Mountaineering Labs Multi-Store Stock Sync for WooCommerce

Run several WooCommerce stores that sell the same products — for example a domestic and an international site — and keep stock quantities in sync automatically.

How it works

• One site is configured as the hub, the authoritative source of stock levels. The other sites are spokes.
• When stock changes anywhere (a sale, a refund/restock, or a manual edit in wp-admin), the change is picked up via WooCommerce’s stock hooks and sent to the hub.
• The hub updates its own stock atomically (safe under concurrent sales on different sites) and broadcasts the resulting authoritative value to all spokes.
• Products and variations are matched across sites by SKU. Works with both simple and variable products.

Reliable by design

• Outbound messages are written to a local queue (a fast database insert) — customer-facing requests never wait on network calls to other sites.
• A background worker delivers queued messages within seconds and retries with backoff if a peer site is temporarily unreachable. Temporary outages cause delay, not data loss.
• Every message carries a unique id; receivers ignore duplicates, so retries can never double-apply a stock change.

Secure

• Sites communicate over a dedicated REST endpoint authenticated with an HMAC-SHA256 signature over a shared secret — no WooCommerce API keys needed.
• Stale requests are rejected and duplicate message ids are ignored (replay protection).

Languages

English admin UI, with bundled translations for Norwegian (Bokmål and Nynorsk), Danish, Swedish, German, French and Spanish. Further translations can be contributed through translate.wordpress.org.