Connection string parsing failed: Unknown keyword 'authority id' is not recognized

[KijkEr]

Describe the bug

When I try to connect to a database using Service Principal Authentication I get the following error:

ConnectionStringParseError
Connection string parsing failed: Unknown keyword 'tenant id' is not recognized

See the console area for a traceback.

Exception message: Unknown keyword 'authority id' is not recognized
Stack trace: Traceback (most recent call last):
  File "/tmp/marimo_46222/__marimo__cell_bkHC_.py", line 13, in <module>
    conn = mssql_python.connect(connection_string)
  File "/home/kesselba/programming/test/.venv/lib/python3.13/site-packages/mssql_python/db_connection.py", line 55, in connect
    conn = Connection(
        connection_str,
    ...<4 lines>...
        **kwargs,
    )
  File "/home/kesselba/programming/test/.venv/lib/python3.13/site-packages/mssql_python/connection.py", line 253, in __init__
    self.connection_str = self._construct_connection_string(connection_str, **kwargs)
                          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/kesselba/programming/test/.venv/lib/python3.13/site-packages/mssql_python/connection.py", line 376, in _construct_connection_string
    parsed_params = parser._parse(connection_str)
  File "/home/kesselba/programming/test/.venv/lib/python3.13/site-packages/mssql_python/connection_string_parser.py", line 273, in _parse
    raise ConnectionStringParseError(errors)
mssql_python.exceptions.ConnectionStringParseError: Connection string parsing failed:
  Unknown keyword 'authority id' is not recognized

To reproduce

import mssql_python

connection_string = """
Server=redacted.database.windows.net;
Database=database-name;
Authentication=ActiveDirectoryServicePrincipal;
UID=client-id;
PWD=client-secret;
Authority Id=tentant-id;
Encrypt=yes;
"""

conn = mssql_python.connect(connection_string)

Expected behavior

A working connection to the database.

Further technical details

Python version: 3.13.4
SQL Server version: Azure SQL Database
Operating system: Azure

Additional context
No additional context.

[github-actions]

Hi @KijkEr, thank you for opening this issue!

Our team will review it shortly. We aim to triage all new issues within 24-48 hours and get back to you.

If you have additional information to share, please feel free to update the issue.

Thank you for your patience!

[jahnvi480]

Hi @KijkEr , thanks for reporting this!

ActiveDirectoryServicePrincipal authentication is supported by mssql-python, it's handled natively by the underlying ODBC Driver 18 for SQL Server.

The error you're seeing is because Authority Id is not a recognized connection string keyword in the driver's connection string parser. We've identified that our wiki documentation incorrectly includes Authority Id in the Service Principal example. We'll be updating the wiki to fix this.

The ODBC driver doesn't require a separate tenant ID keyword. When connecting to Azure SQL, the driver automatically infers the tenant from the server endpoint.

Please try removing the Authority Id parameter from your connection string:

import mssql_python

connection_string = """
Server=redacted.database.windows.net;
Database=database-name;
Authentication=ActiveDirectoryServicePrincipal;
UID=client-id;
PWD=client-secret;
Encrypt=yes;
"""

conn = mssql_python.connect(connection_string)

Let us know if removing Authority Id resolves the issue!