hermes-agent/tui_gateway
Teknium c66ecf0bc3
feat(delegation): async background subagents via delegate_task(background=true) (#40946)
* feat(delegation): async background subagents via delegate_task(background=true)

delegate_task(background=true) dispatches a subagent that runs in the
background and returns a handle immediately, so the user and model keep
working while it runs. The full result — plus the original task source —
re-enters the conversation as a new turn when the subagent finishes,
riding the same completion-queue rail as terminal background processes.

- tools/async_delegation.py: daemon-executor registry, capacity cap,
  rich self-contained completion event pushed onto the shared
  process_registry.completion_queue (type='async_delegation').
- delegate_tool.py: background param + single-task dispatch branch;
  batch async rejected (v1).
- process_registry.py: format_process_notification renders the rich
  task-source block (goal/context/toolsets/model/status/result).
- gateway/run.py: dedicated _async_delegation_watcher drains + injects
  results into the originating session (idle + post-turn), session_key
  routing enrichment, shutdown interrupt of dangling delegations.
- config: delegation.max_async_children (default 3).

Reuses the existing idle-drain wiring rather than mutating a running
agent loop, preserving message-role alternation and prompt-cache
invariants. 13 targeted tests; CLI + gateway paths E2E-verified.

* test(delegation): make async non-blocking tests environment-independent

CI 'test (5)' flaked on a cold, 8-worker runner: the first
delegate_task(background=true) call measured 2.27s of one-time setup
(config load + child-agent construction + imports), tripping the
elapsed < 1.0 wall-clock assertion. That assertion was testing setup
overhead, not blocking.

Replace the wall-clock thresholds with the real invariant: dispatch
returns while the child is still gated (active_count == 1, completion
queue empty), which a synchronous impl could not do. Keep only a loose
4s sanity backstop well under the runner's 5s gate.

* fix(delegation): harden async background delegation

Follow-up review fixes:
- Detach background child from parent._active_children at dispatch —
  otherwise parent-turn interrupts (Ctrl+C, mid-turn steering), cache
  evicts (release_clients), and session close (/new) kill/close the
  detached subagent mid-run, defeating the point of background mode.
  Lifecycle is owned by the async registry's interrupt_fn.
- Make the capacity check atomic with the record insert (TOCTOU: two
  concurrent dispatches could both pass active_count() and exceed the cap).
- TUI dedup: key async_delegation events by delegation_id — the
  fallthrough keyed them all as ("", type), suppressing every completion
  after the first in the desktop/TUI status feed.
- CLI /stop now interrupts running background delegations and /agents
  lists them (they live outside the process registry and were invisible).
- Drop stray unbalanced ']' line from the re-injection block and the
  unused _ASYNC_DEFAULT import.

Tests: detach-at-dispatch + concurrent-capacity race added (15 total in
test_async_delegation.py); 137 delegate + 140 process-registry/notify/watch
+ 7 TUI dedup tests pass.

* fix(delegation): harden async background completion drains
2026-06-15 13:33:12 -07:00
..
__init__.py feat: new tui based on ink 2026-04-02 19:07:53 -05:00
entry.py perf(tui): stop slow/dead MCP servers from freezing TUI startup 2026-05-30 02:53:37 -07:00
event_publisher.py chore: address copilot comments 2026-04-24 12:51:04 -04:00
render.py tui: inherit Python-side rendering via gateway bridge 2026-04-05 18:50:41 -05:00
server.py feat(delegation): async background subagents via delegate_task(background=true) (#40946) 2026-06-15 13:33:12 -07:00
slash_worker.py fix(tui-gateway): reap leaked slash_worker sessions on disconnect + active_list liveness (re-scoped onto current main) 2026-06-08 10:02:05 -07:00
transport.py fix(tui-gateway): harden stdio transport against half-closed pipes + SIGTERM races (#17118) 2026-04-28 17:54:06 -05:00
ws.py feat(desktop): composer status stack, live subagent windows, editable prompts (#44630) 2026-06-12 08:30:06 -05:00