The problem

When a business processes many records automatically, small failures cause big problems: bad data gets through, the same record is processed twice, and one failed API call can stop the whole run with no record of what happened.

What I built

An n8n workflow that processes a batch of records safely and keeps a complete log:

1. Validates each record and sends invalid ones to a separate sheet
2. Removes duplicates and checks Google Sheets for records already processed
3. Calls an external API using an HTTP Request node with automatic retry
4. Logs every success and every error in Google Sheets
5. Produces a final summary of the run

Tools used

n8n, HTTP Request node, Google Sheets, JavaScript (Code nodes), IF node

Result

• Invalid data never reaches the API
• No record is processed twice, even if the workflow is run again
• Temporary API failures are retried automatically
• Every success and error is tracked

Workflow file

Reliable Batch Processor.json