Creating Workflows

Workflows are the core building blocks of automation in Loopstack. They define a sequence of states and transitions that execute tools to accomplish specific tasks, from simple data processing to complex multi-step business processes.

Creating a Workflow

A workflow is created by extending the Workflow base class and decorating it with @BlockConfig. While you can define simple configurations inline, workflows typically use a separate YAML file to define their state machine logic.

Basic Workflow Definition

import { z } from 'zod';
import { Workflow } from '@loopstack/core';
import { BlockConfig, Input } from '@loopstack/shared';
import { AiGenerateText } from '@loopstack/llm';
import { Expose } from 'class-transformer';
 
@BlockConfig({
imports: [AiGenerateText],
properties: z.object({
subject: z.string().default("coffee"),
}),
configFile: __dirname + '/chat.workflow.yaml',
})
export class ChatWorkflow extends Workflow  {
@Input()
@Expose()
lastMessage: any;
}

# chat-with-me-workflow.yaml
type: workflow
title: "Chat"
 
transitions:
- id: create_message
from: start
to: message_added
call:
- id: prompt_message
tool: CreateChatMessage
args:
role: user
content: Write a haiku about {{ args.subject }}
 
- id: prompt
from: message_added
to: prompt_executed
call:
- id: execute_prompt
tool: AiGenerateText
args:
llm:
provider: openai
model: gpt-4o
messagesSearchTag: message
assign:
lastMessage: ${ result.data }
 
- id: display_message
from: prompt_executed
to: end
call:
- tool: CreateChatMessage
args: ${ lastMessage }
 

Key Components

@BlockConfig Decorator

• Marks a class as a Loopstack block
• Links the NestJS service to its YAML configuration via configFile
• Specifies dependencies (tools) through imports

@Expose() Decorator

• Makes properties accessible in YAML templates
• Enables property access via template variables like ${ myData }

@Input() Decorator

• Allows setting properties from within workflow execution
• Enables the assign feature in YAML transitions to store results

YAML Config

• transitions Define the flow of states and the tools executed at each step
• calls Specifies tool calls triggered in a transition
• assing Assigns the result to a workflow property and makes it available for later use

Registering the Workflow

Add your workflow as a module provider and import it in your workspace to make it available for execution.

@Module({
imports: [LoopCoreModule, CoreToolsModule],
providers: [
InvoiceProcessingWorkflow,
// ... other providers
],
})
@ModuleFactory(MyModuleFactoryService)
export class MyModule {}

@BlockConfig({
imports: [
InvoiceProcessingWorkflow,
],
})
export class MyWorkspace extends Workspace {}

Using Your Workflow

Once registered in a workspace, your workflow can be manually executed:

1. Navigate to your workspace in the Loopstack Studio
2. Click Run to create a new execution
3. Select the workflow from the available workflows