Global CO₂ React Native App

A lightweight Expo-powered React Native application that fetches and displays today's global atmospheric CO₂ concentration (in parts per million). The data is sourced dynamically through OpenAI's web search capability.

Getting started

1. Install dependencies

   npm install

   Note In the hosted sandbox used for development the install step fails with a 403 Forbidden response from the npm registry. This is an environment/network restriction rather than an issue with the project. Install the dependencies locally or in any environment that has access to the public npm registry.

2. Configure your OpenAI credentials

   • Create a .env file or export the variable before starting Expo:

     export EXPO_PUBLIC_OPENAI_API_KEY="your_openai_api_key"

   • Alternatively, edit app.json and populate expo.extra.openaiApiKey (not recommended for checked-in secrets).

3. Run the app

   npm run start

   Use the Expo CLI output to open the app on an emulator, a device, or the web.

How it works

• On launch (and whenever the user pulls to refresh), the app calls the OpenAI responses API with the web_search tool enabled.
• The assistant is instructed to return a strict JSON payload containing:
  • ppm: the latest measured global CO₂ concentration.
  • source: a citation URL returned from the search.
  • timestamp: the ISO 8601 date/time for the measurement.
• The UI presents the value, measurement timestamp, and a tappable source link.

Notes

• Error states (e.g., missing API keys or parsing issues) are surfaced to the user so they can resolve configuration problems quickly.
• Because the app depends on OpenAI's live web search, running it requires network connectivity and an account with access to the responses API and the web_search tool.
• Expo SDK 50 is used to maximize compatibility across iOS, Android, and web targets.