SDK Runtime Environment
The Connector SDK runtime environment executes your submitted Python script in an isolated environment. It installs the libraries listed in the requirements.txt or pyproject.toml file, and after installation, it runs the provided Python script.
Python version support
We support the following Python versions:
- 3.14
- 3.13
- 3.12
- 3.11
- 3.10
Python may be global or managed in a virtual environment (venv).
If you do not specify the --python or --python-version argument when running fivetran deploy, Fivetran defaults to Python 3.13.
When explicitly specifying the version in the optional --python or --python-version arguments, you must use one of the above-mentioned Python versions. We do not support any other versions.
Handling Python version upgrades and End of Life
Each year, the oldest minor version of Python reaches its End of Life (EOL). When Python.org stops supporting a particular minor version, we discontinue support for that version of Python as well. You are required to migrate to a newer minor version for your connections to work.
To help you take timely action, we show a warning on the connection dashboard 90 days prior to the EOL date. We also send email notifications about it. If you do not migrate to a newer version, your connections stop working after the EOL date and you see an error on your connection dashboard. In most cases, updating the Python version from the CLI or the setup form is enough. However, if anything breaks, you are required to fix the code and redeploy it. Additionally, we disallow creating new connections 60 days before the EOL date. This applies to any minor Python version approaching End of Life.
If a new patch version is available, we work on adding support for it at the earliest. Once supported, newly created connections are configured to use the latest patch version. We do not immediately remove support for an existing connection using an older patch that's already uploaded and running. Instead, we work with you to transition to an updated, supported Python patch version.
Operating system support
Connector SDK supports the following operating systems for the testing environment:
- Windows: 10 or later, 64-bit only
- macOS: 13 Ventura or later, Apple Silicon arm64 or Intel x86_64
- Linux: Ubuntu 20.04 or later, Debian 10 or later, or Amazon Linux 2 or later, arm64 or x86_64
System resources
Once you deploy your custom connector to production, Fivetran runs it on infrastructure with the following specs:
- 4 GB of RAM
- Less than 0.5 vCPUs of an 8 Core N2 or equivalent machine
- 64-bit Linux (amd64) platform.
Our production infrastructure allows for some variation in resources available to your connections at any given moment, load balancing across multiple connections.
Pre-installed DB drivers
We pre-install the msodbcsql17 and msodbcsql18 drivers for connecting to Microsoft SQL Server. We also pre-install libpq5 and libpq-dev, which are required to support psycopg and psycopg2 respectively.