Looping step execution

This example demonstrates how to create a workflow that executes one or more of it’s steps in a loop until a condition is met

Define Looping workflow

Defines a workflow which calls the executes a nested workflow until the provided condition is met.

looping-workflow.ts


import { createWorkflow, createStep } from '@mastra/core/workflows/vNext'
import { z } from 'zod'
 
const incrementStep = createStep({
  id: 'increment',
  inputSchema: z.object({
    value: z.number(),
  }),
  outputSchema: z.object({
    value: z.number(),
  }),
  execute: async ({ inputData }) => {
    return { value: inputData.value + 1 }
  },
})
 
const sideEffectStep = createStep({
  id: 'side-effect',
  inputSchema: z.object({
    value: z.number(),
  }),
  outputSchema: z.object({
    value: z.number(),
  }),
  execute: async ({ inputData }) => {
    console.log('log', inputData.value)
    return { value: inputData.value }
  },
})
 
const finalStep = createStep({
  id: 'final',
  inputSchema: z.object({
    value: z.number(),
  }),
  outputSchema: z.object({
    value: z.number(),
  }),
  execute: async ({ inputData }) => {
    return { value: inputData.value }
  },
})
 
const workflow = createWorkflow({
  id: 'increment-workflow',
  inputSchema: z.object({
    value: z.number(),
  }),
  outputSchema: z.object({
    value: z.number(),
  }),
})
  .dountil(
    createWorkflow({
      id: 'increment-workflow',
      inputSchema: z.object({
        value: z.number(),
      }),
      outputSchema: z.object({
        value: z.number(),
      }),
      steps: [incrementStep, sideEffectStep],
    })
      .then(incrementStep)
      .then(sideEffectStep)
      .commit(),
    async ({ inputData }) => inputData.value >= 10
  )
  .then(finalStep)
 
workflow.commit()
 
export { workflow as incrementWorkflow }

Register Workflow instance with Mastra class

index.ts


import { Mastra } from '@mastra/core/mastra'
import { createLogger } from '@mastra/core/logger'
import { incrementWorkflow } from './workflows'
 
const mastra = new Mastra({
  vnext_workflows: {
    incrementWorkflow,
  },
  logger: createLogger({
    name: 'Mastra',
    level: 'info',
  }),
})
 
export { mastra }

Execute the workflow

Here, we’ll get the increment workflow from the mastra instance, then create a run and execute the created run with the required inputData.

exec.ts


import { mastra } from "./"
 
const workflow = mastra.vnext_getWorkflow('incrementWorkflow')
const run = workflow.createRun()
 
const result = await run.start({ inputData: { value: 0 } })
console.dir(result, { depth: null })

View Example on GitHub