Start the local backend lab

Before you start: complete Generate pages from content, or make sure you can pass its checkpoint.

Create a server project#

Open another terminal and create a sibling to the View project:

# Run from: your-projects
npx -y @ketvietlab/ketjs@0.2.0 new learn_api
cd learn_api
npm install
npm run build

The generator creates a workspace, a module, development scripts and a deployment test. Keep the scaffold while working through the next lessons. The completed backend lab download adds a Todo API and a learning CLI; extract it into a different directory if you want to compare your implementation.

Use the learning CLI#

Inside the downloaded reference lab:

# Run from: learn_api
npm ci
npm run learn -- doctor
npm run learn -- list
npm run learn -- lesson server-project
npm run learn -- check api

doctor checks prerequisites. list prints the course's terminal lessons. lesson reads the bundled lesson text. check builds this project and runs only the selected executable checkpoint. Available checkpoints are printed by help; a lesson without an automated checkpoint still has a manual acceptance checklist.

The CLI is a project script. It does not publish an npm package, replace ket, or provision cloud resources. It calls the same tools you can run directly, and a failing checkpoint exits with a nonzero status.

Run the API locally#

Use the development command in a dedicated terminal:

# Run from: learn_api
npm run learn -- serve

The lab binds to 127.0.0.1:3711. The starter development identity uses the X-Ket-Company header so you can experiment with company scope locally. This convenience is not a production authentication design.

# Run from: learn_api
curl -H 'X-Ket-Company: lab' http://127.0.0.1:3711/api/todos

The completed project initially returns an empty array. If you created the untouched scaffold instead, its original route is /; the next lessons build the Todo endpoints. Keep that distinction clear when comparing results.

Checkpoint#

Run doctor, understand the difference between scaffold and completed lab, and get a response from the local reference API.

Practice on your own#

Run the API checkpoint, then deliberately stop the server and identify which command starts a development server versus which starts an isolated test deployment.

Reference#

For the complete API contract, read Quick Start.