by smallwat3r



Build Status codecov Maintainability License: MIT

What is it?

Shhh is a tiny Flask app to create encrypted secrets and share them securely with people. The goal of this application is to get rid of plain text sensitive information into emails or chat logs.

Shhh is deployed here, but it's better for organisations and people to deploy it on their own personal / private server for even better security. You can find in this repo everything you need to host the app yourself.

Or you can one-click deploy to Heroku using the below button. It will generate a fully configured private instance of Shhh immediately (using your own server and Postgres database, for free).


How does it work?

The sender has to set an expiration date along with a passphrase to protect the information he wants to share.

A unique link is generated by Shhh that the sender can share with the receiver in an email, alongside the temporary passphrase he created in order to reveal the secret.

The secret will be permanently removed from the database as soon as one of these events happens:

  • the expiration date has passed (max 7 days).
  • the receiver has decrypted the message.
  • or the amount of tries to open the secret has exceeded (max 10).

The secrets are encrypted in order to make the data anonymous, especially in the database, and the passphrases are not stored anywhere.

Encryption method used: Fernet with password, random salt value and strong iteration count (100 000).

Tip: For added security, avoid telling in Shhh what is the use of the secret you're sharing. Instead, explain this in your email, and copy the Shhh link to it with the passphrase.

Is there an API?

Yes, you can find the doc here.

Also, checkout shhh-cli, a Go client to interact with the Shhh API from the terminal.

What's the stack?

Core application

  • Flask, used as our Python backend web-framework.
  • Postgres used to store only: the unique links, the encrypted messages, the creation and expiration dates.
  • Bulma, the CSS framework.


What are the dependencies?

You can find the list of the Python dependencies here, and the list of the frontend dependencies here.

How to launch Shhh locally?

These instructions are for development purpose only. For production use you might want to use a more secure configuration.

Launch it natively


Make sure you have make, yarn, and obviously python@3.8 installed on your machine.


You will need a Postgres server running locally in the background. Create a database named shhh.



You will need to set up a few environment variables. We use them to configure Flask, as well as the application connection to the database.

Rename the file /envs/ to /envs/ and fill in the missing values inside it (these are the values needed to connect to your local Postgres database).

Once done, from the root of the repository, run:

make local

This command will make sure a virtual environment is created and that all the needed dependencies are installed, and finally launch a flask local server.

You can now access the app at http://localhost:5000

Launch it with docker-compose


Make sure you have make, docker and docker-compose installed on your machine.


From the root of the repository, run

make dc-start  # to start the app
make dc-stop   # to stop the app

Once the container image has finished building and has started, you can access:

Note: using docker-compose the application will be running with Gunicorn.

Run development checks

You can run tests and linting / security reports using the Makefile:

make checks  # run all checks

make tests   # run tests
make lint    # run Pylint report
make secure  # run Bandit report
make mypy    # run Mypy report


Existing cool apps that gave me the idea to develop my own version using Python and Flask

Thanks to


See LICENSE file.


Please report issues or questions here.

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