Commit Graph

3 Commits

Author SHA1 Message Date
Brandon Zhang
056ae70e9a feat(mcp): add periodic SSE keepalive notifications during queue wait
When the tool is waiting for an instruction, send ctx.info() log
notifications to the client every KEEPALIVE_INTERVAL_SECONDS (default 20).
Purpose
-------
These notifications write bytes to the SSE stream, resetting any
transport-level HTTP read timeout on the client side (e.g. httpx
Timeout(read=N)).  This prevents premature connection drops when
wait periods exceed the client's inactivity window.
Caveat
------
Application-level wall-clock timers (anyio.fail_after / JS SDK
equivalents) are NOT affected by SSE events -- they count from
request start regardless.  This is confirmed by experiments in
tests/test_keepalive.py and tests/run_keepalive_experiments.py.
Experiment results (summarised in tests/run_keepalive_experiments.py)
----------------------------------------------------------------------
- Exp 1: anyio.fail_after(5s) fires at 5.98s with NO keepalives.
- Exp 2: anyio.fail_after(10s) fires at 10.90s WITH keepalives every 2s.
         Keepalives have ZERO effect on app-level timers.
- Exp 3b: httpx read=8s, keepalive=2s -> SUCCESS at 51s.
          Keepalives DO prevent transport-level read timeouts.
The Copilot extension 60s limit is almost certainly application-level
(hardcoded wall-clock), so default_wait_seconds=50 remains the correct
mitigation (returns before the 60s deadline).  The keepalives provide
defence-in-depth against any proxy/NAT inactivity drops.
2026-03-27 13:54:52 +08:00
589f45ba32 refactor: remove wait_seconds from get_user_request tool
Wait time is now fully server-controlled via default_wait_seconds setting.
Agents can no longer request a different wait duration - only the user
controls this via the web UI.
- Remove wait_seconds param from get_user_request signature
- Simplify actual_wait to min(cfg.default_wait_seconds, MAX_WAIT)
- Update Settings panel label from 'Min Wait' to 'Wait (sec)'
- Update hint text to explain server-only control
- Update README: input schema, behavior rules, settings description, changelog
2026-03-27 04:16:33 +08:00
86eba27a24 init 2026-03-27 03:58:57 +08:00