Process Definitions: JavaScript Workflow Orchestration

Version: 1.1 Last Updated: 2026-01-26 Category: Feature Guide

In Plain English

A process is a recipe that tells Babysitter what to do.

Just like a cooking recipe says "chop vegetables, then cook them, then serve" - a process says "research the codebase, then write tests, then implement, then verify."

You don't need to write processes to use Babysitter. The Process Library has 2,000+ pre-built processes ready to use.

When would you write a process?

You have a specific workflow your team follows
The pre-built processes don't match your needs
You want to customize how quality gates work

Tip for beginners: Start with pre-built processes. Once you're comfortable, come back here to learn how to create your own.

Overview

Process definitions are JavaScript functions that orchestrate workflows in Babysitter. A process defines what tasks to execute, in what order, and how to handle results. The process function acts as the "brain" of your workflow, making decisions and coordinating execution while Babysitter handles state management, persistence, and resumability.

Why Use Process Definitions

Deterministic Execution: Same inputs and journal produce the same execution path
Full JavaScript Power: Use loops, conditionals, and async/await for complex logic
Modular Design: Define reusable tasks and compose them into workflows
Event-Sourced: All state changes recorded for replay and debugging
Resumable: Workflows automatically resume from where they left off

Use Cases and Scenarios

Scenario 1: Simple Build and Test Pipeline

A basic process that builds and tests a project.

import { defineTask } from '@a5c-ai/babysitter-sdk';

export async function process(inputs, ctx) {
  // Build the project
  const buildResult = await ctx.task(buildTask, { target: inputs.target });

  // Run tests
  const testResult = await ctx.task(testTask, { suite: 'unit' });

  // Return results
  return {
    success: buildResult.success && testResult.success,
    build: buildResult,
    tests: testResult
  };
}

const buildTask = defineTask('build', (args, taskCtx) => ({
  kind: 'node',
  title: `Build ${args.target}`,
  node: {
    entry: 'scripts/build.js',
    args: ['--target', args.target]
  },
  io: {
    inputJsonPath: `tasks/${taskCtx.effectId}/input.json`,
    outputJsonPath: `tasks/${taskCtx.effectId}/result.json`
  }
}));

const testTask = defineTask('test', (args, taskCtx) => ({
  kind: 'node',
  title: `Run ${args.suite} tests`,
  node: {
    entry: 'scripts/test.js',
    args: ['--suite', args.suite]
  },
  io: {
    inputJsonPath: `tasks/${taskCtx.effectId}/input.json`,
    outputJsonPath: `tasks/${taskCtx.effectId}/result.json`
  }
}));

Scenario 2: CI Pipeline with Conditional Steps

A more complex pipeline with parallel execution and conditional logic.

export async function process(inputs, ctx) {
  // Build first
  const buildResult = await ctx.task(buildTask, { target: 'app' });

  // Run lint and tests in parallel
  const [lintResult, testResult] = await ctx.parallel.all([
    () => ctx.task(lintTask, { files: buildResult.files }),
    () => ctx.task(testTask, { suite: 'smoke' })
  ]);

  // Conditional: request approval if issues found
  if (!lintResult.ok || !testResult.ok) {
    await ctx.breakpoint({
      question: 'Lint/tests failed. Continue anyway?',
      title: 'Quality Gate',
      context: {
        runId: ctx.runId,
        files: [{ path: 'artifacts/quality-report.md', format: 'markdown' }]
      }
    });
  }

  // Agent-based code review
  const review = await ctx.task(codeReviewAgentTask, { diffRef: buildResult.diffRef });

  return { success: true, review: review.summary };
}

Scenario 3: Multi-Phase Feature Development

A comprehensive workflow with research, planning, implementation, and verification phases.

export async function process(inputs, ctx) {
  const { feature, targetQuality = 85, maxIterations = 5 } = inputs;

  // Phase 1: Research
  const research = await ctx.task(researchTask, { feature });

  // Phase 2: Planning
  const plan = await ctx.task(planningTask, { feature, research });

  // Breakpoint: Approve plan
  await ctx.breakpoint({
    question: `Review plan for "${feature}". Approve to proceed?`,
    title: 'Plan Review',
    context: { runId: ctx.runId, files: [{ path: 'artifacts/plan.md', format: 'markdown' }] }
  });

  // Phase 3: Implementation with quality convergence
  let iteration = 0;
  let quality = 0;

  while (iteration < maxIterations && quality < targetQuality) {
    iteration++;

    const impl = await ctx.task(implementTask, { feature, plan, iteration });
    const score = await ctx.task(scoreQualityTask, { impl });

    quality = score.overall;
    ctx.log(`Iteration ${iteration}: Quality ${quality}/${targetQuality}`);
  }

  // Phase 4: Final verification
  await ctx.breakpoint({
    question: `Quality: ${quality}. Approve for merge?`,
    title: 'Final Approval'
  });

  return { success: quality >= targetQuality, iterations: iteration, quality };
}

Step-by-Step Instructions

Step 1: Create the Process File

Create a JavaScript file with an exported process function.

Location: .a5c/runs/<runId>/code/main.js or a custom path

// main.js
export async function process(inputs, ctx) {
  // Your workflow logic here
  return { success: true };
}

Step 2: Define Tasks

Tasks are the building blocks of your workflow. Define them using defineTask.

import { defineTask } from '@a5c-ai/babysitter-sdk';

export const myTask = defineTask('my-task', (args, taskCtx) => ({
  kind: 'node',
  title: `Execute ${args.action}`,
  node: {
    entry: 'scripts/my-script.js',
    args: ['--action', args.action]
  },
  io: {
    inputJsonPath: `tasks/${taskCtx.effectId}/input.json`,
    outputJsonPath: `tasks/${taskCtx.effectId}/result.json`
  }
}));

Step 3: Use the Process Context

The ctx object provides intrinsics for orchestration.

export async function process(inputs, ctx) {
  // Execute a task
  const result = await ctx.task(myTask, { action: 'build' });

  // Request human approval
  await ctx.breakpoint({ question: 'Approve?' });

  // Sleep until a specific time
  await ctx.sleepUntil('2026-01-26T09:00:00.000Z');

  // Execute tasks in parallel
  const [a, b] = await ctx.parallel.all([
    () => ctx.task(taskA, {}),
    () => ctx.task(taskB, {})
  ]);

  // Log to the journal
  ctx.log('Workflow completed', { result });

  // Get current time (deterministic)
  const now = ctx.now();

  return { success: true };
}

Step 4: Create a Run

Use the CLI to create a run with your process.

babysitter run:create \
  --process-id my-workflow \
  --entry ./code/main.js#process \
  --inputs ./inputs.json \
  --run-id "run-$(date -u +%Y%m%d-%H%M%S)" \
  --prompt "Run my custom workflow"

Step 5: Execute the Run

Use the babysitter skill or CLI to drive execution.

# Via skill
claude "/babysitter:call run my-workflow"

# Via CLI iteration loop
while true; do
  RESULT=$(babysitter run:iterate "$RUN_ID" --json)
  STATUS=$(echo "$RESULT" | jq -r '.status')
  [ "$STATUS" = "completed" ] && break
  [ "$STATUS" = "failed" ] && exit 1
done

Configuration Options

Process Function Signature

async function process(inputs, ctx) {
  // inputs: Object - Initial inputs passed to the run
  // ctx: ProcessContext - Orchestration intrinsics
  // returns: any - Final output of the process
}

Task Definition Schema

defineTask<TArgs, TResult>(id: string, impl: TaskImpl<TArgs>): DefinedTask<TArgs, TResult>

Field	Type	Required	Description
`kind`	string	Yes	Task type: `node`, `shell`, `agent`, `breakpoint`
`title`	string	No	Human-readable title
`description`	string	No	Detailed description
`node.entry`	string	Yes (for node)	Path to Node.js script
`node.args`	string[]	No	Command-line arguments
`node.env`	object	No	Environment variables
`node.cwd`	string	No	Working directory
`node.timeout`	number	No	Timeout in milliseconds
`shell.command`	string	Yes (for shell)	Shell command to execute
`agent.name`	string	Yes (for agent)	Agent name
`agent.prompt`	object	Yes (for agent)	Agent prompt configuration
`io.inputJsonPath`	string	No	Path for input JSON
`io.outputJsonPath`	string	No	Path for output JSON
`labels`	string[]	No	Labels for categorization

Process Context Intrinsics

Method	Description
`ctx.task(taskDef, args, options?)`	Execute a task
`ctx.breakpoint(payload)`	Request human approval
`ctx.sleepUntil(timestamp)`	Sleep until a specific time
`ctx.parallel.all(thunks)`	Execute tasks in parallel
`ctx.parallel.map(items, fn)`	Map items to parallel tasks
`ctx.log(...args)`	Log to the journal
`ctx.now()`	Get current time (deterministic)
`ctx.runId`	The current run ID

Code Examples and Best Practices

Example 1: Node Task Definition

export const buildTask = defineTask('build', (args, taskCtx) => ({
  kind: 'node',
  title: `Build ${args.target}`,
  description: 'Compile and bundle the application',
  node: {
    entry: 'scripts/build.js',
    args: ['--target', args.target, '--effect-id', taskCtx.effectId],
    env: { NODE_ENV: 'production' },
    timeout: 300000  // 5 minutes
  },
  io: {
    inputJsonPath: `tasks/${taskCtx.effectId}/input.json`,
    outputJsonPath: `tasks/${taskCtx.effectId}/result.json`
  },
  labels: ['build', 'production']
}));

Example 2: Shell Task Definition

export const lintTask = defineTask('lint', (args, taskCtx) => ({
  kind: 'shell',
  title: 'Run linter',
  description: 'Check code style and common issues',
  shell: {
    command: `npx eslint ${args.files.join(' ')} --format json --output-file tasks/${taskCtx.effectId}/result.json`
  },
  labels: ['quality', 'lint']
}));

Example 3: Agent Task Definition

export const codeReviewAgentTask = defineTask('code-review', (args, taskCtx) => ({
  kind: 'agent',
  title: 'AI Code Review',
  description: 'LLM-based code review',
  agent: {
    name: 'code-reviewer',
    prompt: {
      role: 'senior software engineer',
      task: 'Review the code changes and provide feedback',
      context: {
        diffRef: args.diffRef
      },
      instructions: [
        'Check for bugs and security issues',
        'Review code quality and style',
        'Suggest improvements'
      ],
      outputFormat: 'JSON with summary, issues, and suggestions'
    },
    outputSchema: {
      type: 'object',
      required: ['summary', 'issues'],
      properties: {
        summary: { type: 'string' },
        issues: { type: 'array', items: { type: 'object' } },
        suggestions: { type: 'array', items: { type: 'string' } }
      }
    }
  },
  io: {
    inputJsonPath: `tasks/${taskCtx.effectId}/input.json`,
    outputJsonPath: `tasks/${taskCtx.effectId}/result.json`
  },
  labels: ['agent', 'code-review']
}));

Example 4: Error Handling in Processes

export async function process(inputs, ctx) {
  try {
    const result = await ctx.task(riskyTask, { data: inputs.data });
    return { success: true, result };
  } catch (error) {
    // Log the error
    ctx.log('Task failed', { error: error.message });

    // Request human intervention
    await ctx.breakpoint({
      question: `Task failed: ${error.message}. How to proceed?`,
      title: 'Error Recovery',
      context: {
        runId: ctx.runId,
        files: [{ path: 'artifacts/error-details.json', format: 'code', language: 'json' }]
      }
    });

    // Retry with different parameters
    const retryResult = await ctx.task(riskyTask, { data: inputs.data, retryMode: true });
    return { success: true, result: retryResult, retried: true };
  }
}

Example 5: Dynamic Task Selection

export async function process(inputs, ctx) {
  const { taskType, config } = inputs;

  // Select task based on input
  let taskDef;
  switch (taskType) {
    case 'build':
      taskDef = buildTask;
      break;
    case 'test':
      taskDef = testTask;
      break;
    case 'deploy':
      taskDef = deployTask;
      break;
    default:
      throw new Error(`Unknown task type: ${taskType}`);
  }

  const result = await ctx.task(taskDef, config);
  return result;
}

Best Practices

Keep Processes Deterministic: Avoid random values or non-deterministic operations; use ctx.now() for timestamps
Use Descriptive Task IDs: Task IDs should clearly indicate what the task does
Handle Errors Gracefully: Implement error handling and recovery strategies
Break Complex Workflows into Phases: Structure processes with clear phases for readability
Document Process Purpose: Add comments explaining the workflow logic
Use Labels for Categorization: Tag tasks with labels for filtering and organization
Separate Task Definitions: Keep task definitions in separate files for reusability

Common Pitfalls and Troubleshooting

Pitfall 1: Non-Deterministic Process Code

Symptom: Process behaves differently on resume.

Cause: Using non-deterministic values.

Wrong:

const timestamp = Date.now();  // Non-deterministic
const id = Math.random().toString(36);  // Non-deterministic

Correct:

const timestamp = ctx.now().getTime();  // Deterministic
const id = `task-${ctx.runId}-${iteration}`;  // Deterministic

Pitfall 2: Missing Input/Output Paths

Symptom: Task results not persisted or not found on resume.

Cause: Missing io configuration.

Solution:

defineTask('my-task', (args, taskCtx) => ({
  kind: 'node',
  node: { entry: 'scripts/task.js' },
  io: {
    inputJsonPath: `tasks/${taskCtx.effectId}/input.json`,   // Add this
    outputJsonPath: `tasks/${taskCtx.effectId}/result.json`  // Add this
  }
}));

Pitfall 3: Process Code Changed Between Iterations

Symptom: Replay produces different results.

Cause: Process code modified after run started.

Solution:

Avoid modifying process code for in-progress runs
The SDK stores processRevision to detect changes
Create a new run if workflow logic needs to change

Pitfall 4: Task Function Not Exported

Symptom: ReferenceError: task is not defined

Cause: Task function not exported or imported incorrectly.

Solution:

// In tasks.js
export const myTask = defineTask('my-task', ...);

// In main.js
import { myTask } from './tasks.js';

export async function process(inputs, ctx) {
  const result = await ctx.task(myTask, { /* args */ });
}

Pitfall 5: Incorrect Entry Point Syntax

Symptom: Error: Cannot find module

Cause: Incorrect entry point format in run:create.

Correct syntax:

--entry ./code/main.js#process
       ^              ^
       path           export name (after #)

Pre-Built Workflows: Methodologies & Processes

Don't start from scratch! Babysitter includes thousands of ready-to-use workflows:

Methodologies (19+) - Development Approaches

High-level approaches you can apply to any project:

TDD Quality Convergence - Test-first with iterative quality improvement
GSD (Get Stuff Done) - Rapid 8-phase execution workflow
Spec-Kit - Specification-driven with governance
Domain-Driven Design - Strategic and tactical DDD patterns
And 15+ more...

Browse methodologies:

Domain Processes (2,000+) - Task-Specific Workflows

Complete process definitions for specific domains:

Domain	Processes	Browse
Development	680+	specializations/
Business	430+	domains/business/
Science & Engineering	550+	domains/science/

See the full catalog with descriptions in the Process Library.

Summary

Process definitions are JavaScript functions that orchestrate workflows. Define reusable tasks, compose them with conditionals and loops, and let Babysitter handle state management. Keep processes deterministic for reliable replay and resumption. Use the full power of JavaScript while benefiting from event-sourced persistence.

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Process Definitions: JavaScript Workflow Orchestration

In Plain English

Overview

Why Use Process Definitions

Use Cases and Scenarios

Scenario 1: Simple Build and Test Pipeline

Scenario 2: CI Pipeline with Conditional Steps

Scenario 3: Multi-Phase Feature Development

Step-by-Step Instructions

Step 1: Create the Process File

Step 2: Define Tasks

Step 3: Use the Process Context

Step 4: Create a Run

Step 5: Execute the Run

Configuration Options

Process Function Signature

Task Definition Schema

Process Context Intrinsics

Code Examples and Best Practices

Example 1: Node Task Definition

Example 2: Shell Task Definition

Example 3: Agent Task Definition

Example 4: Error Handling in Processes

Example 5: Dynamic Task Selection

Best Practices

Common Pitfalls and Troubleshooting

Pitfall 1: Non-Deterministic Process Code

Pitfall 2: Missing Input/Output Paths

Pitfall 3: Process Code Changed Between Iterations

Pitfall 4: Task Function Not Exported

Pitfall 5: Incorrect Entry Point Syntax

Related Documentation

Pre-Built Workflows: Methodologies & Processes

Methodologies (19+) - Development Approaches

Domain Processes (2,000+) - Task-Specific Workflows

Summary

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Process Definitions: JavaScript Workflow Orchestration

In Plain English

Overview

Why Use Process Definitions

Use Cases and Scenarios

Scenario 1: Simple Build and Test Pipeline

Scenario 2: CI Pipeline with Conditional Steps

Scenario 3: Multi-Phase Feature Development

Step-by-Step Instructions

Step 1: Create the Process File

Step 2: Define Tasks

Step 3: Use the Process Context

Step 4: Create a Run

Step 5: Execute the Run

Configuration Options

Process Function Signature

Task Definition Schema

Process Context Intrinsics

Code Examples and Best Practices

Example 1: Node Task Definition

Example 2: Shell Task Definition

Example 3: Agent Task Definition

Example 4: Error Handling in Processes

Example 5: Dynamic Task Selection

Best Practices

Common Pitfalls and Troubleshooting

Pitfall 1: Non-Deterministic Process Code

Pitfall 2: Missing Input/Output Paths

Pitfall 3: Process Code Changed Between Iterations

Pitfall 4: Task Function Not Exported

Pitfall 5: Incorrect Entry Point Syntax

Related Documentation

Pre-Built Workflows: Methodologies & Processes

Methodologies (19+) - Development Approaches

Domain Processes (2,000+) - Task-Specific Workflows

Summary