Spliced from #1531 by @Asunfly: take Change-1 only (the actual bug fix +
cache signature inclusion) and skip Change-2 (auxiliary title-route
extra_body change) which is a separate scope concern.
## What
Two surgical fixes in api/streaming.py:
1. Line 1820 — `_cfg.cfg.get(...)` → `_cfg.get(...)`. `get_config()` returns
a plain dict (not a wrapper exposing `.cfg`). The buggy line raised
AttributeError that the surrounding try/except swallowed, so
`_reasoning_config` was always None regardless of what `/reasoning
<level>` had been set to. Verified locally — `api/streaming.py:1959`
already correctly used `_cfg.get(...)` in the same function, so the
same `_cfg` was being read two different ways in one file.
2. Line 1888 — added `_reasoning_config or {}` to `_sig_blob`. Without
this, switching effort mid-session would fail to take effect because
the per-session agent cache key would still match the old entry.
Mirrors how `resolved_provider` / `resolved_base_url` already
participate in the signature.
## Why splice instead of merge #1531 directly
@Asunfly force-pushed a Change-2 onto #1531 after the original review
that removes `extra_body={"reasoning": {"enabled": False}}` from
`generate_title_raw_via_aux` (the auxiliary title-generation route).
That intent is reasonable (let operator-configured `extra_body.reasoning`
flow through to the title route) but it touches a different surface and
deserves its own PR.
The narrow concern is operators who selected a reasoning-capable
auxiliary title model without explicitly setting
`reasoning.enabled=False` in the task config — pre-Change-2 the WebUI
defended against accidental reasoning on the title hot path; post-Change-2
those configs would reason on every new conversation`s title, with cost
and latency implications.
## What is NOT in this PR
- The `generate_title_raw_via_aux` extra_body refactor (Change-2 from #1531).
- The `test_does_not_override_configured_reasoning_extra_body` test (guards
Change-2). Asunfly can re-open that as its own focused PR.
## Tests
Two new R17b/R17c regression assertions in tests/test_regressions.py:
- `test_streaming_reads_reasoning_effort_from_config_dict` — static-source
guard: `_cfg.cfg` must not return to streaming.py
- `test_streaming_agent_cache_signature_includes_reasoning_config` —
catches removal of `_reasoning_config` from `_sig_blob`
## Closes
- Closes#1531 (the Change-1 portion ships here; Asunfly can re-open
Change-2 as a separate PR if desired)
Co-authored-by: Asunfly <[email protected]>
df0d904d87