hermes-agent/gateway/session_context.py
Teknium cac6178104 fix(gateway): propagate user identity through process watcher pipeline
Background process watchers (notify_on_complete, check_interval) created
synthetic SessionSource objects without user_id/user_name. While the
internal=True bypass (1d8d4f28) prevented false pairing for agent-
generated notifications, the missing identity caused:

- Garbage entries in pairing rate limiters (discord:None, telegram:None)
- 'User None' in approval messages and logs
- No user identity available for future code paths that need it

Additionally, platform messages arriving without from_user (Telegram
service messages, channel forwards, anonymous admin actions) could still
trigger false pairing because they are not internal events.

Fix:
1. Propagate user_id/user_name through the full watcher chain:
   session_context.py → gateway/run.py → terminal_tool.py →
   process_registry.py (including checkpoint persistence/recovery)

2. Add None user_id guard in _handle_message() — silently drop
   non-internal messages with no user identity instead of triggering
   the pairing flow.

Salvaged from PRs #7664 (kagura-agent, ContextVar approach),
#6540 (MestreY0d4-Uninter, tests), and #7709 (guang384, None guard).

Closes #6341, #6485, #7643
Relates to #6516, #7392
2026-04-11 13:46:16 -07:00

123 lines
4.1 KiB
Python

"""
Session-scoped context variables for the Hermes gateway.
Replaces the previous ``os.environ``-based session state
(``HERMES_SESSION_PLATFORM``, ``HERMES_SESSION_CHAT_ID``, etc.) with
Python's ``contextvars.ContextVar``.
**Why this matters**
The gateway processes messages concurrently via ``asyncio``. When two
messages arrive at the same time the old code did:
os.environ["HERMES_SESSION_THREAD_ID"] = str(context.source.thread_id)
Because ``os.environ`` is *process-global*, Message A's value was
silently overwritten by Message B before Message A's agent finished
running. Background-task notifications and tool calls therefore routed
to the wrong thread.
``contextvars.ContextVar`` values are *task-local*: each ``asyncio``
task (and any ``run_in_executor`` thread it spawns) gets its own copy,
so concurrent messages never interfere.
**Backward compatibility**
The public helper ``get_session_env(name, default="")`` mirrors the old
``os.getenv("HERMES_SESSION_*", ...)`` calls. Existing tool code only
needs to replace the import + call site:
# before
import os
platform = os.getenv("HERMES_SESSION_PLATFORM", "")
# after
from gateway.session_context import get_session_env
platform = get_session_env("HERMES_SESSION_PLATFORM", "")
"""
from contextvars import ContextVar
# ---------------------------------------------------------------------------
# Per-task session variables
# ---------------------------------------------------------------------------
_SESSION_PLATFORM: ContextVar[str] = ContextVar("HERMES_SESSION_PLATFORM", default="")
_SESSION_CHAT_ID: ContextVar[str] = ContextVar("HERMES_SESSION_CHAT_ID", default="")
_SESSION_CHAT_NAME: ContextVar[str] = ContextVar("HERMES_SESSION_CHAT_NAME", default="")
_SESSION_THREAD_ID: ContextVar[str] = ContextVar("HERMES_SESSION_THREAD_ID", default="")
_SESSION_USER_ID: ContextVar[str] = ContextVar("HERMES_SESSION_USER_ID", default="")
_SESSION_USER_NAME: ContextVar[str] = ContextVar("HERMES_SESSION_USER_NAME", default="")
_VAR_MAP = {
"HERMES_SESSION_PLATFORM": _SESSION_PLATFORM,
"HERMES_SESSION_CHAT_ID": _SESSION_CHAT_ID,
"HERMES_SESSION_CHAT_NAME": _SESSION_CHAT_NAME,
"HERMES_SESSION_THREAD_ID": _SESSION_THREAD_ID,
"HERMES_SESSION_USER_ID": _SESSION_USER_ID,
"HERMES_SESSION_USER_NAME": _SESSION_USER_NAME,
}
def set_session_vars(
platform: str = "",
chat_id: str = "",
chat_name: str = "",
thread_id: str = "",
user_id: str = "",
user_name: str = "",
) -> list:
"""Set all session context variables and return reset tokens.
Call ``clear_session_vars(tokens)`` in a ``finally`` block to restore
the previous values when the handler exits.
Returns a list of ``Token`` objects (one per variable) that can be
passed to ``clear_session_vars``.
"""
tokens = [
_SESSION_PLATFORM.set(platform),
_SESSION_CHAT_ID.set(chat_id),
_SESSION_CHAT_NAME.set(chat_name),
_SESSION_THREAD_ID.set(thread_id),
_SESSION_USER_ID.set(user_id),
_SESSION_USER_NAME.set(user_name),
]
return tokens
def clear_session_vars(tokens: list) -> None:
"""Restore session context variables to their pre-handler values."""
if not tokens:
return
vars_in_order = [
_SESSION_PLATFORM,
_SESSION_CHAT_ID,
_SESSION_CHAT_NAME,
_SESSION_THREAD_ID,
_SESSION_USER_ID,
_SESSION_USER_NAME,
]
for var, token in zip(vars_in_order, tokens):
var.reset(token)
def get_session_env(name: str, default: str = "") -> str:
"""Read a session context variable by its legacy ``HERMES_SESSION_*`` name.
Drop-in replacement for ``os.getenv("HERMES_SESSION_*", default)``.
Resolution order:
1. Context variable (set by the gateway for concurrency-safe access)
2. ``os.environ`` (used by CLI, cron scheduler, and tests)
3. *default*
"""
import os
var = _VAR_MAP.get(name)
if var is not None:
value = var.get()
if value:
return value
# Fall back to os.environ for CLI, cron, and test compatibility
return os.getenv(name, default)