Priceflow/walkthrough.md

Walkthrough: Vision-First Price Extraction

In response to issues where the AI was being misled by hidden text (like unit prices or old prices in HTML), we have implemented a Vision-Priority Strategy.

Changes Implemented

1. Updated AI System Prompt (app/ai_schema.py)

We completely rewrote the EXTRACTION_PROMPT_TEMPLATE to enforce the following rules:

• Source of Truth = Image: explicit instruction that the screenshot takes precedence over any text.
• Conflict Resolution: "IF IMAGE AND TEXT CONFLICT, TRUST THE IMAGE."
• Visual Focus Rules:
  • Look for the largest/boldest price.
  • Ignore small, styling-less text (often unit prices).
  • Ignore crossed-out text.

Verification

We verified the new prompt generation using verify_vision_priority.py.

Generated Prompt Preview:

You are a Vision-First Price Extraction Agent.
Your Goal: Extract the main product price exactly as a human sees it on the screen.

**SOURCE OF TRUTH = IMAGE**
- The image provided is the **Absolute Truth**.
- The text provided below is scraped HTML content which may contain hidden/old prices.
- **IF IMAGE AND TEXT CONFLICT, TRUST THE IMAGE.**

How to Test

1. Go to "Suivis Prix".
2. Force refresh an item that was previously incorrect (e.g., B&M item showing unit price).
3. The AI should now ignore the "hidden" unit price text and read the main price tag from the image.