write_file/patch targeting AGENTS.md, CLAUDE.md, SOUL.md, .cursorrules, or a
project-local .hermes config dir now ALWAYS prompt the human for approval —
even under --yolo/auto-approve — and fail closed when no human channel
exists. These files steer future agent behavior, so an injected write to
them is a prompt-injection persistence vector.
Design:
- New _check_protected_instruction_write() in tools/file_tools.py, a
sibling of _check_sensitive_path that returns approval-required rather
than a hard error. It realpaths before matching (symlink lesson from
#41351), matches basenames case-insensitively in ANY directory, rejects
'./x/../AGENTS.md' traversal via normpath, and gates files whose
immediate parent dir is `.hermes` (project-local config) while exempting
the authoritative ~/.hermes home (governed by its own guards).
- Approval is ONE-OPERATION only: no session/permanent persistence, no
yolo bypass — intentionally does not route through _run_approval_gate.
Gateway sessions get the button round-trip with allow_permanent and
allow_session both False; CLI uses the per-thread approval callback;
no channel at all = BLOCKED (fail closed).
- Multi-file V4A patches: ONE protected file gates the ENTIRE patch (a
single prompt lists all protected targets; deny applies nothing).
- Config: security.protected_instruction_files (default true) and
security.protected_instruction_extra_patterns (fnmatch on basename).
Config read failure keeps the gate ON.
Tests: 22 new cases in tests/tools/test_file_write_safety.py covering the
adversarial checklist — deny/approve/yolo-bypass attempt, symlink at a
protected target, case variants, relative traversal, arbitrary-directory
basenames, project-local .hermes, checkout-nested-under-~/.hermes
non-gating, patch replace + V4A multi-file atomicity, gateway round-trip,
fail-closed with no human, config off/extra patterns.
Ported from: RooCodeInc/Roo-Code RooProtectedController (Apache-2.0);
companion: #58631 (terminal vector), symlink lesson from #41351.
- write_file: encode content once, share bytes between bytes_written and
the sha256 verification (drops a second full-content encode per write)
- patch_parser: replace the except-TypeError retry around
write_file(pre_content=...) with signature-based feature detection so a
TypeError raised inside a capable implementation propagates instead of
triggering a duplicate write; tests for both duck-typing contracts
- tests: real-ops V4A BOM round-trip + _file_has_bom disk-probe guard
(the teknium1-review regression previously only covered by a fake)
- comment: document dirs_created's long-standing "parent ensured" meaning
Second, deeper pass over tools/gateway/hermes_cli plus first pass over
the trees wave 1 missed (acp, acp_adapter, skills, computer_use, docker,
dashboard, conformance, monitoring, secret_sources, hermes_state,
providers). Same rubric as wave 1 (AGENTS.md test policy); security,
alternation/caching invariants, issue-number regressions, and E2E kept.
Real test-quality fixes found and rooted out along the way:
- tests/tools/test_command_guards.py made real auxiliary-LLM HTTPS calls
(DEFAULT_CONFIG smart-approval leaked in) — pinned approval
mode=manual via autouse fixture: 17.4s → 0.4s.
- test_model_switch_custom_providers.py / test_user_providers_model_switch.py
silently probed live provider catalogs (~2s/test) — stubbed
cached_provider_model_ids/provider_model_ids/fetch_api_models.
- test_telegram_noise_filter.py: 15-platform copy-paste matrix over
shared gateway.run logic → 3 representative platforms (55s → 3.9s).
- test_gateway_shutdown.py: stop()'s 5s interrupt-deadline loop spun on
MagicMock agents — interrupt.side_effect now clears _running_agents
(22s → 1.0s).
- test_gateway_inactivity_timeout.py poll-harness timings shrunk 3-5x
(24s → 1.1s); test_mcp_stability.py backoff/SIGTERM-grace sleeps
patched (15.4s → 2.5s); test_async_delegation.py negative-drain wait
5s → 0.5s.
- test_telegram_init_deadline.py: loop-block margin restored to 1.0s
with rationale comment — the watchdog-dump assertion needs the loop
blocked well past deadline+grace under parallel load (flaked once in
the 40-worker verification run at a 0.2s margin).
Verification: full hermetic suite via scripts/run_tests.sh —
2,438 files, 21,718 tests passed, 0 failed, 293.9s wall.
Suite totals vs original baseline: 46,820 → 19,757 test functions
(−57.8%), wall 583.5s → 293.9s (−50%), subprocess CPU 13,564s → 11,623s.
Exercises the actual ShellFileOperations.write_file and patch_replace
code paths (not just the helper in isolation) to verify that
safe-root denials surface 'outside HERMES_WRITE_SAFE_ROOT' and
credential-path denials surface 'protected system/credential file'.
Adapted from PR #55615 by @liuhao1024.
Return actionable errors when HERMES_WRITE_SAFE_ROOT blocks a path instead of
labeling every denial as a protected credential file. Wire the helper through
write_file, patch, delete/move, and the Copilot ACP shim; sync docs examples.
- Use os.pathsep instead of literal ':' so Windows paths (C:\dir) and
the Windows separator ';' work correctly.
- Add 9 tests covering multi-root behavior: writes inside first/second
root, writes outside all roots, trailing/leading/double separators,
all-separators edge case, static deny priority, duplicate dedup.
- Update hermes_cli/tips.py tip string to mention multiple paths.
- Update docs to mention os.pathsep / ; on Windows.
Follow-up for salvaged PR #49557.
Some Windows editors prepend an invisible UTF-8 BOM (U+FEFF) to text
files. We had no awareness of it, so: read_file surfaced a phantom
U+FEFF as the first character; patch matches against the true first
line could miss; and a write/patch round-trip silently stripped the
marker, changing the file's byte signature.
Now:
- read_file / read_file_raw strip a single leading BOM so the model
never sees it (only on the first chunk — the marker lives at byte 0).
- patch_replace strips the BOM before fuzzy-matching (so an exact
first-line match works) and its post-write verification compares
BOM-stripped content.
- write_file restores the BOM when the original file had one and the
new content doesn't, mirroring the existing line-ending preservation
(detect on disk via a cheap `head -c 3` probe or reuse pre_content,
re-prepend across the edit). Guards against double-BOM.
Mid-content U+FEFF is left alone (it's data there, not a file marker).
Tests: TestBomHandling (real LocalEnvironment) — read-strips, raw-read
strips, write preserves, no-BOM-when-original-had-none, no-double-BOM,
patch round-trip preserves, patch matches first line through a BOM,
plus helper unit tests. 208 file-tool tests green.
* Inspired by Claude Code: /compress here [N] — boundary-aware 'summarize up to here'
Adds a user-chosen compression boundary to the existing /compress command.
/compress here [N] summarizes everything except the most recent N exchanges
(default 2), which are preserved verbatim — letting the user pick the
compression boundary instead of relying on the automatic token-budget heuristic.
Inspired by Claude Code's Rewind 'Summarize up to here' action (v2.1.139,
Week 20, May 2026): https://code.claude.com/docs/en/whats-new/2026-w20
- hermes_cli/partial_compress.py: pure split/parse helpers + seam-alternation
guard (shared by CLI and gateway).
- cli.py / gateway/run.py: route 'here [N]' / '--keep N' to partial compression;
compress only the head, re-append the verbatim tail through the seam guard.
- Preserves message-flow role alternation (seam guard merges any illegal
user->user / assistant->assistant adjacency).
- Reuses the existing _compress_context session-rotation/lock machinery — no
changes to the compression core.
- Bare /compress (full) and /compress <focus> behavior unchanged.
Tests: 12 helper unit tests + 5 CLI integration tests + E2E (interleaved
tool-call transcript, degenerate/multimodal seams, real handler path).
* fix(file-tools): make write_file/patch atomic (temp-file + rename)
write_file streamed content straight into the target via `cat > path`, so
a crash, SIGKILL, or truncated pipe mid-write left the file half-written
and corrupt. patch_replace routes through write_file, so it shared the flaw.
Now writes stream into a temp file in the SAME directory and `mv` it over
the target — a real same-filesystem rename, which is atomic on POSIX and on
every terminal backend (local/docker/ssh/modal). A failed write leaves the
original byte-intact and leaks no temp file. The existing file's mode is
preserved across the swap (stat + chmod, GNU/BSD), and content still rides
stdin so there's no ARG_MAX limit. A trap cleans the temp on any error path.
Tests: added TestAtomicWrite (real LocalEnvironment, no mocks) covering
inode-change-on-overwrite, mode preservation, failed-write-leaves-original,
no-temp-leak, special chars, and patch routing. Updated two mocks in
test_file_operations.py that keyed on the literal `cat >` write command to
key on the stdin_data behavioral signal instead. 200 file-tool tests green.
On macOS, /etc is a symlink to /private/etc, so os.path.realpath()
resolves /etc/hosts to /private/etc/hosts. The sensitive path check
only matched /etc/ prefixes against the resolved path, allowing
writes to system files on macOS.
- Add /private/etc/ and /private/var/ to _SENSITIVE_PATH_PREFIXES
- Check both realpath-resolved and normpath-normalized paths
- Add regression tests for macOS symlink bypass
Closes#8734
Co-authored-by: ElhamDevelopmentStudio (PR #8829)
* fix(security): harden terminal safety and sandbox file writes
Two security improvements:
1. Dangerous command detection: expand shell -c pattern to catch
combined flags (bash -lc, bash -ic, ksh -c) that were previously
undetected. Pattern changed from matching only 'bash -c' to
matching any shell invocation with -c anywhere in the flags.
2. File write sandboxing: add HERMES_WRITE_SAFE_ROOT env var that
constrains all write_file/patch operations to a configured directory
tree. Opt-in — when unset, behavior is unchanged. Useful for
gateway/messaging deployments that should only touch a workspace.
Based on PR #1085 by ismoilh.
* fix: correct "POSIDEON" typo to "POSEIDON" in banner ASCII art
The poseidon skin's banner_logo had the E and I letters swapped,
spelling "POSIDEON-AGENT" instead of "POSEIDON-AGENT".
---------
Co-authored-by: ismoilh <ismoilh@users.noreply.github.com>
Co-authored-by: unmodeled-tyler <unmodeled.tyler@proton.me>
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