A practical guide to building a self-correcting text-to-SQL agent using LangChain, DuckDB, and MotherDuck. Rather than one-shot SQL generation, the agent uses an iterative tool-use loop: it inspects schema, drafts a DuckDB-compliant query, runs it through an LLM-based query checker, executes it, reads any errors, and
Table of contents
Why This Specific StackHow the Agent Actually ThinksSetting Up the EnvironmentStep 1: Connecting to DuckDB and MotherDuckStep 2: Wiring Up the LLM and ToolkitStep 3: Writing a DuckDB-Specific System PromptStep 4: Creating the AgentThe Self-Correction Loop in PracticeWhat Real Queries Look LikeProduction Concerns I Take SeriouslyClosing ThoughtsSort: