Building seen in public

This is a 7 days attempt to refactor a SaaS website called seen I implemented it a while back for my personal use to be able to serve more users.

I'm going to build this in public, documenting every step of the way. Every day there will be:

  1. A GitHub issue containing the intended new features (not set in stone)
  2. A thread of tweets that I will update every time I feel like there is something interesting to add
  3. A blog post (like this one) that is published in the end (or on the next day) summarises the whole experience.

This post is the landing page for the next posts in the coming days, it will be updated with a link to those blog posts once they are published at the end of this page.


I have needed a way to get seen receipt for my important emails before, after a series of frustrating search and trying non-working solutions. I finally decided to implement it on my own.

Initially, it was a simple application that I wrote and hosted on my Kubernetes cluster.

It was publicly available but password-protected so only I could use it. Now after a while I have finally decided to make it public and allow users to sign up and use it.

I'm planning to keep it free of charge for a while, if the costs of maintaining it is not too much I will probably maintain free sign-ups for longer.

How it works

The technology is actually pretty simple. This application generates a unique link to a png file which is basically a transparent single-pixel image.

Users copy the image into their clipboard and paste it into their target email they want to get read receipt for. This is a common practice and is widely used by marketing email services.

The image link is then mapped to the targeted email in the database and every time sometimes tries to access that link database is updated with the reader's request headers (which usually contain things like IP addresses and User Agents).

There is a simple dashboard that users can use to check the status of the emails and the number of times their email is seen.

Use cases

Read receipts are used very often for marketing, allowing the marketers to get the status of the emails they sent and find how interested are the target audience.

My initial usage was not for marketing, but I was genuinely interested in knowing if the recipient of my emails have opened the email. This can be useful for student or job applications as well when you would be anxious to know if your email is opened.

This can also be useful in websites, when you want to see page views (or even components), just load the pixel with your components and get notified whenever it's loaded on the users' side.