n8n Workflow: Reroute Delayed Shipments with OpenAI + Sheets + Slack

Automatically reroute delayed shipments—using OpenAI, Google Sheets, Slack approvals, and carrier TMS updates

This n8n workflow detects delayed shipments from Google Sheets, summarizes delays in Telegram, uses OpenAI (gpt-4o-mini) to recommend alternate routes via a routing HTTP API, and—when needed—requests approval in Slack before updating your carrier TMS. Outcomes are logged back to Google Sheets and communicated via Gmail and Slack.

What this workflow does

• Runs every 30 minutes using a schedule trigger.
• Reads active shipments from Google Sheets and identifies delayed ones by comparing Promised Delivery vs Current ETA (or a “delayed” status), then calculates delay hours.
• Alerts via Telegram when at least one delayed shipment is found, including a delay summary.
• Generates reroute recommendations for each delayed shipment by calling a routing HTTP API to fetch route options, then sending shipment + options to OpenAI (gpt-4o-mini) for a structured reroute recommendation.
• Requests human approval in Slack when the AI flags the decision as requiring approval, and waits for an approve/reject response.
• Updates carrier routing via HTTP (carrier TMS HTTP API) for approved reroutes, updates the shipment record in Google Sheets, emails the customer via Gmail, and posts confirmation to Slack.
• Escalates rejected recommendations by marking the shipment as “escalated for manual review” in Google Sheets and notifying the ops Slack channel.

Use cases

• Ops teams need faster action when ETAs slip across regions or carriers.
• SaaS operators want automated reroute suggestions with Slack approvals to reduce risky fully-automated changes.
• Logistics teams centralize shipment truth in Google Sheets and route changes through a carrier TMS.

Technical details

• Integrations/auth: Google Sheets OAuth2, OpenAI, Telegram Bot API, Slack OAuth2, Gmail OAuth2.
• Core n8n nodes/workflow logic: Schedule trigger, if, set, code, gmail, slack, and split out.
• Decisioning: structured output from gpt-4o-mini, including approve/reject handling.
• Routing updates: HTTP calls to the routing API and carrier TMS HTTP API, with results written back to Google Sheets and posted to Slack.

Get this n8n workflow to operationalize delayed shipment rerouting with AI-assisted routing, Slack approvals, and end-to-end notifications.