basil & EU VAT Diagnostic ToolsRun deterministic, stateless compliance and billing diagnostics directly in your browser or via JSON REST & Model Context Protocol (MCP) endpoints — zero login, zero database persistence, and zero card data required. Updated .
2025-03-31.basil Entitlement & Ghost-Usage AuditorTests multi-subscription accounts where current_period_end moved from the subscription root into items.data[i].current_period_end, catching silent unpaid API/AI token bleed and preventing false lockouts during active dunning grace windows.
Evaluates whether a disputed Stripe charge satisfies Visa CE 3.0 (2+ undisputed prior charges 120d–365d old with IP/Device correlation) and previews an 18,000-char submit: false evidence draft that preserves existing merchant notes.
XI) VIES VAT Batch ValidatorNormalizes Greek GR → EL and Northern Ireland XI VAT numbers, checks 28 member-state regex rules, and detects European Commission VIES HTTP 200 OK soft-failure outage wrappers (MS_UNAVAILABLE).
Simulates 5 wholesale payment-terms presets (deposit_shortfall_hold, deposit_cleared_net30_active, credit_note_overpayment, past_due_delinquent_invoice, cancelled_order_partial_refund) using integer EUR-cent math.
Generates and verifies canonical Stripe-Signature (t=,v1=), X-Shopify-Hmac-Sha256 (Base64), and X-RevClamp-Signature headers over raw UTF-8 bytes with 300s replay checks.
Computes exact monthly and annual B2B margin savings when replacing a 25%–30% contingency dispute agency with flat-rate 0% commission tiers ($19, $59, $199) and recommends the optimal plan for your event volume.
Simulates out-of-order Stripe and Lemon Squeezy webhook arrivals, 72-hour event_id idempotency deduplication, and monotonic createdSec watermarks so delayed updates never resurrect canceled subscriptions.
Audits evidence[access_activity_log] against the 18,000 UTF-16 code-unit ceiling, verifies non-destructive delimiter markers around existing merchant notes, and checks Visa CE 3.0 prior-charge correlation.
Every free diagnostic tool in the browser uses the exact same deterministic verification engine exposed over REST and our Model Context Protocol (MCP) server.
| Tool | Input Payload | Failure Caught | REST & MCP Endpoint |
|---|---|---|---|
Stripe basil Auditor |
customerId, subscriptions, dunningGracePeriodDays |
Missing top-level current_period_end & multi-subscription false lockouts |
POST /api/tools/stripe-basil-auditrevclamp_evaluate_ghost_usage |
| Visa CE 3.0 Checker | disputeId, disputeReason, priorTransactions |
Sub-120d prior charges, missing IP/Device match & destructive evidence overwrites | POST /api/tools/stripe-ce3-checkrevclamp_stage_stripe_dispute_ce3 |
| EU VIES Batch Validator | sellerCountry, vatNumbers (up to 20), mode |
Raw GR prefix rejection & VIES HTTP 200 MS_UNAVAILABLE outages |
POST /api/tools/vies-vat-checkrevclamp_validate_eu_vat_vies |
| B2B Net-Terms Calculator | totalOrderCents, paidAmountCents, creditNoteCents, termsType |
IEEE-754 float deposit drift, partial-payment hold release & credit-note overbilling | POST /api/tools/b2b-net-terms-reconcilerevclamp_reconcile_b2b_net_terms |
| Webhook Signature Tester | provider, secret, rawPayload, timestampSec, signatureHeader |
JSON re-serialization HMAC mismatch, Base64 vs Hex drift & 300s replay skew | POST /api/tools/webhook-signature-verifyrevclamp_verify_webhook_signature |
| 0% Take-Rate ROI Calculator | monthlyWonDisputeUsd, monthlyGhostBleedUsd, contingencyTakeRatePercent, monthlyUsageEvents |
25%–30% contingency chargeback commission erosion & tier quota mis-sizing | POST /api/tools/chargeback-roi-calculaterevclamp_calculate_roi_and_plan_fit |
| Webhook Replay & Out-of-Order Simulator | scenarioPreset, events (1–10), nowSec, idempotencyWindowSec |
Resurrected canceled subscriptions from delayed out-of-order webhooks & 72h duplicate retries | POST /api/tools/webhook-replay-simulaterevclamp_simulate_webhook_replay |
| Dispute Evidence UTF-16 & CE 3.0 Linter | existingMerchantNotes, evidenceLogText, priorMatchedCount, hasIpMatch, hasDeviceMatch |
18,000 UTF-16 code-unit truncation, wiped merchant notes & incomplete CE 3.0 correlation | POST /api/tools/dispute-evidence-lintrevclamp_lint_dispute_evidence |