🔌 APIs & Communication Protocols: Sub-Curriculum Index

Welcome to the APIs & Communication Protocols curriculum. This track covers API design standards, protocol tradeoffs (REST, GraphQL, gRPC, Webhooks), contract specifications (OpenAPI 3.1), modern authentication (OAuth 2.0, OpenID Connect, JWT), pagination, error response RFCs, and API security.

Every guide in this series strictly follows a two-part learning format:

  • ⚡ Quick Dive: Syntax cheat sheets, status code quick references, and protocol comparison matrices.
  • 📖 Extended Guide: Complete schema definitions, request/response payloads, authentication sequence flows, and architectural best practices.

📚 Complete Curriculum Roadmap

Part 1: API Foundations & Design Standards

# Guide Primary Topics Covered
01 API Development Roadmap Progressive engineering roadmap from basic CRUD endpoints to enterprise API platforms.
02 Guide to API Protocols Architectural comparison: REST vs. GraphQL vs. gRPC vs. WebSockets vs. Webhooks.
03 RESTful API Design Guide Resource URI naming conventions, HTTP methods, statelessness, and HATEOAS maturity model.
04 API Design Essentials Core design heuristics: predictability, naming consistency, filtering, sorting, and payload structures.
05 HTTP Status Codes Reference Standard HTTP status codes (2xx, 3xx, 4xx, 5xx), semantics, and when to use 400 vs 422 vs 403 vs 401.
06 Error Response Schema Guide Standardized error payload design using RFC 7807 (Problem Details for HTTP APIs).
07 API Pagination Essentials Offset-based vs. page-based vs. keyset pagination quick overview and trade-offs.
08 Advanced API Pagination Techniques Deep dive into Keyset / Cursor-based pagination, encode/decode opaque cursors, and database performance.
09 API Versioning Strategies URI path versioning, custom request headers, query parameters, content negotiation, and deprecation policies.

Part 2: Protocols, Specs & Documentation

# Guide Primary Topics Covered
10 GraphQL Deep Dive Schemas, Queries, Mutations, Subscriptions, Resolvers, solving N+1 queries with DataLoader, and caching.
11 gRPC & Protocol Buffers Deep Dive Proto3 syntax, HTTP/2 binary framing, unary vs. streaming RPCs, and code generation.
12 Webhooks Architecture & Security Event notification architectures, HMAC SHA-256 signature verification, retries, and idempotency.
13 OpenAPI & Swagger Specification OpenAPI 3.1 YAML definitions, path parameters, request bodies, response schemas, and code generators.
14 API Documentation Best Practices Developer experience (DX), interactive playgrounds, SDKs, changelogs, and documentation tooling.

Part 3: Authentication, Security & Scale

# Guide Primary Topics Covered
15 JSON Web Tokens (JWT) Header, Payload, Signature structure, cryptographic signing (HS256 vs. RS256/Ed25519), and revocation.
16 OAuth 2.0 & OpenID Connect (OIDC) Authorization Code Flow with PKCE, Client Credentials, Refresh Tokens, Scopes, and Identity Tokens.
17 API Security & Hardening OWASP API Top 10 vulnerabilities (BOLA/IDOR, Mass Assignment), CORS headers, rate limiting, and API keys.
18 API Testing and Validation Contract testing, automated regression suites, mocking external APIs, and fuzz testing.
19 Scaling the API Layer API Gateway clustering, response caching, compression (Brotli/Gzip), and horizontal auto-scaling.
⌂ All Guides