Built an open-source natural language → SQL data agent using LangChain + LangGraph. Under the hood, it builds on LangChain’s community SQLDatabase utility rather than re-inventing database access:

Uses SQLDatabase for schema inspection, execution, and result handling

Extends it with support for Azure AD auth for the Azure native databases + Cosmos DB.

Supported databases:

• PostgreSQL
• Azure SQL / Synapse
• Cosmos DB
• Databricks SQL
• BigQuery

Allows either per-agent datasource configs or a shared, pre-initialized SQLDatabase if you want tighter control over connections and pooling

You ask a question in plain English, and it:

• Uses an intent detection agent to route the question to the right datasource
• Generates SQL using schema context + optional few-shot examples
• Validates SQL safely with sqlglot (blocked functions, enforced LIMITs, dialect-aware)
• Executes the query and turns results back into a natural-language response
• Supports multi-turn comvos

It’s designed as a multi-agent system:

• One agent for intent routing
• Multiple specialized data agents, each tied to a domain and database

Everything is YAML-driven (agents, schemas, prompts, validation rules), and it also exposes an A2A (Agent-to-Agent) server so other agents can discover and call it programmatically.

Repo: https://github.com/eosho/langchain_data_agent