Find the bug

Setup your machine

Install pnpm and turbo, and prepare an OpenAI API Key with access to GPT-4o (i.e. with a credit card behind it). We can supply you an API key during the interview.

Set up CopilotKit for development

(make sure you have pnpm and turbo installed)

cd CopilotKit/CopilotKit
pnpm i
pnpm -w freshbuild
turbo link:global
turbo run dev

Configure environment variables

(make sure you put an actual OpenAI API Key with access to GPT-4o!)

cd my-app
echo "OPENAI_API_KEY=\"your_actual_api_key_here\"" > .env

Set up the demo app for development

cd my-app
pnpm i
pnpm link --global @copilotkit/react-ui @copilotkit/react-core @copilotkit/runtime-client-gql @copilotkit/shared @copilotkit/runtime
pnpm run dev

Setup

The app contains a minimal example to reproduce a bug in this version of CopilotKit.

1. First, in the chatbot, write navigate to /home, and observe that the 'path' variable (on the left side) is updated:

2. Then, write in the chatbot alert the path, and observe that the 'path' variable is indeed alerted:

The bug

Now refresh the app to start from scratch, and paste in

navigate to /home and then alert the path

Observe that the path is updated, but CopilotKit doesn't alert the path! I.e. composite actions don't work correctly.

Instructions

• Hint: the bug is in CopilotKit itself -- not in the app, but prove this to yourself first by understanding the useCopilotAction calls in the app
• Hint: focus your efforts on packages/react-core/src/hooks/use-chat.ts
• You can modify the code in the CopilotKit/CopilotKit folder -- and the app will reload with your updated code

The point is not necessarily to fix the bug during the time of the interview, but to see how you approach debugging a real issue you might encounter while working on infrastructure at CopilotKit (and understanding new code).

This may be hard but it's not a trick setup - good luck!