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lib/engine.js

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  1. // LEASH wallet-control — decision engine.
  2. // Evaluates one authorization event against the customer's confirmed mandate and
  3. // returns {decision: approve|decline|step_up, reason_codes, customer_message,
  4. // evidence, uncertainties, flags}.
  5. //
  6. // Guarantees:
  7. // - Deterministic, pure rules over extracted facts, sub-millisecond evaluation,
  8. // identical input -> identical output. The only statistical component is the
  9. // prompt-injection text detector, which can NEVER approve, decline, or loosen
  10. // anything — it can only escalate to the human, same as the regex scan.
  11. // - Merchant-supplied text is data, never instructions: it is scanned for
  12. // manipulation attempts and mined only for structured attributes.
  13. // - Missing/unknown facts produce uncertainty (never silent permission).
  14. // - Unknown rule fields produce uncertainty (never silent permission).
  15. // - Decisions are idempotent per live authorization_id (retries never double-count).
  17. import { round2, toChf, fmtChf, clip, FX } from './util.js';
  18. import {
  19. scanInjection, extractReturnWindow, extractItemAttributes, basketLineSumChf,
  20. lookalikeMatch, trustLookup, popularityLookup, sanctionsLookup, mccRiskLookup,
  21. } from './signals.js';
  22. import { requestedItemSpec } from './policy-compiler.js';
  23. import { scanInjectionModel, getInjectionModel } from './injection-model.js';
  24. import { scoreBehavior, getBehaviorModel } from './behavior-model.js';
  25. import { jevNeedsReview } from './jev.js';
  26. import { qtyCap, statCap } from './item-classes.js';
  27. import { describeResult, normalizeDomain } from './trustedshops.js';
  29. const INTEGRITY_SIGNAL_CODES = new Set(['DEVICE_NOVELTY', 'VELOCITY_BURST', 'UNUSUAL_HOUR']);
  31. // Reason codes ranked for message composition (most important first).
  32. const DECLINE_RANK = [
  33. 'MANDATE_INACTIVE', 'TRUSTLIST_HIT', 'TRUSTEDSHOPS_FAKE_SHOP', 'RETRY_OF_DECLINED', 'INJECTION_ATTEMPT',
  34. 'GIFT_CARD_RISK', 'EXTRA_ITEM_BLOCKED', 'REQUESTED_ITEM_MISMATCH', 'SIZE_MISMATCH',
  35. 'LIMIT_EXCEEDED', 'PERIOD_LIMIT_EXCEEDED', 'CATEGORY_MISMATCH', 'MERCHANT_TYPE_MISMATCH',
  36. 'MERCHANT_UNFAMILIAR', 'RETURN_WINDOW_INSUFFICIENT', 'FULFILMENT_MISMATCH', 'LINE_COUNT_EXCEEDED',
  37. ];
  39. function codeRank(c) {
  40. const i = DECLINE_RANK.indexOf(c);
  41. return i === -1 ? 99 : i;
  42. }
  44. /** Describe a hard-rule check result. */
  45. function check(rule, status, detail) {
  46. return { rule, status, detail };
  47. }
  49. function fieldFacts(event) {
  50. const a = event.authorization;
  51. const lines = (a.items || []).map(it => ({
  52. raw: it,
  53. attrs: extractItemAttributes(it),
  54. ret: extractReturnWindow(it.item_details),
  55. }));
  56. return {
  57. a, lines,
  58. billing: typeof a.billing_amount_chf === 'number' ? round2(a.billing_amount_chf) : null,
  59. simTs: a.timestamp ? new Date(a.timestamp).getTime() : null,
  60. lineSum: basketLineSumChf(a.items || []),
  61. lineSumRaw: round2((a.items || []).reduce((s, it) => s + (it.unit_price || 0) * (it.quantity || 1), 0)),
  62. };
  63. }
  65. /** Does one basket line satisfy the requested-item spec? */
  66. function lineMatchesSpec(line, spec) {
  67. const issues = [];
  68. const at = line.attrs;
  69. if (spec.family) {
  70. if (!at.family) issues.push({ code: 'ITEM_UNCLEAR', level: 'uncertain', detail: `cannot confirm product type from "${clip(line.raw.item_name)}"` });
  71. else if (at.family !== spec.family) {
  72. issues.push({ code: 'REQUESTED_ITEM_MISMATCH', level: 'fail', detail: `basket contains "${clip(line.raw.item_name)}" instead of the requested ${spec.label}` });
  73. } else if (spec.family === 'shoes' && spec.sport === at.sport && spec.terrain && at.terrain && spec.terrain !== at.terrain) {
  74. // same product family and sport, different variety: a substitution the customer may accept
  75. issues.push({ code: 'SUBSTITUTION', level: 'uncertain', detail: `seller offers ${at.terrain}-running shoes instead of ${spec.terrain}-running shoes` });
  76. } else if (spec.sport && at.sport && at.sport !== spec.sport) {
  77. issues.push({ code: 'REQUESTED_ITEM_MISMATCH', level: 'fail', detail: `different sport: ${at.sport} vs requested ${spec.sport}` });
  78. }
  79. if (spec.terrain && at.family === spec.family && at.terrain == null && !issues.some(i => i.code === 'SUBSTITUTION')) {
  80. issues.push({ code: 'TERRAIN_UNVERIFIED', level: 'uncertain', detail: 'seller text does not state the shoe type (road/trail)' });
  81. }
  82. }
  83. if (spec.inches != null && (at.family === spec.family || at.family == null)) {
  84. if (at.inches != null && at.inches !== spec.inches) {
  85. issues.push({ code: 'REQUESTED_ITEM_MISMATCH', level: 'fail', detail: `${at.inches}-inch screen instead of ${spec.inches}-inch` });
  86. } else if (at.inches == null && at.family === spec.family) {
  87. issues.push({ code: 'ITEM_UNCLEAR', level: 'uncertain', detail: 'screen size not stated by seller' });
  88. }
  89. }
  90. if (spec.size && (at.family === spec.family || at.family == null)) {
  91. if (at.size != null && at.size.toUpperCase() !== String(spec.size).toUpperCase()) {
  92. issues.push({ code: 'SIZE_MISMATCH', level: 'fail', detail: `size ${at.size} instead of requested size ${spec.size}` });
  93. } else if (at.size == null) {
  94. issues.push({ code: 'SIZE_UNVERIFIED', level: 'uncertain', detail: 'size not stated by seller' });
  95. }
  96. }
  97. return issues;
  98. }
  100. const DESCRIPTION_FAMILY_TOKENS = [
  101. [/\bmonitors?\b/i, 'monitor'], [/\b(?:running )?shoes?\b/i, 'shoes'], [/\bjackets?\b|\bcoats?\b/i, 'outerwear'],
  102. [/\bgift (?:card|voucher)s?\b|\bvouchers?\b/i, 'gift_card'], [/\bgrocer/i, 'groceries'], [/\bclothing\b|\bclothes\b/i, 'clothing'],
  103. ];
  105. /**
  106. * Evaluate one authorization event.
  107. * @param event full live event {authorization, mandate, context, runtime}
  108. * @param state run state: {approvedSpendInWindow(days, beforeTs), inRunApprovedMerchants(), priorDecisions(), hasRule helper}
  109. * @param profiles HistoryProfiles
  110. * @param trust LEASH trust dataset (optional)
  111. * @param extras network-provided enrichment (optional): {trustedShops} — Trusted Shops
  112. * verification result for the merchant website, fetched by the worker
  113. * ahead of evaluation and always advisory.
  114. */
  115. export function evaluate(event, state, profiles, trust, extras = {}) {
  116. const t0 = process.hrtime.bigint();
  117. const a = event.authorization;
  118. const mandate = event.mandate || {};
  119. const customerId = mandate.customer_id;
  120. const F = fieldFacts(event);
  121. const fails = []; // hard violations -> decline
  122. const uncert = []; // uncertainties -> per uncertainty_policy
  123. const evidence = [];
  124. const flags = { manipulation: [], integrity: [], behavior: [], positive: [] };
  126. const addFail = (code, detail) => fails.push({ code, detail });
  127. const addUnc = (code, detail) => uncert.push({ code, detail });
  128. const ev = (label, value) => evidence.push({ label, value: String(value) });
  129. // Confidence accounting for evidence-based user feedback: `verified` counts
  130. // deterministic checks that completed with readable data; `open` counts facts
  131. // the engine could not verify. Uncertainties surfaced to the customer count
  132. // as open points too, so the percentage always matches what the user is told.
  133. const conf = { verified: 0, open: 0 };
  134. const cv = () => { conf.verified += 1; };
  135. const co = () => { conf.open += 1; };
  137. // -- 0. Mandate state -------------------------------------------------------
  138. if (mandate.status && mandate.status !== 'active') {
  139. addFail('MANDATE_INACTIVE', `wallet policy is ${mandate.status} — no spending is permitted`);
  140. }
  141. cv(); // mandate state read — always a verifiable fact
  143. // -- 1. Untrusted-text manipulation scan (never changes policy, only escalates)
  144. const untrusted = [
  145. ...F.lines.map(l => ({ field: 'item_details', text: l.raw.item_details })),
  146. { field: 'purchase_description', text: a.purchase_description },
  147. { field: 'merchant_name', text: a.merchant?.merchant_name },
  148. ];
  149. const inj = scanInjection(untrusted);
  150. cv(); // manipulation scan completed over all untrusted text fields
  151. if (inj.length) {
  152. flags.manipulation = inj;
  153. // Injection attempts never become hard fails on their own: the merchant text
  154. // must not change the outcome of an otherwise-compliant purchase. Instead the
  155. // purchase is force-escalated to the human (see aggregation) with evidence.
  156. }
  158. // -- 1b. Model-based injection scan (trained on the TensorTrust corpus: ~200k
  159. // attacks vs ~124k benign texts; see merchant-trust-data/models/prompt_injection/).
  160. // Same escalation-only semantics as the regex layer: it
  161. // may only add step_up evidence or an uncertainty note, never a fail, never
  162. // an approval. Gracefully inert when no model artifact is deployed.
  163. const modelScan = scanInjectionModel(untrusted);
  164. if (modelScan?.best) {
  165. const { best, threshold, suspect } = modelScan;
  166. cv(); // trained detector produced a scored verdict for this text
  167. if (best.score >= threshold) {
  168. flags.manipulation.push({
  169. code: 'INJ_MODEL', source: 'model', field: best.field,
  170. score: Number(best.score.toFixed(3)),
  171. why: `trained injection detector scored this text ${best.score.toFixed(2)} vs escalation threshold ${threshold.toFixed(2)}`
  172. + (best.topGrams.length ? `; strongest signals: ${best.topGrams.map(t => `“${t.gram}”`).join(', ')}` : ''),
  173. snippet: best.snippet,
  174. });
  175. } else if (best.score >= suspect && !inj.some(h => h.field === best.field)) {
  176. addUnc('INJECTION_SUSPECT', `${best.field} text scored ${best.score.toFixed(2)} on the injection detector — below escalation threshold, but treat it as untrusted`);
  177. }
  178. }
  180. // -- 2. Basic facts ----------------------------------------------------------
  181. ev('Amount', `${fmtChf(F.billing ?? NaN)}${a.currency && a.currency !== 'CHF' ? ` (${a.amount} ${a.currency} incl. delivery)` : ' incl. delivery'}`);
  182. if (F.billing == null) { addUnc('AMOUNT_MISSING', 'billing amount missing or malformed'); co(); }
  183. else cv();
  184. // price sanity: cart lines are priced in the row currency; items_subtotal uses the
  185. // row currency too; billing_amount_chf must equal (items + delivery) × fixed FX rate.
  186. if (a.items_subtotal != null && Math.abs(F.lineSumRaw - a.items_subtotal) > 0.05) {
  187. addUnc('PRICE_SANITY', `cart lines sum to ${round2(F.lineSumRaw).toFixed(2)} ${a.currency || ''} but items_subtotal says ${round2(a.items_subtotal).toFixed(2)} ${a.currency || ''}`);
  188. }
  189. if (F.billing != null && a.amount != null) {
  190. cv(); // billed total cross-checked against amount × fixed FX rate
  191. if (Math.abs(round2(a.amount * (FX[a.currency] ?? 1)) - F.billing) > 0.05) {
  192. addUnc('PRICE_SANITY', `billed ${fmtChf(F.billing)} does not match ${a.amount} ${a.currency} at the fixed FX rate (${fmtChf(round2(a.amount * (FX[a.currency] ?? 1)))})`);
  193. }
  194. }
  196. // -- 3. Duplicate / retry recognition -----------------------------------------
  197. const signature = `${a.merchant?.merchant_id}|${F.lines.map(l => l.raw.item_id).sort().join('+')}|${F.billing}`;
  198. const relatedStatus = a.related_authorization_status ?? null;
  199. if (relatedStatus === 'declined') {
  200. addFail('RETRY_OF_DECLINED', 'this is a retry of a purchase you (or the wallet) already declined — declined purchases stay declined');
  201. }
  202. const dup = state.findDuplicate({ signature, authId: a.authorization_id, simTs: F.simTs, billing: F.billing, merchantId: a.merchant?.merchant_id });
  203. cv(); // duplicate/retry scan completed against window + run history
  204. if (dup) {
  205. if (dup.kind === 'approved-similar') {
  206. addUnc('DUPLICATE_SUSPECT', `near-identical order at ${a.merchant?.merchant_name} (${fmtChf(dup.billing)}) was already approved ${dup.minutesAgo} min ago — possible duplicate submission`);
  207. } else if (dup.kind === 'declined-similar') {
  208. addFail('RETRY_OF_DECLINED', `an identical order (${fmtChf(dup.billing)} at ${a.merchant?.merchant_name}) was declined ${dup.minutesAgo} min ago; retrying does not change the decision`);
  209. } else if (dup.kind === 'split-suspect') {
  210. addUnc('SPLIT_ORDER', `another order at ${a.merchant?.merchant_name} (${fmtChf(dup.billing)}) was approved only ${dup.minutesAgo} min ago — this looks like the same purchase split in two`);
  211. }
  212. }
  213. ev('Related purchase', relatedStatus ? `${a.related_authorization_id || 'earlier purchase'} → ${relatedStatus}` : 'none');
  215. // -- 3b. Merchant website domain + customer trust status ----------------------
  216. // The domain drives the yellow-list path: a domain the customer explicitly
  217. // trusted (approved on a step-up card) counts as familiar; a domain on NEITHER
  218. // the trusted list NOR a known-bad list is an open question for the customer
  219. // (see 8c) — never silent permission.
  220. const merchantDomain = normalizeDomain(a.merchant?.merchant_url || a.merchant?.website_url || a.merchant?.merchant_domain || a.merchant?.url || null)?.domain?.replace(/^www\./, '') || null;
  221. if (merchantDomain) cv(); else co(); // merchant website identity anchor
  222. const trustedMeta = merchantDomain && state.trustedDomainCheck ? state.trustedDomainCheck(merchantDomain) : null;
  224. // -- 4. Hard rules ------------------------------------------------------------
  225. const rules = mandate.hard_rules || [];
  226. const requestedSpec = requestedItemSpec(mandate.instruction);
  227. let exactMatch = false;
  228. let integrityMonitoring = false;
  229. const ruleResults = [];
  231. for (const rule of rules) {
  232. const f = rule.field, op = rule.operator;
  233. let res;
  234. if (f === 'authorization.billing_amount_chf' && (rule.scope ?? 'purchase') === 'purchase') {
  235. if (F.billing == null) res = check(rule, 'uncertain', 'amount not readable');
  236. else {
  237. const ok = cmp(F.billing, op, rule.value);
  238. res = check(rule, ok ? 'pass' : 'fail', ok ? `${fmtChf(F.billing)} within cap ${fmtChf(rule.value)}` : `${fmtChf(F.billing)} exceeds cap ${fmtChf(rule.value)}`);
  239. if (!ok) addFail('LIMIT_EXCEEDED', `total ${fmtChf(F.billing)} (delivery included) is over your ${fmtChf(rule.value)} per-order cap`);
  240. }
  241. ev('Per-order cap', `${fmtChf(rule.value)} → ${F.billing != null ? fmtChf(F.billing) : '?'}`);
  242. } else if (f === 'period.approved_spend_chf' && rule.scope === 'period') {
  243. const days = rule.period_days || 7;
  244. const before = state.approvedSpendInWindow(days, F.simTs);
  245. const platform = typeof event.context?.approved_spend_in_period_chf === 'number' ? event.context.approved_spend_in_period_chf : null;
  246. const counted = Math.max(before, platform ?? 0); // conservative: never under-count
  247. if (F.billing == null) res = check(rule, 'uncertain', 'amount not readable');
  248. else {
  249. const total = round2(counted + F.billing);
  250. const ok = cmp(total, op, rule.value);
  251. res = check(rule, ok ? 'pass' : 'fail', `approved spend in last ${days}d: ${fmtChf(counted)}; with this: ${fmtChf(total)} vs cap ${fmtChf(rule.value)}`);
  252. if (!ok) addFail('PERIOD_LIMIT_EXCEEDED', `this purchase would take your rolling ${days}-day total to ${fmtChf(total)} — over the ${fmtChf(rule.value)} cap (${fmtChf(counted)} already approved)`);
  253. ev(`Rolling ${days}d spend`, `${fmtChf(counted)} approved + ${fmtChf(F.billing)} = ${fmtChf(total)} / ${fmtChf(rule.value)}`);
  254. }
  255. } else if (f === 'policy.requires_review' && String(rule.value) === 'true') {
  256. res = check(rule, 'uncertain', 'some customer instructions require review');
  257. addUnc('POLICY_UNRESOLVED', 'Your instruction contains unresolved requirements. Review the original instruction before approving this purchase.');
  258. } else if (f === 'booking.nightly_amount_chf') {
  259. const prices = [];
  260. let complete = F.lines.length > 0;
  261. for (const line of F.lines) {
  262. const matches = [...String(line.raw.item_details || '').matchAll(/\b(CHF|EUR|GBP|USD)\s*(\d+(?:\.\d{1,2})?)\s*(?:per night|\/night)\b/gi)];
  263. if (!matches.length) complete = false;
  264. for (const m of matches) prices.push(toChf(Number(m[2]), m[1].toUpperCase()));
  265. }
  266. if (prices.some(price => !cmp(price, op, rule.value))) {
  267. res = check(rule, 'fail', 'a stated nightly rate exceeds the cap');
  268. addFail('LIMIT_EXCEEDED', `a nightly rate exceeds your ${fmtChf(rule.value)} per-night limit`);
  269. } else if (!complete) {
  270. res = check(rule, 'uncertain', 'nightly rates are not explicitly stated for every booking line');
  271. addUnc('NIGHTLY_PRICE_UNKNOWN', 'Cannot verify every nightly rate; the total price is not a per-night price.');
  272. } else res = check(rule, 'pass', `all stated nightly rates are within ${fmtChf(rule.value)}`);
  273. } else if (f === 'basket.total_quantity') {
  274. const quantities = F.lines.map(l => l.raw.quantity);
  275. if (!quantities.length || quantities.some(q => !Number.isInteger(q) || q < 1)) {
  276. res = check(rule, 'uncertain', 'item quantities are missing or invalid');
  277. addUnc('QUANTITY_UNKNOWN', 'Cannot verify the number of units in this basket.');
  278. } else {
  279. const total = quantities.reduce((a, b) => a + b, 0);
  280. const ok = cmp(total, op, rule.value);
  281. res = check(rule, ok ? 'pass' : 'fail', `${total} units vs limit ${rule.value}`);
  282. if (!ok) addFail('QUANTITY_EXCEEDED', `basket contains ${total} units; your permission covers ${rule.value}`);
  283. }
  284. } else if (f === 'basket.line_count') {
  285. const n = F.lines.length;
  286. const ok = cmp(n, op, rule.value);
  287. res = check(rule, ok ? 'pass' : 'fail', `${n} line(s) vs limit ${rule.value}`);
  288. if (!ok) addFail('LINE_COUNT_EXCEEDED', `basket has ${n} items; permission covers ${rule.value}`);
  289. } else if (f === 'basket.categories' && op === 'in') {
  290. const allowed = new Set(rule.value);
  291. const bad = F.lines.filter(l => !l.raw.item_category || !allowed.has(l.raw.item_category));
  292. if (bad.length) {
  293. res = check(rule, 'fail', bad.map(l => `${l.raw.item_name} (${l.raw.item_category || 'category missing'})`).join(', '));
  294. addFail('CATEGORY_MISMATCH', `not everything in the basket is ${rule.value.join('/')}: ${bad.map(l => `“${clip(l.raw.item_name)}” (${l.raw.item_category || 'category missing'})`).join(', ')}`);
  295. } else {
  296. res = check(rule, 'pass', `all ${F.lines.length} line(s) are ${[...allowed].join('/')}`);
  297. }
  298. } else if (f === 'basket.excluded_categories' && op === 'not_in') {
  299. const banned = new Set(rule.value);
  300. const bad = F.lines.filter(l => l.raw.item_category && banned.has(l.raw.item_category));
  301. exactMatch = exactMatch || false;
  302. if (bad.length) {
  303. res = check(rule, 'fail', bad.map(l => l.raw.item_name).join(', '));
  304. addFail('GIFT_CARD_RISK', `basket contains ${bad.map(l => `“${clip(l.raw.item_name)}”`).join(', ')} — gift cards/vouchers are excluded by your wallet policy (irreversible spend, classic agent-fraud vector). The stated purchase (“${clip(a.purchase_description)}”) does not match the basket.`);
  305. } else res = check(rule, 'pass', 'no excluded categories in basket');
  306. } else if (f === 'merchant.merchant_category' && op === 'in') {
  307. const allowed = new Set(rule.value);
  308. const ok = allowed.has(a.merchant?.merchant_category);
  309. res = check(rule, ok ? 'pass' : 'fail', `${a.merchant?.merchant_name} is “${a.merchant?.merchant_category}”, needs ${rule.value.join('/')}`);
  310. if (!ok) addFail('MERCHANT_TYPE_MISMATCH', `${a.merchant?.merchant_name} is a ${a.merchant?.merchant_category} retailer — your policy requires a specialist ${rule.value.join('/')} retailer`);
  311. } else if (f === 'merchant.familiar_to_customer' && op === '=' && String(rule.value) === 'true') {
  312. const hist = profiles.merchantFamiliar(customerId, a.merchant?.merchant_id);
  313. const inRun = state.inRunApprovedMerchant(a.merchant?.merchant_id);
  314. const trusted = Boolean(trustedMeta);
  315. const familiar = hist.familiar || inRun || trusted;
  316. const basis = trusted && !hist.familiar && !inRun
  317. ? `on your trusted merchant list since ${new Date(trustedMeta.addedAt).toISOString().slice(0, 10)}`
  318. : `${hist.approvedCount || 'run'} approved purchase(s) on record`;
  319. res = check(rule, familiar ? 'pass' : hist.available === false ? 'uncertain' : 'fail', familiar ? `${a.merchant?.merchant_name}: ${basis}` : `${a.merchant?.merchant_name}: no purchases on record for you`);
  320. ev('Merchant familiarity', familiar ? `${a.merchant?.merchant_name} — ${basis}` : `${a.merchant?.merchant_name} — familiarity not established from available records`);
  321. if (!familiar && hist.available === false) addUnc('MERCHANT_HISTORY_UNAVAILABLE', 'No purchase history is available for this customer; merchant familiarity needs confirmation.');
  322. else if (!familiar) addFail('MERCHANT_UNFAMILIAR', `${a.merchant?.merchant_name} (${a.merchant?.merchant_city ?? a.merchant?.merchant_country ?? 'unknown'}) is not a shop you have bought from before`);
  323. } else if (f === 'basket.return_window_days_min') {
  324. const need = rule.value;
  325. const structured = a.order_returnable;
  326. let worst = null;
  327. for (const l of F.lines) {
  328. if (worst === null || (l.ret.days ?? Infinity) < (worst.days ?? Infinity)) worst = l.ret;
  329. }
  330. if (structured === 'false') {
  331. res = check(rule, 'fail', `order marked not returnable, needs ≥ ${need} days`);
  332. addFail('RETURN_WINDOW_INSUFFICIENT', `the order is marked non-returnable — you required a return window of at least ${need} days`);
  333. } else if (worst && worst.days === 0) {
  334. res = check(rule, 'fail', `seller: ${worst.basis}, needs ≥ ${need} days`);
  335. addFail('RETURN_WINDOW_INSUFFICIENT', `seller policy: ${worst.basis} — short of your ${need}-day requirement`);
  336. } else if (worst && worst.days != null && worst.days >= need) {
  337. res = check(rule, 'pass', `${worst.basis}`);
  338. ev('Return window', worst.basis);
  339. } else if (worst && worst.days != null) {
  340. res = check(rule, 'fail', `seller: ${worst.basis}, needs ≥ ${need} days`);
  341. addFail('RETURN_WINDOW_INSUFFICIENT', `seller policy: ${worst.basis} — short of your ${need}-day return requirement`);
  342. ev('Return window', worst.basis);
  343. } else {
  344. res = check(rule, 'uncertain', worst ? worst.basis : 'no return terms found', );
  345. addUnc('RETURN_WINDOW_UNKNOWN', `seller did not state a return window; you required ≥ ${need} days (${worst?.basis || 'no terms found'})`);
  346. ev('Return window', worst?.basis || 'not stated');
  347. }
  348. } else if (f === 'basket.requested_item_match' && String(rule.value) === 'true') {
  349. if (!requestedSpec.present) {
  350. res = check(rule, 'uncertain', 'requested item could not be derived from instruction');
  351. addUnc('REQUESTED_ITEM_UNCLEAR', 'policy requires a specific item but it could not be determined from your instruction');
  352. } else {
  353. let lineIssues = [];
  354. for (const l of F.lines) lineIssues.push(...lineMatchesSpec(l, requestedSpec));
  355. const hard = lineIssues.filter(i => i.level === 'fail');
  356. const soft = lineIssues.filter(i => i.level === 'uncertain');
  357. if (hard.length) {
  358. res = check(rule, 'fail', hard.map(i => i.detail).join('; '));
  359. for (const i of hard) {
  360. addFail(i.code, i.detail);
  361. }
  362. } else if (soft.length) {
  363. res = check(rule, 'uncertain', soft.map(i => i.detail).join('; '));
  364. for (const i of soft) addUnc(i.code, i.detail);
  365. } else {
  366. res = check(rule, 'pass', `matches requested ${requestedSpec.label}`);
  367. ev('Requested item', `matches: ${requestedSpec.label}${requestedSpec.size ? `, size ${requestedSpec.size}` : ''}`);
  368. }
  369. }
  370. } else if (f === 'basket.exact_match' && String(rule.value) === 'true') {
  371. exactMatch = true;
  372. res = check(rule, 'pass', 'add-on prohibition active');
  373. } else if (f === 'authorization.fulfillment_method') {
  374. const ok = a.fulfillment_method === rule.value;
  375. res = check(rule, ok ? 'pass' : (a.fulfillment_method ? 'fail' : 'uncertain'), `fulfilment: ${a.fulfillment_method ?? 'unknown'} vs ${rule.value}`);
  376. if (!ok) addUnc('FULFILMENT_MISMATCH', `order fulfilment is “${a.fulfillment_method ?? 'unknown'}”, policy expects “${rule.value}”`);
  377. } else if (f === 'session.integrity_monitoring' && String(rule.value) === 'true') {
  378. integrityMonitoring = true;
  379. res = check(rule, 'pass', 'session-integrity monitoring on');
  380. } else {
  381. res = check(rule, 'uncertain', `engine has no semantics for field “${f}” — treating as unverified`);
  382. addUnc('RULE_UNVERIFIED', `a permission (“${f} ${op} ${JSON.stringify(rule.value)}”) could not be checked by this engine`);
  383. }
  384. ruleResults.push(res);
  385. if (res.status !== 'uncertain') cv(); // rule resolved over readable facts (uncertain cases count via their uncertainty)
  386. }
  388. // -- 5. Extra lines beyond a single requested item ------------------------------
  389. if (requestedSpec.present && F.lines.length > 1) {
  390. const extras = F.lines.filter(l => lineMatchesSpec(l, requestedSpec).some(i => i.level === 'fail' || i.code === 'SUBSTITUTION' || i.code === 'ITEM_UNCLEAR'));
  391. if (extras.length) {
  392. const names = extras.map(l => `“${clip(l.raw.item_name)}” (${fmtChf(toChf((l.raw.unit_price || 0) * (l.raw.quantity || 1), l.raw.currency))})`);
  393. if (exactMatch) {
  394. addFail('EXTRA_ITEM_BLOCKED', `order includes ${names.join(', ')} — you prohibited adding anything beyond the requested ${requestedSpec.label}`);
  395. } else {
  396. addUnc('EXTRA_ITEM', `order includes ${names.join(', ')} beyond the requested ${requestedSpec.label} — confirm you want them`);
  397. }
  398. }
  399. }
  401. // -- 6. Session-integrity & behavioural signals ---------------------------------
  402. const dev = profiles.deviceKnown(customerId, a.customer_device_id);
  403. if (dev.available === false) {
  404. co();
  405. ev('Device', 'Customer device history unavailable; novelty cannot be established.');
  406. if (integrityMonitoring) addUnc('DEVICE_HISTORY_UNAVAILABLE', 'Device history is unavailable; confirm session integrity.');
  407. } else {
  408. cv();
  409. ev('Device', dev.known ? `${a.customer_device_id} — known from your history` : `${a.customer_device_id} — not present in available device history`);
  410. if (!dev.known) {
  411. const d = { code: 'DEVICE_NOVELTY', detail: `device ${a.customer_device_id} is absent from the available history` };
  412. integrityMonitoring ? flags.integrity.push(d) : addUnc(d.code, d.detail);
  413. }
  414. }
  415. const vel = a.recent_attempt_count_10m ?? 0;
  416. if (a.recent_attempt_count_10m != null) cv(); else co(); // velocity counter present?
  417. ev('Recent attempts (10 min)', String(vel));
  418. if (vel >= 2) {
  419. const d = { code: 'VELOCITY_BURST', detail: `${vel} attempts in the last 10 minutes — burst pattern` };
  420. integrityMonitoring ? flags.integrity.push(d) : addUnc(d.code, d.detail);
  421. } else if (vel === 1 && uncert.some(u => u.code === 'DUPLICATE_SUSPECT')) {
  422. addUnc('SPLIT_ORDER', 'another attempt was made minutes ago at the same merchant for a similar amount — possible order splitting');
  423. }
  424. const hour = profiles.hourUnusual(customerId, F.simTs ?? Date.now());
  425. cv(); // hour-of-day baseline computed from your history
  426. if (hour.unusual) {
  427. const d = { code: 'UNUSUAL_HOUR', detail: `attempted at ${String(hour.hour).padStart(2, '0')}:00 UTC — an hour you have never bought at` };
  428. integrityMonitoring ? flags.integrity.push(d) : addUnc(d.code, d.detail);
  429. }
  431. // -- 6b. Trained user-behavior model (advisory only) ---------------------------
  432. // Trained on this customer's own authorization history (challenge pack,
  433. // see merchant-trust-data/models/behavior/). Like the injection detector it
  434. // can NEVER approve, decline, or loosen: the score is always evidence, and a
  435. // strong anomaly becomes an uncertainty routed by the customer's own
  436. // uncertainty policy (ask → step_up). Inert when no artifact is deployed or
  437. // the customer has no learned profile.
  438. const beh = scoreBehavior(a, customerId);
  439. if (beh) {
  440. const pct = Math.round(beh.score * 100);
  441. const drivers = beh.factors.map(f => f.label).join(', ');
  442. ev('Behavior model', `${beh.band} — ${pct}% off-pattern${drivers ? `: ${drivers}` : ''}`);
  443. if (beh.band === 'escalate') {
  444. addUnc('BEHAVIOR_ANOMALY', `this purchase is strongly off-pattern for you (${pct}% deviation${drivers ? `: ${drivers}` : ''}) — outside anything in your spending history, so it needs your confirmation`);
  445. }
  446. }
  448. // -- 6c. Basket quantity sanity (deterministic, advisory-only) -----------------
  449. // Category-conditional plausibility: 500 disposable gloves is a household
  450. // purchase, 500 pairs of shoes is not (lib/item-classes.js). Caps self-adjust
  451. // upward to the customer's own observed per-category maximum, so buyers who
  452. // genuinely order in bulk are not flagged at their normal volumes. Like the
  453. // behavior model this can only add an uncertainty; a severe excess (>3x cap)
  454. // additionally forces a step-up exactly like detected manipulation — even at
  455. // a whitelisted merchant and even under uncertainty_policy "approve" (only a
  456. // "decline" policy suppresses it). Inert when the attempt has no item lines.
  457. if (F.lines.length) {
  458. const profile = getBehaviorModel()?.profiles?.[customerId] || {};
  459. const qtyMax = profile.qty_max_by_category || {};
  460. const qtyHist = profile.qty_hist_by_category || {};
  461. let worst = null;
  462. for (const l of F.lines) {
  463. const qty = Math.max(1, Number(l.raw.quantity) || 1);
  464. const cat = l.raw.item_category ?? l.raw.category ?? null;
  465. // Statistical cap when this customer's own per-category quantity sample
  466. // supports a fit (GEV/GPD/MAD — lib/evstats.js); heuristic otherwise.
  467. const st = qtyHist[cat] ? statCap(cat, qtyHist[cat], qtyMax) : null;
  468. const { cap, adaptive } = st ?? qtyCap(cat, qtyMax);
  469. if (qty > cap && (!worst || qty / cap > worst.qty / worst.cap)) {
  470. worst = { name: l.raw.item_name || cat || 'an item', cat, qty, cap, adaptive, method: st?.method };
  471. }
  472. }
  473. if (worst) {
  474. const severe = worst.qty > worst.cap * 3;
  475. const limitTxt = worst.adaptive
  476. ? (worst.method?.length
  477. ? `${worst.cap} — statistical fit from your own history (${worst.method.join('+')}, ${worst.n} samples)`
  478. : `${worst.cap} — you have bought up to ${Math.round(worst.cap / 3)} of these before`)
  479. : `${worst.cap} (plausible maximum for ${worst.cat || 'this category'})`;
  480. addUnc('ITEM_QTY_ANOMALY', `basket line “${worst.name}” × ${worst.qty} exceeds a plausible quantity — limit ${limitTxt}; confirm this is intentional`);
  481. ev('Basket quantity', `✗ ${worst.name} × ${worst.qty} (cap ${worst.cap}${worst.cat ? `, ${worst.cat}` : ''})${severe ? ' — severe' : ''}`);
  482. if (severe) flags.behavior.push({ code: 'ITEM_QTY_ANOMALY', detail: `“${worst.name}” × ${worst.qty} far exceeds any plausible quantity for ${worst.cat || 'this category'}` });
  483. }
  484. }
  486. // -- 7. Lookalike merchant --------------------------------------------------------
  487. const histFam = profiles.merchantFamiliar(customerId, a.merchant?.merchant_id);
  488. if (!histFam.familiar) {
  489. const look = lookalikeMatch(a.merchant || {}, profiles.knownMerchants(customerId));
  490. if (look) {
  491. const d = { code: 'LOOKALIKE_MERCHANT', detail: `“${a.merchant.merchant_name}” closely resembles “${look.against.name}” (${Math.round(look.score * 100)}% name match), a shop you actually use — possible impersonation/typo-squat` };
  492. flags.integrity.push(d);
  493. // sharpen the unfamiliar-merchant decline with the impersonation evidence
  494. const unfam = fails.find(f => f.code === 'MERCHANT_UNFAMILIAR');
  495. if (unfam) unfam.detail += ` — and its name closely resembles “${look.against.name}”, a shop you actually use (${Math.round(look.score * 100)}% match): possible impersonation`;
  496. else addUnc(d.code, d.detail);
  497. }
  498. }
  500. // -- 8. LEASH merchant-trust dataset (optional, degrades silently) -----------------
  501. const tl = trustLookup(a.merchant || {}, trust);
  502. if (tl) cv(); // merchant screened against the trust dataset
  503. if (tl?.malicious) {
  504. addFail('TRUSTLIST_HIT', `merchant matches known-malicious infrastructure: ${tl.evidence}`);
  505. } else if (tl?.legitimate) {
  506. flags.positive.push({ code: 'REGISTRY_MATCH', detail: tl.evidence });
  507. ev('Merchant trust', 'name found in Swiss company registry dataset (LEASH/GLEIF)');
  508. }
  510. // -- 8a. Sanctions screening (deterministic list hit, same class as TRUSTLIST_HIT) --
  511. // Exact normalized-name match against SECO/OFAC/UN entries (no fuzzy matching —
  512. // a decline must not fire on a guess). Inert when the sanctions dataset is absent.
  513. if (trust?.sanctionsIndex) cv(); // sanctions screen ran over readable data
  514. const san = sanctionsLookup(a.merchant?.merchant_name, trust);
  515. if (san) {
  516. addFail('SANCTIONS_MATCH', `merchant name “${a.merchant?.merchant_name}” matches sanctioned party “${san.name}” on the ${san.source.toUpperCase()} list — payments to listed parties cannot be authorized`);
  517. }
  519. // -- 8a'. Known-malicious infrastructure IPs (FeodoTracker + AbuseIPDB ≥80) --------
  520. const mIp = a.merchant?.merchant_ip || a.merchant?.ip || null;
  521. if (trust?.malicious_ips && mIp) {
  522. cv(); // merchant IP screened against the threat-intel IP set
  523. if (trust.malicious_ips[mIp]) {
  524. addFail('TRUSTLIST_HIT', `merchant IP ${mIp} is known-malicious infrastructure (${trust.malicious_ips[mIp]} in the LEASH threat-intel dataset)`);
  525. }
  526. }
  528. // -- 8b'. Web popularity (Tranco ∪ Majestic top-1M) — evidence only -----------------
  529. // A top-ranked domain is positive context, nothing more: popularity is easy to
  530. // fake with lookalike domains and its absence is normal for small honest shops.
  531. // It never suppresses an uncertainty and never changes a decision.
  532. const pop = merchantDomain ? popularityLookup(merchantDomain, trust) : null;
  533. if (trust?.popularityIndex && merchantDomain) cv(); // popularity screen ran over a readable domain
  534. if (pop) {
  535. ev('Merchant popularity', `#${pop.rank} most-visited site globally (${pop.source} top-1M)`);
  536. if (pop.rank <= 50000) {
  537. flags.positive.push({ code: 'POPULAR_DOMAIN', detail: `${merchantDomain} ranks #${pop.rank} in the global top-1M (${pop.source})` });
  538. }
  539. }
  541. // -- 8b''. MCC fraud prior (TabFormer 24.4M transactions) — escalation-only --------
  542. // Fires ONLY for merchants that are neither familiar nor customer-trusted: a
  543. // *new* shop in a historically fraud-heavy category is the risky combination.
  544. // Pure escalation pressure — it can ask, never approve/decline on its own.
  545. const mccHit = mccRiskLookup(a.merchant?.merchant_mcc, trust);
  546. if (trust?.mccRisk && a.merchant?.merchant_mcc != null && a.merchant?.merchant_mcc !== '') cv(); // category risk screen ran
  547. if (mccHit && !histFam.familiar && !trustedMeta) {
  548. const ratio = mccHit.median ? (mccHit.rate / mccHit.median).toFixed(1) : '?';
  549. addUnc('MCC_FRAUD_PATTERN', `merchant category ${mccHit.mcc} (first purchase at this shop) shows ~${ratio}× the typical fraud rate across ${mccHit.n} historical card transactions (TabFormer corpus) — extra check before first payment in an elevated-risk category`);
  550. }
  552. // -- 8b. Trusted Shops verification (advisory evidence, pre-fetched by the worker) ---
  553. // Presence of the merchant's website on Trusted Shops is positive evidence only;
  554. // absence is neutral — many legitimate shops (digitec, brack) are not members.
  555. // A failed/timed-out check degrades silently. Nothing here can fail, add an
  556. // uncertainty, or change the outcome on its own.
  557. const tsResult = extras?.trustedShops || null;
  558. if (tsResult) cv(); // third-party consumer-protection check ran
  559. const fakeFlagged = Boolean(tsResult?.fake_shop?.flagged);
  560. if (tsResult && !fakeFlagged && (tsResult.listed === true || tsResult.listed === false)) {
  561. ev('Trusted Shops', describeResult(tsResult));
  562. if (tsResult.listed === true) {
  563. flags.positive.push({ code: 'TRUSTEDSHOPS_LISTED', detail: `merchant website is listed on Trusted Shops: ${describeResult(tsResult)}` });
  564. }
  565. }
  566. // A public fake-shop warning is the opposite of listing evidence: authoritative
  567. // third-party knowledge that the shop is a scam (same class as TRUSTLIST_HIT).
  568. // It is a hard fail — the wallet must not send the customer's money to a shop
  569. // that a consumer-protection body has flagged.
  570. const fsWarn = tsResult?.fake_shop;
  571. if (fsWarn?.flagged) {
  572. const m = fsWarn.matches[0] || {};
  573. addFail('TRUSTEDSHOPS_FAKE_SHOP', `the merchant's website is flagged as a fake shop on ${m.site || 'Trusted Shops'}${m.type ? ` — warning type "${m.type}"` : ''}${m.date ? `, warning dated ${m.date}` : ''}`);
  574. ev('Fake-shop check', describeResult(tsResult));
  575. }
  577. // -- 8c. Yellow-list review: domain on neither the trusted list nor a known-bad list
  578. // For an unfamiliar merchant with a website, absence from the trusted list AND
  579. // from every known-bad source (threat intel, fake-shop warnings) is NOT
  580. // permission — it is uncertainty. The customer decides, with the merchant
  581. // dossier (Zefix registry, imprint comparison, socials, payment methods,
  582. // country, reviews) rendered on the step-up card by the UI.
  583. const blacklistedMerchant = fails.some(f => f.code === 'TRUSTLIST_HIT' || f.code === 'TRUSTEDSHOPS_FAKE_SHOP' || f.code === 'SANCTIONS_MATCH');
  584. if (merchantDomain && trustedMeta) {
  585. cv(); // verdict from your own trusted-merchant list
  586. ev('Merchant trust status', `${merchantDomain} — on your trusted list since ${new Date(trustedMeta.addedAt).toISOString().slice(0, 10)}`);
  587. flags.positive.push({ code: 'MERCHANT_TRUSTED', detail: `${merchantDomain} is on your trusted merchant list (added ${new Date(trustedMeta.addedAt).toISOString().slice(0, 10)})` });
  588. } else if (merchantDomain && !histFam.familiar && !blacklistedMerchant) {
  589. addUnc('MERCHANT_UNREVIEWED', `the shop's domain ${merchantDomain} is on neither your trusted list nor any known-bad list, and prior purchases there have not been established — a merchant dossier is prepared for your review`);
  590. ev('Merchant trust status', `${merchantDomain} — unreviewed (yellow)`);
  591. }
  593. // -- 9. Description-vs-basket contradiction -----------------------------------------
  594. const desc = a.purchase_description || '';
  595. const basketText = F.lines.map(l => `${l.raw.item_name} ${l.raw.item_category}`).join(' ').toLowerCase();
  596. for (const [re, fam] of DESCRIPTION_FAMILY_TOKENS) {
  597. if (re.test(desc) && !basketText.includes(fam === 'outerwear' ? 'jacket' : fam) && !(fam === 'shoes' && /shoe/.test(basketText)) && !(fam === 'monitor' && /monitor/.test(basketText))) {
  598. if (fam === 'groceries' && /grocer/.test(basketText)) continue;
  599. if (fam === 'clothing' && /clothing|jacket|coat|shirt|dress/.test(basketText)) continue;
  600. addUnc('DESCRIPTION_CONTRADICTION', `the stated purchase (“${clip(desc)}”) does not match what is actually in the basket`);
  601. break;
  602. }
  603. }
  604. cv(); // description-vs-basket consistency scan completed
  606. // Jev adds typed semantic evidence; it never clears a failed rule or grants permission.
  607. if (extras.jev) {
  608. if (extras.jev.status === 'ok') {
  609. for (const [name, answer] of Object.entries(extras.jev.answers || {})) {
  610. ev(`Jev ${name}`, `${answer.choice}; confidence ${Math.round(answer.confidence * 100)}%; model ${extras.jev.model}`);
  611. if (jevNeedsReview(answer)) addUnc('JEV_REVIEW', `Jev flagged ${name} for customer review; this is advisory model evidence.`);
  612. }
  613. } else ev('Jev', `${extras.jev.status}; deterministic rules remain active`);
  614. }
  616. // -- 10. Aggregate -------------------------------------------------------------------
  617. fails.sort((x, y) => codeRank(x.code) - codeRank(y.code));
  618. const policy = mandate.uncertainty_policy || 'ask';
  619. let decision;
  620. const manipulationPresent = flags.manipulation.length > 0;
  621. const integrityBreach = integrityMonitoring && flags.integrity.length > 0;
  623. if (fails.length) decision = 'decline';
  624. else if (manipulationPresent || integrityBreach || flags.behavior.length || uncert.some(u => u.code === 'POLICY_UNRESOLVED' || u.code === 'JEV_REVIEW')) decision = policy === 'decline' ? 'decline' : 'step_up';
  625. else if (uncert.length) decision = policy === 'ask' ? 'step_up' : policy;
  626. else decision = 'approve';
  628. // -- 10b. Confidence: share of decision-relevant facts verified by deterministic
  629. // checks. Every uncertainty surfaced to the customer is an open point, as is any
  630. // fact the engine could not verify. Capped at 99% — never claim certainty.
  631. const openPoints = uncert.length + conf.open;
  632. const factTotal = conf.verified + openPoints;
  633. const confidence = {
  634. percent: factTotal > 0 ? Math.min(99, Math.round((100 * conf.verified) / factTotal)) : 0,
  635. verified_facts: conf.verified,
  636. open_points: openPoints,
  637. method: 'share of decision-relevant facts verified by deterministic checks',
  638. };
  639. const confStr = `${confidence.percent}% confidence (${conf.verified}/${factTotal} decision facts verified, ${openPoints} open)`;
  640. const basisStr = evidence.slice(0, 5).map(e => e.label).join(' · ');
  642. // -- 11. Compose message ---------------------------------------------------------------
  643. // Every user-facing message states its confidence percentage and cites the
  644. // evidence it rests on — approvals, declines, and step-ups alike.
  645. const merchantName = a.merchant?.merchant_name || 'unknown merchant';
  646. const amountStr = F.billing != null ? fmtChf(F.billing) : 'an unreadable amount';
  647. let message;
  648. if (decision === 'decline') {
  649. const reasons = fails.map(f => sentence(f.detail)).join(' ');
  650. message = `Declined ${amountStr} at ${merchantName} — ${confStr}. ${reasons} Verified basis: ${basisStr}.`;
  651. if (manipulationPresent) message += ` Note: ${merchantName}'s product text also attempted to manipulate the wallet (“${clip(flags.manipulation[0].snippet)}”) — it was ignored and did not influence this decision.`;
  652. } else if (decision === 'step_up') {
  653. const lead = manipulationPresent
  654. ? `⚠️ Manipulation attempt detected in ${merchantName}'s product text — the purchase is paused for your review; the embedded instructions were NOT followed.`
  655. : integrityBreach
  656. ? `Paused for you: this purchase shows session signals that don't look like you (${flags.integrity.map(i => i.detail).join('; ')}).`
  657. : flags.behavior.length
  658. ? `Paused for you: this order contains an implausible basket quantity (${flags.behavior.map(b => b.detail).join('; ')}) — confirm it is really yours.`
  659. : uncert.some(u => u.code === 'MERCHANT_UNREVIEWED')
  660. ? `Paused for your review — ${merchantName}, ${amountStr}. This shop is on neither your trusted list nor a known-bad list; its merchant dossier (registry, imprint, reviews) is shown below so you can decide whether to trust it.`
  661. : `Paused for your review — ${merchantName}, ${amountStr}.`;
  662. const lead2 = /[.!?…]/.test(lead.trim().slice(-1)) ? lead.trim().replace(/[.!?…]+$/, '') : lead.trim();
  663. message = `${lead2} — ${confStr}. ${uncert.length ? 'Open points: ' + uncert.map(u => sentence(u.detail)).join(' ') : ''} Verified basis: ${basisStr}.`.trim();
  664. } else {
  665. const notes = [...flags.integrity.map(i => i.detail)];
  666. message = `Approved ${amountStr} at ${merchantName} — within your policy, ${confStr}. Verified basis: ${basisStr}.${notes.length ? ` Notes: ${notes.join('; ')}.` : ''}`;
  667. }
  669. const reasonCodes = [
  670. ...fails.map(f => f.code),
  671. ...(manipulationPresent ? ['INJECTION_ATTEMPT'] : []),
  672. ...(integrityBreach ? flags.integrity.map(i => i.code) : []),
  673. ...uncert.map(u => u.code),
  674. ];
  675. const uniqueCodes = [...new Set(reasonCodes)];
  677. const ms = Number(process.hrtime.bigint() - t0) / 1e6;
  678. return {
  679. decision,
  680. reason_codes: uniqueCodes,
  681. customer_message: message,
  682. confidence,
  683. evidence,
  684. uncertainties: uncert.map(u => ({ code: u.code, detail: u.detail })),
  685. rule_results: ruleResults,
  686. flags,
  687. signature,
  688. evaluation_ms: Math.round(ms * 100) / 100,
  689. engine_version: 'leash-engine 1.3.0',
  690. };
  691. }
  693. function cmp(actual, op, value) {
  694. switch (op) {
  695. case '<': return actual < value;
  696. case '<=': return actual <= value;
  697. case '>': return actual > value;
  698. case '>=': return actual >= value;
  699. case '=': return String(actual) === String(value);
  700. case '!=': return String(actual) !== String(value);
  701. case 'in': return Array.isArray(value) && value.map(String).includes(String(actual));
  702. case 'not_in': return Array.isArray(value) && !value.map(String).includes(String(actual));
  703. default: return false;
  704. }
  705. }
  707. /** Ensure a reason detail reads as a standalone sentence (capitalized, period-terminated). */
  708. function sentence(s) {
  709. s = String(s || '').trim();
  710. if (!s) return s;
  711. s = s.charAt(0).toUpperCase() + s.slice(1);
  712. if (!/[.!?…]$/.test(s)) s += '.';
  713. return s;
  714. }