OpenFeature AWS SSM Parameter Store Provider

This provider enables the use of AWS Systems Manager (SSM) Parameter Store as a backend for OpenFeature feature flags in Python.

Installation

pip install openfeature-provider-aws-ssm

For async support:

pip install openfeature-provider-aws-ssm[async]

Usage

Basic Usage

from openfeature import api
from openfeature.contrib.provider.awsssm import AwsSsmProvider

# Initialize the provider
provider = AwsSsmProvider()

# Set the provider
api.set_provider(provider)

# Get a client
client = api.get_client()

# Evaluate a flag
is_enabled = client.get_boolean_value("my-feature-flag", default_value=False)

With Configuration

from botocore.config import Config
from openfeature.contrib.provider.awsssm import (
    AwsSsmProvider,
    AwsSsmProviderConfig,
    CacheConfig,
)

config = AwsSsmProviderConfig(
    config=Config(
        region_name="us-west-2",
        retries={"max_attempts": 10, "mode": "standard"},
        connect_timeout=5,
        read_timeout=60,
    ),
    enable_decryption=True,  # For SecureString parameters
    cache_config=CacheConfig(
        cache_type="ttl",
        size=1000,
        ttl=300,  # 5 minutes in seconds
    ),
)

provider = AwsSsmProvider(config=config)
api.set_provider(provider)

Async Usage

from openfeature import api
from openfeature.contrib.provider.awsssm import AwsSsmProvider

provider = AwsSsmProvider()
api.set_provider(provider)

client = api.get_client()

# Async flag evaluation
is_enabled = await client.get_boolean_value_async(
    "my-feature-flag", default_value=False
)

Flag Key Mapping

Flag keys are mapped to SSM parameter names with the following rules:

• If the flag key starts with /, it's used as-is
• Otherwise, a leading / is automatically prepended

Examples:

• Flag key my-feature → Parameter /my-feature
• Flag key /app/prod/feature → Parameter /app/prod/feature

Flag Types

The provider supports all OpenFeature flag types:

Configuration Options

AwsSsmProviderConfig

CacheConfig

The provider supports multiple caching strategies to optimize performance. To disable caching entirely, pass cache_config=None when creating the provider config.

Cache Types

• "lru" (default): Least Recently Used cache with size-based eviction only. Cached values persist until evicted due to size limits.
• "ttl": Time-To-Live cache with both time-based expiration AND size-based eviction. Cached values automatically expire after the configured TTL, even if space remains in the cache.

Cache Examples

# LRU cache (default) - size-based eviction only
cache_config=CacheConfig(cache_type="lru", size=500)

# TTL cache - expires after 60 seconds
cache_config=CacheConfig(cache_type="ttl", ttl=60, size=500)

# No caching - pass cache_config=None to the provider config
provider_config = AwsSsmProviderConfig(cache_config=None)

For more information on the Config object, see the boto3 configuration documentation.

License

Apache 2.0 - See LICENSE for more information.