Add DBOS To Your App

This guide shows you how to add the open-source DBOS Transact library to your existing application to durably execute it and make it resilient to any failure.

1. Install DBOS

pip install DBOS into your application. Then, create a DBOS configuration file (this file is optional but is used by tooling like the DBOS CLI and debugger).

pip install dbos
dbos init my-app --config

2. Add the DBOS Initializer

Add these lines of code to your program's main function. They initialize DBOS when your program starts.

import os
from dbos import DBOS, DBOSConfig

config: DBOSConfig = {
    "name": "my-app",
    "database_url": os.environ.get("DBOS_DATABASE_URL"),
}
DBOS(config=config)
DBOS.launch()

3. Start Your Application

Try starting your application. When DBOS.launch() is called, it will attempt to connect to a Postgres database. If your project already uses Postgres, set the DBOS_DATABASE_URL environment variable to a connection string to your Postgres database. Otherwise, DBOS will automatically guide you through launching a new Postgres database (using Docker if available, else DBOS Cloud) and connecting to it.

After you've connected to Postgres, your app should run normally, but log Initializing DBOS and DBOS launched! on startup. Congratulations! You've integrated DBOS into your application.

4. Start Building With DBOS

At this point, you can add any DBOS decorator or method to your application. For example, you can annotate one of your functions as a workflow and the functions it calls as steps. DBOS durably executes the workflow so if it is ever interrupted, upon restart it automatically resumes from the last completed step.

You can add DBOS to your application incrementally—it won't interfere with code that's already there. It's totally okay for your application to have one DBOS workflow alongside thousands of lines of non-DBOS code.

To learn more about programming with DBOS, check out the guide.

@DBOS.step()
def step_one():
    ...

@DBOS.step()
def step_two():
    ...

@DBOS.workflow()
def workflow():
    step_one()
    step_two()