API Builder — Overview
The API Builder lets you create custom integrations with any REST API — even those not natively supported by Vantage. You design the integration using a step-by-step wizard, and the result becomes a reusable workflow node you can drop into any workflow.
Technical Knowledge Required: The API Builder is designed for users who understand REST APIs, HTTP methods, headers, authentication flows, and JSON response structures. This guide covers those concepts, but hands-on experience with APIs will help you move faster.
Who Is This For?
The API Builder is for teams that need to connect Vantage workflows to external services — CRMs, weather APIs, payment processors, inventory systems, or any service that exposes a REST API. If your data lives behind an API that Vantage doesn't have a built-in integration for, the API Builder bridges that gap.
What you'll be able to do after reading this guide:
- Understand what a REST API is and how it works
- Know where to find the information you need from an API provider's documentation
- Build a complete custom integration from scratch
- Map API response data into structured workflow outputs
- Debug common integration issues
How It Works
The API Builder uses a 4-step wizard to assemble your integration:
┌──────────┐ ┌──────────────┐ ┌──────────────────┐ ┌──────────────┐
│ Warning │ ──▶ │ General Info │ ──▶ │ Define Endpoints │ ──▶ │ Review & Save│
│ │ │ │ │ │ │ │
│ Confirm │ │ Name │ │ Method + Path │ │ Summary │
│ expertise│ │ Base URL │ │ Parameters │ │ Confirmation │
│ │ │ Auth Type │ │ Response Mapping │ │ Save │
└──────────┘ └──────────────┘ └──────────────────┘ └──────────────┘
Each step builds on the last, progressively assembling your integration definition. After saving, you add credentials and the integration becomes available as a workflow node.
Accessing the API Builder
- Navigate to Integrations in the sidebar.
- Click "API Builder" or "Create Custom Integration".
- The API Builder wizard opens.
Editing an Existing Integration
- To edit an existing integration, navigate to the API Builder with the integration ID — the wizard loads your saved configuration.
- To view a workflow's integration, navigate to the API Builder with the workflow ID — it loads the integration used by that workflow.
Guide Contents
This documentation is organized into focused sections. Read them in order for a complete education, or jump to the section you need:
| Section | What You'll Learn |
|---|---|
| REST API Fundamentals | HTTP methods, URLs, authentication, parameters, and JSON — the concepts behind every field in the wizard |
| Finding API Documentation | Where to find base URLs, auth requirements, and sample responses before you start building |
| Wizard Walkthrough | Step-by-step guide through the 4-step wizard, with the why behind each design decision |
| JSON Response Parser | Deep dive into the response mapping system — the most powerful part of the builder |
| Examples | Three complete real-world integrations built from scratch |
| Troubleshooting & Glossary | Common issues, root causes, and a quick-reference glossary of all technical terms |