Define the feature boundary

We will build a local activity summarizer.

Its input is factual application data:

const activity = {
  focusMinutes: 52,
  completedTasks: 3,
  interrupted: false,
}

Its output is one sentence plus a confidence label:

{
  summary: 'You focused for 52 minutes and completed 3 tasks.',
  confidence: 'high',
}

The original activity record remains the source of truth. The generated sentence is a convenience.

Define failure before writing the request. If Ollama is missing, the model is unavailable, the request times out, or the response fails validation, the application will create a deterministic sentence from the original fields.

This boundary keeps the product useful without AI. It also gives us an exact contract to test.