A skill declaring `required_environment_variables: [ANTHROPIC_TOKEN]` in
its SKILL.md frontmatter silently bypassed the `execute_code` sandbox's
credential-scrubbing guarantee. `register_env_passthrough` had no
blocklist, so any name a skill chose flipped `is_env_passthrough(name) =>
True`, which shortcircuits the sandbox's secret filter.
Fix: reject registration when the name appears in
`_HERMES_PROVIDER_ENV_BLOCKLIST` (the canonical list of Hermes-managed
credentials — provider keys, gateway tokens, etc.). Log a warning naming
GHSA-rhgp-j443-p4rf so operators see the rejection in logs.
Non-Hermes third-party API keys (TENOR_API_KEY for gif-search,
NOTION_TOKEN for notion skills, etc.) remain legitimately registerable —
they were never in the sandbox scrub list in the first place.
Tests: 16 -> 17 passing. Two old tests that documented the bypass
(`test_passthrough_allows_blocklisted_var`, `test_make_run_env_passthrough`)
are rewritten to assert the new fail-closed behavior. New
`test_non_hermes_api_key_still_registerable` locks in that legitimate
third-party keys are unaffected.
Reported in GHSA-rhgp-j443-p4rf by @q1uf3ng. Hardening; not CVE-worthy
on its own per the decision matrix (attacker must already have operator
consent to install a malicious skill).
Automated dead code audit using vulture + coverage.py + ast-grep intersection,
confirmed by Opus deep verification pass. Every symbol verified to have zero
production callers (test imports excluded from reachability analysis).
Removes ~1,534 lines of dead production code across 46 files and ~1,382 lines
of stale test code. 3 entire files deleted (agent/builtin_memory_provider.py,
hermes_cli/checklist.py, tests/hermes_cli/test_setup_model_selection.py).
Co-authored-by: alt-glitch <balyan.sid@gmail.com>
* 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).
