Build Your First Workflow

This tutorial walks through the smallest useful platform flow:

Define a workflow
Load it with WorkflowEngine
Execute it with patient context
Inspect the result

Step 1: Define the workflow


id: first-thyroid-workflow-v1
name: First Thyroid Workflow
version: 1.0.0
steps:
  - id: check-tsh
    type: check_biomarker
    action:
      type: check_value
      params:
        biomarker: TSH
        threshold: 2.5
        operator: ">"
  - id: recommend-selenium
    type: recommend_supplement
    condition: "check-tsh.result === true"
    action:
      type: recommend
      params:
        supplement: Selenium
        dosage: 200mcg

Step 2: Load the workflow


import { WorkflowEngine } from '@loop/workflow-engine';
 
const workflow = WorkflowEngine.load(`
id: first-thyroid-workflow-v1
name: First Thyroid Workflow
version: 1.0.0
steps:
  - id: check-tsh
    type: check_biomarker
    action:
      type: check_value
      params:
        biomarker: TSH
        threshold: 2.5
        operator: ">"
  - id: recommend-selenium
    type: recommend_supplement
    condition: "check-tsh.result === true"
    action:
      type: recommend
      params:
        supplement: Selenium
        dosage: 200mcg
`);

Step 3: Execute with context


const result = await workflow.execute({
  patientId: 'patient-42',
  data: {
    biomarker: { TSH: 4.2 },
  },
});

Step 4: Inspect output


console.log(result.executedSteps);
console.log(result.recommendations);

Example output:


{
  "executedSteps": ["check-tsh", "recommend-selenium"],
  "recommendations": [
    {
      "type": "supplement",
      "details": {
        "supplement": "Selenium",
        "dosage": "200mcg"
      }
    }
  ]
}

Step 5: Test the negative branch


const result = await workflow.execute({
  patientId: 'patient-42',
  data: {
    biomarker: { TSH: 1.9 },
  },
});
 
console.log(result.stepResults['recommend-selenium']?.result);
// "skipped"

Why this workflow is a good first example

It uses a real built-in step type
It shows a prior-step condition
It produces a concrete recommendation
It is easy to test and reason about

Next steps

Expand the context with Patient Graph Workflow Guide
Add tests with Testing Workflows
Keep the field list handy in DSL Reference