An intelligent conversational AI system that manages doctor appointments through natural language. Built with LangGraph's multi-agent architecture, it uses a supervisor pattern to coordinate specialized agents that handle appointment inquiries and bookings. Users can check doctor availability, book appointments, cancel, or reschedule—all through plain English queries via a Streamlit web interface or REST API.

The system implements a supervisor-worker pattern with three core nodes:

Acts as the orchestrator and decision-maker

Uses GPT-4o with structured output to route queries to appropriate agents Analyzes conversation context to determine when tasks are complete

Implements recursion limits and circular conversation detection to prevent infinite loops

Specialized agent for availability queries

Provides doctor availability by name or specialization

Uses ReAct (Reasoning + Acting) pattern with two tools:

check_availability_by_doctor - searches by specific doctor name

check_availability_by_specialization - searches by dental specialty (general, cosmetic, pediatric, etc.)

Handles all appointment modifications

Equipped with three tools:

set_appointment - books new appointments

cancel_appointment - cancels existing appointments

reschedule_appointment - moves appointments to new time slots

User submits query with ID number via Streamlit UI or API

FastAPI endpoint initializes agent state with message and user ID

Supervisor analyzes intent and routes to appropriate specialized agent

Specialized agent executes tools against CSV database

Agent returns to supervisor with results

Supervisor decides: continue to another agent or FINISH

Final response returned to user

Uses Pydantic models with regex validators:

DateModel: DD-MM-YYYY format

DateTimeModel: DD-MM-YYYY HH:MM format

IdentificationNumberModel: 7-8 digit patient IDs

CSV-based storage (doctor_availability.csv) tracks:

Doctor names and specializations

Available time slots

Booking status

Patient assignments

LangGraph - Multi-agent orchestration and state management

LangChain - LLM abstraction and tool integration

FastAPI - REST API server

Uvicorn - ASGI server

Pydantic - Data validation and settings management

Streamlit - Interactive web UI for user queries

Python - Base language