Version Compatibility

Full Version Compatibility

• All versions of WHMCS v9.0
• All versions of WHMCS v8.12
• Selected versions of WHMCS v8.10
      8.10.0
• Selected versions of WHMCS v8.8
      8.8.0
• All versions of WHMCS v8.6

System Requirements

• PHP 7.2+
• Snelstart Account

Support for this product

The best place to start if you need help with a specific product is to contact the developer. All WHMCS Marketplace developers have both a website and support URL listed.

Developed By CodeFromNowhere

Changelog

v1.0.2 Released June 16th, 2026

Latest Version

Changelog

All notable feature changes for the WHMCS SnelStart Sync addon are documented here.

1.0.0 - 2026-06-16

Added

• Introduced the SnelStart Sync addon identity with WHMCS metadata, product links, and a single encrypted CodeFromNowhere license key setting.
• Added a queue-based invoice synchronization flow. WHMCS invoice hooks now enqueue work for invoice creation, total updates, paid, unpaid, refunded, and cancelled events.
• Added bounded cron processing through AfterCronJob, including invoice queue processing and SnelStart payment reconciliation in the regular WHMCS cron lifecycle.
• Added idempotent invoice export through the CodeFromNowhere proxy v1 API, including stable external IDs, invoice numbers, dates, currency, tax-exclusive lines, tax totals, credits, balances, and WHMCS status.
• Added client relation upsert support before invoice export so WHMCS clients are created or updated in SnelStart before their invoices are synchronized.
• Added invoice status synchronization through /v1/invoices/{whmcsInvoiceId}/status for paid, unpaid, cancelled, and refunded events.
• Added SnelStart payment and refund reconciliation through the v1 cursor endpoint. Imported events are recorded as WHMCS transactions with transaction IDs, dates, amounts, fees, exchange rates, and payment/refund direction.
• Added durable sync tables for invoice mappings, queue jobs, payment events, and module state.
• Added persistent state tracking for schema version, last successful run, payment cursor, and historical backfill offset.
• Added retry handling with exponential backoff for retryable proxy failures, capped at eight attempts.
• Added stale worker lock recovery for queue jobs that remain locked for more than fifteen minutes.
• Added duplicate prevention for pending invoice events and processed SnelStart payment transaction IDs.
• Added payload hashing so unchanged invoices that are already synced are skipped.
• Added correlation IDs and idempotency keys to proxy requests for supportability and safe replay.
• Added operational logs with correlation IDs, context type, and optional context ID.
• Added a WHMCS admin dashboard with connection health, masked license display, queue statistics, failed job visibility, operational logs, and last successful processing details.
• Added secure SnelStart coupling support from the admin dashboard, including validated https://web.snelstart.nl activation links.
• Added manual admin actions for testing the connection, resynchronizing a single invoice, retrying failed jobs, previewing historical invoice backfill, enqueueing historical invoice batches, and saving the default ledger category.
• Added server-side ledger category loading and saving through v1 settings endpoints.
• Added paginated and status-filterable log retrieval for dashboard display.
• Added compatibility fallbacks for currently deployed legacy proxy endpoints: relation lookup/create, invoice export, invoice categories, invoice category, and the existing coupling check.
• Added preservation of existing sync, accounting, client mapping, and log history on addon deactivation.
• Added migration of legacy client mappings from mod_snelstartmoduleclients into the new client mapping table.
• Added proxy API v1 documentation covering request headers, response envelopes, relation upsert, invoice upsert, invoice status updates, payment cursor events, connection status, settings, and legacy rollout behavior.
• Added Composer development tooling with PHPUnit and PHPStan scripts.
• Added PHPUnit coverage for stable invoice payload generation, payload hashes, credits, negative lines, and required invoice field validation.

Changed

• Reworked the addon from direct synchronous invoice export into an asynchronous, replay-safe synchronization system.
• Moved invoice synchronization responsibility into InvoiceController, with hooks limited to queueing events.
• Replaced browser-facing API behavior with server-to-server proxy requests using the stored WHMCS addon license key.
• Normalized proxy request handling around JSON envelopes, retryable errors, malformed responses, network timeouts, and legacy plain-text success responses.
• Normalized invoice payload amounts to six-decimal strings for stable hashing and predictable proxy validation.
• Updated client synchronization to prefer v1 relation upserts while retaining legacy lookup/create behavior when v1 is unavailable.
• Updated invoice synchronization to prefer v1 invoice upserts while retaining legacy /invoice export behavior when v1 is unavailable.
• Updated payment handling so SnelStart is treated as authoritative for payment and refund events while WHMCS remains authoritative for invoice content and lifecycle events.
• Updated database setup so activation and upgrade create or migrate all required tables without dropping operational history.
• Updated admin templates for the connected, not connected, loading, and no-access states with clearer operational feedback and safer license handling.
• Updated WHMCS marketplace metadata to describe reliable invoice export, queued retries, payment reconciliation, and secure administration.

Security and Reliability

• Added CSRF validation to all admin POST actions.
• Added license key normalization and validation before proxy requests.
• Kept the license key out of browser-rendered templates by displaying only a masked value.
• Added public-safe admin error messages while writing detailed errors to module logs.
• Added validation for payment event shape, transaction ID, invoice ID, type, amount, currency, and date before creating WHMCS transactions.
• Added retryable-error detection for proxy envelopes, HTTP 408, HTTP 429, and HTTP 5xx responses.
• Added fixed request connect and total timeouts for proxy calls.
• Added safe handling for duplicate WHMCS transaction IDs so replayed payment events are marked processed instead of failing repeatedly.

Documentation

• Rewrote the README around the supported accounting model, requirements, installation, upgrade behavior, operations, retry policy, and development commands.
• Added docs/proxy-api-v1.md as the implementation contract for the CodeFromNowhere proxy.