Closes#2223. The write-path prior-art trigger's semantic arm shared
auto-inject's 0.55 threshold, which was tuned on prose. Code embeddings
sit on a much higher similarity floor — any two Python-shaped payloads
share keywords, indentation and structure — so 0.55 landed INSIDE the
noise band. Measured against the live instance:
near-duplicate of a recorded helper 0.73-0.74 true positive
unrelated colour math / Vue SFC / CSS 0.55-0.63 false positive
`x = 1` 0.58 false positive
6 of 8 probe payloads produced a nudge; 4 were noise. The margin gate
couldn't help — _AUTOINJECT_BAND is relative to the top hit, so with a
single hit it never engages.
Two gates are now the write-path arm's own:
- kb_writepath_threshold, default 0.68 — above every measured false
positive, still 0.05 below both true positives. Auto-inject keeps
0.55; it was tuned on prose and is not implicated. The comment this
replaces explicitly reserved the split for when telemetry showed the
surfaces wanted different values, so this is the change it described,
not a reversal of it.
- WRITEPATH_MIN_CODE_CHARS = 48 non-whitespace chars, below which the
semantic arm doesn't run at all. Whitespace is excluded so a deeply
indented one-liner can't pass on padding. 48 sits under the smallest
plausible reusable helper (~60) and well over a degenerate edit, so it
errs toward keeping recall — precision is the threshold's job. This is
the cheap half of the operator's #89 idea; the full length<->threshold
curve stays open there, since they asked to brainstorm it rather than
have a scale invented for them.
top_k stays shared — "how many titles at once" means the same thing on
both surfaces.
The existing tests were passing `code="x"` / `code="def f(): ..."` into
the semantic arm, i.e. exactly the payloads the floor now drops, so the
gate tests were never exercising a realistic payload. They now use a
REAL_CODE fixture, plus new coverage for the floor (trivial payload,
padding, place-arm unaffected, real helper passes) and a guard on the
constant itself.
Settings UI carries the new knob with the reasoning in its hint, and the
write-path checkbox no longer claims it shares the threshold.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UaYUaouG9jjhATyuxCKrQs
The location filter's section comment says THE TWO MUST CHANGE TOGETHER and
names tests/test_retrieval_scopes.py as what enforces it. The drift-check
filter added in #2086 has the same two-dialect structure and the same
hazard — a predicate applied in only one arm makes a record findable one
way and invisible another — but pointed at no guard, so the next person
had to discover that tests/test_snippet_drift_check.py walks both.
Also names the case that motivated `attention` existing at all: an ok
verdict whose code_sha has gone stale is neither `drifted` nor
`unverified`, and is the one shape a reader is likely to think redundant
and remove.
Written while verifying the plugin fixes end-to-end — this edit is what
the write-path trigger fired on, correctly surfacing snippet #2192 as
prior art at this exact path.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UaYUaouG9jjhATyuxCKrQs
bvandeusenandClaude Opus 5