Idempotency means running something twice doesn't break anything. It's the difference between "oops" and "disaster."
The Problem It Solves
Imagine your automation sends a welcome email when someone signs up. The system glitches and runs twice. Without idempotency, your customer gets two identical emails. Annoying, but survivable.
Now imagine it's a payment processor that charges them twice. That's a lawsuit waiting to happen.
What Idempotent Operations Look Like
An idempotent operation produces the same result no matter how many times you run it:
- ✅ Set status to "active" — Running twice still = active
- ✅ Create record if not exists — Second run finds existing record, skips
- ❌ Add $50 to balance — Running twice = +$100 (NOT idempotent)
- ❌ Send email — Running twice = two emails (NOT idempotent)
How to Make Operations Idempotent
- 1. Use unique IDs — Check if this exact operation already ran
- 2. Check before acting — "Does this record already exist?"
- 3. Use "upsert" patterns — Create or update, not just create
- 4. Track completion — Log when operations finish successfully
Build idempotency into every automation, and you'll sleep better at night.