Find customers by name or email (exact, partial, or fuzzy/misspelled). Returns contact details, order count and lifetime spend for each match. If ambiguous is true, several customers fit equally well: ask the user which one they mean (e.g. by email or city) before acting.

Full detail for one order: status (and which statuses it may move to next), customer, line items, totals in cents, refunds already issued, refundable remainder, invoice, and delivery timing (promised vs actual date, days late). Call this before any write on an order.

Search orders with filters (status, customer, placed date range, total range, late-only) and pagination. Each row includes total, amount refunded, and delivery timing (promised vs delivered date, days late).

Sales for a date range (by order placed date), grouped by day, ISO week, month, product, or customer. Reports gross, refunds and net (gross minus refunds issued against those orders), all in cents. Pending and cancelled orders are excluded because no money was captured.

Products whose stock is strictly below their reorder threshold, most urgent first, each with a suggested reorder quantity (refill to target stock, rounded up to the supplier case pack).

Move an order through its lifecycle: pending->paid|cancelled, paid->shipped, shipped->delivered. Any other transition is rejected (CONFLICT) with the allowed next statuses. 'refunded' is never set directly (use issue_refund). Setting the current status again is a no-op. Changes are audit-logged.

Refund money on a paid order. Guardrails: amount must be > 0 and within the remaining refundable amount; unpaid, cancelled and fully-refunded orders are refused; a reason and an idempotency_key are required, and repeating a key replays the original refund instead of paying twice. When refunds reach the order total the order becomes 'refunded'. Every refund is written to the audit log.

Issue the invoice for an order (amount = order total). Each order can have only one invoice: a second request is refused with the existing invoice number (CONFLICT). Cancelled and refunded orders cannot be invoiced.