Skip to main content
Problem 23

Build a Basic Health Check Route

EASYBUILD
REST APIs / Routes+2

Add a GET /health route to the FastAPI app in main.py. The route must return a JSON response with two fields: status (always the string "ok") and uptime_seconds (the number of whole seconds since the app started, as an integer).

Health checks are how load balancers, container orchestrators, and monitoring systems know whether your service is alive. The response shape needs to be exact — anything that polls /health compares against a hardcoded schema, so misspellings or wrong types break the integration.

The uptime field forces you to capture a reference timestamp at module-load time. Don't compute a fresh start time inside the handler — that would give you 0 on every request.

Requirements
  • Register a GET /health route on the existing FastAPI app instance in main.py.
  • The route must respond with HTTP status code 200.
  • The response body must be JSON with exactly two keys: status and uptime_seconds.
  • status must always be the string "ok".
  • uptime_seconds must be a Python int (not a float, not a bool).
  • uptime_seconds must reflect whole seconds since the process started — it must grow monotonically across requests, never reset to 0 on a fresh request.
Examples
Example 1
Input
GET /health (immediately after the app starts)
Output
200 OK
{"status": "ok", "uptime_seconds": 0}
Note

Right at boot, uptime hasn't accumulated a full second yet.

Example 2
Input
GET /health (10 seconds after the app starts)
Output
200 OK
{"status": "ok", "uptime_seconds": 10}
Note

Uptime grows as the process keeps running. Always returns whole seconds, never fractional.

Constraints
  • Use FastAPI for route definition (the app object is already created in main.py).
  • Response body must be valid JSON.
  • uptime_seconds must be a Python int, not a float.
Follow-up

How would you extend `/health` to also report the status of each external dependency (database, Redis, etc.) without making the route slow under normal traffic?

Hints
Related Practice
Track
Backend Basics

Keep moving through related backend basics problems and build a stronger search-friendly practice loop around this topic.

View track →
Problem 3
Password Strength Tagger
easy
Problem 20
Refactor Duplicate Validation
medium
Problem 24
Validate Request Payloads
easy
Console output will appear here...