Mission 3 of 12 · Updated November 2026

Build an API-Powered Search App

Talk to the internet. Learn how HTTP, REST and JSON work, test real endpoints in Bruno, then build a search app on a public REST API with ES modules, async/await, loading states and proper error handling. The AI is off: you debug with breakpoints, stack traces and the Network tab.

By the end of this mission: “I can fetch and display live API data with async JavaScript, handle failures gracefully, and debug with DevTools instead of guessing.”

The tech stack for this mission

JavaScript logoJavaScriptBruno logoBrunoChrome DevTools logoChrome DevToolsGitHub logoGitHub

What you learn, checkpoint by checkpoint

  1. Checkpoint A

    Explore a public REST API in Bruno and read real HTTP requests and responses

    • How HTTP, REST and JSON fit together in a client-server app
    • Send requests and read responses, status codes and headers in Bruno
    • Read an API’s documentation and the shape of the JSON it returns

  2. Checkpoint B

    Fetch data with async/await across ES modules and render the results

    • Split code into ES modules with import and export
    • Work with promises and async/await
    • Call the API with the Fetch API and render the search results

  3. Checkpoint C

    Handle loading, empty and error states, and debug with breakpoints

    • Show loading, empty and error states with try/catch
    • Debug with breakpoints, stack traces and the Network tab - no AI
    • Write a short note on every bug you found and how you fixed it

AI companion mode · No AI Companion

AI OFF · you debug on your own

AI is locked for this mission. Debug from docs, DevTools and code reading only. Proves you can think without autocomplete.

What proves you’re done

Working search app + Bruno collection + notes on the bugs you found and fixed

Every mission ships something real you can show. If you can’t explain it, you can’t submit it.

Deliberately left out of this mission

GraphQL · WebSockets · Advanced networking

Depth is set on purpose: you master what this mission needs, not everything at once. The advanced material lives in optional self-study after Mission 12.

Free · no card needed

Reading is not building.

This mission is part of the paid 12-week programme - but the way we teach is free to try. The free trial puts you inside Sigmo, the learning portal our students use daily, with the 6 Projects in 6 Days precourse: real projects, real code, published to your own GitHub.

Start the free trial

Mission 2

Build an Interactive Task Manager

Mission 4

Build a Job Board Frontend in React

Ready for the real thing?

The AI-Native Software Development Programme - all 12 missions with a live cohort, daily Buildroom, and mentors watching your back.

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