Examples

Real-world business rules written in Flow. Each example is a complete, runnable .flow file — the rule and the executable are the same artifact.

Available examples

Transaction Fraud

Real-time fraud decisioning that combines AI risk scoring, rule-based screening, velocity checks, and human escalation into a single workflow.

step DecisionEngine:
    set ai-score to ai-confidence times 100 rounded to 0
    set combined-score to rule-score plus ai-score divided by 2 rounded to 0

    if combined-score is above 75:
        set decision to "block"
    otherwise if combined-score is above 40:
        set decision to "review"
    otherwise:
        set decision to "approve"

Payment Reconciliation

Compares ledger records against payment processor settlements. Loops through settlements to calculate running totals, detects mismatches, and uses AI to analyze discrepancies.

step CalculateTotals:
    set settlement-total to 0
    set settlement-count to 0

    for each settlement in settlements:
        set settlement-total to settlement-total plus settlement.amount
        set settlement-count to settlement-count plus 1

step CompareResults:
    set total-difference to ledger-total minus settlement-total
    if total-difference is not 0:
        set has-mismatch to true

Chargeback Dispute

Gathers evidence from multiple sources, asks AI for a dispute recommendation, then uses string matching to decide whether to contest or accept.

step BuildResponse:
    ask CaseBuilder to "analyze this chargeback dispute..."
        save the result as recommendation
        save the confidence as recommendation-confidence

    if recommendation-confidence is below 0.5:
        set action to "escalate"
    otherwise if recommendation contains "contest":
        set action to "contest"
    otherwise:
        set action to "accept"

Email Verification

Validates an email address submitted through a form. Demonstrates service calls, conditionals, and completion/rejection.

verify email using EmailVerifier with address email

if email is not empty:
    complete with status "verified"
otherwise:
    reject with "The email address could not be verified"

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Order Processing

Processes a new order: checks inventory, calculates totals with tax, charges payment with retry logic, and generates an AI confirmation message.

step CalculateTotal:
    set subtotal to order.subtotal
    set tax to subtotal times 0.08
    set total to subtotal plus tax

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GitHub Scout

Fetches a GitHub user profile from the public API and evaluates their popularity and activity level. Works with real data — no API key needed.

get profile using GitHub at "/users/{request.username}"
    save the result as profile
set followers to profile.followers

if followers is above 1000:
    set popularity to "star"

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Stripe Checkout

Processes a payment through Stripe's API with authenticated headers, status checking, retry logic, and Slack notification.

services:
    Stripe is an API at "https://api.stripe.com/v1"
        with headers:
            Authorization: "Bearer {env.STRIPE_SECRET_KEY}"

step CreateCharge:
    create charge using Stripe with amount amount and currency currency
        save the result as charge
        save the status as status-code
        on failure:
            retry 3 times waiting 5 seconds

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Slack Notification

Sends a formatted deployment notification to Slack with conditional message building based on deploy status.

step BuildMessage:
    if deploy-status is "success":
        set message to "Deployed {service-name} v{version} successfully"
    otherwise if deploy-status is "rollback":
        set message to "Rolled back {service-name} to v{version}"
    otherwise:
        set message to "Deployment of {service-name} v{version} failed"

Try in Playground

SendGrid Email

Sends a transactional email through SendGrid with authentication, input validation, and delivery status verification.

services:
    SendGrid is an API at "https://api.sendgrid.com/v3"
        with headers:
            Authorization: "Bearer {env.SENDGRID_API_KEY}"
            Content-Type: "application/json"

step SendEmail:
    send email using SendGrid at "/mail/send" with to recipient and subject subject
        save the status as status-code

Try in Playground

Inventory Lookup

Queries a SQLite database to check product stock levels using the database connector. Demonstrates table-mode queries, empty checks, and conditional logic.

services:
    DB is a database at "./inventory.sqlite"

step CheckProduct:
    get product using DB at "products" with id request.product-id
        save the result as product

    if product is empty:
        reject with "Product not found"

Customer Database

Queries a PostgreSQL database to look up a customer, aggregates their order history, and classifies them into a loyalty tier based on total spending.

services:
    DB is a database at "postgresql://localhost:5432/customers"

step GetOrderHistory:
    list orders using DB at "orders" with customer_id customer-id
        save the result as orders

    set total-spent to 0
    for each order in orders:
        set total-spent to total-spent plus order.amount

Daily Sales Report

Aggregates daily sales from a database, calculates revenue metrics, evaluates performance against targets, and sends a summary to Slack. Designed to run on a schedule.

step CalculateMetrics:
    if order-count is above 0:
        set average-order to total-revenue divided by order-count

step EvaluatePerformance:
    if total-revenue is above 50000:
        set performance to "exceptional"
    otherwise if total-revenue is above 25000:
        set performance to "strong"

flow schedule examples/daily-sales-report.flow --every "day at 18:00" --mock

SLA Monitor

Checks the health of critical services and alerts via PagerDuty when any are down. Designed to run every few minutes on a schedule.

step CheckPaymentAPI:
    get health using PaymentAPI at "/health"
        save the status as payment-status
        on failure:
            retry 2 times waiting 3 seconds
            if still failing:
                set payment-status to 0

    if payment-status is not 200:
        set failed-services to failed-services plus 1
        log "ALERT: PaymentAPI is not responding"

flow schedule examples/sla-monitor.flow --every "5 minutes" --mock --verbose

Running examples

With mock services

flow test examples/email-verification.flow --dry-run --verbose

With real APIs

The GitHub Scout example works with real data:

flow run examples/github-scout.flow --input '{"username": "torvalds"}'

As webhooks

Serve all examples as HTTP endpoints:

flow serve examples/ --mock --port 3000

Then trigger any workflow:

curl -X POST http://localhost:3000/github-scout \
  -H "Content-Type: application/json" \
  -d '{"username": "octocat"}'

Creating your own

Every Flow file follows the same structure:

config:
    name: "My Workflow"
    version: 1

services:
    # Declare your services here

workflow:
    trigger: when something happens

    # Your logic here

    complete with result data

See the Getting Started guide to create your first workflow, or the Language Reference for the complete syntax.