The gateway's startup warm-up (_warm_turn_machinery_sync) primed the
run_agent import graph, tool schemas and context files, but left the
process-local Python toolchain probe to the first AIAgent. That agent
starts the probe worker in its constructor and its first system-prompt
build then blocks in get_environment_probe_line() on the python/pip
subprocesses (~250 ms measured) before the first model request — with
local models too, so provider metadata warm-up (#105999) does not cover it.
Call the same resolver from the warm-up: it owns the agent.environment_probe
opt-out check here, and the resolver itself owns remote-backend omission,
the single worker, its cache and the bounded fail-open wait, so the first
turn simply finds the line cached. No agent is constructed and no session
prompt is frozen at startup; a disabled probe or a remote terminal backend
leaves the host untouched.
Slim redo of #106075 by @francip: same mechanism, folded into the existing
sync warm-up instead of a new module + asyncio.gather + second suppress
block; the two behavior tests are kept, the concurrency tests dropped.
Co-authored-by: Franci Penov <49422+francip@users.noreply.github.com>
Teknium
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