REST API Design
The course teaches HTTP fundamentals, RESTful resource design, request/response patterns, authentication, and error handling, enabling developers to build clean, consistent, and maintainable APIs for real-world applications.
Who Should Take This
It is ideal for front‑end engineers, back‑end developers, or technical leads who have basic web knowledge and regularly consume or expose JSON APIs. Participants seek to deepen their understanding of REST conventions, improve API consistency, and make informed design trade‑offs to enhance maintainability and client experience.
What's Included in AccelaStudy® AI
Adaptive Knowledge Graph
Practice Questions
Lesson Modules
Console Simulator Labs
Exam Tips & Strategy
20 Activity Formats
Course Outline
65 learning goals
1
HTTP Protocol Fundamentals
3 topics
HTTP Methods and Semantics
- Describe the semantics of HTTP methods (GET, POST, PUT, PATCH, DELETE, HEAD, OPTIONS) and identify which methods are safe, idempotent, or cacheable.
- Apply the correct HTTP method for a given operation based on its semantics, distinguishing between resource creation (POST), full replacement (PUT), and partial update (PATCH).
- Analyze scenarios where the standard HTTP method mapping is insufficient (batch operations, search with complex parameters, state transitions) and evaluate common workarounds.
- Describe the difference between JSON Merge Patch (RFC 7396) and JSON Patch (RFC 6902) and apply the appropriate PATCH format based on the complexity of partial updates required.
Status Codes and Headers
- Identify the five HTTP status code categories (1xx-5xx) and describe the meaning and appropriate usage of the most common codes (200, 201, 204, 301, 304, 400, 401, 403, 404, 409, 422, 429, 500, 503).
- Apply appropriate status codes to API responses for success, client error, and server error scenarios, avoiding the anti-pattern of returning 200 with an error body.
- Describe essential HTTP headers for API communication (Content-Type, Accept, Authorization, Cache-Control, ETag, If-None-Match, Location, Retry-After) and their role in content negotiation and caching.
- Apply HTTP caching headers (Cache-Control, ETag, If-None-Match, Last-Modified) to reduce unnecessary data transfer for frequently accessed API resources.
- Analyze how security-related headers (Strict-Transport-Security, X-Content-Type-Options, X-Frame-Options, Content-Security-Policy) protect API consumers and recommend a baseline security header configuration.
Content Negotiation
- Describe how content negotiation works using Accept and Content-Type headers and explain when an API should support multiple response formats (JSON, XML, CSV).
- Apply content negotiation to design an API endpoint that serves different representations of the same resource based on client preferences and quality factors.
2
RESTful Resource Design
4 topics
URI Design and Naming Conventions
- Describe RESTful URI naming conventions including plural nouns for collections, hierarchical path segments for sub-resources, and consistent use of lowercase and hyphens.
- Apply URI design principles to model a domain with collections, singletons, and sub-resources, ensuring URIs represent nouns (resources) rather than verbs (actions).
- Analyze edge cases in URI design including action-oriented endpoints, singleton resources, cross-cutting resources, and composite keys and propose RESTful solutions.
Resource Relationships and Nesting
- Describe strategies for representing resource relationships (nested URIs, link objects, embedded resources) and the trade-offs of nesting depth versus flat resource design.
- Apply resource nesting to model parent-child relationships and use link relations to connect independent resources without deep URI hierarchies.
- Evaluate when to use HATEOAS link relations versus documentation-driven discovery and assess the practical benefits and costs of hypermedia-driven APIs.
REST Maturity and Constraints
- Describe the Richardson Maturity Model levels (0: Swamp of POX, 1: Resources, 2: HTTP Verbs, 3: Hypermedia Controls) and identify the level of a given API design.
- Describe the six REST architectural constraints (client-server, stateless, cacheable, uniform interface, layered system, code-on-demand) and explain how each affects API design.
- Analyze the trade-offs between strict REST adherence and pragmatic API design, identifying when violating REST constraints is justified by developer experience or performance needs.
Resource Representation and Media Types
- Describe common API data formats (JSON, XML, Protocol Buffers, MessagePack) and explain the trade-offs between human readability, payload size, and parsing performance.
- Apply consistent JSON naming conventions (camelCase vs snake_case), date formatting (ISO 8601), and null handling strategies across all API endpoints.
3
Request and Response Patterns
3 topics
Pagination and Filtering
- Describe the three main pagination strategies (offset-based, cursor-based, keyset-based) and identify the performance and consistency trade-offs of each approach.
- Apply cursor-based pagination to a collection endpoint, including response metadata (next/previous links, total count, page size) that enables clients to traverse the full result set.
- Apply filtering and sorting query parameters to collection endpoints using consistent naming conventions and explain how to combine multiple filter criteria.
- Analyze the performance implications of deep offset pagination on large datasets and recommend migration strategies from offset-based to cursor-based pagination.
- Apply bulk operation patterns to design API endpoints that accept arrays of resources for batch creation, update, or deletion while reporting per-item success and failure status.
Response Shaping and Representation
- Describe sparse fieldsets (field selection) and resource expansion (embedding related resources) and explain how each reduces the number of API round-trips.
- Apply envelope patterns and consistent response structures to wrap API responses with metadata (pagination, timestamps, request IDs) alongside the resource data.
- Evaluate the trade-offs between over-fetching (returning too many fields) and under-fetching (requiring multiple requests) and compare REST field selection with GraphQL's approach.
Idempotency and Async Operations
- Define idempotency in the context of API operations and explain why idempotent endpoints are critical for safe retries in unreliable network conditions.
- Apply idempotency keys to make non-idempotent operations (POST) safely retriable by tracking request identifiers and returning cached responses for duplicate requests.
- Apply the asynchronous request pattern (202 Accepted with status polling endpoint) to handle long-running operations that cannot complete within a typical HTTP timeout.
4
Authentication and Authorization
4 topics
Authentication Mechanisms
- Describe common API authentication mechanisms (API keys, Basic Auth, Bearer tokens, mutual TLS) and identify the security level, ease of use, and appropriate use cases for each.
- Explain the structure of a JSON Web Token (header, payload, signature), describe common claims (sub, exp, iat, aud, iss), and explain the token validation process.
- Apply JWT-based authentication to a stateless API design, including token issuance, refresh token rotation, and secure token storage recommendations for different client types.
- Apply scope-based authorization to restrict API access based on token claims, differentiating between authentication (who are you?) and authorization (what can you do?).
OAuth 2.0 Flows
- Describe the four OAuth 2.0 grant types (authorization code, client credentials, implicit, resource owner password) and identify which grant is appropriate for each client type.
- Apply the Authorization Code flow with PKCE to secure a public client (single-page application or mobile app) and explain why PKCE mitigates the authorization code interception attack.
- Analyze the security trade-offs between OAuth 2.0 flows for different deployment scenarios (server-side web app, SPA, mobile, machine-to-machine) and recommend the appropriate flow.
Rate Limiting and CORS
- Describe rate limiting strategies (fixed window, sliding window, token bucket, leaky bucket) and the HTTP headers used to communicate rate limit status to clients.
- Apply rate limiting to an API with tiered limits by client plan, including appropriate 429 responses and Retry-After headers that enable clients to implement backoff.
- Describe CORS (Cross-Origin Resource Sharing) including preflight requests, allowed origins, methods, headers, and credentials and explain how misconfigured CORS creates security vulnerabilities.
- Apply CORS configuration to an API that serves browser-based clients from different origins while maintaining security by restricting allowed origins, methods, and headers.
API Security Best Practices
- Describe common API security threats (injection attacks, broken authentication, excessive data exposure, mass assignment) and their relationship to the OWASP API Security Top 10.
- Apply input sanitization and request size limits to protect API endpoints from injection attacks and denial-of-service through oversized payloads.
- Evaluate an API design for excessive data exposure vulnerabilities and recommend field-level access control to ensure responses contain only data the requesting client is authorized to see.
5
Error Handling and Validation
3 topics
Error Response Design
- Describe the RFC 7807 Problem Details standard for error responses and explain how structured error objects (type, title, status, detail, instance) improve client error handling.
- Apply a consistent error response format across all API endpoints including machine-readable error codes, human-readable messages, and field-level validation errors.
- Analyze the information leakage risks in error responses and design error messages that are helpful to legitimate developers without exposing internal implementation details.
Input Validation Strategies
- Describe request validation layers (schema validation, business rule validation, authorization checks) and explain the order in which they should be applied.
- Apply field-level validation to API request bodies with clear error reporting that identifies which fields failed, what the constraint was, and what value was provided.
- Evaluate the 400 vs 422 status code debate for validation errors and establish a consistent convention for distinguishing malformed requests from semantically invalid ones.
Graceful Degradation and Retries
- Describe retry-safe API design principles including idempotency guarantees, Retry-After headers, and exponential backoff with jitter for client-side retry logic.
- Apply circuit breaker concepts to API client design, explaining how clients should handle 503 Service Unavailable and degrade gracefully when a dependency is down.
6
API Versioning and Documentation
4 topics
Versioning Strategies
- Describe the three main API versioning strategies (URI path versioning, header versioning, query parameter versioning) and identify the trade-offs of each approach.
- Apply a versioning strategy to an API with breaking and non-breaking changes, distinguishing between additive changes (safe) and removing or renaming fields (breaking).
- Analyze the long-term maintenance costs of different versioning strategies and recommend a deprecation timeline that balances backward compatibility with API evolution.
API Documentation and OpenAPI
- Describe the OpenAPI (Swagger) specification structure including paths, operations, parameters, request bodies, responses, schemas, and security definitions.
- Apply OpenAPI specification to document an API endpoint with path parameters, query parameters, request body schema, response schemas for success and error cases, and authentication requirements.
- Evaluate the trade-offs between design-first (write spec then implement) and code-first (generate spec from code) API documentation approaches.
Changelogs and Deprecation
- Describe best practices for API changelogs including categorizing changes as additions, deprecations, and removals and communicating migration paths to consumers.
- Apply the Sunset header and deprecation warnings to communicate upcoming endpoint removal while providing a migration window for API consumers.
Developer Experience and API Design Review
- Describe API design review practices including style guides, linting rules, and consistency checks that maintain quality across large API surfaces with multiple contributors.
- Evaluate API developer experience by assessing time-to-first-call, error message clarity, documentation completeness, and SDK quality and recommend specific improvements.
Hands-On Labs
3 labs
~50 min total
Console Simulator
Code Sandbox
Practice in a simulated cloud console or Python code sandbox — no account needed. Each lab runs entirely in your browser.
Scope
Included Topics
- HTTP protocol fundamentals: request/response model, methods (GET, POST, PUT, PATCH, DELETE, HEAD, OPTIONS), status codes (1xx-5xx), headers (Content-Type, Accept, Authorization, Cache-Control, ETag), and connection management.
- RESTful resource design: URI naming conventions, resource identification, collection vs. singleton resources, sub-resources, resource relationships, HATEOAS principles, and Richardson Maturity Model levels 0-3.
- Request and response patterns: content negotiation, pagination (offset, cursor, keyset), filtering, sorting, field selection (sparse fieldsets), bulk operations, long-running operations (async patterns), and idempotency.
- Authentication and authorization: API keys, OAuth 2.0 flows (authorization code, client credentials, PKCE), JWT structure and validation, bearer tokens, scopes, rate limiting, and CORS configuration.
- Error handling and validation: standard error response formats (RFC 7807 Problem Details), input validation strategies, field-level error reporting, retry-after headers, and graceful degradation.
- API versioning and documentation: URI versioning, header versioning, query parameter versioning, semantic versioning for APIs, OpenAPI/Swagger specification, API changelogs, and deprecation strategies.
- Brief comparison with GraphQL and gRPC for context: when REST is the right choice versus when alternatives may be more appropriate.
Not Covered
- Framework-specific implementation details for Express.js, Flask, Django REST Framework, Spring Boot, ASP.NET Web API, or any other web framework.
- Database design, ORM configuration, or data modeling beyond what is needed to explain resource design.
- WebSocket protocols, Server-Sent Events, or real-time communication patterns beyond brief mentions as REST alternatives.
- API gateway configuration, service mesh setup, or infrastructure-level concerns (load balancing, reverse proxy).
- GraphQL schema design, gRPC protobuf definitions, or deep dives into non-REST API paradigms.
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