Walmart Product Reviews Fetcher

Use this endpoint when you need to retrieve structured customer reviews for a specific Walmart product by its product ID, especially when you need filtering by rating or sorting by recency/relevancy. Prefer this over general search endpoints when you already have the product ID and want review-specific data.

• Invalid or nonexistent product_id returns empty results or 404
• product_id is required — omitting it causes a validation error
• limit out of range (must be 1-50) causes a schema validation error
• page below 1 causes a validation error
• Invalid sort enum value causes a bad request error
• Domain must be 'us' or 'ca' — other values fail validation
• Payment failure (x402) if USDC balance is insufficient