Create your first flow

Now that pgflow is installed, let’s create a simple greeting workflow that demonstrates the core concepts.

Creating a Simple Greeting Flow

Our workflow will:

Take a person’s first and last name as input
Format a full name
Create a personalized greeting

1. Set up your project structure

First, create a directory for your flow:

mkdir -p supabase/functions/_flows

Directorysupabase
- Directoryfunctions
  - Directory_flows
    greet_user.ts

2. Create the flow definition

Create a file called supabase/functions/_flows/greet_user.ts with this content:

import { Flow } from 'npm:@pgflow/dsl';

type Input = {
  first_name: string;
  last_name: string;
};

export default new Flow<Input>({
  slug: 'greet_user',
})
  .step(
    { slug: 'full_name' },
    (input) => `${input.run.first_name} ${input.run.last_name}`
  )
  .step(
    { slug: 'greeting', dependsOn: ['full_name'] },
    (input) => `Hello, ${input.full_name}!`
  );

How this flow works

Input: The flow receives first_name and last_name parameters
first_name step: Combines the names using input.run to access the flow input
greeting step: Takes the result of the first step (via input.full_name) and creates a greeting

When run with {"first_name": "Alice", "last_name": "Smith"}, this produces { "greeting": "Hello, Alice Smith!" }.

For more in-depth explanation of the Flow DSL, see Understanding the Flow DSL.