745859babb
* feat: env var passthrough for skills and user config Skills that declare required_environment_variables now have those vars passed through to sandboxed execution environments (execute_code and terminal). Previously, execute_code stripped all vars containing KEY, TOKEN, SECRET, etc. and the terminal blocklist removed Hermes infrastructure vars — both blocked skill-declared env vars. Two passthrough sources: 1. Skill-scoped (automatic): when a skill is loaded via skill_view and declares required_environment_variables, vars that are present in the environment are registered in a session-scoped passthrough set. 2. Config-based (manual): terminal.env_passthrough in config.yaml lets users explicitly allowlist vars for non-skill use cases. Changes: - New module: tools/env_passthrough.py — shared passthrough registry - hermes_cli/config.py: add terminal.env_passthrough to DEFAULT_CONFIG - tools/skills_tool.py: register available skill env vars on load - tools/code_execution_tool.py: check passthrough before filtering - tools/environments/local.py: check passthrough in _sanitize_subprocess_env and _make_run_env - 19 new tests covering all layers * docs: add environment variable passthrough documentation Document the env var passthrough feature across four docs pages: - security.md: new 'Environment Variable Passthrough' section with full explanation, comparison table, and security considerations - code-execution.md: update security section, add passthrough subsection, fix comparison table - creating-skills.md: add tip about automatic sandbox passthrough - skills.md: add note about passthrough after secure setup docs Live-tested: launched interactive CLI, loaded a skill with required_environment_variables, verified TEST_SKILL_SECRET_KEY was accessible inside execute_code sandbox (value: passthrough-test-value-42).
100 lines
3.4 KiB
Python
100 lines
3.4 KiB
Python
"""Environment variable passthrough registry.
|
|
|
|
Skills that declare ``required_environment_variables`` in their frontmatter
|
|
need those vars available in sandboxed execution environments (execute_code,
|
|
terminal). By default both sandboxes strip secrets from the child process
|
|
environment for security. This module provides a session-scoped allowlist
|
|
so skill-declared vars (and user-configured overrides) pass through.
|
|
|
|
Two sources feed the allowlist:
|
|
|
|
1. **Skill declarations** — when a skill is loaded via ``skill_view``, its
|
|
``required_environment_variables`` are registered here automatically.
|
|
2. **User config** — ``terminal.env_passthrough`` in config.yaml lets users
|
|
explicitly allowlist vars for non-skill use cases.
|
|
|
|
Both ``code_execution_tool.py`` and ``tools/environments/local.py`` consult
|
|
:func:`is_env_passthrough` before stripping a variable.
|
|
"""
|
|
|
|
from __future__ import annotations
|
|
|
|
import logging
|
|
import os
|
|
from pathlib import Path
|
|
from typing import Iterable
|
|
|
|
logger = logging.getLogger(__name__)
|
|
|
|
# Session-scoped set of env var names that should pass through to sandboxes.
|
|
_allowed_env_vars: set[str] = set()
|
|
|
|
# Cache for the config-based allowlist (loaded once per process).
|
|
_config_passthrough: frozenset[str] | None = None
|
|
|
|
|
|
def register_env_passthrough(var_names: Iterable[str]) -> None:
|
|
"""Register environment variable names as allowed in sandboxed environments.
|
|
|
|
Typically called when a skill declares ``required_environment_variables``.
|
|
"""
|
|
for name in var_names:
|
|
name = name.strip()
|
|
if name:
|
|
_allowed_env_vars.add(name)
|
|
logger.debug("env passthrough: registered %s", name)
|
|
|
|
|
|
def _load_config_passthrough() -> frozenset[str]:
|
|
"""Load ``tools.env_passthrough`` from config.yaml (cached)."""
|
|
global _config_passthrough
|
|
if _config_passthrough is not None:
|
|
return _config_passthrough
|
|
|
|
result: set[str] = set()
|
|
try:
|
|
hermes_home = Path(os.environ.get("HERMES_HOME", Path.home() / ".hermes"))
|
|
config_path = hermes_home / "config.yaml"
|
|
if config_path.exists():
|
|
import yaml
|
|
|
|
with open(config_path) as f:
|
|
cfg = yaml.safe_load(f) or {}
|
|
passthrough = cfg.get("terminal", {}).get("env_passthrough")
|
|
if isinstance(passthrough, list):
|
|
for item in passthrough:
|
|
if isinstance(item, str) and item.strip():
|
|
result.add(item.strip())
|
|
except Exception as e:
|
|
logger.debug("Could not read tools.env_passthrough from config: %s", e)
|
|
|
|
_config_passthrough = frozenset(result)
|
|
return _config_passthrough
|
|
|
|
|
|
def is_env_passthrough(var_name: str) -> bool:
|
|
"""Check whether *var_name* is allowed to pass through to sandboxes.
|
|
|
|
Returns ``True`` if the variable was registered by a skill or listed in
|
|
the user's ``tools.env_passthrough`` config.
|
|
"""
|
|
if var_name in _allowed_env_vars:
|
|
return True
|
|
return var_name in _load_config_passthrough()
|
|
|
|
|
|
def get_all_passthrough() -> frozenset[str]:
|
|
"""Return the union of skill-registered and config-based passthrough vars."""
|
|
return frozenset(_allowed_env_vars) | _load_config_passthrough()
|
|
|
|
|
|
def clear_env_passthrough() -> None:
|
|
"""Reset the skill-scoped allowlist (e.g. on session reset)."""
|
|
_allowed_env_vars.clear()
|
|
|
|
|
|
def reset_config_cache() -> None:
|
|
"""Force re-read of config on next access (for testing)."""
|
|
global _config_passthrough
|
|
_config_passthrough = None
|