Workflow

Many real-world tasks are too complex for one LLM call. The solution is Task Decomposition: decompose them into a chain of multiple Nodes.

You don't want to make each task too coarse, because it may be too complex for one LLM call. You don't want to make each task too granular, because then the LLM call doesn't have enough context and results are not consistent across nodes.

You usually need multiple iterations to find the sweet spot. If the task has too many edge cases, consider using Agents.

Example: Article Writing

import asyncio
from caskada import Node, Flow, Memory

# Assume call_llm is defined elsewhere
# async def call_llm(prompt: str) -> str: ...

class GenerateOutline(Node):
    async def prep(self, memory): return memory.topic
    async def exec(self, topic): return await call_llm(f"Create a detailed outline for an article about {topic}")
    async def post(self, memory, prep_res, exec_res):
        memory.outline = exec_res
        self.trigger('default')

class WriteSection(Node):
    async def prep(self, memory): return memory.outline
    async def exec(self, outline): return await call_llm(f"Write content based on this outline: {outline}")
    async def post(self, memory, prep_res, exec_res):
        memory.draft = exec_res
        self.trigger('default')

class ReviewAndRefine(Node):
    async def prep(self, memory): return memory.draft
    async def exec(self, draft): return await call_llm(f"Review and improve this draft: {draft}")
    async def post(self, memory, prep_res, exec_res):
        memory.final_article = exec_res
        # No trigger needed if this is the end of the flow

# Connect nodes
outline = GenerateOutline()
write = WriteSection()
review = ReviewAndRefine()

outline >> write >> review

# Create and run flow
writing_flow = Flow(start=outline)

async def main():
    memory = {"topic": "AI Safety"}
    await writing_flow.run(memory) # Pass memory object
    print("Final Article:", memory.get("final_article", "Not generated")) # Access memory object

if __name__ == "__main__":
    asyncio.run(main())

import { Flow, Memory, Node } from 'caskada'

// Assuming callLLM is defined elsewhere
declare function callLLM(prompt: string): Promise<string>

class GenerateOutline extends Node {
  async prep(memory): Promise<string> {
    return memory.topic // Read topic from memory
  }
  async exec(topic: string): Promise<string> {
    console.log(`Generating outline for: ${topic}`)
    return await callLLM(`Create a detailed outline for an article about ${topic}`)
  }
  async post(memory, prepRes: any, outline: string): Promise<void> {
    memory.outline = outline // Store outline in memory
    this.trigger('default')
  }
}

class WriteSection extends Node {
  async prep(memory): Promise<string> {
    return memory.outline // Read outline from memory
  }
  async exec(outline: string): Promise<string> {
    console.log('Writing draft based on outline...')
    return await callLLM(`Write content based on this outline: ${outline}`)
  }
  async post(memory, prepRes: any, draft: string): Promise<void> {
    memory.draft = draft // Store draft in memory
    this.trigger('default')
  }
}

class ReviewAndRefine extends Node {
  async prep(memory): Promise<string> {
    return memory.draft // Read draft from memory
  }
  async exec(draft: string): Promise<string> {
    console.log('Reviewing and refining draft...')
    return await callLLM(`Review and improve this draft: ${draft}`)
  }
  async post(memory, draft: any, finalArticle: string): Promise<void> {
    memory.final_article = finalArticle // Store final article
    console.log('Final article generated.')
    // No trigger needed - end of workflow
  }
}

// --- Flow Definition ---
const outline = new GenerateOutline()
const write = new WriteSection()
const review = new ReviewAndRefine()

// Connect nodes sequentially using default trigger
outline.next(write).next(review)

// Create the flow
const writingFlow = new Flow(outline)

// --- Execution ---
async function main() {
  const data = { topic: 'AI Safety' }
  console.log(`Starting writing workflow for topic: "${data.topic}"`)

  await writingFlow.run(data) // Run the flow

  console.log('\n--- Workflow Complete ---')
  console.log('Final Memory State:', data)
  console.log(`\nFinal Article:\n${data.final_article ?? 'Not generated'}`)
}

main().catch(console.error)

For dynamic cases, consider using Agents.

Last updated 3 months ago

import { Flow, Memory, Node } from 'caskada' // Assuming callLLM is defined elsewhere declare function callLLM(prompt: string): Promise<string> class GenerateOutline extends Node { async prep(memory): Promise<string> { return memory.topic // Read topic from memory } async exec(topic: string): Promise<string> { console.log(`Generating outline for: ${topic}`) return await callLLM(`Create a detailed outline for an article about ${topic}`) } async post(memory, prepRes: any, outline: string): Promise<void> { memory.outline = outline // Store outline in memory this.trigger('default') } } class WriteSection extends Node { async prep(memory): Promise<string> { return memory.outline // Read outline from memory } async exec(outline: string): Promise<string> { console.log('Writing draft based on outline...') return await callLLM(`Write content based on this outline: ${outline}`) } async post(memory, prepRes: any, draft: string): Promise<void> { memory.draft = draft // Store draft in memory this.trigger('default') } } class ReviewAndRefine extends Node { async prep(memory): Promise<string> { return memory.draft // Read draft from memory } async exec(draft: string): Promise<string> { console.log('Reviewing and refining draft...') return await callLLM(`Review and improve this draft: ${draft}`) } async post(memory, draft: any, finalArticle: string): Promise<void> { memory.final_article = finalArticle // Store final article console.log('Final article generated.') // No trigger needed - end of workflow } } // --- Flow Definition --- const outline = new GenerateOutline() const write = new WriteSection() const review = new ReviewAndRefine() // Connect nodes sequentially using default trigger outline.next(write).next(review) // Create the flow const writingFlow = new Flow(outline) // --- Execution --- async function main() { const data = { topic: 'AI Safety' } console.log(`Starting writing workflow for topic: "${data.topic}"`) await writingFlow.run(data) // Run the flow console.log('\n--- Workflow Complete ---') console.log('Final Memory State:', data) console.log(`\nFinal Article:\n${data.final_article ?? 'Not generated'}`) } main().catch(console.error)