Add storage that remembers your work

What you’ll be able to do

• Define a small inventory record and its validation rules.
• Explain why durable data belongs behind an authorized backend.
• Test create, read, update, and reload behavior.

Get the idea

Model the task, not the universe

An inventory item might need an ID, name, location, and status. Avoid adding fields merely because an assistant suggests them. Decide which fields are required and how duplicates should behave.

Durability is a service responsibility

A browser’s in-memory list disappears. A managed database can retain records across sessions, but the application still needs validation, error handling, and access rules. A database connection is not automatically a secure API.

Keep privileged access server-side

Use the official SDK in the backend. Prefer appropriate identity-based access where supported. Do not deliver database account keys to the frontend. Partition-key choices affect how Cosmos DB distributes and queries data.

Try it yourself

1. Define the inventory record and four acceptance criteria: valid creation, rejected invalid input, update, and persistence after reload.
2. Follow the linked Node.js Cosmos DB quickstart in a dedicated lab scope. Review its resource settings and price before deployment.
3. Ask an AI assistant to explain the sample’s database, container, and partition key. Check its explanation against the sample.
4. Build a small server-side inventory API using the sample’s supported SDK pattern. Add validation and return safe errors; do not expose it publicly until authorization is implemented.
5. Create a fictional item, restart the client, read it back, update its status, and delete it. Record which component makes the data durable.

Example · commands or prompt

Using this reviewed Cosmos DB Node.js sample, design an inventory
record and server-side CRUD handlers.
Validate name and status; define a partition key deliberately.
Never put database credentials in frontend code.
Explain how callers will be authorized before public deployment.
Include tests for invalid input, missing records, and persistence.

Finish the lab

Remove the fictional records and dedicated database resources when finished. Check all resources created by the quickstart. Do not claim this is a free or production-ready deployment.

Take this with you

Let the platform handle storage infrastructure while you define data, access, and correctness.

Go deeper

• Cosmos DB for NoSQL Node.js quickstart

AI-assisted lesson · Reference links checked October 3, 2026. Exercises are teaching examples; they have not been executed against your Azure subscription.