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dlt

Python library for declarative data loading that LLMs can generate

open sourceupdated Apr 21, 2026

dlt (data load tool) is a Python library for building data pipelines with declarative, schema-aware loading that is simple enough for LLMs to generate correctly. It extracts data from APIs, databases, and files, normalizes nested structures, handles schema evolution, and loads into warehouses and lakes. Supports 30+ destinations including BigQuery, Snowflake, DuckDB, and PostgreSQL. Over 5,200 GitHub stars.

dlt simplifies data pipeline development by providing a Python-native approach to extracting, normalizing, and loading data that handles the tedious parts of data engineering automatically. Developers define data sources as Python generators that yield records, and dlt handles schema inference from the data shape, nested structure flattening into relational tables, incremental loading with state management, and type-appropriate loading into the destination warehouse or database.

The schema evolution capability is particularly valuable for pipelines consuming APIs where response shapes change over time. dlt detects new fields, changed types, and structural modifications, automatically evolving the destination schema to accommodate changes without pipeline failures. This resilience reduces the maintenance burden that makes data pipelines fragile in production environments.

With over 5,200 GitHub stars, dlt has positioned itself as the data loading library that LLMs can generate correctly due to its simple, declarative API. AI coding assistants produce working dlt pipelines more reliably than they generate equivalent code for complex ETL frameworks, making dlt a natural fit for AI-augmented data engineering. The library supports over 30 destinations including BigQuery, Snowflake, Redshift, DuckDB, PostgreSQL, and filesystem-based data lakes with Parquet and Delta Lake formats.

Pricing

Free and open-source under Apache 2.0

Platforms

Python, 30+ data destinations, any OS

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FAQ

What is dlt?

dlt (data load tool) is a Python library for building data pipelines with declarative, schema-aware loading that is simple enough for LLMs to generate correctly. It extracts data from APIs, databases, and files, normalizes nested structures, handles schema evolution, and loads into warehouses and lakes. Supports 30+ destinations including BigQuery, Snowflake, DuckDB, and PostgreSQL. Over 5,200 GitHub stars.

Is dlt free?

Yes — dlt is open source and free to use. Free and open-source under Apache 2.0

Is dlt open source?

Yes — dlt is open source.

What are the best dlt alternatives?

The top editor-verified dlt alternatives are Maxun, Scrapling.