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API Development for Beginners

Build the invisible engines that power apps and payments — and get paid to do it in naira and dollars.

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About this course

Learn what an API really is and how to build one from scratch: endpoints, HTTP methods, status codes, JSON, authentication, versioning, error handling and clean documentation, all tested in Postman. You'll also learn to consume third-party APIs the way Nigerian apps talk to Paystack and Flutterwave. By the end you can design, build, document and test a small secured API — the core skill behind backend jobs and contracts paying ₦250,000+ a month locally and $1,500+ per project from foreign clients.

Every time you fund your Opay wallet, check a bank balance or pay on Jumia, an API is doing the work behind the scenes. An API is simply how two pieces of software talk to each other — and learning to BUILD them is one of tech's most durable, best-paid skills.

What you'll learn

Course syllabus — 7 lessons

  1. What an API actually is — the invisible engine behind every app you use12 min
  2. REST, endpoints and HTTP methods — the grammar of every web API13 min
  3. Requests, responses, JSON and status codes — how data actually travels14 min
  4. Testing APIs with Postman — your hands-on workshop and best friend14 min
  5. Query parameters, request bodies and validation — taking the right input cleanly13 min
  6. Authentication, versioning and error handling — making your API secure and durable14 min
  7. Consuming third-party APIs and documenting your own — Paystack, payments and getting paid14 min

Your project

Design, build (or fully spec) and test a small secured API

A single link to a public GitHub repo OR shared doc that contains: (1) your API design with at least 4 endpoints under a /v1 version prefix using correct REST methods, including at least one query parameter and clearly marked authenticated endpoints; (2) per-endpoint specs with body fields/types, validation rules with their 400 messages, success status codes and one consistent error shape; (3) a README documenting every endpoint with example request and response; and (4) a link to (or export of) your Postman collection with one tested request per endpoint. If you deployed a live API, include its base URL; otherwise the spec plus Postman collection is fully accepted.

Certificates on Skillnaija are earned, not issued for attendance: you submit this project, it is graded against a rubric, and passing issues a certificate anyone can verify.

Frequently asked questions

Is API Development for Beginners free?

Yes. API Development for Beginners is completely free on Skillnaija. You need a free account to open the lessons, and there is no charge for the course, the project, or the certificate.

How long does API Development for Beginners take to complete?

6 weeks · ~4 hrs/week. There are 7 lessons, about 2 hours of material in total. You learn at your own pace and your progress is saved.

Do I need any experience to start API Development for Beginners?

Beginner-friendly. You can start from scratch — no prior experience is assumed.

What will I learn in API Development for Beginners?

You will build practical skills in REST principles, endpoints & HTTP methods, Status codes, JSON & request/response design, Query params, request bodies & validation, API key / token authentication & versioning, Error handling & clear API documentation, Testing APIs with Postman, Consuming third-party APIs (Paystack/Flutterwave-style). Every lesson is written for a Nigerian context, with examples drawn from how the work is actually done and paid for here.

Do I get a certificate for API Development for Beginners?

Yes, but it has to be earned. You complete the course project — Design, build (or fully spec) and test a small secured API and submit it for grading. Passing the project issues a verifiable certificate; finishing the lessons alone does not.

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