run_agent._dispatch_delegate_task forces background=True for every top-level
delegation, and async_delivery_supported() returns True for any session that
never binds the capability. On runners that cannot receive a completion after
their turn ends, that combination silently discards every subagent result: the
model gets a dispatch handle, ends its turn, and reports 'waiting for results'.
Two such runners never bind the capability:
* hermes -z (one-shot) prints one final response and exits. It bypasses cli.py,
so nothing drains process_registry.completion_queue (only the interactive
process_loop and the gateway watchers do).
* cron run_job clears the HERMES_SESSION_* routing keys, so a completion event
carries session_key="" — _enrich_async_delegation_routing cannot resolve it
and _inject_watch_notification drops it ("no routing metadata"). By then
run_job has already shipped the job's final response via _deliver_result;
there is no turn left to re-enter. Worse, get_current_session_key() can fall
back to the ambient os.environ HERMES_SESSION_KEY, so a cron subagent's output
can be routed into an unrelated user chat rather than merely dropped.
Add declare_stateless_channel() and bind it in both runners, routing
delegate_task to its existing inline/synchronous path — the same fallback the
stateless HTTP adapter already relies on, and the fix suggested in #63142. The
helper binds only the capability: set_session_vars() would also latch
_session_context_engaged, which a pure single-process one-shot must not trigger.
Also correct two agent-facing strings that hardcoded 'stateless HTTP API' as the
only channel without async delivery (delegate_tool, terminal_tool); they now name
the actual condition.
Repro (before): hermes -z 'Use delegate_task to spawn a subagent that replies
BANANA. Report its reply.' -> "Waiting for the subagent's response...", exit 0,
no BANANA. After: BANANA is returned in-turn.
Fixes#53027Fixes#63142
* fix(api-server): stop silently promising async delivery on stateless HTTP path
terminal(notify_on_complete=True / watch_patterns) and delegate_task(background=True)
silently no-op'd on the API server / WebUI path (#10760): the watcher / detached
child registered, but every API-server route (OpenAI-spec /v1/chat/completions
and /v1/responses, plus the proprietary /v1/runs SSE stream) tears down its
channel when the turn ends, and APIServerAdapter.send() is a no-op stub. A
completion that fires after the response closed had nowhere to go — from the
agent side, indistinguishable from a hang.
There is no spec-compliant surface to wake the agent later on a stateless HTTP
client, so make the no-op honest instead of silent:
- Add a per-adapter capability flag supports_async_delivery (default True;
APIServerAdapter = False), propagated into a HERMES_SESSION_ASYNC_DELIVERY
contextvar via async_delivery_supported(). Toggle on the adapter, not a
hardcoded platform string — a future stateless adapter is correct-by-default.
- terminal: when delivery is unsupported, skip watcher registration, force
notify_on_complete off, and return a notify_unsupported note telling the
agent to process(action='poll').
- delegate_task: when delivery is unsupported, fall back to SYNCHRONOUS
execution (work runs and returns in the same response) with a note, instead
of handing out a handle that never resolves.
CLI (in-process completion_queue) and the real gateway platforms are unchanged.
Fixes#10760
* refactor(api-server): route session binding through a single no-delivery chokepoint
Add APIServerAdapter._bind_api_server_session() and route both agent-entry
paths (_run_agent for /v1/chat/completions + /v1/responses, and the /v1/runs
_run_sync path) through it. The helper hardwires platform="api_server" and
async_delivery=False with no async_delivery parameter to pass, so a future
route added to the API server physically cannot reintroduce the silent
no-op (#10760) by forgetting to mark the channel as non-delivering.
The binding stays request-scoped (cleared per turn), so a session resumed
later on a delivering interface (CLI / gateway platform) re-binds fresh and
is NOT blocked — the no-delivery decision tracks the interface handling the
current turn, never the session.
