External events into Shopify Flow

# External events into Shopify Flow

Canonical: https://docs.flowrelay.app/use-cases/external-events-to-shopify-flow/
Markdown: https://docs.flowrelay.app/use-cases/external-events-to-shopify-flow.md

Use this path when the important event starts outside Shopify but the workflow should stay inside Shopify Flow.

## When to use this
Use FlowRelay when Shopify Flow is the right workflow system, but the event source is not a native Shopify trigger.


## What FlowRelay owns
FlowRelay owns intake, authentication, validation, receipt history, and the handoff to Shopify Flow. Shopify Flow owns workflow branches and downstream actions.


## What to avoid
Do not paste real event bodies, customer data, endpoint secrets, authentication headers, or copied incidents into examples. Use synthetic values while proving the setup.


## Typical path
A typical path starts from the scenario, then moves into setup and verification.
1. Identify the sender
   Identify the outside system that will send the event, such as a supplier portal, warehouse tool, ERP, custom app, or partner system.
2. Create the endpoint
   Enter an Endpoint name and Source label, then choose the service that will send the POST request. FlowRelay applies compatible authentication instructions without connecting to or authorizing that service.
3. Adjust only when needed
   Open Change trigger when Shopify Flow needs a particular resource context. Open Advanced authentication and mapping when custom code should use HMAC-SHA256 or the payload needs custom event fields, identifiers, or required paths.
4. Add the Flow trigger
   Add the matching FlowRelay trigger to the Shopify Flow workflow.
5. Prove one test event
   Send one test event with synthetic data, then use the FlowRelay receipt to confirm the trigger was handed to Shopify Flow.

## Handoff Boundary
Delivered means FlowRelay handed the trigger to Shopify Flow. It does not mean downstream Shopify Flow branches, app calls, fulfillment changes, emails, or later systems completed.

## Related
- [Create an endpoint](https://docs.flowrelay.app/setup/endpoints.md)
- [Add the Shopify Flow trigger](https://docs.flowrelay.app/setup/shopify-flow-trigger.md)
- [Read receipts](https://docs.flowrelay.app/operate/receipts.md)

## Safety Boundary
Do not share endpoint secrets, authentication headers, HMAC values, tokens, raw event bodies, customer records, Shopify sessions, store passwords, or database URLs in public examples.