d4c-service-geo-assistant/docs/index.md

Geo Assistant

The Geo Assistant agent is a LangGraph-based ReAct agent that can answer questions and perform tasks related to locations and geographic data.

Architecture

The agent follows the ReAct (Reasoning + Acting) pattern, which interleaves reasoning traces and task-specific actions to solve queries. It uses LangGraph to manage state transitions and tool execution.

Available Tools

The agent has access to the following tools:

• get_place: Retrieve place information from the Overture Maps database
• get_search_area: Create a buffer area (in km) around a place defined in the agent state
• fetch_naip_img: Fetch NAIP aerial imagery for a given area and date range
• summarize_sat_img: Analyze and summarize satellite image contents using an LLM

State Management

The agent maintains the following state throughout the conversation:

• messages: The conversation history (always updated with each interaction)
• place: Current place feature from Overture Maps (updated by get_place tool)
• search_area: Buffer area around the place (updated by get_search_area tool)
• naip_img_bytes: NAIP imagery data (updated by fetch_naip_img tool)

Tools update the state based on user queries, and these state changes are reflected in the Streamlit frontend in real-time.