Hardened n8n Lead Pipeline: 35 Nodes Built for What Breaks

Three n8n workflows (35 nodes, 22 in the main chain) that turn an inbound email into a scored CRM record, and keep telling you the truth when something breaks. Published on GitHub so anyone can import the JSON and judge the work before hiring.

The trigger stops firing. A dead trigger leaves no failed execution, so the log looks healthy. A separate watchdog on its own clock checks a heartbeat row and alarms when it goes stale or goes missing.

The same lead arrives twice. A hashed idempotency key is claimed atomically in Postgres before any write, so a retry never creates a second CRM record.

The LLM returns the wrong shape. A strict schema gate sends invalid output to a dead letter with the raw response attached, never downstream.

One write succeeds, the next fails. The first write is compensated, so no half-record survives.

The JSON imports cleanly into n8n. It is a reference implementation of the failure handling: wiring it to a real inbox, CRM and database is the last mile, and that is the part I build for clients at a fixed price.

Stack: n8n, PostgreSQL, an LLM step, Slack alerts. MIT licensed.