Getting Started

Goal

This snapshot advances Rivermouth Dispatch by teaching you to create a minimal FastAPI app on port 8001.

Every numbered folder is a complete app. Run this stage independently, then compare it with the previous folder.

Prerequisites

Use Python 3.11+, a terminal, and Docker for Postgres stages. You should recognize functions, modules, and HTTP verbs.

Port 8001 must be free. Copy .env.example before starting database stages.

• Python 3 and pip/venv
• A code editor and terminal
• Docker from part 4 onward

Concepts

FastAPI builds an ASGI application with typed route functions and automatic OpenAPI docs.

Keep request handling thin: routes accept input, services/models enforce rules, and Jinja templates escape output by default.

Walkthrough

Create the app object, return JSON from the root path, and run Uvicorn on port 8001.

Read the example, then open the matching snapshot. The repository includes the surrounding setup and error handling.

from fastapi import FastAPI
app = FastAPI(title="Rivermouth Dispatch")
@app.get("/")
def home():
    return {"message": "Rivermouth Dispatch is live"}

Run and verify

Enter 01-Getting-Started, create a virtualenv, install requirements, copy .env.example when present, and start Uvicorn on port 8001.

Open http://127.0.0.1:8001. Watch the terminal for validation and database errors.

git clone https://github.com/michaeldunga1/fcc-fastapi-blog.git
cd fcc-fastapi-blog/01-Getting-Started
python3 -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt
cp .env.example .env
uvicorn main:app --reload --port 8001

Troubleshooting

If the browser cannot connect, confirm Uvicorn is still running. Address already in use means another process owns 8001.

Import errors usually mean the virtualenv is inactive or you installed packages in another snapshot. For Postgres failures, confirm Docker and the rivermouth_NN database name.

• Read the first error first
• Restart after environment changes
• Never commit .env or .venv

Try this

Add a /health route that returns JSON ok: true.

Test a happy path and one invalid or unauthorized request.

• Make one small change
• Test it in the browser
• Compare with the next snapshot only after it works