09 / 11 · BARGAIN
Bargain Agent
Ask for a weekend away from Madrid on a budget and get ranked destinations with weather, deals and hotel prices, each price with its link and none invented.
The problem
Travel answers from an LLM sound right and quote prices that do not exist. Deal titles are written by strangers, so they are also an injection risk.
What I did
A LangGraph supervisor with parallel weather and deals agents, an MCP server of its own, human approval before spending API quota, and grounding by construction: models choose by reference and code prints every price.
What changed
No price is ever written by a model, and an injected deal title can at worst attach a real deal. Covered by evals and tests.