Hestia App Uses Strands AI Agents to Flag Household Money Leaks Without Overstepping

Hestia is a household finance app built for the AWS Agents for Humans hackathon that uses two Strands AI agents to help families catch overlooked expenses like lapsed warranties, unwanted subscriptions, and missing receipts. The app runs on Amazon Bedrock using Claude Haiku 4.5 and is designed so that the AI only reads and flags issues, while all date and amount calculations are handled by plain Python code. A review agent scans household data through four read-only tools and produces a short briefing, while a separate reading agent converts pasted text into proposed records — neither agent can write, send, or modify any data. To prevent the model from overstating conclusions, the system prompt explicitly bars it from implying refund entitlements or inventing deadlines, restricting it to facts drawn directly from tool outputs. The code also independently verifies the model's responses after each run, treating the prompt as a guideline rather than a guaranteed constraint.