -777,7 +777,7 @@ async def rl_start_training() -> str:
     if "wandb_name" in _current_config and _current_config["wandb_name"]:
         run_config["env"]["wandb_name"] = _current_config["wandb_name"]
     
-    with open(config_path, "w") as f:
+    with open(config_path, "w", encoding="utf-8") as f:
         yaml.dump(run_config, f, default_flow_style=False)
     
     # Create run state
@@ -1206,7 +1206,7 @@ async def rl_test_inference(
             stderr_text = "\n".join(stderr_lines)
             
             # Write logs to files for inspection outside CLI
-            with open(log_file, "w") as f:
+            with open(log_file, "w", encoding="utf-8") as f:
                 f.write(f"Command: {cmd_display}\n")
                 f.write(f"Working dir: {TINKER_ATROPOS_ROOT}\n")
                 f.write(f"Return code: {process.returncode}\n")
@@ -1238,7 +1238,7 @@ async def rl_test_inference(
                 # Parse the output JSONL file
                 if output_file.exists():
                     # Read JSONL file (one JSON object per line = one step)
-                    with open(output_file, "r") as f:
+                    with open(output_file, "r", encoding="utf-8") as f:
                         for line in f:
                             line = line.strip()
                             if not line:

tools/skills_hub.py

@@ -219,7 +219,7 @@ class GitHubAuth:
             key_file = Path(key_path)
             if not key_file.exists():
                 return None
-            private_key = key_file.read_text()
+            private_key = key_file.read_text(encoding="utf-8")
 
             now = int(time.time())
             payload = {
@@ -2667,7 +2667,7 @@ def append_audit_log(action: str, skill_name: str, source: str,
         parts.append(extra)
     line = " ".join(parts) + "\n"
     try:
-        with open(AUDIT_LOG, "a") as f:
+        with open(AUDIT_LOG, "a", encoding="utf-8") as f:
             f.write(line)
     except OSError as e:
         logger.debug("Could not write audit log: %s", e)

tools/tirith_security.py

@@ -126,7 +126,7 @@ def _read_failure_reason() -> str | None:
         mtime = os.path.getmtime(p)
         if (time.time() - mtime) >= _MARKER_TTL:
             return None
-        with open(p, "r") as f:
+        with open(p, "r", encoding="utf-8") as f:
             return f.read().strip()
     except OSError:
         return None
@@ -160,7 +160,7 @@ def _mark_install_failed(reason: str = ""):
     try:
         p = _failure_marker_path()
         os.makedirs(os.path.dirname(p), exist_ok=True)
-        with open(p, "w") as f:
+        with open(p, "w", encoding="utf-8") as f:
             f.write(reason)
     except OSError:
         pass
@@ -257,7 +257,7 @@ def _verify_cosign(checksums_path: str, sig_path: str, cert_path: str) -> bool |
 def _verify_checksum(archive_path: str, checksums_path: str, archive_name: str) -> bool:
     """Verify SHA-256 of the archive against checksums.txt."""
     expected = None
-    with open(checksums_path) as f:
+    with open(checksums_path, encoding="utf-8") as f:
         for line in f:
             # Format: "<hash>  <filename>"
             parts = line.strip().split("  ", 1)

tools/voice_mode.py

@@ -110,7 +110,7 @@ def detect_audio_environment() -> dict:
     # WSL detection — PulseAudio bridge makes audio work in WSL.
     # Only block if PULSE_SERVER is not configured.
     try:
-        with open('/proc/version', 'r') as f:
+        with open('/proc/version', 'r', encoding="utf-8") as f:
             if 'microsoft' in f.read().lower():
                 if os.environ.get('PULSE_SERVER'):
                     notices.append("Running in WSL with PulseAudio bridge")

trajectory_compressor.py

@@ -125,7 +125,7 @@ class CompressionConfig:
     @classmethod
     def from_yaml(cls, yaml_path: str) -> "CompressionConfig":
         """Load configuration from YAML file."""
-        with open(yaml_path, 'r') as f:
+        with open(yaml_path, 'r', encoding="utf-8") as f:
             data = yaml.safe_load(f)
         
         config = cls()
@@ -1174,7 +1174,7 @@ Write only the summary, starting with "[CONTEXT SUMMARY]:" prefix."""
         # Save metrics
         if self.config.metrics_enabled:
             metrics_path = output_dir / self.config.metrics_output_file
-            with open(metrics_path, 'w') as f:
+            with open(metrics_path, 'w', encoding="utf-8") as f:
                 json.dump(self.aggregate_metrics.to_dict(), f, indent=2)
             console.print(f"\n💾 Metrics saved to {metrics_path}")
     

tui_gateway/server.py

@@ -660,7 +660,7 @@ def _load_cfg() -> dict:
             if _cfg_cache is not None and _cfg_mtime == mtime and _cfg_path == p:
                 return copy.deepcopy(_cfg_cache)
         if p.exists():
-            with open(p) as f:
+            with open(p, encoding="utf-8") as f:
                 data = yaml.safe_load(f) or {}
         else:
             data = {}
@@ -679,7 +679,7 @@ def _save_cfg(cfg: dict):
     import yaml
 
     path = _hermes_home / "config.yaml"
-    with open(path, "w") as f:
+    with open(path, "w", encoding="utf-8") as f:
         yaml.safe_dump(cfg, f)
     with _cfg_lock:
         _cfg_cache = copy.deepcopy(cfg)
@@ -2613,7 +2613,7 @@ def _(rid, params: dict) -> dict:
         f"hermes_conversation_{_time.strftime('%Y%m%d_%H%M%S')}.json"
     )
     try:
-        with open(filename, "w") as f:
+        with open(filename, "w", encoding="utf-8") as f:
             json.dump(
                 {
                     "model": getattr(session["agent"], "model", ""),