Module 6: The Web, HTTP and APIs

Build and inspect a real local API exchange. Learn the address/message/validation model before frameworks, cloud accounts or distributed-systems theory. This turns the CS overview into a concrete client that can explain its failures.

Planning allowance: 16–24 focused hours, included in semester workload. Authored candidate; executable checks do not replace independent review or learner calibration. Full-book reading is not required.

Before you start

Complete the immediate Programming Basics gate and Module 5 representation/schema lessons. You need functions, exceptions and JSON shapes. Use the supplied server and transport adapters; you do not need to implement sockets or learn a web framework.

Diagnostic: Explain how a relative file path differs from a URL. Read a JSON list and identify its element types. If JSON validation is unclear, repair that boundary in Modules 0/08; lack of networking experience is expected.

Outcomes

• Explain URL parts and distinguish connection failures from HTTP statuses.
• Inspect method, path, status, headers and bounded response bytes.
• Validate a JSON response without hiding errors as empty success.
• Separate fixture evidence from a real local client/server exchange.

Concept map

Concept clusters and learning order

Cluster 1: The Network Model

• URLs, Hosts and Ports
• HTTP Requests and Responses

Apply both lessons in Practice 1.

Cluster 2: API Boundaries

• JSON API Contracts
• Errors, Timeouts and Retries

Apply both lessons in Practice 2.

Cluster 3: A Local API Client

• Observe a Real Exchange
• Fixtures and Integration Checks

Apply both lessons in Practice 3.

Build, review and assess

Use worked examples, guided lab, exercises, case studies and mistake clinic. Finish the independent assessment under the rubric, then consult calibration.

Workload and outputs

Lessons/selected reading 5–7; cluster practice 3–5; implementation and local exchange 6–9; assessment and one repair 2–3: 16–24 hours.

Preserve your implementation, original predictions, actual results, a repaired defect and transfer evidence. Use existing Git/assistance records; keep generated code and copied examples distinguishable from independent work. The common lab archive is downloaded once, but each module implements and verifies a distinct boundary.

Depth and future connection

Reading guide → resources → reference. Capstone throughline explains what to retain. Technical integration specifies prerequisites, evidence reuse and later-semester boundaries.