Onboarding Developers with API Collections

Introduction

In this post, we’ll discuss how a product-thinking approach to designing APIs with API collections created with tools like Postman, Bruno, or Insomnia can be very effective as onboarding artifacts.

These collections are interactive guides that help developers experiment with workflows using real-world data, reduce friction, and become productive more quickly. They are more than request builders.

We'll examine the reason why OpenAPI specs, though valuable, tend to fail in promoting actual adoption. We'll also discuss how collections can communicate the story of your API, remain consistent with versioned codebases, and enable a culture of usability and iteration.

Prerequisites

To follow along, you’ll need:

• A tool like Postman, Bruno, or Insomnia (examples use Postman)

• Access to Vonage API keys or test environment

• Familiarity with basic API concepts

What Is an API Collection?

An API collection is a pre-defined set of requests that show how to work with an API in an organized, example-driven fashion. They're typically used in tools such as Postman, Bruno, or Insomnia, but you can even create them using structured cURL scripts.

What makes collections particularly potent is their interactivity. Instead of reading about an endpoint, developers can execute it, modify parameters, and observe responses in real time.

An API collection consists of:

• Request definitions (method, URL, headers, body)

• Environment variables (e.g., auth tokens or base URLs)

• Folder structures representing workflows (e.g., Auth, Create User, Send Message)

• Inline documentation

• Test scripts for validation

Why Traditional API Onboarding Falls Short

API Specs Tell, But Don’t Show

OpenAPI specs are wonderful for tooling, validation, and automatically generated documentation. But they're still blueprints, not actual buildings. They define what's there, not when or how to use it. They don't have sequence, narrative, or context.

Documentation Can’t Predict Developer Intent

A developer just trying to “send a test SMS” might get lost in deep dives on rate limits or optional fields they don’t yet need. Without good examples, developers resort to guesswork:

• Do I need this header?

• Should I encode this URL parameter?

• Why am I getting a 401 when my token looks valid?

No Safe Playground

Collections provide a structured and editable environment where developers or users can test workflows without worrying about triggering unintended behavior.

Benefits of API Collections

API collections improve Developer Experience in tangible ways, for both internal and external audiences.

Provide a Quick Start

API Collections do away with the blank page issue. Rather than beginning from scratch, developers open a collection and instantly see:

• Pre-filled requests

• Auth variables managed

• Clear structure for frequent use cases

This helps developers quickly achieve success, building early momentum.

Enable Interactive Learning

API collections support exploration in a way that static documents can’t. They can encourage a learn by doing mindset, for example:

• What happens if I change this parameter?

• Can I combine these calls?

• How does error handling work?

Enable Debugging

Collections serve as a shared language across teams:

• Developers can export failing requests

• Support engineers can replay and isolate issues

• QA teams can validate flows in staging

Enable Safe and Repeatable Testing

With environment variables, collections make it easy to test across:

• Local development setups

• Staging or sandbox APIs

• Production environments (carefully)

API collection can be used in automated tests or validating acceptance criteria during code reviews.

Improve Cross-Team Communication

Collections help different teams align on API behavior. They serve as living documentation that evolves with the product.

Build Trust Through Transparency

Collections show exactly what’s being sent and received. This visibility builds confidence,-8 especially in enterprise or regulated environments where transparency is critical.

How to Create and Share API Collections

In the following subsections, you can find a step-by-step approach for building an effective API collection.

Start with a Use Case, Not Endpoints

Don’t just import your OpenAPI spec into Postman. Do start with real workflows:

• What are the most common developer actions?

• What’s the “Hello, World” for your API?

• What does a full journey look like?

For example:

• Create a test user → Simulate login → Generate a token

• Send an SMS → Retrieve message status

Use a Tool That Fits the Product Technical Stack

Pick a tool that fits your team’s workflow - Postman, Bruno, Insomnia, or even VS Code REST Client.

Set Up and Configure a New Collection Project

Create a Project/Workspace and add:

1. A new collection (e.g., Customer Onboarding API)

2. Folders for logical groupings (Auth, Users, Payments)

3. Requests with:

   1. Descriptive names (Create User, Get Token)Valid default parameters

   2. Short inline descriptions

Add Environment Variables

Replace hardcoded values with variables for example: {{api_key}}, {{base_url}}, and {{access_token}}.

Create environments for:

• Local development

• Staging

• Production

For internal use, share environment configs through workspaces. 

For external users, include example values and setup instructions.

Optional: Add pre-request scripts to generate tokens automatically for OAuth flows.

Include Example Responses and Tests

For every request:

• Add successful example responses

• Include common error responses (401, 403, 500)

• Write test scripts to validate responses and extract values (like tokens or IDs) that can be reused in subsequent requests

Keep It Versioned

Treat collections like code:

• Store in a GitHub repo

• Update during sprint reviews

• Version with tags or branches aligned to release notes

Share in the Right Way

For External Customers

• Publish the collection via Public Workspaces or GitHub

• Include a README with setup instructions

• Provide a base environment template

For Internal Teams

• Store in GitHub or shared workspaces

• Pin to your internal portal, Notion, or onboarding docs

• Use Slack bots to surface links, e.g., "Need to test login? Use the Auth API Collection → [link]"

Vonage Contact Center API with Postman Example

If you'd like to integrate with the Vonage Contact Center API, you can do so using the official Postman collection. In the following steps, I'll show you what the onboarding flow looks like. Here’s what the onboarding flow looks like. You can find the official Vonage Postman collection to explore more.

Fork the Collection

In the image below, you can see what the root-level folders in this collection:

Root-Level API Folders in Postman Collection

From the public Postman page, click Fork.

Fork a Postman Collection for Vonage APIs

Create/Choose workspace (e.g., customer-support-dev).

Create Postman workspace from Fork

Set Up the Environment

Create a new environment.

Root-Level API Folders in Postman CollectionAdd variables like {{client_id}}, {{client_secret}} and {{region}} .

Vonage Auth Token Request from PostmanSelect this environment from the dropdown in Postman.

Select Environment in Postman

Authenticate

Run the POST auth/connect/token request.

Note: Postman will autofill the variables using the environment settings from previous steps.

Vonage User API GET Request from Postman

Make a Real API Call

Run GET /users from the Users folder.

Vonage Auth Endpoint Setup in PostmanCongratulations, you’re authenticated and ready to test the flow.

You can also:

• Extend with new folders

• Modify parameters

• Share across your team

• Version it alongside your app code

Conclusion

You could extend this with automated testing or CI integrations, or adapt the collection to other Vonage APIs like Voice or Messages.

When we treat API onboarding as a product experience, API collections are more than just convenient, they become a strategic companion. A carefully created collection of APIs can:

• Simplify the initial setup and learning curve for new developers.

• Empower developers to quickly understand and utilize the APIs effectively.

• Guide developers through the intended use cases and capabilities of the API ecosystem.

By integrating API collection into the documentation and version control practices, we can build an environment where learning is interactive, feedback is immediate, and API adoption feels truly seamless.