Python Server SDK

pip install launchdarkly-server-sdk

pip install launchdarkly-observability

import ldclient
from ldclient.config import Config

# Optional — launchdarkly-observability package; requires Python SDK v9.12+
# from ldobserve import ObservabilityPlugin

import os
import sys

import ldclient
from ldclient.config import Config

if __name__ == "__main__":
    sdk_key = os.environ.get("LAUNCHDARKLY_SDK_KEY")
    if not sdk_key or not sdk_key.strip():
        print(
            "LAUNCHDARKLY_SDK_KEY is not set. Use Project settings > Environments > SDK key.",
            file=sys.stderr,
        )
        raise SystemExit(1)

    ldclient.set_config(Config(sdk_key))
    client = ldclient.get()

    if not client.is_initialized():
        print("LaunchDarkly client failed to initialize", file=sys.stderr)
        raise SystemExit(1)

    # For onboarding only — events are normally flushed in the background.
    client.flush()
    print("LaunchDarkly client ready.")