Stage 1
Stage 2
Client
Server
Redis
Client
Server
Redis
POST /webhook (Tx #1001)
HTTP Timeout (Response Lost)
POST /webhook (Retry Tx #1001)
⚠️ Duplicate Execution Risk!
POST [Idempotency-Key: 4c9b-8f1a]
EXISTS key:4c9b-8f1a
HIT: { status: 200, body: ... }
HTTP 200 OK (Cached Response)
✓ Duplicate Logic Bypassed