flipt-client-python

Flipt Client Python

The flipt-client-python library contains the Python source code for the Flipt client-side evaluation client.

Installation

pip install flipt-client

How Does It Work?

The flipt-client-python library is a wrapper around the flipt-engine-ffi library.

All evaluation happens within the SDK, using the shared library built from the flipt-engine-ffi library.

Because the evaluation happens within the SDK, the SDKs can be used in environments where the Flipt server is not available or reachable after the initial data is fetched.

Data Fetching

Upon instantiation, the flipt-client-python library will fetch the flag state from the Flipt server and store it in memory. This means that the first time you use the SDK, it will make a request to the Flipt server.

Polling (Default)

By default, the SDK will poll the Flipt server for new flag state at a regular interval. This interval can be configured using the update_interval option when constructing a client. The default interval is 120 seconds.

Streaming (Flipt Cloud Only)

Flipt Cloud users can use the streaming fetch method to stream flag state changes from the Flipt server to the SDK.

When in streaming mode, the SDK will connect to the Flipt server and open a persistent connection that will remain open until the client is closed. The SDK will then receive flag state changes in real-time.

Supported Architectures

This SDK currently supports the following OSes/architectures:

• Linux x86_64
• Linux arm64
• MacOS x86_64
• MacOS arm64
• Windows x86_64

Usage

In your Python code you can import this client and use it as so:

from flipt_client import FliptEvaluationClient

# "namespace" and "options" are two keyword arguments that this constructor accepts
# namespace: which namespace to fetch flag state from
# options: follows the model ClientOptions in the models.py file. Configures the url of the upstream Flipt instance, the interval in which to fetch new flag state, and the authentication method if your upstream Flipt instance requires it
flipt_evaluation_client = FliptEvaluationClient()

variant_result = flipt_evaluation_client.evaluate_variant(flag_key="flag1", entity_id="entity", context={"fizz": "buzz"})

print(variant_result)

Constructor Arguments

The FliptEvaluationClient constructor accepts two optional arguments:

• namespace: The namespace to fetch flag state from. If not provided, the client will default to the default namespace.
• options: An instance of the ClientOptions class that supports several options for the client. The structure is:
  • url: The URL of the upstream Flipt instance. If not provided, the client will default to http://localhost:8080.
  • update_interval: The interval (in seconds) in which to fetch new flag state. If not provided, the client will default to 120 seconds.
  • authentication: The authentication strategy to use when communicating with the upstream Flipt instance. If not provided, the client will default to no authentication. See the Authentication section for more information.
  • reference: The reference to use when fetching flag state. If not provided, reference will not be used.
  • fetch_mode: The fetch mode to use when fetching flag state. If not provided, the client will default to polling.

Authentication

The FliptEvaluationClient supports the following authentication strategies:

• No Authentication (default)
• Client Token Authentication
• JWT Authentication

Contributing

Contributions are welcome! Please feel free to open an issue or submit a Pull Request.

License

This project is licensed under the MIT License.