Deploy Your Second App

This guide walks you through deploying a two-service FastAPI stack from the howl-cloud/awesome-hostess examples repo.

This guide assumes you have the Hostess CLI installed and are logged in. If not, follow Deploy Your First App first.

What You'll Deploy

api — KickOff Sports product catalog endpoints, with metrics and traces in Studio
traffic — HTTP service that sends synthetic requests to api, so you have real data to look at in the Metrics tab

Clone the example

Terminal

git clone https://github.com/howl-cloud/awesome-hostess.git
cd awesome-hostess/simple-fastapi-app

pyproject.toml

hostess.yml

Review the hostess.yml

hostess.yml

version: "1.0"
name: simple-fastapi-app

services:
  api:
    type: fastapi
    source: ./api
    public: true
    resources: small

  traffic:
    type: fastapi
    source: ./traffic
    public: true
    env:
      API_URL: ${api.url}
    depends_on:
      - api
    resources: small

A few things to notice:

source: — Hostess installs application dependencies from the project and starts the FastAPI application.
public: true on both services — both get a public HTTPS URL.
${api.url} — the internal URL of api is injected into traffic at deploy time. The traffic service uses it to know where to send requests.

API Insights

The api service is type: fastapi with source:. Route-level Insights work with no application code.

On the Metrics tab in Studio you'll get per-route traffic, latency, and status-code breakdowns, plus sampled distributed traces you can open as a waterfall. See Insights.

Validate and deploy

Terminal

hostess validate

✓ hostess.yml is valid
  2 services: api, traffic

Terminal

hostess deploy

No project found. Create one?
  Project name: simple-fastapi-app
✓ Project "simple-fastapi-app" created

Environment: preview

  api     → Installing
  traffic → Installing

  api     ✓ built
  traffic ✓ built

✓ Deployment complete (dep_def456)

  api:     https://simple-fastapi-app-api-able-arc.hostess.run
  traffic: https://simple-fastapi-app-traffic-swift-meadow.hostess.run

Both services build in parallel. The CLI streams live phase labels as each image is built and pushed.

Browse the API

FastAPI generates interactive documentation at /docs. Open the api URL from the deploy output with /docs appended:

https://simple-fastapi-app-api-able-arc.hostess.run/docs

You'll see all available endpoints — products, categories, and orders — and can try them directly from the browser.

Generate traffic

The traffic service exposes a GET /run endpoint that fires a burst of requests at the api. Visit the URL from the deploy output:

Terminal

curl https://simple-fastapi-app-traffic-swift-meadow.hostess.run/run

{"sent": 20, "ok": 18, "errors": 2}

The count query parameter controls how many requests to send:

Terminal

curl "https://simple-fastapi-app-traffic-swift-meadow.hostess.run/run?count=100"

Run it a few times to build up enough data to see in Studio.

View metrics in Studio

Open hostess.sh and navigate to your simple-fastapi-app project. Select the deployment, then click the api service and open the Metrics tab.

You'll see:

Request rate and latency per route (e.g. GET /products, GET /products/{product_id}, POST /orders)
Status code breakdown — including the intentional 404s the traffic service sends to /products/99
Traces — click any route row to open sampled traces as a span waterfall

What's Next

Next.js + FastAPI + Postgres — Add a frontend and database to your API
Managing Secrets — Store API keys and credentials securely
Custom Domains — Point your own domain at your services
Insights — Learn what the Metrics tab shows and how sampling works

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