Day 126 — API Integration: The Moment of Truth
What We’re Building Today
A live FastAPI server with 18 documented endpoints — auth, users, teams, metrics, security
A Python SDK (
InfraStackClient) with chainable resource namespaces, typed errors, and exponential backoff45 integration tests across 5 suites — all passing before we move on
A React dashboard styled after Postman’s collection runner — live test execution, latency charts, status distribution
A single self-contained
setup.shthat builds, tests, and demos the whole thing in one command
Prerequisites: Python 3.11+, Node.js 20+, Docker (optional) Completed: Days 122–125 (API Security, Documentation, Testing, SDKs)
Project Structure
Everything in this project is created by setup.sh — you don’t manually create anything.
day126/
├── setup.sh # one-command master script
├── docker-compose.yml
├── backend/
│ ├── main.py # FastAPI app (18 endpoints)
│ ├── requirements.txt
│ ├── sdk/
│ │ └── client.py # Python SDK (InfraStackClient)
│ └── tests/
│ ├── conftest.py
│ └── test_integration.py # 45 tests, 5 suites
├── frontend/
│ ├── package.json
│ └── src/App.jsx # React dashboard
└── diagrams/
Why Integration Testing Deserves Its Own Day
You can have 100% unit test coverage and still ship a broken API. Unit tests verify functions in isolation; integration tests verify the system as a whole — authentication gates holding, database writes surviving network roundtrips, SDK error handling matching actual server behavior.
Stripe’s payment API has a dedicated integration sandbox because even minor contract drift between client and server can cause millions in failed transactions. GitHub’s API runs end-to-end tests on every deployment. This isn’t paranoia — it’s engineering maturity.
Today we prove our Week 11 API stack actually works, together. Every piece we built across Days 120–125 gets validated end-to-end: auth, users, teams, metrics, security headers, SDK contracts, documentation coverage, and latency baselines.
The Five Test Dimensions
Every production API needs validation along five distinct axes. Miss any one and you ship blind. Our 45-test suite covers all five — a standard you’ll carry into every job you take.
