The rules that decide before anything is asked of a model.

What the engine is allowed to see

The engine accepts exactly five fields. There is no client record, no matter history, no timekeeper file, and no prior invoice. This is deliberate: a rule that cannot reach outside its payload produces the same answer every time it is given the same input, which is what makes the result reproducible in an audit.

export interface RawBillingPayload {
  line_item_id: string;
  timekeeper_role: string;
  hourly_rate_usd: number;
  hours_logged: number;
  raw_narrative_text: string;
}

export interface RuleViolation {
  rule_id: string;
  description: string;
  action: 'STRIP_AND_RECALCULATE'
        | 'FLAG_FOR_AI_CONSENSUS_REWRITE';
}

Prohibited administrative overhead

The first family answers a question with an objectively correct answer: does this narrative describe work the guidelines say cannot be billed at all? Printing, photocopying and scanning are administrative overhead under a common Outside Counsel Guideline. No interpretation is required to recognise them, so no interpretation is invited.

Semantic vagueness — where the engine stops

The second family answers a different kind of question: is this narrative specific enough for a client to understand what they paid for? That question has no mechanical answer. “Research” may be perfectly adequate on one line and unacceptably thin on another, and only the surrounding context decides.

So the engine does not decide. It records that a judgment is required, sets a flag, and stops. No hours are deducted and no money moves when this family fires.

The arithmetic, in full

Four numbers, three multiplications, one subtraction. The engine performs no other financial operation. Below is the documented worked example, executed step by step exactly as the code executes it.

const originalValue =
  payload.hours_logged * payload.hourly_rate_usd;

const adjustedValue =
  adjustedHours * payload.hourly_rate_usd;

const leakagePrevented =
  originalValue - adjustedValue;

What comes back, and who consumes it

Every field in the result exists because something downstream needs it. Original values are retained alongside adjusted ones so that no comparison requires re-reading the source file, and every finding keeps its rule identifier so an adjustment can always be attributed.

Order of operations — and why it is not arbitrary

The two rule families run in sequence, not in parallel, and the sequence changes the result. Administrative rules run first and modify the working text. Vagueness rules then run against the already-stripped narrative, not against the original.

// Phase 1 — administrative overhead
for (const [keyword, description] of forbiddenKeywords) {
  if (textBuffer.toLowerCase().includes(keyword)) {
    violations.push({ /* OCG-04 */ });
    adjustedHours = Math.max(0, adjustedHours - 0.5);
    textBuffer = textBuffer.replace(regex, '').trim();
  }
}

// Phase 2 — runs against the MODIFIED buffer
for (const vagueWord of vagueKeywords) {
  if (textBuffer.toLowerCase().includes(vagueWord)) {
    violations.push({ /* OCG-11 */ });
    needsAiConsensus = true;
  }
}

Run the engine yourself

This is the rule logic described above, ported faithfully to the browser — the same keyword maps, the same 0.5-hour constant, the same strip expression, the same order. Change any field and the result recalculates immediately. Nothing is transmitted; everything runs on this page.

Documented boundaries of the current implementation

The following behaviours are present in the implementation as supplied. They are published here because a reviewer will find them in ten minutes, and because a system that claims determinism has to be willing to state precisely what it currently does. Each is reproducible in the evaluator above.

"printed and collated binders"
includes("print")  → true   → −0.5 h
/\bprint\b/        → no match → text unchanged

"deposition of Dr. Scanlon"     → "scan"  → −0.5 h
"the blueprint specifications"  → "print" → −0.5 h
Result: 3.0 h → 2.0 h, $900 deducted

"Printed pleadings; scan of correspondence"
→ 2 × OCG-04 → −1.0 h
→ violations_detected.length === 2

private forbiddenKeywords = new Map([...]);
private vagueKeywords = ['research', ...];
adjustedHours - 0.5

What this component is, and what it is not

DRE addresses outside-counsel billing and Outside Counsel Guidelines review for corporate legal departments. The compliance engine occupies one clearly bounded position inside that scope.