Log n8n workflow errors to your REST API with Slack alerts and metrics

Track all n8n workflow failures with automatic error capture, severity classification, duplicate detection, Slack alerting, performance metrics, and log retention. WHAT IT DOES: Runs as an error sub-workflow attached to any workflow you want to monitor Captures execution metadata (workflow name, ID, duration, mode, failed node, stack trace) Extracts environment info (timezone, node version, platform) Classifies error severity (critical, warning, info) based on configurable keywords Deduplicates alerts within 5-minute windows to prevent flooding Saves structured logs to your database via REST API Routes alerts to the appropriate Slack channel by severity Calculates performance metrics and updates daily aggregates Auto-cleans old logs based on configurable retention policy Includes a fallback error handler to prevent cascading failures from the logger itself INCLUDED FLOWS: New critical error: Error Trigger → Extract metadata → Classify as critical → Check duplicate → Save log → Slack alert to workflow-alerts → Calculate metrics → Update aggregates → Cleanup old logs New warning error: Same capture flow → Classify as warning → Slack alert to workflow-warnings → Metrics and retention New info error: Same capture flow → No keyword match → Logged only, no alert → Metrics and retention Duplicate error: Same workflowId + errorNode + errorType within 5-minute window → Skipped, no alert or log saved Logger failure: Logger Error Trigger → Format error → Immediate Slack alert to system-errors, prevents cascading SEVERITY CLASSIFICATION: Critical (immediate alert to workflow-alerts): payment, database, authentication, authorization, critical, fatal, connection, timeout Warning (alert to workflow-warnings): retry, temporary, unavailable, rate limit, quota Info (logged only, no alert): any error not matching critical or warning keywords LOG DATA STRUCTURE: Each log entry contains executionid, workflowid, workflowname, status, severity, startedat, endedat, durationseconds Error details include errormessage, errortype, errornode, errorstack (truncated to 2000 chars) Deduplication fields: errorhash, dedupekey Additional fields: mode, environment (JSON), createdat timestamp SETUP: HTTP Header Auth credential with API key and base URL for your logging REST API Slack credential with access to three channels: workflow-alerts (critical), workflow-warnings (warnings), system-errors (logger failures) Backend API with endpoints: GET /api/logs/dedupe/:dedupeKey, POST /api/logs/execution, POST /api/logs/metrics, POST /api/logs/aggregate, DELETE /api/logs/cleanup To monitor a workflow, set this workflow as its error sub-workflow in the workflow settings CUSTOMIZABLE: Critical and warning keywords are editable arrays in the Classify Error code node Deduplication window is adjustable in the Generate Error Hash code node (default: 5 minutes) Retention period is configurable in the Calculate Retention code node (default: 30 days) Metrics calculation logic is editable in the Calculate Metrics code node Slack channel names are configurable in each Slack alert node Stack trace truncation length is adjustable in the Format Log Entry code node (default: 2000 chars) Add email alerts by connecting a Gmail node after any Slack alert node Add PagerDuty or Opsgenie integration after the critical alert path for on-call escalation IDEAL FOR: DevOps teams, n8n administrators, and automation engineers who need centralized error monitoring, alerting, and performance tracking across multiple n8n workflows.