Flipt Client Python SDK

1.4.1 verified Fri May 01 auth: no python

Python client for Flipt feature flag evaluation. Version 1.4.1 supports synchronous and asynchronous evaluation via REST and gRPC. Active development with monthly releases.

pip install flipt-client

Common errors

error flipt_client.exceptions.FliptClientError: Failed to connect to remote host ↓

cause Flipt server not running or wrong URL/port.

fix

Start the Flipt server and double-check the 'url' parameter (e.g., http://localhost:8080).

error flipt_client.exceptions.FliptClientError: Invalid authentication token ↓

cause The 'authentication_token' is missing or incorrect.

fix

Set FLIPT_AUTH_TOKEN environment variable or pass a valid token to the client.

Warnings

breaking The constructor argument 'auth_token' was renamed to 'authentication_token' in v1.3.0. ↓

fix Use 'authentication_token' instead of 'auth_token'.

gotcha If the Flipt server is unreachable, the client may raise a connection error; ensure the gRPC or HTTP port is correct. ↓

fix Verify the 'url' includes the correct port (e.g., http://localhost:8080 for REST, localhost:9000 for gRPC).

deprecated The synchronous client uses requests under the hood; consider switching to async for high-throughput scenarios. ↓

fix Use FliptEvaluationClientAsync for non-blocking calls.

Imports

FliptEvaluationClient
```
from flipt_client import FliptEvaluationClient
```
Main client class for synchronous evaluation.
FliptEvaluationClientAsync
```
from flipt_client import FliptEvaluationClientAsync
```
Async client for non-blocking evaluation.

Quickstart

Create a client and evaluate a boolean/variant flag.

import os
from flipt_client import FliptEvaluationClient

client = FliptEvaluationClient(
    namespace="default",
    url="http://localhost:8080",
    authentication_token=os.environ.get('FLIPT_AUTH_TOKEN', '')
)

flag_key = "my-flag"
entity_id = "user123"
context = {"plan": "enterprise"}

response = client.evaluate_variant(flag_key, entity_id, context)
print(response.match)
print(response.variant_key)