Create Dynamic API Gateway with HTTP Router and Workflow Orchestration

Overview
This workflow provides a universal webhook endpoint that dynamically routes incoming requests to different subflows. It allows you to manage multiple API-like endpoints from a single entry point, while ensuring proper error handling and consistent responses.

How it works
Webhook Receiver – A single URL accepts requests.
Method Detection – Branches capture the request method.
Route Resolver – Matches the action parameter and method against your route configuration. Execute Subflow – If valid, the matching workflow is executed.
Error Handling – If invalid, the workflow responds with a clear status code and JSON error.

About the action parameter
The action query parameter is the key that controls routing:

In your Routes Config, every route is defined with an action name, a list of allowed HTTP methods, and the target subflow ID.
When a request comes in, the workflow looks up the provided action in this config.
If the action is valid and the method is allowed, the corresponding subflow is executed.
If not, the workflow returns a structured error.

In other words:
Config side** → map action → subflow ID
Request side** → send ?action=... → determines which subflow runs

This makes action both the mapping key in the configuration and the control key for triggering the correct logic.

Setup steps
Import the workflow into n8n.
Define your routes in the Routes Config node. Each route contains:
action name
allowed HTTP methods
target subflow ID

This workflow is useful if you want to:
Expose multiple clean API endpoints without creating many Webhook nodes
Ensure consistent error handling across all endpoints
Keep your n8n setup more structured and maintainable

👉 A practical solution to turn n8n into a flexible and maintainable API gateway.