Stufe 1 from the core principle: Client calls the Claude Messages API
directly over net/http (no SDK dependency, stays consistent with
"Go-Standard-Library wo möglich") and forces tool-use with a strict JSON
schema instead of parsing free text. Extract() returns rules.Facts
directly rather than an intermediate DTO, since producing exactly that
is the point of this stage. Platform is supplied by the caller, never
guessed by the model.
Every failure mode returns an error instead of a zero-value Facts:
network errors, non-200 API responses, a missing tool_use block, and —
critically — a gegenleistung value outside the four allowed enum
values, which would otherwise get silently coerced into a wrong fact.
Tested entirely against an httptest fake server, no real API calls.
Building this surfaced a real gap in internal/rules: Evaluate() treated
Consideration=="unklar" the same as any other value, i.e. it just
produced an empty finding list — indistinguishable from "everything's
fine". That contradicts the core principle (uncertain extraction should
trigger a user clarification, never a judgment). Evaluate() now returns
(findings, needsClarification), with a golden case covering it.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
internal/rules implements Stufe 2 from the core principle: the LLM
extracts facts, this deterministic engine judges them against versioned
YAML rules. Facts/Condition/Rule/Finding types, a loader that refuses to
load on a missing id/version or a duplicate rule id rather than silently
skipping a bad file, and Evaluate() matching facts against rules.
Two real rules grounded in verified research (see rules/OPEN.md for the
open questions that surfaced along the way):
- WK-001: no disclosure at all despite consideration (§ 5a Abs. 4 UWG,
§ 22 Abs. 1 MStV)
- WK-004: disclosure present but hidden behind a "mehr anzeigen" cut
(§ 5a Abs. 4 UWG, Leitfaden der Medienanstalten, LG Köln 12.05.2026)
The two are deliberately disjoint (WK-004 requires disclosure_present=
true) so a post with no disclosure at all doesn't double-fire both
rules. Golden suite in testdata/golden/ covers both rules plus two clean
cases; it's this suite, not the UI, that's the actual asset per
CLAUDE.md.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
