dlt-fabric

dlt-fabric is a maintained fork of dlt with fixes for the Microsoft Fabric Warehouse destination and the related MS SQL family of destinations (mssql, synapse).

dlt's Fabric, mssql, and synapse destinations have open issues around authentication and reliability that are not yet released upstream. This fork carries the fixes on top of each dlt release so they can be used today, while the changes work their way through upstream review.

What this fork carries

This fork applies the following changes on top of the corresponding upstream dlt release:

• dlt-hub/dlt#4140: Microsoft Entra ID authentication for the mssql, synapse, and fabric destinations (service principal, managed identity, Azure CLI, interactive, and device code flows, in addition to plain SQL login).
• dlt-hub/dlt#4141: migration of the mssql, synapse, and fabric destinations from pyodbc to the mssql-python driver.
• dlt-hub/dlt#4142: a staging-optimized replace strategy for the Fabric destination, including a fix that makes concurrent multi-table-chain loads safe.
• dlt-hub/dlt#4147: support for an injectable pre-fetched access_token or an externally constructed azure_credential on the mssql, synapse, and fabric credentials, bypassing the usual authentication resolution.
• dlt-hub/dlt#4258: a mssql_arrow backend for sql_database that uses mssql-python's native Arrow C Data Interface for zero-copy batch extraction.
• dlt-hub/dlt#4259: correct nvarchar-to-varchar length scaling in the Fabric type mapper (character precision × 4 for UTF-8 byte semantics).
• dlt-hub/dlt#4260: allow time columns through the Parquet load path on Fabric (the inherited Synapse rejection does not apply).
• dlt-hub/dlt#4261: map SQL Server MONEY and SMALLMONEY types to decimal(19,4) and decimal(10,4) in sql_database schema inference.

These are proposed as pull requests against upstream dlt. Until they are merged and released, this fork is rebased onto each new dlt release to stay current.

Installation

dlt-fabric is a drop-in replacement for dlt. Install it instead of the upstream package:

pip install dlt-fabric
# or
uv add dlt-fabric

Then use it exactly as you would use dlt:

import dlt

Both packages install the same dlt import path, so dlt-fabric cannot be installed alongside the upstream dlt package in the same environment.

Documentation

This fork does not maintain separate documentation. For everything beyond the fixes listed above, the upstream resources apply directly:

• Documentation and usage: https://dlthub.com/docs
• Upstream project: https://github.com/dlt-hub/dlt