n8n Shopping Assistant Workflow: GPT-4.1 Mini + Product APIs + Slack

Turn product questions into approved orders—automatically

This n8n Shopping Assistant Workflow lets customers chat with an OpenAI (GPT-4.1-mini)-powered assistant that searches your HTTP product-catalog API for real-time prices and availability, collects explicit user approval, then submits checkout requests and posts the final order status to Slack.

What this workflow does

• Starts from chat via an n8n Chat Trigger (or you can run a manual test), when a user submits a shopping request.
• Finds the right products with live data by using GPT-4.1-mini with function calling to query a product-catalog search API for up-to-date price and availability.
• Returns a structured shopping response: the workflow parses the agent’s JSON into (1) a reply message, (2) an optional shortlist (up to three items), and (3) a purchase-intent signal with selected product and quantity.
• Requests explicit confirmation:
  • If there’s no purchase intent, it immediately returns the assistant’s reply.
  • If there is purchase intent, it pauses for user confirmation using a resume webhook, then pauses again for explicit purchase approval.
• Places the order with approval by submitting to the store via a checkout/order API using the selected item, quantity, customer, payment method, and shipping details.
• Posts order status to Slack after receiving an asynchronous order-confirmation callback (via a third resume webhook).

Use cases

• SaaS storefronts that want a chat-based shopping assistant with safe, approval-gated ordering.
• Operations teams who need Slack alerts for final order status and reconciliation.
• n8n engineers connecting existing product catalog and checkout APIs without building a full frontend.

Technical details

• Integrations/credentials: OpenAI, Slack, and HTTP Header Auth for both the product-catalog search and checkout/order APIs.
• Core nodes used: if, set, code, wait, slack, sticky note.
• Control flow: uses resume webhooks to pause for (1) product confirmation and (2) purchase approval, then handles an async order callback.

Configure the catalog and order base URLs, currency, customer ID, and default shipping/payment parameters to match your store.