Summary

Memory providers' on_session_end hook now receives the real conversation transcript on both gateway session teardown and CLI exit, instead of an empty list. Fixes #15165.

Salvaged from #15481 (@briandevans) with the CLI sibling site fixed in a follow-up commit.

The bug

Both teardown paths called shutdown_memory_provider with an effectively-empty list:

• Gateway (gateway/run.py): agent.shutdown_memory_provider() — no args, so on_session_end([]) fired on every provider.
• CLI (cli.py): shutdown_memory_provider(getattr(agent, 'conversation_history', None) or []) — AIAgent has no conversation_history attribute, so the or [] branch always fired.

Providers that early-return on empty input (Holographic, Hindsight mid-batch) never persisted the session. Hindsight specifically buffers turns and only flushes at retain_every_n_turns boundaries — any turns held below the modulus at restart/idle-expiry/exit were silently dropped.

The fix

Both sites now forward agent._session_messages — the transcript AIAgent maintains and refreshes every turn in _persist_session (run_agent.py:3378) and several loop paths.

session_messages = getattr(agent, "_session_messages", None)
if isinstance(session_messages, list):
    agent.shutdown_memory_provider(session_messages)
else:
    agent.shutdown_memory_provider()

The isinstance(..., list) guard is deliberate — it protects against MagicMock agents (whose attribute access auto-synthesises a child mock) falling through to providers that expect List[Dict], keeping existing test suites green.

Scope

Part A of #15165 only (plus the CLI sibling). Part B (adding an on_session_end implementation to the Hindsight plugin) is a separate concern that benefits from this landing first — without Part A the hook would still receive [].

Commits

1. fix(gateway): pass session messages to shutdown_memory_provider — @briandevans, cherry-picked from fix(gateway): pass session messages to shutdown_memory_provider (#15165) #15481
2. fix(cli): pass session messages to shutdown_memory_provider — widens the same fix to the CLI exit path; fix(gateway): pass session messages to shutdown_memory_provider (#15165) #15481 was gateway-only

Test plan

• tests/gateway/test_shutdown_memory_provider_messages.py (7 cases, from fix(gateway): pass session messages to shutdown_memory_provider (#15165) #15481) — populated list forwarded, empty list forwarded, missing attribute falls back, MagicMock falls back, provider exception swallowed, None agent no-op, agent without method tolerated.
• tests/cli/test_cli_shutdown_memory_messages.py (4 cases, new) — populated, empty, non-list fallback, provider exception swallowed.
• Regression guard verified: reverted the CLI fix → 3 of 4 new CLI tests fail with Expected: mock([...]) / Actual: mock(); restored → all pass.
• Related gateway suites green: test_shutdown_cache_cleanup, test_compress_command, test_agent_cache, test_session_hygiene, test_background_command, test_compress_plugin_engine, test_session_boundary_hooks (92 + 15 = 107 passing).

Related

• Fixes [Bug]: Gateway restart drops session memory — shutdown_memory_provider receives empty messages #15165 (Part A)
• Supersedes fix(gateway): pass session messages to shutdown_memory_provider (#15165) #15481 (@briandevans's authorship preserved via rebase merge)
• /new and /reset commands don't trigger OpenViking session commit #7759 (closed) — /new / /reset memory commit, different code path
• [Bug]: The on_session_finalize hook is not being fired when gateway sessions expire due to configured idle time. #14981 — on_session_finalize not fired on idle timeout (orthogonal)
• [Bug]: Hindsight sync can race interpreter shutdown after successful one-shot CLI exit #15073 — Hindsight sync races interpreter shutdown (orthogonal)