KB LabsDocs
Open app
KB Labs/Getting Started/First workflow

First workflow

This guide walks you through creating a real workflow from scratch. You'll write a YAML definition, a TypeScript handler, and run it locally.

Define the workflow

Create workflows/greet.yaml:

id: greet
name: Hello workflow
steps:
  - id: say-hello
    handler: plugins/hello/say-hello
    input:
      name: "World"
  - id: log-result
    handler: plugins/hello/log
    input:
      message: "{{ steps.say-hello.output.greeting }}"

Write the handler

Create plugins/hello/say-hello.ts:

import type { HandlerContext } from '@kb-labs/sdk';

type Input = { name: string };
type Output = { greeting: string };

export async function handler(input: Input, ctx: HandlerContext): Promise<Output> {
  ctx.logger.info(`Greeting ${input.name}`);
  return { greeting: `Hello, ${input.name}!` };
}

Handlers are plain async functions. No framework, no magic — just TypeScript with a typed context object.

Run the workflow

kb workflow run greet

Output:

✓ Step say-hello completed in 12ms
  → { greeting: "Hello, World!" }
✓ Step log-result completed in 3ms
✓ Workflow greet finished in 18ms

How step outputs flow

Each step's output is available to subsequent steps via template syntax:

message: "{{ steps.say-hello.output.greeting }}"

The engine resolves these at runtime before passing input to the handler.

Next steps