fix(cli): synchronize HERMES_SESSION_ID across environment and contextvar during session switches

agent/agent_init.py

@@ -976,16 +976,14 @@ def init_agent(
 
     # Expose session ID to tools (terminal, execute_code) so agents can
     # reference their own session for --resume commands, cross-session
-    # coordination, and logging.  Uses the ContextVar system from
-    # session_context.py for concurrency safety (gateway runs multiple
-    # sessions in one process).  Also writes os.environ as fallback for
-    # CLI mode where ContextVars aren't used.
-    os.environ["HERMES_SESSION_ID"] = agent.session_id
+    # coordination, and logging. Keep the ContextVar and os.environ
+    # fallback synchronized because different tool paths still read both.
     try:
-        from gateway.session_context import _SESSION_ID
-        _SESSION_ID.set(agent.session_id)
+        from gateway.session_context import set_current_session_id
+
+        set_current_session_id(agent.session_id)
     except Exception:
-        pass  # CLI/test mode — ContextVar not needed
+        os.environ["HERMES_SESSION_ID"] = agent.session_id
 
     # Session logs go into ~/.hermes/sessions/ alongside gateway sessions
     hermes_home = get_hermes_home()

agent/conversation_compression.py

@@ -381,12 +381,12 @@ def compress_context(
             agent._session_db.end_session(agent.session_id, "compression")
             old_session_id = agent.session_id
             agent.session_id = f"{datetime.now().strftime('%Y%m%d_%H%M%S')}_{uuid.uuid4().hex[:6]}"
-            os.environ["HERMES_SESSION_ID"] = agent.session_id
             try:
-                from gateway.session_context import _SESSION_ID
-                _SESSION_ID.set(agent.session_id)
+                from gateway.session_context import set_current_session_id
+
+                set_current_session_id(agent.session_id)
             except Exception:
-                pass
+                os.environ["HERMES_SESSION_ID"] = agent.session_id
             agent._session_db_created = False
             agent._session_db.create_session(
                 session_id=agent.session_id,

cli.py

@@ -775,8 +775,6 @@ from rich.markup import escape as _escape
 from rich.panel import Panel
 from rich.text import Text as _RichText
 
-import fire
-
 # Import agent and tool systems lazily. Bare interactive startup only needs the
 # prompt; the full agent/tool registry is initialized on first use.
 def AIAgent(*args, **kwargs):
@@ -818,6 +816,13 @@ def validate_toolset(*args, **kwargs):
 
     return _validate_toolset(*args, **kwargs)
 
+
+def _sync_process_session_id(session_id: str) -> None:
+    """Keep process-local session-id consumers aligned after CLI switches."""
+    from gateway.session_context import set_current_session_id
+
+    set_current_session_id(session_id)
+
 # Cron job system for scheduled tasks (execution is handled by the gateway)
 def get_job(*args, **kwargs):
     from cron import get_job as _get_job
@@ -6281,6 +6286,7 @@ class HermesCLI:
         self.conversation_history = []
         self._pending_title = None
         self._resumed = False
+        _sync_process_session_id(self.session_id)
 
         if self.agent:
             self.agent.session_id = self.session_id
@@ -6567,6 +6573,7 @@ class HermesCLI:
         self.session_id = target_id
         self._resumed = True
         self._pending_title = None
+        _sync_process_session_id(target_id)
 
         # Load conversation history (strip transcript-only metadata entries)
         restored = self._session_db.get_messages_as_conversation(target_id)
@@ -6740,6 +6747,7 @@ class HermesCLI:
         self.session_start = now
         self._pending_title = None
         self._resumed = True  # Prevents auto-title generation
+        _sync_process_session_id(new_session_id)
 
         # Sync the agent
         if self.agent:
@@ -14777,4 +14785,6 @@ def main(
 
 
 if __name__ == "__main__":
+    import fire
+
     fire.Fire(main)

gateway/session_context.py

@@ -83,6 +83,21 @@ _VAR_MAP = {
 }
 
 
+def set_current_session_id(session_id: str) -> None:
+    """Synchronize ``HERMES_SESSION_ID`` across ContextVar and ``os.environ``.
+
+    Long-lived single-process entrypoints like the CLI can rotate sessions via
+    ``/new``, ``/resume``, ``/branch``, or compression splits without
+    reconstructing the entire agent. Tools still consult
+    ``get_session_env("HERMES_SESSION_ID")`` with an ``os.environ`` fallback,
+    so both storage paths must move together when the active session changes.
+    """
+    import os
+
+    os.environ["HERMES_SESSION_ID"] = session_id
+    _SESSION_ID.set(session_id)
+
+
 def set_session_vars(
     platform: str = "",
     chat_id: str = "",

tests/cli/test_branch_command.py

@@ -168,6 +168,25 @@ class TestBranchCommandCLI:
 
         assert cli_instance._resumed is True
 
+    def test_branch_rotates_hermes_session_id_env_and_context(self, cli_instance, session_db):
+        """Branching must update process-local session-id readers too."""
+        from cli import HermesCLI
+        from gateway.session_context import _UNSET, _VAR_MAP, get_session_env
+
+        old_session_id = cli_instance.session_id
+        os.environ["HERMES_SESSION_ID"] = old_session_id
+        _VAR_MAP["HERMES_SESSION_ID"].set(old_session_id)
+
+        try:
+            HermesCLI._handle_branch_command(cli_instance, "/branch")
+
+            assert cli_instance.session_id != old_session_id
+            assert os.environ["HERMES_SESSION_ID"] == cli_instance.session_id
+            assert get_session_env("HERMES_SESSION_ID") == cli_instance.session_id
+        finally:
+            os.environ.pop("HERMES_SESSION_ID", None)
+            _VAR_MAP["HERMES_SESSION_ID"].set(_UNSET)
+
     def test_branch_fires_on_session_switch_hook(self, cli_instance, session_db):
         """The /branch command must notify memory providers of the rotation.
 

tests/cli/test_cli_init.py

@@ -333,6 +333,33 @@ class TestHistoryDisplay:
         assert "Checking Running Hermes Agent" in output
         assert "Use /resume <session id or title> to continue" in output
 
+    def test_resume_updates_hermes_session_id_env_and_context(self, tmp_path):
+        from gateway.session_context import _UNSET, _VAR_MAP, get_session_env
+        from hermes_state import SessionDB
+
+        cli = _make_cli()
+        cli.session_id = "current_session"
+        cli.conversation_history = []
+        cli.agent = None
+        cli._session_db = SessionDB(db_path=tmp_path / "state.db")
+        cli._session_db.create_session("current_session", "cli")
+        cli._session_db.create_session("target_session", "cli")
+        cli._session_db.append_message("target_session", "user", "hello from resumed session")
+
+        os.environ["HERMES_SESSION_ID"] = "current_session"
+        _VAR_MAP["HERMES_SESSION_ID"].set("current_session")
+
+        try:
+            cli._handle_resume_command("/resume target_session")
+
+            assert cli.session_id == "target_session"
+            assert os.environ["HERMES_SESSION_ID"] == "target_session"
+            assert get_session_env("HERMES_SESSION_ID") == "target_session"
+        finally:
+            cli._session_db.close()
+            os.environ.pop("HERMES_SESSION_ID", None)
+            _VAR_MAP["HERMES_SESSION_ID"].set(_UNSET)
+
     def test_sessions_command_no_args_lists_recent_sessions(self, capsys):
         """/sessions with no args prints the recent-sessions table (TUI parity).
 

tests/cli/test_cli_new_session.py

@@ -8,6 +8,8 @@ import sys
 from datetime import datetime, timedelta
 from unittest.mock import MagicMock, patch
 
+import pytest
+
 from hermes_state import SessionDB
 from tools.todo_tool import TodoStore
 
@@ -138,6 +140,15 @@ def _prepare_cli_with_active_session(tmp_path):
     return cli
 
 
+@pytest.fixture(autouse=True)
+def _reset_session_id_context():
+    from gateway.session_context import _UNSET, _VAR_MAP
+
+    yield
+    os.environ.pop("HERMES_SESSION_ID", None)
+    _VAR_MAP["HERMES_SESSION_ID"].set(_UNSET)
+
+
 def test_new_command_creates_real_fresh_session_and_resets_agent_state(tmp_path):
     cli = _prepare_cli_with_active_session(tmp_path)
     old_session_id = cli.session_id
@@ -164,6 +175,21 @@ def test_new_command_creates_real_fresh_session_and_resets_agent_state(tmp_path)
     cli.agent._invalidate_system_prompt.assert_called_once()
 
 
+def test_new_command_rotates_hermes_session_id_env_and_context(tmp_path):
+    from gateway.session_context import _VAR_MAP, get_session_env
+
+    cli = _prepare_cli_with_active_session(tmp_path)
+    old_session_id = cli.session_id
+    os.environ["HERMES_SESSION_ID"] = old_session_id
+    _VAR_MAP["HERMES_SESSION_ID"].set(old_session_id)
+
+    cli.process_command("/new")
+
+    assert cli.session_id != old_session_id
+    assert os.environ["HERMES_SESSION_ID"] == cli.session_id
+    assert get_session_env("HERMES_SESSION_ID") == cli.session_id
+
+
 def test_reset_command_is_alias_for_new_session(tmp_path):
     cli = _prepare_cli_with_active_session(tmp_path)
     old_session_id = cli.session_id