Building your first API with Nitric

What we'll be doing

  1. Use Nitric to create an API to create and update profiles
  2. Create handlers for the following API operations
MethodRouteDescription
GET/profiles/Get all profiles
GET/profiles/[id]Get a specific profile by its Id
POST/profilesCreate a new profile
DELETE/profiles/[id]Delete a profile
  1. Run locally for testing
  2. Deploy to a cloud of your choice
  3. (Optional) Add handlers for the following API operations
MethodRouteDescription
GET/profiles/[id]/image/uploadGet a profile image upload URL
GETprofiles/[id]/image/downloadGet a profile image download URL
GETprofiles/[id]/image/viewView the image that is downloaded

Prerequisites

Getting started

We'll start by creating a new project for our API.

nitric new my-profile-api py-starter

Next, open the project in your editor of choice.

cd my-profile-api

Make sure all dependencies are resolved using uv:

uv sync

The scaffolded project should have the following structure:

+--.venv/
+--services/
| +-- api.py
+--.env
+--.gitignore
+--nitric.yaml
+--.pythonversion
+--pythonproject.toml
+--uv.lock
+--README.md

Start the Nitric server to emulate cloud services on your machine:

nitric start

Building the Profile API

This example uses UUIDs to create unique IDs to store profiles against, let's start by adding a library to help with that:

uv add uuid

Applications built with Nitric can contain many APIs, let's start by adding an API and a key value store to this project to serve as the public endpoint.

import json
from uuid import uuid4
from nitric.resources import api, kv, bucket
from nitric.application import Nitric
from nitric.context import HttpContext
# Create an api named public
profile_api = api("public")
# Access profile key value store with permissions
profiles = kv('profiles').allow('get', 'set', 'delete')
Nitric.run()

Here we're creating:

  • An API named public,
  • A key value store named profiles and giving our service permission to get and set to that store.

From here, let's add some features to that service that allow us to work with profiles.

You could separate some or all of these request handlers their own services if you prefer. For simplicity we'll group them together in this guide.

Create profiles with POST

@profile_api.post("/profiles")
async def create_profile(ctx: HttpContext) -> None:
pid = str(uuid4())
name = ctx.req.json['name']
age = ctx.req.json['age']
hometown = ctx.req.json['homeTown']
await profiles.set(pid, { 'name': name, 'age': age, 'hometown': hometown} )
ctx.res.body = { 'msg': f'Profile with id {pid} created.'}

Retrieve all profiles with GET

@profile_api.get("/profiles")
async def get_all_profile(ctx: HttpContext) -> None:
profile_list = []
async for id in profiles.keys():
d = await profiles.get(id)
profile_list.append(d)
ctx.res.body = json.dumps(profile_list)
ctx.res.headers['Content-Type'] = 'application/json'

Retrieve a profile with GET

@profile_api.get("/profiles/:id")
async def get_profile(ctx: HttpContext) -> None:
pid = ctx.req.params['id']
d = await profiles.get(pid)
ctx.res.body = json.dumps(d)
ctx.res.headers['Content-Type'] = 'application/json'

Remove a profile with DELETE

@profile_api.delete("/profiles/:id")
async def delete_profiles(ctx: HttpContext) -> None:
pid = ctx.req.params['id']
try:
d = await profiles.delete(pid)
ctx.res.body = { 'msg': f'Profile with id {pid} deleted.'}
except:
ctx.res.status = 404
ctx.res.body = { 'msg': f'Profile with id {pid} not found.'}

Ok, let's run this thing!

Now that you have an API defined with handlers for each of its methods, it's time to test it locally.

Start the Nitric server to emulate cloud services on your machine:

nitric start

Once it starts, the application will receive requests via the API port. You can use cURL, Postman or any other HTTP client to test the API.

We will keep it running for our tests. If you want to update your services, just save them, they'll be reloaded automatically.

Test your API

Update all values in brackets [] and change the URL to your deployed URL if you're testing on the cloud.

Create Profile

curl --location --request POST 'http://localhost:4001/profiles' \
--header 'Content-Type: text/plain' \
--data-raw '{
"name": "Peter Parker",
"age": "21",
"homeTown" : "Queens"
}'

Fetch Profile

curl --location --request GET 'http://localhost:4001/profiles/[id]'

Fetch all Profiles

curl --location --request GET 'http://localhost:4001/profiles'

Delete Profile

curl --location --request DELETE 'http://localhost:4001/profiles/[id]'

Deploy to the cloud

At this point, you can deploy what you've built to any of the supported cloud providers. In this example we'll deploy to AWS. Start by setting up your credentials and configuration for the nitric/aws provider.

Next, we'll need to create a stack file (deployment target). A stack is a deployed instance of an application. You might want separate stacks for each environment, such as stacks for dev, test, and prod. For now, let's start by creating a file for the dev stack.

The stack new command below will create a stack named dev that uses the aws provider.

nitric stack new dev aws

Edit the stack file nitric.dev.yaml and set your preferred AWS region, for example us-east-1.

provider: nitric/aws@latest
region: us-east-1

You are responsible for staying within the limits of the free tier or any costs associated with deployment.

Let's try deploying the stack with the up command:

nitric up

When the deployment is complete, go to the relevant cloud console and you'll be able to see and interact with your application.

To tear down your application from the cloud, use the down command:

nitric down

Optional - Add profile image upload/download support

If you want to go a bit deeper and create some other resources with Nitric, why not add images to your profiles API.

Access profile buckets with permissions

Define a bucket named profilesImg with reading/writing permissions

photos = bucket("photos").allow('read','write')

Add imports for time and date so that we can set up caching/expiry headers

from datetime import datetime, timedelta, UTC

Get a URL to upload a profile image

@profile_api.get("/profiles/:id/image/upload")
async def upload_profile_image(ctx: HttpContext) -> None:
pid = ctx.req.params['id']
photo = photos.file(f'images/{pid}/photo.png')
photo_url = await photo.upload_url(expiry=timedelta(seconds=3600))
expires = datetime.now(UTC) + timedelta(seconds=(3600))
expires = expires.strftime("%a, %d %b %Y %H:%M:%S GMT")
ctx.res.headers['Expires'] = expires
ctx.res.body = photo_url

Get a URL to download a profile image

@profile_api.get("/profiles/:id/image/view")
async def download_profile_image(ctx: HttpContext) -> None:
pid = ctx.req.params['id']
photo = photos.file(f'images/{pid}/photo.png')
photo_url = await photo.download_url(expiry=timedelta(seconds=3600))
expires = datetime.now(UTC) + timedelta(seconds=(3600))
expires = expires.strftime("%a, %d %b %Y %H:%M:%S GMT")
ctx.res.headers['Expires'] = expires
ctx.res.body = photo_url

You can also directly redirect to the photo URL.

@profile_api.get("/profiles/:id/image/view")
async def download_profile_image(ctx: HttpContext) -> None:
pid = ctx.req.params['id']
photo = photos.file(f'images/{pid}/photo.png')
photo_url = await photo.download_url(expiry=timedelta(seconds=3600))
expires = datetime.now(UTC) + timedelta(seconds=(3600))
expires = expires.strftime("%a, %d %b %Y %H:%M:%S GMT")
ctx.res.headers['Expires'] = expires
ctx.res.headers['Location'] = [photo_url]
ctx.res.status = 303

Time to test the updated API

Update all values in brackets [] and change the URL to your deployed URL if you're testing on the cloud.

Get an image upload URL

curl --location --request GET 'http://localhost:4001/profiles/[id]/image/upload'

Using the upload URL with curl

curl --location --request PUT '[url]' \
--header 'content-type: image/png' \
--data-binary '@/home/user/Pictures/photo.png'

Get an image download URL

curl --location --request GET 'http://localhost:4001/profiles/[id]/image/download'
Last updated on Jan 6, 2025