Production failure post-mortems and architectural playbooks on Stripe 2025-03-31.basil period normalization, Visa Compelling Evidence 3.0 routing, and European Commission VIES HTTP 200 OK soft-failure circuit breakers.
basil API broke my grace-period logic, and CE 3.0 turned out to be a routing problemWhy top-level current_period_end silently evaluates to false in 2025-03-31.basil, how multi-subscription customers trigger false lockouts, and why Visa 10.4 disputes require 2-tier routing with submit: false.
HTTP 200 when it's down, and I charged the wrong VAT because of itHow the European Commission VIES REST endpoint returns HTTP 200 OK with actionSucceed: false and MS_MAX_CONCURRENT_REQ during national database outages, plus prefix normalization across 27 EU member states + Northern Ireland (XI).
| Diagnostic Utility | Protocol / Standard | Primary Guardrail | Direct Endpoint |
|---|---|---|---|
Stripe basil Entitlement Auditor |
Stripe API 2025-03-31.basil |
Item-level current_period_end aggregation & multi-subscription reconciliation |
/tools/stripe-basil-auditor |
| Visa CE 3.0 Readiness Checker | Visa 10.4 Compelling Evidence 3.0 | 120d–365d prior charge & IP/Device overlap + submit: false draft preview |
/tools/stripe-ce3-checker |
| EU & XI VIES Batch Validator | EC VIES REST API (28 VAT Prefixes) | Greece GR → EL normalization & HTTP 200 outage wrapper detection |
/tools/vies-vat-validator |
| Next.js 12-Line Edge Guard | HMAC-SHA256 Signed Webhooks | Blocks unpaid API/LLM token bleed on 2025-03-31.basil subscriptions |
/docs/stripe-setup |
| Model Context Protocol (MCP) Server | JSON-RPC 2.0 Streamable HTTP | 5 B2B revenue & VAT tools (stateless sandbox or workspace key) | POST /api/mcp (spec) |
| Merchant Revenue Console | Self-Serve Workspace & CSV Vault | 5,000 events/mo free forever; flat monthly tiers with 0% dispute take-rate | /dashboard |