QA: Reasoning (Custom) — LlamaIndex

Prerequisites

• Demo is deployed and accessible
• Agent backend is healthy (check /api/health)

Test Steps

1. Basic Functionality

• Navigate to the reasoning-custom demo page (/demos/reasoning-custom)
• Verify the chat interface loads with placeholder "Type a message"
• Send a basic question such as "Why is the sky blue?"
• Verify the agent responds with a text answer

2. Reasoning Slot Override

• Ask a question that encourages step-by-step thinking
• Verify the custom reasoning block (data-testid="reasoning-block") is visible in the chat when reasoning tokens surface
• Verify the "Reasoning" badge is shown
• Verify the body of the reasoning block is italic

3. Regression

• Multiple turns preserve conversation history
• Reasoning block disappears when starting a fresh conversation