email-queue.md

Email Queue (Redis List)

Demonstrates a simple job queue backed by a Redis list. Jobs are pushed to the head and processed from the tail, giving FIFO (first-in, first-out) ordering.

Source: ../src/queue.js

Concept

The list queue:emails acts as a queue:

• LPUSH adds new jobs to the left (head) of the list.
• RPOP removes jobs from the right (tail) of the list.

Combining left-push with right-pop yields FIFO processing order.

Endpoints

POST /emails-queue

Enqueue an email job.

• Body:

{
	"to": "user@example.com",
	"subject": "Hello",
	"body": "Welcome to the app!"
}

• Response:

{
	"status": "queued",
	"job": {
		"to": "user@example.com",
		"subject": "Hello",
		"body": "Welcome to the app!",
		"createdAt": "2026-07-28T00:00:00.000Z"
	}
}

subject defaults to "No Subject" and body defaults to "No content" when omitted.

GET /emails-queue/process-one

Dequeue and process the next job (FIFO).

• Response (job available):

{
	"status": "Email sent Successfully",
	"job": {
		"to": "user@example.com",
		"subject": "Hello",
		"body": "Welcome to the app!",
		"createdAt": "2026-07-28T00:00:00.000Z"
	}
}

• Response (queue empty):

{
	"message": "No jobs in the queue"
}

Quick Test Commands

Queue an email job:

curl -X POST http://localhost:3000/emails-queue \
	-H "Content-Type: application/json" \
	-d '{"to":"user@example.com","subject":"Hello","body":"Welcome!"}'

Process the next job:

curl http://localhost:3000/emails-queue/process-one

Redis Commands Used

• LPUSH - add a job to the head of the list
• RPOP - remove a job from the tail of the list