Rest API Crash Course

Lesson 1 • REST Architectural Style

Covers the six REST constraints defined by Fielding and how they shape API design. Connects architectural principles to practical design decisions.

Lesson 2 • HTTP Protocol Fundamentals

Explains HTTP as the transport layer for REST APIs, covering requests, responses, and headers. Provides the protocol knowledge needed for all subsequent chapters.

Lesson 3 • REST vs. Other API Styles

Compares REST to SOAP, GraphQL, and gRPC across key dimensions. Helps learners choose the right style for a given use case.

Lesson 1 • Core HTTP Methods

Covers GET, POST, PUT, PATCH, and DELETE with their intended semantics and safe/idempotent properties. Forms the action vocabulary for every REST endpoint.

Lesson 2 • Idempotency and Safety

Defines idempotency and safety as method properties that affect retry logic and caching. Connects these properties to reliable API behaviour.

Lesson 3 • HTTP Status Code Classes

Explains the five status code classes (1xx–5xx) and their meaning in REST responses. Enables accurate interpretation of any API response.

Lesson 1 • Resource Modelling Basics

Teaches how to identify resources from domain entities and represent them as nouns in URLs. Anchors endpoint design in a resource-first mindset.

Lesson 2 • URL Structure and Hierarchy

Covers path segments, nested resources, and query parameters to express relationships and filters. Produces URLs that are readable and logically structured.

Lesson 3 • Endpoint Design Review Process

Introduces a structured checklist for evaluating endpoint designs before implementation. Connects design quality to downstream developer experience.

Lesson 4 • Naming Conventions and Standards

Establishes consistent casing, delimiter, and versioning conventions for endpoint names. Ensures APIs are predictable across teams and projects.

Lesson 1 • Response Body Design

Covers envelope patterns, resource representation, and error response structures. Ensures consumers receive consistent, actionable data.

Lesson 2 • Content Negotiation

Explains Accept and Content-Type headers for format negotiation between client and server. Enables APIs to support multiple formats without breaking consumers.

Lesson 3 • JSON as the Standard Format

Covers JSON syntax, data types, and serialisation rules as the dominant REST payload format. Provides the data-format foundation for all payload design work.

Lesson 1 • OAuth 2.0 Flows

Explains the four OAuth 2.0 grant types and when to apply each. Enables learners to implement delegated authorisation for user-facing APIs.

Lesson 2 • API Security Fundamentals

Introduces authentication vs. authorisation and common threat vectors targeting APIs. Sets the security mindset required for all subsequent implementation topics.

Lesson 3 • Role-Based Access Control

Applies authorisation rules to endpoints using roles and scopes. Ensures APIs enforce least-privilege access at the resource level.

Lesson 4 • API Key Authentication

Covers API key generation, transmission via headers or query params, and rotation strategies. Provides a simple auth mechanism suitable for server-to-server scenarios.

Lesson 1 • Offset and Limit Pagination

Covers the offset-limit pattern, its query parameter conventions, and its limitations at scale. Provides the most widely used pagination baseline.

Lesson 2 • Why Pagination Matters

Explains the performance and usability problems caused by unbounded collection responses. Motivates the need for pagination before introducing implementation strategies.

Lesson 3 • Cursor-Based Pagination

Introduces cursor pagination as a stable, performant alternative to offset pagination. Addresses real-time data and large dataset scenarios.

Lesson 4 • Sorting and Field Selection

Teaches sort parameter conventions and sparse fieldset patterns to reduce payload size. Completes the data retrieval toolkit for efficient API consumption.

Lesson 1 • Error Response Design

Establishes a standard error response schema including code, message, and detail fields. Consistent error shapes reduce consumer debugging time.

Lesson 2 • Returning Validation Errors

Teaches how to aggregate and return multiple validation errors in a single response. Improves developer experience by surfacing all issues at once.

Lesson 3 • Input Validation Strategies

Covers server-side validation of request bodies, path params, and query params. Prevents invalid data from reaching business logic or the database.

Lesson 1 • Why APIs Need Versioning

Explains breaking vs. non-breaking changes and the consumer impact of unversioned evolution. Establishes the business case for a versioning strategy.

Lesson 2 • OpenAPI Specification

Introduces the OpenAPI Specification as the standard for describing REST APIs in a machine-readable format. Connects spec-first design to documentation and code generation.

Lesson 3 • Versioning Strategies

Compares URL path, query parameter, and header-based versioning with trade-offs for each. Enables an informed choice of versioning approach for any project.

Lesson 4 • Maintaining and Deprecating Versions

Provides a process for communicating deprecations, setting sunset dates, and retiring old versions. Protects consumers while enabling API evolution.